JP7205789B2 - preform - Google Patents

Description

The present invention relates to preforms used in making plastic bottles.

Conventionally, there is known a plastic bottle comprising a spout portion having an outer screw, a turnip positioned below the outer screw, a support ring positioned below the turnip, and a bottle body provided below the spout portion. It is

Such plastic bottles are gripped and transported by horizontally arranged grippers. In this case, the gripper holds the turnip and the support ring of the plug portion.

By the way, there is currently a demand for weight reduction of plastic bottles. Reference 1).

On the other hand, the grippers that hold the plastic bottles are installed in advance on the plastic bottle molding line and the filling line, and it is difficult to change the shape of the grippers according to changes in the shape of the plastic bottles. Moreover, conventionally, the cap attached to the mouth of the plastic bottle has a predetermined shape, and it is difficult to change the shape of the cap to match the shape of the mouth of the plastic bottle. For this reason, various restrictions are imposed when reducing the weight of the plug portion of the plastic bottle.

JP 2010-95269 A

The present invention has been made in consideration of these points, and it is possible to reduce the weight of the whole by thinning a part of the plug portion without changing the shape of the existing gripper and cap. , intended to provide preforms.

The present invention provides a preform comprising: a plug portion having an outer thread; a turnip positioned below the outer screw; and a support ring positioned below the turnip; a preform body having a lower minimum wall thickness portion, a body portion, and a bottom portion, wherein a concave annular surface is formed on an outer surface of the plug portion between the turnip and the support ring; A surface of the ring on the side of the concave annular surface is formed in multiple steps having steps, and the support ring has an outer region positioned radially outward of the steps and a support ring positioned radially inward of the steps. wherein the thickness of the minimum thickness portion below the support ring of the preform body, the thickness of the trunk portion, and the thickness of the bottom portion are such that the thickness of the minimum thickness portion < The preform is characterized in that the thickness of the bottom portion is smaller than the thickness of the body portion.

In the present invention, the preform is characterized in that 10°<α<16°, where α is an angle between the surface of the outer region of the support ring and the lower surface of the support ring.

In the present invention, when the radial length of the outer region of the support ring is L1 and the radial length of the inner region of the support ring is L2, 1.5<L1/L2<4.0. This preform is characterized by:

The present invention is a preform characterized in that the thickness of the outer edge of the support ring is 1.0 mm to 1.5 mm.

The present invention is a preform characterized in that an annular groove recessed radially inward is formed in the concave annular surface.

The present invention provides a preform for molding a plastic bottle having a resin weight of 21.0 g or less and a capacity of 600 ml or less, wherein the total length of the preform is less than 92.5 mm, and the outside of the body of the preform is The diameter is less than 24.0 mm, the minimum thickness portion below the support ring has a length of 3.0 to 10.0 mm, and the thickness of the body portion is less than the minimum thickness below the support ring. It is formed to have a thickness in the range of 1.19 to 1.9 times the thickness of the thick portion, the bottom portion gradually becomes thinner toward the gate portion, and the bottom portion extends below the support ring. 1.11 to 1.19 times the thickness of the minimum thickness portion of the preform.

The present invention is a preform characterized by having a total length of 80.0 to 85.0 mm and a barrel diameter of 22.0 to 23.0 mm.

The present invention is a preform characterized in that the minimum thickness portion below the support ring has a length of 3.0 to 7.5 mm.

The present invention is sealed by a screw-type cap having at least an inner ring, the plug portion is a preform that has not been crystallized, and the plug portion has a top surface and extends from the top surface. and an inner peripheral surface extending from the top surface and in contact with the inner ring. A preform characterized by being formed.

The present invention is a preform characterized in that the angle of the chamfered portion with respect to the top surface is 20° or more and 60° or less.

The present invention is characterized in that a distance between a contact portion of the inner peripheral surface with the inner ring and an end portion of the chamfered portion on the inner peripheral surface side is 1.5 mm or more and 3.0 mm or less. is a preform.

In the present invention, the cap has a contact ring that contacts the top surface, and a distance between a contact portion of the top surface with the contact ring and an end of the chamfered portion on the top surface side is 0. A preform, characterized in that it is greater than or equal to 0.05 mm and less than or equal to 0.8 mm.

In the present invention, the inner diameter of the plug portion is 21.61 mm or more and 21.87 mm or less,
The preform is characterized in that the outer diameter of the plug portion is 24.81 mm or more and 25.07 mm or less.

The present invention is a preform characterized in that the winding angle θ from the upper end to the lower end of the outer thread is 550° to 800°.

The present invention is a preform characterized in that a turnip diameter dA, which is the diameter of the turnip, is 25 mm to 32 mm, and the diameter dB of the concave annular surface is 24 mm to 27 mm.

The present invention is characterized in that the plug portion has a top surface and an inner peripheral surface extending from the top surface, and a chamfered portion is formed on a ridgeline of a joint portion between the top surface and the inner peripheral surface. It is a preform that

The present invention is a preform characterized in that an annular groove recessed radially inward is formed in the concave annular surface.

In the present invention, the relationship 1.125≤d1/d2≤1.165 is established, where d1 is the thread ridge diameter, which is the outer diameter of the outer thread, and d2 is the root diameter, which is the inner diameter of the outer thread. A preform characterized by:

The present invention is a preform characterized in that a turnip diameter dA, which is the diameter of the turnip, is 25 mm to 32 mm, and the diameter dB of the concave annular surface is 24 mm to 27 mm.

The present invention is characterized in that the plug portion has a top surface and an inner peripheral surface extending from the top surface, and a chamfered portion is formed on a ridgeline of a joint portion between the top surface and the inner peripheral surface. It is a preform that

The present invention is a preform characterized in that an annular groove recessed radially inward is formed in the concave annular surface.

The present invention comprises a container having an opening, a plurality of preforms arranged in the container, and a lid closing the opening, and each preform is attached with a sterilizing liquid supplied in advance. The preform-containing container is characterized by:

The present invention comprises a step of supplying a sterilizing solution to a plurality of preforms, a step of storing the preforms to which the sterilizing solution is attached in a storage body having an opening, and a step of closing the opening with a lid. A preform sterilization method characterized by:

In the present invention, the sterilizing liquid is measured, the measured sterilizing liquid is sprayed onto each preform as a linearly continuous liquid, and an image of the sterilizing liquid that is linearly continuous is captured to determine the injection amount of the sterilizing liquid. A method for sterilizing preforms characterized in that suitability is determined, only preforms to which an appropriate amount of sterilizing liquid has adhered are stored in the storage body, and then the storage body is closed and held for a predetermined period of time.

The present invention is a preform sterilization method, wherein the sterilization liquid is sprayed toward the side surface of each preform.

According to the present invention, each preform contains a 30 to 35% by weight aqueous hydrogen peroxide solution as the sterilizing liquid, and ethyl A 0.1 to 10% hydrogen peroxide aqueous solution diluted with a volatile solvent such as alcohol, methyl alcohol, isopropyl alcohol, or acetone is added dropwise, and the preform to which the hydrogen peroxide aqueous solution has been dropped is placed in the container. The preform sterilization method is characterized in that the inner surface of the preform and the outer surface of the preform are sterilized by the hydrogen peroxide vapor vaporized in the container, and the container is sealed with a lid.

The present invention is a method for sterilizing preforms, wherein the amount of the aqueous hydrogen peroxide solution dropped per preform is 0.05 to 100 μl as hydrogen peroxide.

According to the present invention, the surface of the support ring on the side of the concave annular surface is formed in multiple steps with steps, and the support ring includes an outer region outside the steps and an inner region inside the steps. there is
Therefore, the thickness of a part of the plug portion (support ring) can be reduced, and the weight of the preform as a whole can be reduced. In addition, since the thickness of the minimum-thickness portion<thickness of the bottom portion<thickness of the body portion, the moldability of the preform can be improved.

1 is a side view showing a plastic bottle according to a first embodiment of the present invention; FIG. FIG. 2 is a plan view showing the plastic bottle according to the first embodiment of the present invention (view in the direction of arrow II in FIG. 1). FIG. 3 is an enlarged side view showing the mouth plug portion of the plastic bottle according to the first embodiment of the present invention; FIG. 4 is an enlarged side view showing the support ring for the plastic bottle according to the first embodiment of the present invention; FIG. 5 is a side view showing a preform according to the first embodiment of the invention; 6(a) and 6(b) are enlarged views showing the action of the support ring during heating. 7(a) and 7(b) are enlarged views showing the action of the support ring when the cap is attached. FIG. 8 is a side view showing a modification of the plastic bottle; FIG. 9 is a side view showing a modification of the preform; FIG. 10 is a schematic cross-sectional view showing a heating device for heating the preform; FIG. 11 is a side sectional view showing an example of a preform; Fig. 12 is a side view showing a plastic bottle according to a second embodiment of the present invention; FIG. 13 is a plan view showing a plastic bottle according to a second embodiment of the present invention (a direction arrow view in FIG. 12). FIG. 14 is an enlarged side view showing the mouth plug portion of the plastic bottle according to the second embodiment of the present invention; 15 is an enlarged side view showing a support ring for a plastic bottle according to a second embodiment of the present invention; FIG. FIG. 16 is an enlarged cross-sectional view showing the upper end portion of the plug portion of the plastic bottle according to the second embodiment of the present invention; FIG. 17 is a partial cross-sectional view showing a state in which a screw-type cap is screwed onto the mouth portion of the plastic bottle according to the second embodiment of the present invention; FIG. 18 is a side view showing a preform according to a second embodiment of the invention; FIG. 19 is a side view showing a modification of the plastic bottle; FIG. 20 is a side view showing a modification of the preform; FIG. 21 is an enlarged cross-sectional view of the end of the plug portion; FIG. 22 is a diagram showing the measurement results of the closing torque of the cap manufactured by NCC. FIG. 23 is a diagram showing the measurement results of the closing torque of the cap manufactured by CSI. 24 is a front view showing an example of a preform according to a third embodiment of the present invention; FIG. 25 is a cross-sectional view of the preform of FIG. 24; FIG. FIG. 26 is a schematic diagram showing an example of an injection molding apparatus for manufacturing a preform; FIG. 27 is a sectional view showing an example of a preform heating device; FIG. 28 is a cross-sectional view schematically showing a preform and a PET bottle after blow molding. FIG. 29 is a front view showing a PET bottle formed from the preform according to the third embodiment; FIG. 30 is a front view showing another PET bottle formed from the preform according to the third embodiment; FIG. 31(A) is a vertical sectional view showing a preform that can be sterilized by the sterilization method and apparatus according to the fourth embodiment of the present invention, and FIG. partial cut-away elevational view of the bottle as shown. FIG. 32 is an elevational view showing an outline of a sterilizer according to a fourth embodiment; FIG. 33 is a plan view showing an outline of a sterilizer according to a fourth embodiment; FIG. 34 is a block diagram showing an apparatus for preparing a sterilizing liquid; Figure 35 is a vertical cross-sectional view of the injection device; FIG. 36 is an explanatory diagram of the operation of the injection device; FIG. 37 is an explanatory diagram showing the positional relationship between the injection device and the preform; FIG. 38 is a view showing a monitor screen of the liquid volume determination device; FIG. 39 is an elevational view showing another form of the conveying device of the sterilizer according to the fourth embodiment; FIG. 40 is an explanatory diagram when the sterilization method according to the fifth embodiment of the present invention is applied to a preform; FIG. 41 is a diagram showing a process of forming a bottle from the preform using the sterilization method of the fifth embodiment, and aseptically filling the bottle. FIG. 42 is an explanatory view of forming a bottle using a pre-sterilized preform, sterilizing the mouth plug portion of the bottle with ultraviolet rays, and aseptically filling the bottle in the fifth embodiment. FIG. 43 is a diagram showing a concrete example in the fifth embodiment;

<First Embodiment>
An embodiment of the present invention will be described below with reference to the drawings.

First, a plastic bottle 10 according to this embodiment will be described with reference to FIGS. 1 to 4. FIG. In this specification, the terms "upper" and "lower" respectively refer to the upper and lower sides when the plastic bottle 10 is erected (FIG. 1).

As shown in FIGS. 1 and 2, the plastic bottle 10 includes a mouthpiece 15 and a bottle body 11 provided below the mouthpiece 15 . Among them, the plug portion 15 has an outer thread 13 , a turnip 16 positioned below the outer thread 13 , and a support ring 17 positioned below the turnip 16 .

A tamper-resistant cap (not shown) is attached to the plug portion 15, and this cap has a peeling ring that is peeled off when unsealed. When the cap is removed and opened, the peeling ring of the cap comes into contact with the cover 16 of the plug portion 15 and peels off from the cap body, and the peeling ring peeled off from the cap body falls to the annular surface 18 and falls to this support. It is retained on ring 17 .

The external thread 13 is a single thread and has an upper end 13a and a lower end 13b. A vent slot 14 is formed in the external thread 13 parallel to the axis A of the plastic bottle 10 . The vent slot 14 plays a role in preventing the cap from flying by releasing the internal pressure when the bottle is opened when carbonated beverages are used as the content liquid to be filled in the plastic bottle 10, or when the content liquid is putrefied and the internal pressure rises. Fulfill. Therefore, when water or the like is used as the content liquid, the vent slot 14 may not necessarily be provided.

The external thread 13 has a predetermined winding angle θ (see FIG. 2) from the upper end 13a to the lower end 13b. The winding angle θ is preferably 550° to 850°, more preferably 650° to 780°. The winding angle θ is the angle at which the outer thread 13 is arranged from the upper end 13a to the lower end 13b when viewed from the plane direction (see FIG. 2). 13 makes two turns around the plug portion 15 . By setting the winding angle θ to 550° or more, it is possible to prevent the cap from flying due to the pressure of the content liquid. On the other hand, by setting the winding angle θ to 850° or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

When the external thread 13 is a double thread, the winding angle θ is preferably 90° to 300°, and when the external thread 13 is a triple thread, the winding angle θ of each screw is 70°. It is preferable to set the angle to 180°.

Further, the thread width wA (see FIG. 3) of the external thread 13 is preferably 0.5 mm to 1.1 mm. By setting the thread width wA to 0.5 mm or more, it is possible to prevent the occurrence of a problem called short circuit (incomplete filling) when the preform 30 (described later) is injection molded. On the other hand, by setting the thread width wA to 1.1 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

By the way, the plug portion 15 has the cover 16 at the upper portion and the support ring 17 at the lower portion as described above.

As shown in FIG. 3, the turnip 16 has an inclined surface 16a over which the peeling ring rides when the cap is attached. A turnip diameter dA, which is the diameter of the turnip 16, is preferably 25 mm to 32 mm. By setting the cover diameter dA to 25 mm or more, it is possible to prevent the problem that the plastic bottle 10 falls from the gripper (not shown) when the plastic bottle 10 is conveyed in the molding line and the filling line of the plastic bottle 10 . On the other hand, by setting the cover diameter dA to 32 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

Further, the width wB of the turnip 16 is preferably 1.2 mm to 2.0 mm. By setting the width wB of the cover 16 to 1.2 mm or more, it is possible to prevent the problem that the peeling ring partially remains on the cover 16 when the cap is attached and the cap is attached obliquely (slanted covering). On the other hand, by setting the width wB of the turnip 16 to 2.0 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

By the way, as shown in FIG. 3, a concave annular surface 18 is formed on the outer surface of the plug portion 15 between the turnip 16 and the support ring 17 so as to be recessed radially inward. The concave annular surface 18 is formed over the entire circumference of the plug portion 15, and the diameter dB of the concave annular surface 18 is uniform in the vertical direction along the axis A of the plastic bottle 10. As shown in FIG.

The diameter dB of the concave annular surface 18 is preferably between 24 mm and 27 mm. By setting the diameter dB of the concave annular surface 18 to 24 mm or more, the problem of the plastic bottle 10 falling from a gripper (not shown) when the plastic bottle 10 is conveyed in the molding line and the filling line of the plastic bottle 10 is prevented. be able to. On the other hand, by setting the diameter dB of the concave annular surface 18 to 27 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing. A relation of dB/dA<1 is established between the diameter dB of the concave annular surface 18 and the turnip diameter dA.

Further, as shown in FIGS. 1 and 3, the upper surface 17a of the support ring 17 (that is, the surface on the side of the concave annular surface 18) has steps 21 and is formed in multiple steps. In this case, the support ring 17 has one step 21 and is formed in two steps. On the other hand, the lower surface 17b (surface on the side of the bottle body 11) of the support ring 17 is a horizontal flat surface.

The support ring 17 also includes an outer region 22 positioned radially outward of the step 21 (horizontal direction in FIG. 3) and an inner region 23 positioned radially inward of the step 21 . Since the support ring 17 has the step 21 in this manner, the volume of the support ring 17 can be reduced by the step 21 . Therefore, the weight of the support ring 17 can be reduced as compared with the case where the step 21 is not provided.

As shown in FIG. 4, the surface 22a of the outer region 22 of the support ring 17 is an inclined surface. In this case, when the angle between the surface 22a of the outer region 22 and the lower surface 17b of the support ring 17 is α, it is preferable that 10°<α<16°. When the angle α exceeds 10°, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and injection moldability can be improved. Also, by providing an angle, the thickness of the base can be secured, and the strength of the support ring is improved. On the other hand, since the angle α is less than 16°, it is possible to prevent the height of the concave annular surface 18 from being shortened and to prevent the plastic bottle 10 from being transported incorrectly.

Further, the surface 23a of the inner region 23 of the support ring 17 is an inclined surface. In this case, when the angle between the surface 23a of the inner region 23 and the lower surface 17b of the support ring 17 is β, it is preferable that β>α. Also, the angle β is preferably set to 20°<β<60°. When the angle β exceeds 20°, good injection moldability can be obtained. Also, by providing an angle, the thickness of the base can be secured, and the strength of the support ring is improved. On the other hand, since the angle β is less than 60°, it is possible to prevent the height of the concave annular surface 18 from being shortened and to prevent the plastic bottle 10 from being transported incorrectly.

Furthermore, as shown in FIG. 4, when the radial length of the outer region 22 is L1 and the radial length of the inner region 23 is L2, the relationship 1.5<L1/L2<4.0 holds. is preferred. When the value of L1/L2 exceeds 1.5, it is possible to prevent the weight of the plastic bottle 10 from increasing. On the other hand, when the value of L1/L2 is less than 4.0, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and the injection moldability is improved. be able to.

Furthermore, the thickness tA at the outer end of the support ring 17 (that is, the outer end of the outer region 22) is preferably 1.0 mm to 1.5 mm. By setting the thickness tA to 1.0 mm or more, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and the injection moldability can be improved. Further, by setting the thickness tA to 1.5 mm or less, it is possible to prevent the height of the recessed annular surface 18 from being shortened, thereby preventing transportation failures when the plastic bottle 10 is transported.

By the way, the shape of the bottle body 11 is not particularly limited, and may have various conventionally known shapes. For example, in FIG. 1, the bottle body 11 has a neck portion 11a, a shoulder portion 11b, a body portion 11c, and a bottom portion 11d.

Also, the size (capacity) of the plastic bottle 10 is not limited, and the bottle may be of any size, for example, 500 ml to 600 ml.

As the main material of the plastic bottle 10, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate). For example, it is also possible to use PLA (polylactic acid). The plastic bottle 10 is preferably sterilized by adding hydrogen peroxide or peracetic acid.

Next, the preform 30 according to this embodiment will be described with reference to FIG. FIG. 5 is a diagram showing a preform 30 used when manufacturing the plastic bottle 10 shown in FIGS. 1 to 4. FIG.

As shown in FIG. 5 , the preform 30 includes a plug portion 15 and a preform body 31 provided below the plug portion 15 . Among them, the plug portion 15 has an outer thread 13 , a turnip 16 positioned below the outer thread 13 , and a support ring 17 positioned below the turnip 16 . The preform body 31 corresponds to the bottle body 11 described above, and has a substantially cylindrical body portion 31a and a substantially hemispherical bottom portion 31b. Note that the preform body 31 is not limited to this, and may have various conventionally known shapes.

A concave annular surface 18 is formed on the outer surface of the plug portion 15 between the turnip 16 and the support ring 17 . Further, the surface of the support ring 17 on the concave annular surface 18 side has steps 21 and is formed in multiple steps. The support ring 17 includes an outer region 22 positioned radially outwardly of the step 21 and an inner region 23 positioned radially inwardly of the step.

In FIG. 5, the configuration of the plug portion 15 is the same as the configuration of the plug portion 15 of the plastic bottle 10 shown in FIGS. In FIG. 5, the same parts as in the embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Next, the operation of this embodiment having such a configuration will be described.
First, thermoplastic resin pellets such as PET (polyethylene terephthalate) are put into an injection molding machine (not shown), and the pellets are heated, melted and pressurized by the injection molding machine.

The pellets then become molten plastic and are injected into an injection mold having an internal shape corresponding to the preform 30 (see FIG. 5).

After a period of time, the molten plastic hardens in the injection mold to form preform 30 . After that, the injection mold is separated, and the preform 30 shown in FIG. 5 is taken out from the injection mold.

The preform 30 is then heated in a heating device 50 within the blow molding machine (see Figure 10). At this time, the preform 30 is conveyed by the mandrel 51 with the plug portion 15 facing downward, and is evenly heated in the circumferential direction by the heater 52 of the heating device 50 while rotating about the central axis. Reference numeral 53 denotes a reflector for reflecting heat from the heater 52 toward the preform 30, and reference numeral 54 denotes a shielding member for preventing the heat from the heater 52 from escaping to the outside of the heating device 50. be. Incidentally, depending on the structure of the mandrel 51 and the blow molding machine, the spout portion 15 may be conveyed in a state facing upward.

During this time, the preform 30 is heated to a temperature of 80° C. to 140° C., for example, by the heater 52 of the heating device 50 . After that, the heated preform 30 is sent to a blow molding section (not shown).

The preform 30 sent to the blow molding section is inserted into the blow molding mold of the blow molding section. After that, high-pressure air is supplied into the preform 30 from a stretching rod inserted into the preform 30, and the preform 30 is stretched by stretching the stretching rod, and biaxial stretching blow molding is performed (blow molding process). By such blow molding, the plastic bottle 10 shown in FIGS. 1 and 2 is obtained.

By the way, when the preform 30 is heated by the heater 52, since the spout portion 15 of the preform 30 is not stretched, it is preferably not heated.
Actually, however, it is conceivable that the support ring 17 adjacent to the preform body 31 is heated by the heater 52 and the support ring 17 is thermally deformed.

In contrast, according to the present embodiment, as shown in FIG. 6A, even when the support ring 17 is heated, the step 21 serves as a fulcrum (marked by a circle in FIG. 6A). , only the outer region 22 located outside the step 21 is deformed, and the deformation of the inner region 23 is suppressed. Therefore, although the volume of the support ring 17 is reduced, thermal deformation of the support ring 17 can be reduced. As a result, it is possible to prevent troubles such as the support ring 17 from occurring. On the other hand, as shown in FIG. 6B as a comparative example, when the support ring 17 is not provided with the step 21, the root portion of the support ring 17 becomes the fulcrum (circled in FIG. 6B). For this reason, the support ring 17 is curved around the fulcrum, and thermal deformation of the support ring 17 as a whole is increased. In this case, clogging may occur in the blow molding machine or the conveying line.

The plastic bottle 10 molded on the blow molding line is conveyed from the blow molding section into a filling machine (not shown) by air conveying means or neck conveying means. After that, the plastic bottle 10 is filled with the content liquid in the filling machine, and then the plastic bottle 10 is capped using a capper. At this time, the plastic bottle 10 is supported by the lower surface 17b of the support ring 17, and the cap is attached so as to cover the spout portion 15. As shown in FIG. At this time, the peeling ring of the cap climbs over the turnip 16 and contacts the upper surface 17a of the support ring 17 to stop. When the peeling ring comes into contact with the upper surface 17a of the support ring 17, a downward force is applied to the support ring 17, and the support ring 17 may be deformed.

On the other hand, according to the present embodiment, as shown in FIG. becomes a fulcrum (marked with a circle in FIG. 7A), only the outer region 22 positioned outside the step 21 is deformed, and the deformation of the inner region 23 is suppressed. Therefore, even though the volume of the support ring 17 is reduced, the deformation of the support ring 17 can be reduced. As a result, the support ring 17 can be prevented from having problems such as cracks. On the other hand, as shown in FIG. 7(b) as a comparative example, when the support ring 17 is not provided with the step 21, the root portion of the support ring 17 becomes the fulcrum (circled in FIG. 7(b)). Therefore, the support ring 17 is curved around the fulcrum, and the deformation of the support ring 17 as a whole is increased. In this case, the support ring 17 may crack.

As described above, according to the present embodiment, the upper surface 17a of the support ring 17 is formed in multiple steps having the steps 21, and the support ring 17 includes the outer region 22 positioned radially outward of the steps 21, and an inner region 23 located radially inward of the step 21 . Therefore, the thickness of the support ring 17 can be reduced, and the overall weight of the plastic bottle 10 and the preform 30 can be reduced. In this case, the existing grippers and existing caps can be used as they are in the molding line and the filling line for the plastic bottles 10, so there is no need to change the shapes of the grippers and caps.

<Modification>
Next, a modified example of this embodiment will be described.
In the embodiment described above, the concave annular surface 18 has a uniform diameter along the vertical direction (direction of the axis A), but is not limited to this.

As shown in FIGS. 8 and 9, the concave annular surface 18 may be formed with an annular groove 26 that is concave radially inward. The concave annular surface 18 has a clamping portion 25 which is clamped by a gripper during transport, and an annular groove 26 having a smaller diameter than the clamping portion 25 . That is, the holding portion 25 and the annular groove 26 have circular cross sections with different diameters.
The annular groove 26 is formed over the entire circumference of the concave annular surface 18 .

By providing the annular groove 26 in the concave annular surface 18 in this manner, the volume of the mouth plug portion 15 can be further reduced, and the weight of the plastic bottle 10 and the preform 30 as a whole can be reduced.

8 and 9 are substantially the same as the embodiment described above, except for the shape of the concave annular surface 18. FIG. In FIGS. 8 and 9, the same parts as those in the embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Next, a specific example of this embodiment will be described.
First, the following six types of plastic bottles (Examples 1 to 5 and Comparative Example 1) were produced.

(Example 1)
A preform 30 according to the present embodiment shown in FIG. 5 was produced by injection molding, and the preform 30 was blow-molded to obtain the plastic bottle 10 (Example 1) shown in FIGS. In this plastic bottle 10 (Example 1), the angle α between the surface 22a of the outer region 22 of the support ring 17 and the lower surface 17b of the support ring 17 was set to 14°. Also, the ratio (L1/L2) of the radial length L1 of the outer region 22 to the radial length L2 of the inner region 23 was set to 3.10. The weight of the plastic bottle 10 (Example 1) was 18 g.

(Example 2)
A plastic bottle 10 (Example 2) was produced in the same manner as in Example 1, except that the angle α was set to 8°.

(Example 3)
A plastic bottle 10 (Example 3) was produced in the same manner as in Example 1, except that the angle α was set to 18°.

(Example 4)
A plastic bottle 10 (Example 4) was produced in the same manner as in Example 1 except that the value of L1/L2 was 1.30 and the weight was 19 g.

(Example 5)
A plastic bottle 10 (Example 5) was produced in the same manner as in Example 1, except that the value of L1/L2 was set to 4.50.

(Comparative example 1)
A plastic bottle (Comparative Example 1) was produced in the same manner as in Example 1, except that the upper surface 17a of the support ring 17 did not have a step 21 formed thereon. The weight of the plastic bottle (Comparative Example 1) was 18 g.

Here, 10,000 of each of the six types of plastic bottles (Examples 1 to 5 and Comparative Example 1) were produced. Next, each plastic bottle was filled with green tea, and then each plastic bottle was capped using a capper.

Each of Examples 1 to 5 and Comparative Example 1 was evaluated for injection moldability of the preform. In addition, in the plastic bottle molding line and filling line, it was investigated whether the support ring was deformed and the plastic bottle was clogged. Furthermore, the percentage of the capped plastic bottles with cracks in the support ring was calculated.

As a result, the plastic bottles 10 of Examples 1 and 4 had good injection moldability, clogging of the plastic bottles did not occur in the molding line and the filling line, and no cracks occurred in the support ring. did not exist.

In addition, the plastic bottles 10 of Examples 2 and 5 had good injection moldability, and clogging of the plastic bottles did not occur in the molding line and the filling line. Cracking of the support ring occurred.

Further, the plastic bottles 10 of Example 3 had good injection moldability, and there were no cracks in the support ring.

On the other hand, the plastic bottle of Comparative Example 1 had good injection moldability, but clogging of the plastic bottle occurred in the molding line and the filling line. In addition, 17% of them had cracks in the support ring.

Table 1 summarizes the above results. In Table 1, the evaluation criteria "⊚" indicate "excellent", the evaluation criteria "○" indicate "good", and the evaluation criteria "×" indicate "poor".

Next, referring to FIG. 11, the shape of the plastic bottle molding preform 30 of the present invention will be described.
The preform 30 has a plug portion 15, a support ring 17, and a preform main body 31 having a trunk portion 31a and a bottom portion 31b. A minimum thickness portion 31c having a length of 3 to 7.5 mm is formed downward, and the body portion 31a is thicker than the minimum thickness portion 31c, and the bottom portion 31b gradually tapers toward the gate portion 31d. The thickness is thin.

The minimum thickness portion 31c is desirably formed to have a length of 3 to 7.5 mm.
When the length of the minimum thickness portion 31c is less than 3 mm, sufficient stretchability of the minimum thickness portion 31c cannot be obtained, and the maximum thickness portion of the preform 30 tends to be stretched, resulting in a thin bottle body. is formed.
On the other hand, when the length of the minimum thickness portion 31c is greater than 7.5 mm, the bottle shoulder is thin.

The thickness of the gate portion below the bottom portion 31b should be 1.11 to 1.19 times the thickness of the minimum thickness portion 31c in the case of a commonly used plastic bottle molding preform having a capacity of 600 ml or less. is desirable.
If the thickness of the gate portion is less than 1.11 times, the flow of the resin becomes poor during injection molding, and there is a high possibility that problems such as poor molding will occur.
On the other hand, if the thickness of the gate portion is more than 1.19 times, the difference between the thickness and the thickness of the body portion becomes smaller, and the gate portion of the preform becomes difficult to stretch, resulting in the formation of a thin bottle body portion. .

The thickness of the body portion 31a is desirably 1.19 to 1.9 times the thickness of the minimum thickness portion 31c in the case of a commonly used preform for molding a plastic bottle having a volume of 600 ml or less.
When the thickness is less than 1.19 times, sufficient centrifugal force cannot be obtained from the minimum thickness portion 31c below the support ring, and the maximum thinness portion of the preform tends to be stretched, resulting in the formation of a significantly thin bottle body. put away.
When the thickness is more than 1.9 times, the temperature difference between the inner surface and the outer surface of the preform tends to occur during preheating for blow molding, and the temperature of the inner surface of the preform is low, which adversely affects the physical properties and appearance of the bottle.

The length of the preform 30 below the support ring 17 is preferably 59.0-63.0 mm.

Considering that the general barrel diameter of a plastic bottle with a capacity of 600 ml or less is about 66 mm, the outer diameter of the extraction taper start position 31e is preferably 22.5 to 22.6 mm.

In addition, in order to prevent the preforms from overlapping each other during preform transportation, the outer diameter of the extraction taper start position 31e must be larger than the inner diameter of the plug portion 15 of the preform 30 by 0.4 mm or more. becomes.

The extraction taper angle is required when the bottle is removed from the injection molding die, and is preferably 0.2 to 0.5°.

It is desirable that the length from the bottom of the support ring 17 to the extraction taper start position 31e is determined so as to correspond to the shoulder of the plastic bottle.
Therefore, it is desirable that the length from the bottom of the support ring to the extraction taper start position is 12.0 to 14.5 mm.

In the present invention, it is desirable that the total length of the preform is 85.0 mm and the barrel diameter is 22.2 mm, or the total length is 80.0 mm and the barrel diameter is 22.2 mm.

The preform shown in FIG. 11 is an example of a preform for molding a plastic bottle with a resin weight of 19.9 g and a total length of 85 mm and 500 ml (or a resin weight of 17.7 g and a total length of 80 mm and 500 ml). Each value for the preform 30 with a resin weight of 19.9 g is shown below, and each value for the preform with a resin weight of 17.7 g is shown in parentheses. . In FIG. 11, 1a indicates the length of the minimum thickness portion 31c below the support ring 17=3 mm (3 mm), and 1b indicates the thickness of the minimum thickness portion 31c below the support ring 17=2.1 mm. (21.1 mm), 1c indicates the length from the support ring 17 to the extraction taper start position 31e=14.5 mm (12 mm), and 1d indicates the thickness of the trunk portion 31a.

1e indicates the total length of the preform=85.0 mm (80.0 mm), 1f indicates the outer diameter of the body portion 31a of the preform=22.2 mm (22.2 mm), and 1g indicates the thickness of the gate portion.

1h indicates the length from the tip of the preform to the bottom of the support ring 17=21.01 mm (21.01 mm).
1i indicates the length under the support ring.

In the plastic bottle molding preform 1 of the present invention, the length of the minimum thickness portion 31c below the support ring 17 is 3 to 7.5 mm, and the thickness of the bottom portion 31b is gradually reduced toward the gate portion 31d. As a result, the stretchability of the minimum-thickness portion 31c below the support ring 17 is improved, and the body of the bottle can be formed thicker, thereby improving the physical properties of the bottle. Further, by setting the length of the minimum thickness portion 31c below the support ring 17 to 3 to 7.5 mm, the thickness of the shoulder portion of the bottle can be kept within a range that does not affect the physical properties of the bottle.

Examples of the thermoplastic resin that constitutes the plastic bottle molding preform 1 of the present invention include thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, and copolymers thereof; Resins or blends with other resins are preferred, and ethylene terephthalate-based thermoplastic polyesters such as polyethylene terephthalate are particularly preferred.

Acrylonitrile resin, polypropylene, propylene-ethylene copolymer, etc. can also be used.

Various additives, such as colorants, ultraviolet absorbers, release agents, lubricants, nucleating agents, antioxidants, antistatic agents, etc., are added to the above-described resins within a range that does not impair the quality of the molded product. be able to.

As the ethylene terephthalate-based thermoplastic resin that constitutes the preform 30, ethylene terephthalate units account for most of the ester repeating portion, generally 70 mol% or more, and have a glass transition point (Tg) of 50 to 90°C. and a melting point (Tm) in the range of 200 to 275°C.

Further, as an ethylene terephthalate-based thermoplastic polyester, polyethylene terephthalate is particularly excellent in terms of pressure resistance and the like. Copolyesters containing small amounts of units can also be used.

The preform 30 can also be constructed of two or more thermoplastic polyester layers.

Further, when the preform 30 is composed of two or more thermoplastic polyester layers, it can be provided with an intermediate layer such as a barrier layer or an oxygen absorbing layer between the layers.

As the oxygen absorbing layer, a combination of an oxidizable organic component and a transition metal catalyst, or a layer containing a substantially non-oxidizing gas barrier resin or the like can be used.

Next, the process of molding a plastic bottle using the preform 30 of the present invention will be described.

First, the preform 30 of the present invention is set in a mold heated to 140 to 150° C., and the preform 1 is stretched upward by a stretching rod and air is blown into the preform from a blow port.

After that, it is held for several seconds in order to be heat-set in the mold, and air is blown into the molded product to cool it, and at the same time, it is exhausted from the blow port.
The mold is then opened and the product is removed. In this way, plastic bottles can be molded.

<Second Embodiment>
A second embodiment of the present invention will be described below with reference to the drawings.
First, the plastic bottle 10 according to this embodiment will be described with reference to FIGS. 12 to 17. FIG. In this specification, the terms "upper" and "lower" respectively refer to the upper and lower sides of the plastic bottle 10 in the upright state (FIG. 12).

As shown in FIGS. 12 and 13, the plastic bottle 10 includes a mouthpiece 15 and a bottle body 11 provided below the mouthpiece 15 . Among them, the plug portion 15 has an outer thread 13 , a turnip 16 positioned below the outer thread 13 , and a support ring 17 positioned below the turnip 16 . A concave annular surface 18 is formed on the outer surface between the turnip 16 and the support ring 17 and is recessed radially inward.

A tamper-resistant cap 60 (see FIG. 17) is attached to the plug portion 15, and the cap 60 has a peeling ring 70 that is peeled off when unsealed. When the cap 60 is removed and opened, the peeling ring 70 of the cap 60 abuts against the turnip 16 of the plug portion 15 and peels off from the cap main body 61. It falls onto the annular surface 18 and is retained on the support ring 17 . Note that the configuration of the cap 60 will be described later.

The plug portion 15 has a generally cylindrical shape as a whole, has an opening plug portion 19 at one end, and is connected to the bottle main body 11 at the other end. The plug portion 15 includes a top surface 15a that is an end surface on the opening plug portion 19 side, an outer peripheral surface 15b that extends from the top surface 15a toward the bottle main body 11 side in the radial direction outside the plug portion 15, and the top surface. It has an inner peripheral surface 15c that extends radially inward of the plug portion 15 from 15a toward the bottle body 11 side. In addition, the top surface 15a is a flat surface.

An outer thread 13 is provided on the outer peripheral surface 15 b of the plug portion 15 . The outer thread 13 is preferably a single start thread but may be a double or triple start thread and has an upper end 13a and a lower end 13b.
A vent slot 14 is formed in the external thread 13 parallel to the axis A of the plastic bottle 10 . The vent slot 14 plays a role in preventing the cap from flying by releasing the internal pressure when the bottle is opened when carbonated beverages are used as the content liquid to be filled in the plastic bottle 10, or when the content liquid is putrefied and the internal pressure rises. Fulfill. Therefore, the vent slot 14 does not necessarily have to be provided when a liquid that does not contain carbonic acid, such as water, is used as the content liquid.

The external thread 13 has a predetermined winding angle θ (see FIG. 13) from the upper end 13a to the lower end 13b. The winding angle θ is preferably 550° to 800°, more preferably 650° to 750°. The winding angle θ is the angle at which the outer thread 13 is arranged from the upper end 13a to the lower end 13b when viewed from the plane direction (see FIG. 13). 13 makes two turns around the plug portion 15 . By setting the winding angle θ to 550° or more, it is possible to prevent the cap from flying due to the pressure of the content liquid. On the other hand, by setting the winding angle θ to 800° or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

As shown in FIG. 14, the outer diameter (thread diameter d1) of the outer screw 13 is preferably, for example, 26 mm to 28 mm. A cap can be used to seal the spout 15 . The inner diameter (root diameter d2) of the outer thread 13, ie, the diameter of the outer peripheral surface 15b, is preferably 23 mm to 25 mm, for example. Further, the diameter of the inner peripheral surface 15c of the plug portion 15 (inner diameter d3) is preferably 21 mm to 23 mm, for example.

In this case, the relationship 1.125≤d1/d2≤1.165 is preferably established between the thread ridge diameter d1 and the thread root diameter d2. By setting the value d1/d2 to 1.125 or more, the size of the screw thread diameter d1 can be changed to a size that can be attached to an existing cap that is generally distributed without changing the shape of the existing cap 60. Since the size of the root diameter d2 can be reduced while maintaining the thickness, the weight of the plug portion 15 can be reduced.
On the other hand, by setting the value d1/d2 to 1.165 or less, it is possible to improve the injection moldability when the preform 30 (described later) is injection molded. Further, by setting the value d1/d2 to 1.165 or less, it is possible to prevent the strength of the plug portion 15 from being lowered. When is heated, it is possible to prevent the problem that the plug portion 15 is deformed by the heat. Further, by setting the value d1/d2 to 1.165 or less, a gap is not generated between the cap 60 and the outer thread 13 of the plug portion 15, and the sealing performance of the cap 60 can be maintained. .

Further, the thread width wA of the external thread 13 is preferably 0.5 mm to 1.0 mm. By setting the thread width wA to 0.5 mm or more, it is possible to prevent the occurrence of a problem called short circuit (incomplete filling) when the preform 30 (described later) is injection molded.

On the other hand, by setting the thread width wA to 1.0 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

By the way, the plug portion 15 has the cover 16 at the upper portion and the support ring 17 at the lower portion as described above.

The turnip 16 has an inclined surface 16a over which the peeling ring 70 rides when the cap 60 is attached. A turnip diameter dA, which is the diameter of the turnip 16, is preferably 25 mm to 32 mm. By setting the cover diameter dA to 25 mm or more, it is possible to prevent the problem that the plastic bottle 10 falls from the gripper (not shown) when the plastic bottle 10 is conveyed in the molding line and the filling line of the plastic bottle 10 . On the other hand, by setting the cover diameter dA to 32 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

Further, the width wB of the turnip 16 is preferably 1.2 mm to 2.0 mm. By setting the width wB of the cover 16 to 1.2 mm or more, it is possible to prevent the problem that the peeling ring 70 partially remains on the cover 16 when the cap 60 is attached and the cap 60 is attached obliquely (slanted covering). can. On the other hand, by setting the width wB of the turnip 16 to 2.0 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing.

On the other hand, the concave annular surface 18 is formed along the entire circumference of the plug portion 15, and the diameter dB of the concave annular surface 18 is uniform in the vertical direction along the axis A of the plastic bottle 10.

The diameter dB of the concave annular surface 18 is preferably between 24 mm and 27 mm. By setting the diameter dB of the concave annular surface 18 to 24 mm or more, the problem of the plastic bottle 10 falling from a gripper (not shown) when the plastic bottle 10 is conveyed in the molding line and the filling line of the plastic bottle 10 is prevented. be able to. On the other hand, by setting the diameter dB of the concave annular surface 18 to 27 mm or less, it is possible to prevent the weight of the plastic bottle 10 from increasing. A relation of dB/dA<1 is established between the diameter dB of the concave annular surface 18 and the turnip diameter dA.

Further, as shown in FIGS. 12 and 14, the upper surface 17a of the support ring 17 (that is, the surface on the side of the concave annular surface 18) has steps 21 and is formed in multiple steps. In this case, the support ring 17 has one step 21 and is formed in two steps. On the other hand, the lower surface 17b (surface on the side of the bottle body 11) of the support ring 17 is a horizontal flat surface.

The support ring 17 also includes an outer region 22 positioned radially outward of the step 21 (horizontal direction in FIG. 14) and an inner region 23 positioned radially inward of the step 21 . Since the support ring 17 has the step 21 in this manner, the volume of the support ring 17 can be reduced by the step 21 . Therefore, the weight of the support ring 17 can be reduced as compared with the case where the step 21 is not provided.

As shown in FIG. 15, the surface 22a of the outer region 22 of the support ring 17 is an inclined surface. In this case, when the angle between the surface 22a of the outer region 22 and the lower surface 17b of the support ring 17 is α, it is preferable that 10°<α<16°. When the angle α exceeds 10°, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and injection moldability can be improved. Also, by providing an angle, the thickness of the base can be secured, and the strength of the support ring is improved. On the other hand, since the angle α is less than 16°, it is possible to prevent the height of the concave annular surface 18 from being shortened and to prevent the plastic bottle 10 from being transported incorrectly.

Further, the surface 23a of the inner region 23 of the support ring 17 is an inclined surface. In this case, when the angle between the surface 23a of the inner region 23 and the lower surface 17b of the support ring 17 is β, it is preferable that β>α. Also, the angle β is preferably set to 20°<β<60°. When the angle β exceeds 20°, good injection moldability can be achieved. Also, by providing an angle, the thickness of the base can be secured, and the strength of the support ring is improved. On the other hand, since the angle β is less than 60°, it is possible to prevent the height of the concave annular surface 18 from being shortened and to prevent the plastic bottle 10 from being transported incorrectly.

Furthermore, as shown in FIG. 15, when the radial length of the outer region 22 is L1 and the radial length of the inner region 23 is L2, the relationship 1.5<L1/L2<4.0 holds. is preferred. When the value of L1/L2 exceeds 1.5, it is possible to prevent the weight of the plastic bottle 10 from increasing. On the other hand, when the value of L1/L2 is less than 4.0, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and the injection moldability is improved. be able to.

Furthermore, the thickness tA at the outer end of the support ring 17 (that is, the outer end of the outer region 22) is preferably 1.0 mm to 1.5 mm. By setting the thickness tA to 1.0 mm or more, the resin can be sufficiently spread to the tip of the support ring 17 when the preform 30 is injection molded, and the injection moldability can be improved. Further, by setting the thickness tA to 1.5 mm or less, it is possible to prevent the height of the recessed annular surface 18 from being shortened, thereby preventing transportation failures when the plastic bottle 10 is transported.

In FIG. 14, the distance h1 between the top surface 15a of the plug portion 15 and the bottom surface 17b of the support ring 17 is, for example, 20 mm to 22 mm. is, for example, 18 mm to 20 mm, and the distance h3 between the top surface 15a of the plug portion 15 and the lower surface of the turnip 16 is, for example, 13 mm to 15 mm.

FIG. 16 is an enlarged cross-sectional view showing the vicinity of the upper end portion of the plug portion 15. As shown in FIG. As shown in FIG. 16, a chamfered portion 15d is formed on the ridgeline of the junction between the top surface 15a and the inner peripheral surface 15c. Thus, by forming the chamfered portion 15d on the ridgeline of the joint portion between the top surface 15a and the inner peripheral surface 15c, the weight of the plug portion 15 can be reduced and the top surface 15a of the plug portion 15 can be reduced. and the inner peripheral surface 15c (near the location where the chamfered portion 15d is provided) can be reduced.

Further, an end portion 15e of the chamfered portion 15d on the side of the top surface 15a (the ridgeline of the joint portion between the chamfered portion 15d and the top surface 15a) and an end portion 15f of the chamfered portion 15d on the side of the inner peripheral surface 15c (the chamfered portion 15d and the inner A rounded portion is formed on each edge line of the joint with the peripheral surface 15c. The radius of the rounded portion is preferably 0.2 mm to 0.4 mm. If the chamfered portion is not formed, the ridgeline of the junction between the chamfered portion 15d and the top surface 15a and the ridgeline of the junction between the chamfered portion 15d and the inner peripheral surface 15c are edges. When the cap 60 described later is screwed onto the plug portion 15, the inner ring 65 and the contact ring 66 of the cap 60 come into contact with this edge. This contact with the edge may damage the inner ring 65 and the contact ring 66 of the cap 60 . Therefore, as described above, it is desirable to form rounded portions at the ends 15e and 15f.

Here, the angle γ of the chamfered portion 15d with respect to the top surface 15a is preferably 20° to 60°. When the angle γ of the chamfered portion 15d is less than 20° or more than 60°, the impact near the junction between the top surface 15a and the inner peripheral surface 15c of the plug portion 15 (near the location where the chamfered portion 15d is provided), which will be described later. It may become difficult to reduce scratches such as marks.

Moreover, the width w1 in the radial direction of the chamfered portion 15d and the width w2 in the height direction of the chamfered portion 15d are preferably 0.15 mm to 0.45 mm. When the width w1 or the width w2 of the chamfered portion 15d is less than 0.15 mm, the chamfered portion 15d is small, and therefore the vicinity of the joint portion between the top surface 15a and the inner peripheral surface 15c of the plug portion 15 (to be described later) (the chamfered portion 15d It is not possible to reduce scratches such as dents in the vicinity of the provided location). Further, if the width w1 or the width w2 of the chamfered portion 15d exceeds 0.45 mm, the chamfered portion 15d is too large, so that the plug portion 15 may not be properly sealed or capped by the cap 60, which will be described later.

An annular projecting portion 27 projecting sideways is formed at the upper end of the outer peripheral surface 15b.

FIG. 17 shows a state in which a screw-type cap 60 is screwed onto the plug portion 15 . As shown in FIG. 17, the plug portion 15 is sealed by screwing a cap 60 thereon. The cap 60 is composed of a cap body 61 and a peeling ring 70 . The cap main body 61 is composed of a disk-shaped upper portion 62 and a cylindrical body portion 63 hanging down from the peripheral edge of the upper portion 62 . An internal thread 64 is formed on the inner peripheral surface of the body portion 63 to be screwed with the external thread 13 of the plug portion 15 . An inner ring 65 , a contact ring 66 and an outer ring 67 are formed on the upper portion 62 .

The inner ring 65 , contact ring 66 , and outer ring 67 are annular protrusions hanging from the inner surface of the upper portion 62 . A protruding portion that protrudes outward from the cap 60 is formed on the outer peripheral surface of the inner ring 65 . The projecting portion of the inner ring 65 contacts the inner peripheral surface 15 c of the plug portion 15 . A lower tip portion of the contact ring 66 contacts the top surface 15 a of the plug portion 15 . A protruding portion protruding toward the inside of the cap 60 is formed on the inner peripheral surface of the outer ring 67 . The projecting portion of the outer ring 67 contacts the annular projecting portion 27 of the plug portion 15 .

The stripping ring 70 is ring-shaped. A plurality of flaps 71 projecting inward and upward are formed on the inner peripheral surface of the peeling ring 70 . The cap main body 61 and the peeling ring 70 are connected via a connecting member 72 that can be broken when the cap 60 is initially opened.

The flap 71 is positioned between the turnip 16 and the support ring 17 at the time of initial sealing. When the cap 60 is rotated in the unsealing direction, the upper end of the flap 71 comes into contact with the turnip cover 16, preventing the peeling ring 70 from moving. Furthermore, when the cap 60 is rotated, the connecting member 72 is broken, and the cap main body 61 and the peeling ring 70 are separated. The peeling ring 70 is held between the cover 16 and the support ring 17 , and the cap body 61 can be removed from the plug portion 15 .

By the way, the shape of the bottle body 11 is not particularly limited, and may have various conventionally known shapes. For example, in FIG. 12, the bottle body 11 has a neck portion 11a, a shoulder portion 11b, a body portion 11c and a bottom portion 11d. When a carbonated beverage is used as the content liquid to be filled in the plastic bottle 10, the bottom portion 11d may have a petaloid shape.

Also, the size (capacity) of the plastic bottle 10 is not limited, and the bottle may be of any size, for example, 500 ml to 600 ml.

As the main material of the plastic bottle 10, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate). For example, it is also possible to use PLA (polylactic acid). The plastic bottle 10 is preferably sterilized by adding hydrogen peroxide or peracetic acid.

Next, the preform 30 according to this embodiment will be described with reference to FIG. FIG. 18 is a diagram showing a preform 30 used when manufacturing the plastic bottle 10 shown in FIGS. 12-17.

As shown in FIG. 18 , the preform 30 includes a plug portion 15 and a preform body 31 provided below the plug portion 15 . Of these, the plug portion 15 is formed on the outer thread 13, the turnip 16 positioned below the outer thread 13, the support ring 17 positioned below the turnip 16, and the outer surface between the turnip 16 and the support ring 17. and a curved concave annular surface 18 . The preform body 31 corresponds to the bottle body 11 described above, and has a substantially cylindrical body portion 31a, a substantially hemispherical bottom portion 31b, a minimum thickness portion 31c, and a central portion of the bottom portion 31b. and a gate portion 31d. Note that the preform body 31 is not limited to this, and may have various conventionally known shapes.

As described above, in the plug portion 15, the chamfered portion 15d is formed on the ridgeline of the joint portion between the top surface 15a and the inner peripheral surface 15c. When the bottom portion 31b of another preform 30 is inserted into the opening plug portion 19 of the plug portion 15, the outer peripheral surface of the bottom portion 31b and the chamfered portion 15d collide. Further, when the plug portion 15 of another preform 30 is inserted into the opening plug portion 19 of the plug portion 15, the outer peripheral surface 15b of the plug portion 15 collides with the chamfered portion 15d. At this time, since the collision part is the chamfered portion 15d, the occurrence of scratches on the top surface 15a and the inner peripheral surface 15c of the plug portion 15 can be reduced. By reducing the occurrence of scratches on the plug portion 15, it is possible to reduce the occurrence of scratches on the inner ring 65 and the contact ring 66 when the cap 60 is screwed. Further, the sealing performance of the plug portion 15 by the cap 60 can be improved.

18, the configuration of the plug portion 15 is the same as the configuration of the plug portion 15 of the plastic bottle 10 shown in FIGS. 12 to 17. FIG. In FIG. 18, the same parts as in the embodiment shown in FIGS. 12 to 17 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Next, the operation of this embodiment having such a configuration will be described.
First, thermoplastic resin pellets such as PET (polyethylene terephthalate) are put into an injection molding machine (not shown), and the pellets are heated, melted and pressurized by the injection molding machine.
The pellets then become molten plastic and are injected into an injection mold having an internal shape corresponding to the preform 30 (see FIG. 18).

After a period of time, the molten plastic hardens in the injection mold to form preform 30 . After that, the injection mold is separated, and the preform 30 shown in FIG. 18 is taken out from the injection mold.

The preform 30 is then heated in a heating device (not shown) within the blow molding machine.
At this time, the preform 30 is conveyed in the heating device and is evenly heated in the circumferential direction by the heater while rotating about the central axis. During this time, the preform 30 is heated to a temperature of, for example, 80.degree. C. to 140.degree. After that, the heated preform 30 is sent to a blow molding section (not shown).

The preform 30 sent to the blow molding section is inserted into the blow molding mold of the blow molding section. After that, high-pressure air is supplied into the preform 30 from a stretching rod inserted into the preform 30, and the preform 30 is stretched by stretching the stretching rod, and biaxial stretching blow molding is performed (blow molding process). By such blow molding, the plastic bottle 10 shown in FIGS. 12 and 13 is obtained.

The plastic bottle 10 molded on the blow molding line is conveyed from the blow molding section into a filling machine (not shown) by air conveying means or neck conveying means. Thereafter, the plastic bottle 10 is filled with the content liquid in the filling machine, and then the cap 60 is attached to the plastic bottle 10 using a capper. At this time, the plastic bottle 10 is supported by the lower surface 17b of the support ring 17, and the cap is attached so as to cover the spout portion 15. As shown in FIG. At this time, the peeling ring 70 of the cap 60 climbs over the turnip 16 and contacts the upper surface 17a of the support ring 17 to stop.

As described above, according to this embodiment, the winding angle from the upper end to the lower end of the external thread 13 is 550° to 800°. As a result, the volume of a part of the mouth plug portion 15 (outer screw 13) can be reduced without changing the shape of the existing cap 60, and the overall weight of the plastic bottle 10 and the preform 30 can be reduced. can be done.

Further, according to the present embodiment, a relationship of 1.125≤d1/d2≤1.165 is established between the thread ridge diameter d1 and the thread root diameter d2. As a result, the volume of a part of the mouth plug portion 15 (outer screw 13) can be reduced without changing the shape of the existing cap 60, and the overall weight of the plastic bottle 10 and the preform 30 can be reduced. can be done.

<Modification>
Next, a modified example of this embodiment will be described.
In the embodiment described above, the concave annular surface 18 has a uniform diameter along the vertical direction (direction of the axis A), but is not limited to this.

As shown in FIGS. 19 and 20, the concave annular surface 18 may be formed with an annular groove 26 that is concave radially inward. The concave annular surface 18 has a clamping portion 25 which is clamped by a gripper during transport, and an annular groove 26 having a smaller diameter than the clamping portion 25 . That is, the holding portion 25 and the annular groove 26 have circular cross sections with different diameters. The annular groove 26 is formed over the entire circumference of the concave annular surface 18 .

By providing the annular groove 26 in the concave annular surface 18 in this manner, the volume of the mouth plug portion 15 can be further reduced, and the weight of the plastic bottle 10 and the preform 30 as a whole can be reduced.

19 and 20 are substantially the same as the embodiment described above, except for the shape of the concave annular surface 18. As shown in FIG. 19 and 20, the same parts as in the embodiment shown in FIGS. 12 to 18 are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Example)
Next, a specific example of this embodiment will be described.
First, the following three types of plastic bottles (Example 1 and Comparative Examples 1 and 2) were produced.

(Example 1)
A preform 30 according to the present embodiment shown in FIG. 18 was produced by injection molding, and the preform 30 was blow-molded to obtain the plastic bottle 10 (Example 1) shown in FIGS. In this plastic bottle 10 (Example 1), the winding angle θ from the upper end 13a to the lower end 13b of the external thread 13 was set to 700°. Also, the ratio (d1/d2) of the thread ridge diameter d1 to the thread root diameter d2 was set to 1.135. The weight of the plug portion of the plastic bottle 10 (Example 1) was 4.2 g.

(Comparative example 1)
A plastic bottle (Comparative Example 1) was produced in the same manner as in Example 1, except that the winding angle θ of the external thread 13 was set to 500°. The weight of the plug portion was 3.5 g.

(Comparative example 2)
A plastic bottle (Comparative Example 2) was produced in the same manner as in Example 1, except that the winding angle θ of the outer thread 13 was set to 800°. The weight of the plug portion was 5.0 g.

Here, 10,000 of each of the above three types of plastic bottles (Example 1 and Comparative Examples 1 and 2) were produced. Next, each plastic bottle was filled with a carbonated beverage, and then each plastic bottle was capped using a capper.

For each of Example 1 and Comparative Examples 1 and 2, whether or not a weight reduction effect was obtained and the injection moldability of the preform were evaluated.

In addition, a cap sealability confirmation test (leakage test) and a cap fly test were conducted, and the percentage of bottles with cap sealability and the percentage of bottles with cap flakes were calculated, respectively. Among these, in the cap sealability confirmation test (leakage test), a sealed plastic bottle was immersed in water, and when 0.7 MPa of air was injected from the top surface of the cap, it was confirmed whether or not bubbles were generated in the water. . In the cap fly test, it was confirmed whether or not the cap flew when the bottle was suddenly opened.

As a result, for the plastic bottle 10 of Example 1, the effect of reducing the weight and the injection moldability of the preform were both good. There were also no jumps.

On the other hand, the plastic bottle of Comparative Example 1 was excellent in the weight reduction effect, the injection moldability of the preform was good, and no leakage occurred in the cap sealability confirmation test. Some caps flew off.

In addition, regarding the plastic bottles of Comparative Example 2, the injection moldability of the preform was good, there were no cases where leakage occurred in the cap sealability confirmation test, and there were cases where cap jumping occurred in the cap flying test. However, no weight reduction effect was obtained.

Table 2 summarizes the above results. In Table 2, the evaluation criteria "⊚" indicate "excellent", the evaluation criteria "○" indicate "good", and the evaluation criteria "X" indicate "poor".

<Modification>
Next, a modification of this embodiment will be described with reference to FIGS. 21 to 23. FIG.
In this modified example, the structure of the plug portion 15 having the chamfered portion 15d is further explained, and the same parts as in the second embodiment shown in FIGS. Description is omitted.

As shown in FIG. 21, when the cap 60 is screwed onto the plug portion 15, the inner peripheral surface 15c of the plug portion 15 contacts the protrusion on the outer peripheral surface of the inner ring 65 at the contact portion C1. That is, the contact portion C<b>1 is the portion of the inner peripheral surface 15 c of the plug portion 15 that contacts the inner ring 65 .

The top surface 15a of the plug portion 15 contacts the lower tip portion of the contact ring 66 at the contact portion C2. That is, the contact portion C<b>2 is a portion of the top surface 15 a of the plug portion 15 that contacts the contact ring 66 .

The outer peripheral surface 15b of the plug portion 15 comes into contact with the projecting portion of the inner peripheral surface of the outer ring 67 at the contact portion C3. That is, the contact portion C<b>3 is a portion of the outer peripheral surface 15 b of the plug portion 15 that contacts the outer ring 67 .

The plug portion 15 is sealed by these three contact portions C1, C2, and C3, which are contact portions between the plug portion 15 and the cap 60. As shown in FIG.

Here, the distance L1 between the contact portion C1 of the inner peripheral surface 15c and the end portion 15f of the chamfered portion 15d on the inner peripheral surface 15c side is preferably 1.5 mm or more and 3.0 mm or less. Further, the distance L2 between the contact portion C2 of the top surface 15a and the end portion 15e of the chamfered portion 15d on the top surface 15a side is preferably 0.05 mm or more and 0.8 mm or less.

If the distance L1 is less than 1.5 mm, the protrusion on the outer peripheral surface of the inner ring 65 may be positioned at the chamfered portion 15d or the rounded portion formed at the end portion 15f, depending on the screwed state of the cap 60 and dimensional errors. I have something to do. Therefore, the inner ring 65 may not be in contact with the inner peripheral surface 15c of the plug portion 15, and the sealing performance of the plug portion 15 may be deteriorated.

Further, if the distance L1 exceeds 3.0 mm, it becomes impossible to ensure the dimension of the width W2 in the height direction of the chamfered portion 15d in order to obtain proper capping.

If the distance L2 is less than 0.05 mm, the lower tip of the contact ring 66 may be positioned at the chamfered portion 15d or the rounded portion formed at the end portion 15e, depending on the screwed state of the cap 60 and dimensional errors. I have something to do. Therefore, the contact ring 66 may not be in contact with the top surface 15a of the plug portion 15, and the sealing performance and capping suitability of the plug portion 15 may deteriorate.

Further, when the distance L2 exceeds 0.8 mm, the lower tip of the contact ring 66 may be located outside the outer end of the top surface 15a and may not make contact with the top surface 15a. Therefore, the sealing performance of the plug portion 15 may deteriorate.

The distance L1 is longer than the distance L2 even when the cap 60 is not completely closed (there is a slight gap between the cap 60 and the top surface 15a of the plug portion 15). , to enable the plug portion 15 to be sealed.

Note that the cap 60 is not limited to the shape described above. Any screw-type cap that includes at least an inner ring 65 and that allows the inner peripheral surface 15 c of the plug portion 15 to come into contact with the inner ring 65 to seal the plug portion 15 may be used.

For example, the cap 60 may be configured without the contact ring 66 and the outer ring 67 .

Also, the cap 60 may be of a one-piece specification in which the cap main body 61 is made of the same material, and the parts that come into contact with the top surface 15a, the outer peripheral surface 15b, the inner peripheral surface 15c, etc. of the plug portion 15 may be used. may be a two-piece specification having a so-called liner inside, which is formed by a separate member. As a form of two-piece specifications, for example, the top surface 15a and the outer peripheral surface 15b of the plug portion 15 may be in contact with each other, and the inner ring 65 may not be in contact with the inner peripheral surface 15c.

Further, the contact of each of the inner ring 65, the contact ring 66, and the outer ring 67 with the plug portion 15 is not limited to the above-described mode.

Next, transportation of the preform 30 will be described in detail. As described above, in the manufacture of the plastic bottle 10, the injection molding process of the preform 30 and the blow molding process of the plastic bottle 10 are generally not performed as continuous processes in some cases.

There are several reasons for this, one of which is that transporting the preform 30 to the bottle manufacturing and filling process reduces storage space and transport costs, thereby reducing costs.

Therefore, the preform 30 is transported between the injection molding process of the preform 30 and the blow molding process of the plastic bottle 10 .

An example of the method of transporting the preform 30 will be described. The preforms 30 are randomly housed in a rectangular parallelepiped box made up of a container. In order to reduce the transportation cost, the preforms 30 are not arranged in a line or cushioning materials or the like are placed between the preforms 30 for storage.

In this way, when the preforms 30 are transported in contact with each other, the preforms 30 may strongly collide with each other due to vibration during transportation.

Here, in the conventional preform, the chamfered portion 15d is not provided on the ridgeline of the junction between the top surface 15a and the inner peripheral surface 15c of the plug portion 15, and instead, an outwardly curved rounded portion is formed. is provided. The radius of the rounded portion is generally 0.3 mm.

Damage such as dents rarely occurs in the rounded portion due to collision between the preforms 30 due to vibration during transportation.

Although the definite cause for the formation of this dent is unknown, the bottom portion 31b of another preform 30 and the plug portion 15 are inserted into the opening plug portion 19 of the plug portion 15, and the outer circumference of the bottom portion 31b The cause is considered to be the collision between the surface or the outer peripheral surface 15b of the plug portion 15 and the corner R.

Then, when the screw cap 60 is screwed onto the plug portion 15 having the dent, the inner ring 65 and the contact ring 66 rotate and come into contact with the dent. A raised protrusion may be formed in the damage such as the dent, and the protrusion damages the inner ring 65 and the contact ring 66 .

Here, as the cap 60 rotates, the inner ring 65 and the contact ring 66 also rotate. Therefore, due to the projection of the damage such as the dent of the plug portion 15, the inner ring 65 and the contact ring 66 are continuously damaged in the circumferential direction.

Scratches on the inner ring 65 and the contact ring 66 cause leakage of the filled contents.

Here, in the preform 30 according to this embodiment, as described above, the chamfered portion 15d is formed on the ridgeline of the joint portion between the top surface 15a and the inner peripheral surface 15c. When the bottom portion 31b of another preform 30 is inserted into the opening plug portion 19 of the plug portion 15, the outer peripheral surface of the bottom portion 31b and the chamfered portion 15d collide. Further, when the plug portion 15 of another preform 30 is inserted into the opening plug portion 19 of the plug portion 15, the outer peripheral surface 15b of the plug portion 15 collides with the chamfered portion 15d.

At this time, since the collision part is the chamfered portion 15d, the occurrence of scratches on the top surface 15a and the inner peripheral surface 15c of the plug portion 15 can be reduced. By reducing the occurrence of scratches on the plug portion 15, it is possible to reduce the occurrence of scratches on the inner ring 65 and the contact ring 66 when the cap 60 is screwed. Further, the sealing performance of the plug portion 15 by the cap 60 can be improved.

Here, the clear reason why the occurrence of scratches on the top surface 15a and the inner peripheral surface 15c of the plug portion 15 is reduced by forming the chamfered portion 15d is unknown. However, unlike the conventional rounded portion, the chamfered portion 15d is not curved outward. Therefore, when the chamfered portion 15d collides with the outer peripheral surface of the bottom portion 31b, it is possible to suppress the concentration of the collision load compared to the case of the rounded portion, and it is considered that the occurrence of scratches is reduced. .

It should be noted that the one-piece cap is desired to reduce the occurrence of dents more than the two-piece cap. As described above, the scratches when the cap is screwed are caused by contact with the dents while the inner ring and the contact ring are rotating. Here, the two-piece cap brings the top surface 15a of the plug portion 15 into contact more than the one-piece cap, thereby enhancing the sealing performance. This is because even if the rounded portion of the plug portion 15 or its vicinity is damaged, the sealability of the top surface 15a portion of the plug portion 15 is improved, and leakage tends to be difficult. In addition, since the one-piece cap is less expensive than the two-piece cap, from the viewpoint of cost reduction, the sealing performance of the mouth part is improved in the configuration where the mouth part is sealed with the one-piece cap. It is desirable that

EXAMPLES Next, the present invention will be specifically described with reference to examples, but these examples are not intended to limit the present invention in any way.

(Example 1)
A preform 30 whose main material is PET was molded by an injection molding machine. This preform 30 is used for a 500 ml round plastic bottle for carbonic acid, and the spout portion 15 is not subjected to crystallization treatment. The outer diameter of the plug portion 15 was 25.8 mm. The angle θ of the chamfered portion 15d was 30°, the width W1 was 0.39 mm, and the width W2 was 0.22 mm.

(Example 2)
A preform in which only the shape of the chamfered portion 15d in Example 1 was changed was molded by an injection molding machine. The angle θ of the chamfered portion 15d was 45°, and the width W1 and the width W2 were both 0.35 mm.

(Comparative example 1)
A preform 30 having a chamfered portion instead of the chamfered portion 15d in Example 1 and having a plug portion 15 was molded by an injection molding machine. The radius of the rounded portion was 0.3 mm. This is the shape of the plug that is commonly available.

(drop test)
The preforms of Examples 1 and 2 and Comparative Example 1 were stored in constant temperature baths of 35°C and 45°C, respectively, and stored for 6 hours so that the surface temperatures of the preforms reached 35°C and 45°C. After storage, 90 preforms were placed in cylinders of length 335 mm, width 280 mm, and height 600 mm, and dropped from a height of 1 m at room temperature. One set of 90 samples was dropped, and a total of 180 preforms were dropped in two batches. Table 3 shows the results. The number of preforms with scratches near the chamfered portion or rounded portion and the size of the scratches were evaluated. The size of the scratch was classified into three types according to the size of the maximum outer shape: large: 1.5 mm or more, small: 1 mm or more and less than 1.5 mm, and extremely small: less than 1 mm.

As shown in Table 3, Examples 1 and 2 were able to reduce the occurrence of scratches more than Comparative Example 1 at any storage temperature. Moreover, Example 1 was able to reduce the occurrence of scratches more than Example 2.

(Seamless momentary pressure resistance test)
Using the preforms of Examples 1 and 2 and Comparative Example 1, 500 ml round plastic bottles for carbonated drinks having the shape shown in FIG. 12 were molded by a blow molding machine. Carbonated water of gas volume (GV) 4 was filled into this plastic bottle using the sodium bicarbonate citric acid method. A cap comprising an inner ring, a contact ring, and an outer ring shown in FIG. 17 was screwed to the plug portion of the plastic bottle, and the plug portion was closed by hand tightening. This cap is a one-piece specification cap used for a plastic bottle whose content is a carbonated drink, and is a TA cap (hereinafter referred to as NCC) manufactured by Nippon Closure Co., Ltd. and a GA-LOK cap manufactured by CSI Japan Co., Ltd. (hereinafter referred to as GA-LOK cap). CSI) were used. Each cap has a TA band and the crimping angle is 255° for NCC and 280° for CSI.

The plastic bottle with the cap screwed thereon was submerged in a water bath at 22° C., and the pressure inside the plastic bottle was raised to 0.88 MPa at a rate of increase of 34.4 kpa/sec. In this state, the plastic bottle was held in the water bath for 1 minute. At that time, it was confirmed whether or not air bubbles were generated from the mouth plug portion and the cap. The number of samples for Examples 1 and 2 and Comparative Example 1 was 5 for each cap. Table 4 shows the results.

As shown in Table 4, the plugs of Examples 1 and 2 and Comparative Example 1 did not leak from both caps manufactured by NCC and CSI, confirming good sealing performance.

(Clogging property evaluation test)
Using the preforms of Examples 1 and 2 and Comparative Example 1, 500 ml round plastic bottles for carbonated drinks having the shape shown in FIG. and CSI caps were screwed onto the mouthpiece to seal the mouthpiece. The torque (capping torque) at the time of winding the cap at this time was measured. The plugging torque was measured using an automatic torque measuring device (manufactured by Kyoto Giken Kogyo Co., Ltd.: MTP). The closing speed of the cap was 3 rpm.

The results for the NCC cap are shown in FIG. 22, and the results for the CSI cap are shown in FIG. Here, the result of Example 1 is indicated by a dotted line, the result of Example 2 is indicated by a dashed line, and the result of Comparative Example 1 is indicated by a solid line. The vertical axis is the plugging torque (N·cm), and the horizontal axis is the rotation angle (°) of the cap.

As shown in FIGS. 22 and 23, there was no significant difference in plugging torque between Examples 1 and 2 and Comparative Example 1, and there was no difference in pluggability.

Therefore, since Examples 1 and 2 satisfy the requirements for sealing, they can be used as preforms having a sealable plug portion. Furthermore, since Examples 1 and 2 are not different from Comparative Example 1 in capping performance, the capping process can be performed in the same manner as in the conventional process.

The preform of the present invention contains, for example, various non-carbonated beverages such as green tea, oolong tea, black tea, coffee, and fruit juice, carbonated beverages, natural sparkling water, medicines, cosmetics, and seasonings such as sauces and mirin. Useful for making any plastic bottle containing food or the like.

<Third Embodiment>
Details of the third embodiment of the present invention will be described below with reference to the drawings. First, the configuration of a preform 100 (preformed body) for PET (Poly Ethylene Terephthalate) bottle molding according to the present embodiment will be described in detail. FIG. 24 is a front view showing an example of the preform 100 according to this embodiment. Furthermore, FIG. 25 is a cross-sectional view of the preform 100 of FIG. In the following, for convenience of explanation, the plug portion 111 of the preform 100 in the state shown in FIG.

The preform 100 according to the present embodiment has a cylindrical shape with an open end and includes a plug portion 111 on the open side and a preform body 120 on the bottom side. The plug portion 111 has a circular opening plug portion 112 at its upper end and an annular support ring 114 protruding outward at its lower end.

A threaded portion 113 is provided on the outer periphery of the spout portion 111 for attaching a lid (not shown) after the preform 100 is formed into a bottle shape by a blow molding machine. An outwardly projecting annular turnip 115 is provided between the threaded portion 113 and the support ring 114 .
Further, the shape of the plug portion 111 does not change even after being molded by a blow molding machine. Therefore, it is preferable that the inner diameter D1 and the outer diameter D2 (corresponding to the thread root diameter) of the mouth plug portion 111 of the preform 100 are, for example, the dimensions normally used for PET bottles for beverages (see FIG. 25). ).

The plug portion 111 may have dimensions corresponding to, for example, the PCO1810 standard or the PCO1881 standard. The length L1 of the plug portion 111 is the distance from the lower surface of the support ring 114 to the upper end of the plug portion 111 . More specifically, the length L1 of the plug portion 111 is preferably 21.00 mm±0.25 mm (PCO1810 standard).

The preform body 120 is cylindrical and expands into a bottle shape during blow molding. The preform body 120 is connected to the lower end (lower surface) of the support ring 114 of the plug portion 111 . The preform body 120 includes a large diameter portion 121 connected to the lower end of the support ring 114, a constricted portion 122 connected to the lower end of the large diameter portion 121, and a constricted portion 122 connected to the lower end of the constricted portion 122. It has a small diameter portion 123 and a bottom portion 124 connected to the lower end of the small diameter portion 123 . The total length L2 of the preform body 120 is the distance from the lower surface of the support ring 114 to the lower end of the bottom portion 124 .

The large diameter portion 121 and the small diameter portion 123 are cylindrical, and the outer diameter D3 of the large diameter portion 121 is larger than the outer diameter D4 of the small diameter portion 123 . The constricted portion 122 is formed in a truncated cone shape by gradually decreasing in diameter downward, that is, from the large diameter portion 121 side to the small diameter portion 123 side. The upper end and lower end of the constricted portion 122 are smoothed to the lower end of the large diameter portion 121 and the upper end of the small diameter portion 123, respectively. The outer diameter at the upper end of the constricted portion 122 is the outer diameter D3 of the large diameter portion 121 and the outer diameter at the lower end is the outer diameter D4 of the small diameter portion 123 .

The preform body 120 does not have a uniform thickness, and has portions with different thicknesses. The preform main body 120 has a minimum thickness portion 125 in which the minimum thickness is uniformly formed downward from the lower end of the support ring 114 of the plug portion 111, and a minimum thickness portion 125. An increased thickness portion 126 formed so that the thickness gradually increases downward from the lower end, and a predetermined thick portion 127 formed uniformly downward from the lower end of the increased thickness portion 126. and The thickness at the upper end of the increased thickness portion 126 is the thickness T1 of the minimum thickness portion 125, and the thickness at the lower end is the thickness T2 of the predetermined thickness portion 127. FIG. Also, the lower end of the predetermined thickness portion 127 corresponds to the lower end of the small diameter portion 123 .

The bottom portion 124 is configured in a substantially hemispherical shape curved outward. The bottom portion 124 is formed such that the thickness gradually decreases from the lower end of the small-diameter portion 123 toward the center. The bottom portion 124 may be conical, cylindrical with rounded corners, or any other shape. Attached to the bottom center 128 is a solidified portion concomitantly formed at the molten resin inlet (gate) when the preform 100 is made by injection molding. In addition, FIG.24 and FIG.25 shows the form after the part was cut off. Here, the thickness T1 of the minimum thickness portion 125, the thickness T2 of the predetermined thickness portion 127, and the thickness T3 of the bottom center portion 128 have a relationship of T1<T3<T2.

Thus, the preform main body 120 is formed with a constricted portion 122 whose diameter gradually decreases from the large diameter portion 121 side toward the small diameter portion 123 side, thereby reducing the weight of the preform 100 . there is Further, the preform body 120 has a minimum-thickness portion 125 formed with a uniform minimum thickness directly below the support ring 114, so that the weight of the preform 100 is reduced. Furthermore, the bottom portion 124 of the preform body 120 is formed so that the thickness gradually decreases toward the center, and this configuration also contributes to the weight reduction of the preform 100 .

Here, in the preform 100 according to the present embodiment, the total length L2 of the preform body 120 is 59 mm or more and 65 mm or less, and the total length L2 of the preform body 120 extends from directly below the support ring 114 to the lower end of the minimum thickness portion 125. The ratio L4/L2 of the distance L4 to the support ring 114 is 0.02 or more and 0.25 or less, and the ratio L6/L2 of the distance L6 from directly below the support ring 114 to the upper end of the constricted portion 122 with respect to the total length L2 of the preform body 120 is L6/L2. is 0.02 or more and 0.20 or less. Although the details will be described later, the minimum thickness portion 125 and the constricted portion 122 are formed in the preform main body 120 in this manner, so that an injection molding machine can be used to mold the preform 100. It is configured to have good moldability and to have appropriate stretchability from directly under the support ring 114 to the constricted portion 122 when the preform 100 is molded into a bottle shape by a blow molding machine. It should be noted that the preform 100 is designed in consideration of not only injection moldability and blow moldability but also transportability. Therefore, the preform 100 according to the present embodiment exhibits comprehensively excellent performance from the raw material to the finished product.

Next, an example of a method for manufacturing the preform 100 according to this embodiment will be described in detail. FIG. 26 is a schematic diagram showing an example of an injection molding apparatus 140 for manufacturing the preform 100. As shown in FIG. The injection molding device 140 includes a hopper dryer 141 , a hopper 142 , a heating cylinder 143 and a mold 144 .

The hopper dryer 141 is an inlet for a pellet-shaped molding material, which is the main raw material of the preform 100 . The hopper dryer 141 is configured to dry the molding material and then deliver it to the hopper 142 . The hopper dryer 141 may be of a hot air drying type, a dehumidifying hot air drying type, or a reduced pressure heat transfer drying type, as long as it can dry the charged molding material to a predetermined moisture content.

The injection molding apparatus 140 is configured such that a molding material put into a hopper 142 is melted and plasticized by a heating cylinder 143 and delivered to a mold 144 . The cylindrical heating cylinder 143 has a heater (not shown) on its outer periphery and a screw (not shown) for injection into the mold 144 inside. The heating cylinder 143 is configured to heat the molding material to, for example, 270.degree. C. to 300.degree. C. by heat transfer from the heater.

A mold 144 that is divided into a plurality of parts is formed with a cavity 145 that is a space corresponding to the shape of the preform 100 as a molded product. In addition, the cavity 145 is formed so as to correspond to the characteristic shape of the preform 100 according to the present embodiment. The molding material injected from the heating cylinder 143 is configured to be injected into the cavity 145 . The mold 144 is provided with a heater (not shown) for heating the mold 144 and a cooler (not shown) for cooling the mold 144 . The mold 144 is configured to mold the preform 100 by injecting a molten molding material into a cavity 145 heated by a heater, pressurizing it, and then cooling it by a cooler.

The preform 100 is manufactured using such an injection molding apparatus 140 . First, the PET resin dried by the hopper dryer 141 of the injection molding device 140 and then put into the hopper 142 is melted and plasticized by the heating cylinder 143 and injected into the mold 144 . The preform 100 is molded by injecting the PET resin from the heating cylinder 143 into the cavity 145 of the mold 144, pressurizing it, and then cooling it by a cooler.

The molded preforms 100 may be boxed, palletized, and temporarily stored in a warehouse or the like, or may be continued to the next step as they are.
That is, a so-called cold parison method (two-stage method) in which molding of the preform 100 and blow molding are performed in different locations or devices may be used, and molding of the preform 100 and blow molding may be performed in the same manner. A so-called hot parison method (one-stage method), which is performed at a place or with an apparatus, may also be used. Furthermore, the manufacturing process from molding of the preform 100 to filling of the contents may be continuous in-line.

Next, an example of a method of molding the preform 100 according to this embodiment into a bottle shape will be described in detail. When the preform 100 is molded into a bottle shape, the preform 100 is first heated. FIG. 27 is a cross-sectional view showing an example of the heating device 150 for the preform 100. As shown in FIG. Note that FIG. 27 shows a cross section perpendicular to the transport direction of the preform 100 .

The heating device 150 includes a conveying device 151 and a heater 152 . The transport device 151 is configured to transport the preform 100 while rotating it about its axis in order to evenly heat the preform 100 in the circumferential direction. The heater 152 is composed of a plurality of halogen lamps, for example, and is configured to heat the preform 100 to a temperature suitable for blow molding, for example, 80.degree. C. to 140.degree. Further, the heating device 150 includes a reflecting plate 153 for reflecting the heat from the heater 152 to the preform 100, a shielding member 154 for preventing the heat from the heater 152 from escaping to the outside of the heating device 150, and the like. may be provided.
27, the preform 100 is conveyed and heated with the plug portion 111 facing downward.

Here, the preform body 120 of the preform 100 according to the present embodiment includes a large diameter portion 121 connected to the lower end of the support ring 114 and a large diameter portion 121 connected to the bottom portion 124 side. It has a constricted portion 122 with a reduced diameter and a small diameter portion 123 connected to the constricted portion 122 . That is, the positional relationship between the heater 152 and the preform main body 120 is such that the large diameter portion 121 is the closest, and gradually becomes farther from the large diameter portion 121 side of the constricted portion 122 toward the small diameter portion 123 side, and the small diameter portion 123 configured to be the furthest. Therefore, the large-diameter portion 121 that is close to the heater 152 is easily warmed and stretched. On the other hand, compared to the large-diameter portion 121, the constricted portion 122 gradually becomes less likely to warm toward the bottom portion 124 side (upward in FIG. 27), and thus becomes less likely to be gradually stretched toward the bottom portion 124 side. .

In addition, the preform body 120 includes a minimum thickness portion 125 in which the minimum thickness is uniformly formed from the lower end of the support ring 114 toward the bottom portion 124 side (upward in FIG. 27), and from the minimum thickness portion 125 The increased thickness portion 126 is formed so that the thickness gradually increases toward the bottom portion 124 side, and the predetermined thickness is formed uniformly from the increased thickness portion 126 toward the bottom portion 124 side. 127. That is, the preform main body 120 is easily warmed and stretched at the minimum thickness portion 125 having the minimum thickness. On the other hand, as compared with the minimum thickness portion 125, the increased thickness portion 126 gradually becomes less likely to warm toward the bottom portion 124 side, and thus becomes less likely to gradually stretch toward the bottom portion 124 side.

In the preform 100, the total length L2 of the preform body 120 is 42 mm or more and 65 mm or less, and the ratio of the distance L4 from directly below the support ring 114 to the lower end of the minimum thickness portion 125 to the total length L2 of the preform body 120 L4/L2 is 0.02 or more and 0.25 or less, and the ratio L6/L2 of the distance L6 from directly below the support ring 114 to the upper end of the constricted portion 122 with respect to the total length L2 of the preform body 120 is 0.02 or more, 0.20 or less. In other words, the preform 100 has the overall length L2 of the preform main body 120 within a predetermined range, and has the minimum thickness portion 125 and the constricted portion 122, thereby achieving weight reduction. An easily stretchable region corresponding to the thick portion 125 is formed in a predetermined range from directly below the support ring 114 toward the bottom portion 124 side. In addition, the preform 100 has regions corresponding to the constricted portion 122 and the increased thickness portion 126, and a region is formed in which it becomes difficult to extend gradually from the lower end of the easy-to-stretch region toward the bottom portion 124 side. The design is such that when the preform 100 is molded into a bottle shape by a blow molding machine, the resin in the constricted portion 122 is effectively stretched from directly below the support ring 114 .

The heated preform 100 is then molded into a plastic bottle, such as a PET bottle 100A, by a blow molding machine. FIG. 28 is a cross-sectional view schematically showing the preform 100 and the PET bottle 100A after blow molding. A biaxial stretch blow molding device 160 as an example of a blow molding machine includes a mold 161, a stretching rod 162, a high pressure air supply device (not shown), and a control device (not shown) for controlling them. Although FIG. 28 illustrates a downward blow molding method, an upward blow molding method in which the material is less susceptible to gravity may be used.

The mold 161 has a shape corresponding to the PET bottle 100A to be formed. The mold 161 has, for example, a trunk mold 161a divided in half corresponding to the trunk portion 130 and a bottom mold 161b corresponding to the bottom portion 140A. The temperature of the surface of the mold 161 is appropriately set according to the application of the PET bottle 100A, particularly the heat resistance. The temperature of the surface of the is configured to be controlled at 5°C to 30°C.

The extension rod 162 is configured to extend and retract within the mold 161 . The extension rod 162 is configured to extend the preform main body 120 and the bottom portion 124 of the preform 100 to which the plug portion 111 is attached to the mold 161 in the vertical (axial) direction. The high-pressure air supply device is configured to blow out high-pressure air A whose temperature has been adjusted. The high-pressure air A may be supplied inside the preform 100 attached to the mold 161 , may be blown from the stretching rod 162 , or may be blown from a member other than the stretching rod 162 . The high-pressure air A is configured to stretch the preform body 120 of the preform 100 in the lateral (diameter) direction and to lower the surface temperature of the preform body 120 after stretching.

Heated preform 100 is mounted in mold 161 of biaxial stretch blow molding apparatus 160 . Thereafter, the preform body 120 and the bottom portion 124 of the preform 100 mounted in the mold 161 are longitudinally stretched by the stretching rods 162 . At this time, the longitudinal draw ratio from the preform 100 to the PET bottle 100A is preferably 1.3 times or more and 3.6 times or less.

Here, the longitudinal draw ratio is the distance from the upper end of the neck portion 110A to the lower end of the bottom portion 140A of the PET bottle 100A with respect to the length L2 (see FIG. 24) from the upper end of the preform main body 120 to the lower end of the bottom portion 124 of the preform 100. It is the ratio of the length L3 (see FIGS. 28 and 29). In addition, the distance from the lower surface of the support ring 114 to the bottom wall 141A at the lower end of the bottom portion 140A is the length L3. Molecules of the preform 100 having an amorphous structure, which is an aggregate of amorphous parts and crystalline parts, are oriented and crystallized by stretching, and as a result, the strength, rigidity, heat resistance, etc. of the PET bottle 100A are increased. . When the longitudinal draw ratio is less than 1.3 times, the molecular orientation of the PET bottle 100A (preform 100) does not increase. Difficult to mold.

Furthermore, the preform body 120 of the preform 100 stretched in the longitudinal direction is stretched in the transverse direction by the high-pressure air A until it hits the mold 161 . At this time, the transverse draw ratio from the preform 100 to the PET bottle 100A is preferably 2.0 times or more and 4.1 times or less.

Here, the lateral stretch ratio is the ratio of the outer diameter D5 of the body portion 130 of the PET bottle 100A to the outer diameter D4 (see FIGS. 24 and 25) of the small diameter portion 123 of the preform main body 120 of the preform 100 . The molecules of the preform 100 are similarly oriented and crystallized by stretching in the horizontal direction, and as a result, the strength, rigidity, heat resistance, etc. of the PET bottle 100A are increased. When the lateral draw ratio is less than 2.0, the molecular orientation of the PET bottle 100A (preform 100) does not increase. become difficult.

Thus, the molding by the biaxial stretch blow molding device 160 has a longitudinal draw ratio of 1.3 times or more and 3.6 times or less and a transverse direction draw ratio of 2.0 times or more and 4.1 times or less. According to the configuration of biaxially stretched blow molding, the preform 100 can be molded into the PET bottle 100A with better blow moldability and reduced weight.

Here, the neck portion 110A to the shoulder portion 120A of the PET bottle 100A are formed by stretching the resin in the constricted portion 122 in the vertical and horizontal directions from approximately directly below the support ring 114 of the preform 100. FIG. Further, as described above, the preform 100 has an easily stretchable region defined in a predetermined range corresponding to the large diameter portion 121 and the minimum thickness portion 125 directly below the support ring 114 . Therefore, when the preform 100 is stretched in the longitudinal direction, the resin corresponding to the large-diameter portion 121 and the minimum-thickness portion 125, which are the easy-to-stretch regions, is effectively stretched. Sufficient resin can be spread over 120A, and the preform 100 can be molded into a lightweight PET bottle 100A with good blow moldability.

The total length L2 of the preform main body 120 of the preform 100 is 42 mm or more and 65 mm or less. If the total length L2 of the preform main body 120 is more than 65 mm, the thickness T2 of the predetermined thick portion 127 becomes too thin, and the blow moldability deteriorates, which is undesirable. On the other hand, if the total length L2 is less than 42 mm, the center of gravity of the preform 100 is too close to the plug portion 111 side. Although detailed description is omitted, the preform 100 holds the portion below the cover 115 of the plug portion 111 and the portion below the support ring 114 in the state shown in FIG. 24 in which the plug portion 111 faces upward. It may be carried by a gripping device. When conveying using such a gripping device, if the center of gravity of the preform 100 is too close to the plug portion 111 side, the preform 100 tends to wobble and may fall sideways and become jammed. Therefore, if the total length L2 is less than 42 mm, the suitability for transporting is lowered, which is not preferable. Further, if the total length L2 is less than 42 mm, the length L3 from the top end of the neck portion 110A to the bottom end of the bottom portion 140A of the PET bottle 100A that can be well blow-molded is shortened, and the versatility of the preform 100 is reduced. I don't like it.

In addition, as described above, the range of the easily stretchable region corresponding to the large diameter portion 121 and the minimum thickness portion 125 extends from directly below the support ring 114 with respect to the total length L2 of the preform body 120 to the lower end of the minimum thickness portion 125. The ratio L4/L2 of the distance L4 is 0.02 or more and 0.25 or less, and the ratio L6/L2 of the distance L6 from directly below the support ring 114 to the upper end of the constricted portion 122 with respect to the total length L2 of the preform body 120 is 0. 0.02 or more and 0.20 or less. In addition, it is designed so that stretching from the lower part of the easily stretchable region to the upper part of the constricted portion 122 and the increased thickness portion 126 is appropriate, depending on the balance between the range of the large diameter portion 121 and the range of the minimum thickness portion 125. .

If the ratio L4/L2 is less than 0.02, the range of the minimum thickness portion 125 will be narrowed, and the effect of reducing the weight of the PET bottle 100A (preform 100) will be difficult to achieve. In addition, the range of the easily stretchable region becomes narrower, the shoulder portion 120A of the PET bottle 100 becomes thicker, and the bottom portion 140A of the PET bottle 100A becomes thin because the resin does not reach the bottom portion 140A of the PET bottle 100A sufficiently. Therefore, the blow moldability of the PET bottle 100A is deteriorated, which is not preferable. On the other hand, if the ratio L4/L2 is greater than 0.25, the cavity 145 when the preform 100 is injection molded has a longer portion corresponding to the minimum thickness portion 125, which is a narrow flow path space. Therefore, the flow of resin from the gate becomes poor at the portion corresponding to the minimum thickness portion 125 of the cavity 145, and molding defects such as short molds and welds are likely to occur, and the injection moldability deteriorates, which is undesirable. Further, when the ratio L6/L2 is less than 0.02, the range of the large diameter portion 121 as the easily stretchable region becomes narrow, the shoulder portion 120A of the PET bottle 100A becomes thick, and the bottom portion of the PET bottle 100A becomes thick. Sufficient resin does not reach 140A, and the bottom portion 140A becomes thin. Therefore, the blow moldability of the PET bottle 100A is deteriorated, which is not preferable. On the other hand, when the ratio L6/L2 is greater than 0.20, the range of the large diameter portion 121 as the easily stretchable region is widened, and the large diameter portion 121 is stretched too much, resulting in a thin shoulder portion 120A of the PET bottle 100A. become. Therefore, the blow moldability of the PET bottle 100A is deteriorated, which is not preferable. In addition, the range of the constricted portion 122 and the small diameter portion 123 is narrowed, and the effect of reducing the weight of the PET bottle 100A (preform 100) is less likely to be exhibited.
In addition, the inclination of the constricted portion 122 with respect to the vertical direction becomes large, and when the preform 100 is injection molded, the flow of resin from the gate deteriorates at the portion corresponding to the constricted portion 122 of the cavity 145, and the injection moldability deteriorates. I don't like it.

From the viewpoint of improving the injection moldability of the preform 100 and the blow moldability when molding the lightweight PET bottle 100A from the preform 100, the support ring 114 is positioned directly below the entire length L2 of the preform main body 120. The ratio L7/L2 of the distance L7 to the lower end of the hollow neck portion 122 is preferably 0.10 or more and 0.40 or less. When the ratio L7/L2 is less than 0.10, the inclination of the constricted portion 122 with respect to the vertical direction increases, and the resin flows from the gate into the constricted portion 122 of the cavity 145 during injection molding of the preform 100. Corresponding parts become worse, and the injection moldability deteriorates, which is not preferable. In addition, the constricted portion 122 becomes difficult to stretch in the horizontal direction, and the blow moldability is deteriorated, which is not preferable.
On the other hand, when the ratio L7/L2 is greater than 0.40, the range of the small diameter portion 123 is narrowed, and the effect of reducing the weight of the PET bottle 100A (preform 100) is difficult to achieve.

Also, the ratio L5/L2 of the distance L5 from directly below the support ring 114 to the lower end of the increased thickness portion 126 with respect to the total length L2 of the preform body 120 is preferably 0.10 or more and 0.32 or less. If the ratio L5/L2 is less than 0.10, the range of the increased thickness portion 126 is narrowed, so that the thickness of the increased thickness portion 126 varies locally, and the blow moldability deteriorates, which is not preferable. On the other hand, if the ratio L5/L2 is greater than 0.32, the range of the predetermined thickness portion 127 is narrowed, and the thickness of the body portion 130 of the PET bottle 100A tends to be uneven during blow molding. .

Moreover, the ratio T1/T2 of the thickness T1 of the minimum thickness portion 125 to the thickness T2 of the predetermined thickness portion 127 is preferably 0.60 or more and 0.85 or less. If the ratio T1/T2 is less than 0.6, the minimum thickness portion 125 is not effectively stretched during blow molding, and the shoulder portion 120A of the PET bottle 100A becomes thicker, and the PET bottle 100A The bottom portion 140A is thin, and the blow moldability is deteriorated, which is not preferable. Further, when the preform 100 is injection molded, the flow of resin from the gate becomes poor at the portion corresponding to the minimum thickness portion 125 of the cavity 145, and the injection moldability deteriorates, which is not preferable. Also, the thickness of the neck portion 110A of the PET bottle 100A is reduced, making it difficult to impart sufficient strength to the neck portion 110A. On the other hand, when the ratio T1/T2 is greater than 0.6, the effect of reducing the weight of the PET bottle 100A (preform 100) is less likely to be exhibited. In addition, the minimum thickness portion 125 as the easily stretchable region is not effectively stretched, and the thickness of the shoulder portion 120A and the bottom portion 140A of the PET bottle 100A tends to be uneven.

Also, the ratio T3/T1 of the thickness T3 of the bottom central portion 128 to the thickness T1 of the minimum thickness portion 125 is preferably 1.01 or more and 1.30 or less. If the ratio T3/T1 is less than 1.01, the bottom center 128 is not effectively stretched during blow molding, and the shoulder 120A of the PET bottle 100A becomes thin and the bottom 140A of the PET bottle 100A. becomes thick, and the blow moldability deteriorates, which is not preferable. Moreover, when the preform 100 is injection molded, the flow of resin from the gate becomes poor at the portion corresponding to the bottom center 128 of the cavity 145, and the injection moldability deteriorates, which is not preferable. On the other hand, if the ratio T3/T1 is greater than 1.30, the central bottom portion 128 will not be effectively stretched during blow molding, and the thickness of the shoulder portion 120A and the bottom portion 140A of the PET bottle 100A will be uneven. more likely to occur. In addition, the effect of reducing the weight of the PET bottle 100A (preform 100) is less likely to be exhibited.

Moreover, the ratio D4/D3 of the outer diameter D4 of the small diameter portion 123 to the outer diameter D3 of the large diameter portion 121 is preferably 0.60 or more and 0.90 or less. If the ratio D4/D3 is less than 0.60, the inclination of the constricted portion 122 with respect to the vertical direction increases, and the flow of resin from the gate corresponds to the constricted portion 122 of the cavity 145 during injection molding of the preform 100. It is not preferable because it deteriorates at the portion where the injection molding is performed, and the injection moldability deteriorates. In addition, the constricted portion 122 becomes difficult to stretch in the horizontal direction, and the blow moldability is deteriorated, which is not preferable. On the other hand, when the ratio D4/D3 is greater than 0.90, the effect of reducing the weight of the PET bottle 100A (preform 100) is less likely to be exhibited.

Moreover, it is preferable that the lower end of the minimum thickness portion 125 is located near the upper end inside the constricted portion 122 , and the lower end of the increased thickness portion 126 is located near the lower end inside the constricted portion 122 . With such a configuration, the extensibility of the preform body 120 is reduced at the joints between the minimum thickness portion 125 and the increased thickness portion 126 and at the joints between the increased thickness portion 126 and the predetermined thickness portion 127. does not change abruptly, and the blow moldability can be improved when the preform 100 is molded into the lightweight PET bottle 100A. However, the arrangement of the minimum thickness portion 125 and the increased thickness portion 126 with respect to the neck portion 122 is not limited to the configuration described above, and can be appropriately designed according to the shape and weight of the PET bottle 100A. The lower end of the minimum thickness portion 125 may be positioned within the large diameter portion 121 , and the lower end of the increased thickness portion 126 may be positioned within the small diameter portion 123 . Also, the lower end of the predetermined thickness portion 127 may be positioned within the bottom portion 124 . Also, the bottom portion 124 may be formed to have a uniform thickness, or may be formed to gradually decrease in thickness from a position below the upper end of the bottom portion 124 toward the center. However, from the viewpoint of effectively reducing the weight of the PET bottle 100A (preform 100), the bottom portion 124 is preferably formed such that the thickness gradually decreases from the lower end of the small diameter portion 123 toward the center.

As described above, in the method for manufacturing the PET bottle 100A according to the present embodiment, the preform body 120 has the large-diameter portion 121, the constricted portion 122, the small-diameter portion 123, and the bottom portion 124. a minimum thickness portion 125 having a uniform thickness, an increased thickness portion 126 having a gradually increasing thickness, and a predetermined thickness portion 127 having a uniform thickness. The total length L2 of the preform body 120 is 42 mm or more and 65 mm or less, and the ratio L4/L2 of the distance L4 from directly below the support ring 114 to the lower end of the minimum thickness portion 125 with respect to the total length L2 of the preform body 120 is 0. 0.02 or more and 0.25 or less, and the ratio L6/L2 of the distance L6 from directly below the support ring 114 to the upper end of the constricted portion 122 with respect to the total length L2 of the preform body 120 is 0.02 or more and 0.20 or less. A process of manufacturing a certain preform 100 with an injection molding machine 140 and a process of molding the preform 100 into a bottle shape with a biaxial stretch blow molding machine 160 are provided. By this manufacturing method, the PET bottle 100A with good blow moldability and reduced weight can be manufactured from the preform 100 . In that case, there is no need to use a special manufacturing method.

In addition, it is preferable that the wall thickness T4 of the body portion 130 of the PET bottle 100A after molding is 0.05 mm or more and 0.18 mm or less. If the thickness of the body portion 130 is within this range, the preform 100 can be molded into the PET bottle 100A with better blow moldability and reduced weight.

Furthermore, in the preform 100, the lower portion of the large-diameter portion 121 and the constricted portion 122 may be molded so as to form a shoulder portion 120A inclined with respect to the horizontal direction in the PET bottle 100A. preferable. By molding in this way, the preform 100 can be molded into the PET bottle 100A with better blow moldability and reduced weight.

In addition, in this embodiment, the use of the molded PET bottle 100A is not limited. Therefore, the PET bottle 100A may be molded to have pressure resistance, heat resistance, and the like. Furthermore, the method of filling the PET bottle 100A with the contents is not limited either. Therefore, the PET bottle 100A may be used for hot filling or aseptic filling.

As described above, the PET bottle 100A according to the present embodiment is formed by molding the preform 100 into a bottle shape by the biaxial stretch blow molding device 160 . By using the biaxially stretched blow molding apparatus 160, the preform 100 according to the present embodiment can be effectively molded into a lightweight PET bottle 100A with good blow moldability.

Next, the configuration of the PET bottle 100A formed from the preform 100 according to this embodiment will be described in detail. FIG. 29 is a front view showing a PET bottle 100A formed from the preform 100 according to this embodiment. The PET bottle 100A illustrated in FIG. 29 is a rectangular bottle whose horizontal cross-sectional view is substantially square. As described above, PET bottle 100A has spout portion 111, neck portion 110A, shoulder portion 120A, body portion 130, and bottom portion 140A. As described above, the configuration of the plug portion 111 of the PET bottle 100A is the same as the configuration of the plug portion 111 of the preform 100. FIG.

The upper side of the neck portion 110A is connected to the lower surface of the support ring 114 of the plug portion 111, while the lower side is connected to the shoulder portion 120A. The neck 110A has a cylindrical shape.

The shoulder portion 120A is connected to the neck portion 110 on its upper side and connected to the body portion 130 on its lower side. The shoulder portion 120A has a substantially truncated quadrangular pyramid shape that expands in diameter from top to bottom.

The trunk portion 130 has four wall portions 131 of the same shape connected to each other in the circumferential (horizontal) direction, so that the trunk portion 130 has a substantially square cylindrical shape as a whole. Each of the walls 131 has a pressure absorbing panel 132, a plurality of lateral grooves 133, longitudinal grooves 134, and the like. When the pressure inside the PET bottle 100A changes to the decompression side, the uneven pressure absorption panel 132 absorbs the pressure change by deforming itself, and also absorbs the load on the PET bottle 100A, especially in the horizontal direction. It has a function of maintaining sidewall strength, which is strength to withstand The lateral grooves 133 also have the function of maintaining the sidewall strength of the body portion 130 . On the other hand, the vertical groove 134 has a function of improving the buckling strength, which is the strength to withstand the vertical load of the trunk portion 130 .

The upper side of the bottom portion 140A continues to the lower side of the trunk portion 130 . The bottom portion 140A has a bottom wall 141A, a dome 142A, and the like. A substantially flat annular bottom wall 141A extends in a direction perpendicular to the body portion 130 and serves as a contact surface for the PET bottle 100A. The dome 142A is configured to protrude inward (upward) from the PET bottle 100A from the inner circumference of the bottom wall 141A, and has a function of improving the strength of the bottom portion 140A. The configuration of the bottom portion 140A is not limited to that illustrated in FIG. 29, and may be a shape corresponding to the contents, such as a shape with radial ribs or a so-called petaloid shape.

The shape of the PET bottle 100A, particularly below the support ring 114, is not limited to the example shown in FIG. For example, in this embodiment, the square bottle shown in FIG. 29 can be suitably formed. However, the plastic bottle formed in this embodiment is not limited to a square bottle, and may be a round bottle. Furthermore, the body portion 130 may have a shape in which the width expands downward. Further, the shape of the pressure absorbing panel 132 formed in the body portion 130, the lateral groove 133, and the vertical groove 134 can be freely designed.

FIG. 30 is a front view showing another PET bottle 100A formed from the preform 100 according to this embodiment. Similar to the square PET bottle 100A described above, the PET bottle 100A has a spout portion 111, a neck portion 110A, a shoulder portion 120A, a body portion 130, and a bottom portion 140A. In this embodiment, the round bottle shown in FIG. 30 can also be suitably formed.

The PET bottle 100A molded in this manner, the contents to be filled in the PET bottle 100A, and the cap for sealing the PET bottle 100A filled with the contents constitute a filling body.

The PET bottle 100A according to this embodiment is not limited by size, and can be applied to various sizes. For example, the PET bottle 100A may have a volume of 100 ml to 2000 ml, and is particularly suitable for the PET bottle 100A having a volume of 200 ml to 600 ml. In particular, it is preferable that the total height of the PET bottle 100A is 100 mm to 250 mm and the outer diameter D5 of the body portion 130 is 40 mm to 80 mm, so that the effects of the PET bottle 100A according to the present embodiment can be preferably obtained.

In the above, an example in which PET is used as a particularly suitable material for the preform 100 according to this embodiment has been shown. However, in this embodiment, any material that is suitable for blow molding will suffice. Therefore, thermoplastic resin is preferably used as the material of the PET bottle 100A according to this embodiment.

Thermoplastic resins constituting the PET bottle 100A include, in addition to polyethylene terephthalate, thermoplastic polyesters such as polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, or copolymers thereof, resins thereof, Alternatively, blends with other resins are suitable, and in particular, ethylene terephthalate-based thermoplastic polyesters such as polyethylene terephthalate can be suitably used. Furthermore, acrylonitrile resin, polyethylene, polypropylene, propylene-ethylene copolymer, etc. can also be used. Furthermore, it is also possible to use plant-derived biomass-based plastics such as polylactic acid (PLA).

Various additives such as colorants, UV absorbers, mold release agents, lubricants, nucleating agents, antioxidants, antistatic agents, etc. can do. The PET bottle 100A is preferably sterilized by adding hydrogen peroxide and peracetic acid.

As the ethylene terephthalate-based thermoplastic resin constituting the PET bottle 100A, the ethylene terephthalate unit occupies most of the repeating ester portion, generally 70 mol% or more, and has a glass transition point (Tg) of 50 to 90°C. and those having a melting point (Tm) in the range of 200 to 275° C. are suitable. As an ethylene terephthalate-based thermoplastic polyester, polyethylene terephthalate is particularly excellent in terms of pressure resistance and the like. Copolyesters containing a small amount of ester units composed of diols such as, for example, can also be used.

Furthermore, the PET bottle 100A can also be composed of two or more thermoplastic polyester layers. Further, when the PET bottle 100A is composed of two or more thermoplastic polyester layers, it can be provided with an intermediate layer such as a barrier layer or an oxygen absorbing layer between the layers. As the oxygen absorbing layer, a layer containing a combination of an oxidizable organic component and a transition metal catalyst, or a layer containing a substantially non-oxidizing gas barrier resin or the like can be used.

Since the preform 100 according to the present embodiment is made of plastic, particularly PET, it has appropriate strength and plastic deformability, and can be effectively molded from a highly versatile material. Plastic, particularly PET, is easy to mold into the PET bottle 100A, and the PET bottle 100A can be manufactured with a highly versatile apparatus.

As described above, the preform 100 according to the present embodiment includes the plug portion 111 having the support ring 114 at its lower end, and the preform main body 120 connected to the lower end of the support ring 114. The preform body 120 has a cylindrical bottom shape, and includes a large-diameter portion 121 connected to the lower end of the support ring 114 and a constricted portion 122 connected to the lower end of the large-diameter portion 121 and having a diameter that decreases downward. , a small-diameter portion 123 connected to the lower end of the constricted portion 122, and a bottom portion 124 connected to the lower end of the small-diameter portion 123. A minimum thickness portion 125 in which the minimum thickness is uniformly formed downward from the lower end of 114, and a thickness formed so that the thickness gradually increases downward from the lower end of the minimum thickness portion 125. The preform main body 120 has an increased portion 126 and a predetermined thickness portion 127 having a uniform thickness downward from the lower end of the increased thickness portion 126, and the total length L2 of the preform body 120 is 42 mm or more and 65 mm or less. , the ratio L4/L2 of the distance L4 from directly below the support ring 114 to the lower end of the minimum thickness portion 125 with respect to the total length L2 of the preform body 120 is 0.02 or more and 0.25 or less, and the total length of the preform body 120 The ratio L6/L2 of the distance L6 from directly below the support ring 114 to the upper end of the constricted portion 122 with respect to L2 is configured to be 0.02 or more and 0.20 or less. Further, according to the configuration of this embodiment, it is possible to improve the blow moldability when the preform 100 is molded into a lightweight bottle by the biaxial stretch blow molding apparatus 160 .

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described with reference to the drawings.

<Embodiment 1>
In this embodiment, a preform 201 shown in FIG. 31(A) is a concave body which is an object to be sterilized. According to the sterilization method and apparatus of the present invention, not only the preform 201 but also bottles 202 obtained by blow molding the preform 201 shown in FIG. Containers can be sterilized.

As shown in FIG. 31(A), the preform 201 has a concave shape as a whole, and includes a plug portion 203 having a male screw 203a, a bottomed cylindrical body portion 204 continuing from the plug portion 203, and a plug portion. A flange portion 205 and the like are formed at the lower end of 203, and are integrally formed by, for example, injection molding polyethylene terephthalate (PET). The injection-molded preform 201 is sprayed with a sterilizing liquid, as described later, and then placed in a container for transportation and storage. A bottle 202 having a larger volume as shown. Then, the bottle 202 is filled with contents and is capped with a cap (not shown) or the like.

The apparatus for sterilizing the preform 201 has the configuration shown in FIGS. Then, only the preform 201 to which an appropriate amount of sterilizing liquid is adhered is stored from the opening in the container 206, which is a storage body, and then the opening of the container 206 is closed and held for a predetermined time. It is designed to produce a reformed storage body.

As the sterilizing solution, for example, a solution obtained by diluting an aqueous hydrogen peroxide solution with a volatile solvent is used. The concentration of hydrogen peroxide in the sterilizing solution is, for example, 0.1-10% by weight. As the solvent, for example, ethyl alcohol, methyl alcohol, acetone, isopropyl alcohol, or a mixed solvent in which a plurality of kinds of solvents are mixed is used. A hydrogen peroxide solution can be used alone as the sterilizing solution, but by diluting it with a volatile solvent, the hydrogen peroxide solution spreads quickly as a thin film on the inner surface of the preform 201 . Therefore, the evaporation of hydrogen peroxide is accelerated, and the sterilization time for the inner surface of the concave preform 201 is shortened.

Specifically, as shown in FIGS. 32 and 33, the sterilization apparatus includes a transportation device 207 which is a means for transporting the preform 201 which is a concave body, and a sterilizing liquid which measures the preform 201 during transportation. An injection device 208 that is means for injecting into the recess, a sterilizing liquid supply device 212 that is means for supplying the sterilizing liquid to the injection device 208, and an image of the sterilizing liquid injected from the injection device 208 to check the appropriateness of the liquid amount. It comprises a liquid amount discriminating device 209 which is means for discriminating, and a container 206 which is a container for enclosing the preform 201 to which the sterilizing liquid is adhered.

The transport device 207 includes a plurality of turntables 207a and 207b. Each of the turntables 207a and 207b has clamps 210 around which a large number of preforms 201 are held at equal intervals. Reform 201 is given and received. For example, an injection molding machine 211 is connected to the upstream turntable 207a via a supply conveyor 207c. A preform 201 injection-molded by an injection molding machine 211 is delivered to a clamp 210 on a turntable 207a by a supply conveyor 207c. If the injection molding machine 211 is placed at another location, a large number of injection-molded preforms 201 are transported to the entrance of the supply conveyor 207c by a container or the like (not shown) and supplied from the supply conveyor 207c to the turntable 207a. be done. A container 206, which is a storage body, is connected to the turntable 207b on the downstream side via a discharge conveyor 207d. The preforms 201 sprayed with the sterilizing liquid by the injector 208 while being transported by the turntable 207b on the downstream side are discharged from the turntable 207b on the downstream side onto the discharge conveyor 207d, and the discharge conveyor 207d transports the preforms 201 into the container 206. put into The turntables 207a and 207b are intermittently fed at regular intervals so that the preforms 201 can be accurately transferred, but they can also be fed continuously.

The sterilizing liquid supply device 212 has a cushion tank 213 . The cushion tank 213 is a vertically long tank to which a sterilizing liquid introduction pipe 214, circulation pipes 215a and 215b, a drain pipe 216 and the like are connected. An upper level sensor 217a and a lower level sensor 217b are attached in the cushion tank 213, and the inflow of the sterilizing liquid is controlled so that the liquid level 218 of the sterilizing liquid is between the upper and lower level sensors 217a and 217b.

One end of the introduction pipe 214 extends from the sterilizing liquid storage tank 219 to the cushion tank 213, and the other end is connected to the circulation pipe 215b. The introduction pipe 214 is provided with a supply pump 220 , a filter 221 and valves 222 and 223 . Circulation pipes 215 a and 215 b are annularly connected to cushion tank 213 . The circulation pipes 215a and 215b are provided with a circulation pump 224, various valves 225, 226 and 227, a densitometer 228 and the like, and are connected to a solvent storage tank 229, a drain pipe 230 and the like.

The densitometer 228 is a device for controlling the concentration of the sterilizing liquid. For example, a UV densitometer that measures the concentration of the sterilizing liquid by detecting the amount of ultraviolet light absorbed by the sterilizing liquid is used. Of course, the densitometer is not limited to the UV densitometer, and a densitometer that absorbs visible light and infrared light, a densitometer that measures the density by detecting the amount of refraction of light, and the like can be used.

The sterilizing liquid supply device 212 is attached with a sterilizing liquid preparation device. As shown in FIG. 34, this preparation device 231 includes a sterilant storage tank 232 storing hydrogen peroxide water, a sterilant measuring tank 233 for measuring the sterilant, and a volatile solvent such as ethyl alcohol. A solvent storage tank 234, a solvent measurement tank 235 for measuring the solvent, a mixing tank 236 for mixing the sterilant and the solvent, a sterilizing liquid storage tank 219 for storing the mixed sterilizing liquid, and connecting these various tanks. and a pipeline. Various valves, pumps, etc. are arranged on the pipeline. By controlling various valves, pumps, etc., a predetermined amount of hydrogen peroxide solution is sent from the sterilant storage tank 232 to the mixing tank 236 via the sterilant measuring tank 233, and the solvent is mixed from the solvent storage tank 234 via the solvent measuring tank 235. A predetermined amount is sent to the tank 236, and the hydrogen peroxide solution and the solvent are mixed in the mixing tank 236 to produce a sterilizing liquid. This sterilizing liquid is stored in the sterilizing liquid storage tank 219 , and the sterilizing liquid storage tank 219 is transported to the vicinity of the cushion tank 213 . Of course, the sterilizing liquid storage tank 219 and the cushion tank 213 may be directly connected by piping.

The sterilization process by this sterilization liquid supply device proceeds as follows.
First, prior to the operation of the sterilizer, the sterilizing liquid exchange process in the sterilizer is performed in the following manner.
The cushion tank 213 and the valves of the drain pipes 216 of the circulation pipes 215a and 215b are opened to remove all the sterilizing solution used in the previous operation.

Next, the valve 226 from the solvent storage tank 229 is switched, the circulation pump 224 is operated, and the solvent is discharged from the valve of the drain pipe 230, while the densitometer 228 is set to the zero level.

When the zero level of the densitometer 228 is set, the valve 226 is switched to discharge the sterilizing liquid from the valve of the drain pipe 230 while measuring the concentration of the sterilizing liquid. If the concentration is out of the set range, a signal from the densitometer 228 issues an alarm. This stops the disinfectant solution replacement process, redispenses the disinfectant solution, and starts over with the densitometer 228 set to zero level.

When it is confirmed that the concentration of the prepared sterilizing liquid is normal, the valve 226 is closed, the supply pump 220 is operated to fill all the pipes with the sterilizing liquid, and the liquid level 218 in the cushion tank 213 reaches the upper level sensor. 217a is reached, the supply pump 220 is stopped.
This completes the sterilizing solution exchange process and makes it ready for the sterilization process.

At the start of the sterilization process, the valve 223 is closed, and the circulation pump 224 circulates the sterilization liquid in the cushion tank 213 through the circulation pipe 215a, the densitometer 228, and the circulation pipe 215b. The concentration of the sterilizing solution is monitored by the densitometer 228 at all times during the sterilization process. A signal from the densitometer 228 provides an alarm when the concentration of the sterilizing solution is outside the set range. When a concentration abnormality is detected, the sterilization device is stopped, the sterilization solution is prepared again, and the densitometer 228 is restarted from the zero level setting.

During the sterilization process, when the sterilizing liquid is consumed and the liquid level 218 in the cushion tank 213 reaches the lower level sensor 217b, the supply pump 220 operates to sterilize the liquid in the cushion tank 213 until the liquid level 218 reaches the upper level sensor 217a. Supply liquid.

The injection device 208 cooperates with the cushion tank 213 to meter the sterilizing liquid. That is, as shown in FIGS. 32 and 33, the injection device 208 is connected to the cushion tank 213 by a sterilizing liquid conduit 237, and the inside of the injection device 208 is at the same height as the liquid surface 218 of the sterilizing liquid in the cushion tank 213. The sterilizing liquid is accumulated on the liquid surface 218 of the.
A liquid level gauge 238 is attached to the injector 208 so that the liquid height of the sterilizing liquid can be monitored from outside the injector 208 . In the illustrated example, the injection device 208 is arranged so as to face two front and rear preforms 201 on the turntable 207a. Of course, only one injection device 208 may be arranged to face one preform 201 , or three or more injection devices may be arranged to face three or more preforms 201 .

This injection device 208 is a device for measuring a predetermined amount of sterilizing liquid accumulated in the injection device 208 at the same liquid height as the liquid height of the cushion tank 213 and for jetting it in a certain direction, and as shown in FIG. A cylinder 239 having 239a is provided. A conduit 237 from the cushion tank 213 is connected to the cylinder 239 , and an opening 239 b for overflow is formed above the connection point of the conduit 237 .

A pipe 239c is attached to the overflow opening 239b to prevent the overflowing sterilizing liquid from running down the outer wall surface of the cylinder 239 toward the preform 201. FIG.

Inside the cylinder 239, there are a tubular measure valve 240 for taking in a certain amount of the sterilizing liquid in the cylinder 239, a plunger 241 slidable inside the measure valve 240, and a needle valve facing a nozzle 239a slidable in the center of the plunger 241. 242 are provided. The container valve 240, the plunger 241 and the needle valve 242 are each driven by an air cylinder device (not shown) using working fluid such as air. It is also possible to employ a drive method using a servomotor or the like instead of the drive method using a working fluid.

The injection device 208 operates as shown in FIG. 36, and when the preform 201 reaches below the nozzle 239a, it injects a constant amount of sterilizing liquid toward the opening of the recess of the preform 201. As shown in FIG. First, as shown in FIG. 35, the trough valve 240 descends toward the nozzle 239a to meter and capture a certain amount of the sterilizing liquid (FIG. 36A), and the needle valve 242 rises to open the nozzle 239a (FIG. 36B). ), the plunger 241 descends to eject the sterilizing liquid in the valve 240 from the nozzle 239a in the direction of the arrow (FIG. 36C). Although the injection amount of the sterilizing liquid varies depending on the volume, inner surface area, etc. of the preform 201, it is generally a predetermined amount within the range of 0.05 to 100 μl. As the sterilizing liquid is sprayed onto the preform 201, the needle valve 242 is lowered to close the nozzle 239a (Fig. 36D), followed by the rise of the trough valve 240 (Fig. 36E). Finally, plunger 241 is lifted (FIG. 36F) and sterilizing liquid flows from cushion tank 213 into cylinder 239 . The above operation is repeated for each preform 201, and a measured amount of sterilizing liquid is injected into each preform 201. FIG.

The sterilizing liquid injection means is not limited to the injection means shown here, and other injection methods can be adopted as long as the injection speed follows the production capacity of the line and the injection amount is stable. It is also possible to

The injection device 208 may be arranged so that its axis is on the extension of the axis of the preform 201. Preferably, as shown in FIG. It is installed so that the axes are inclined and the axes intersect each other. As a result, the sprayed sterilizing liquid adheres to the inner surface of the body portion 204 or the plug portion 203, which is the side wall of the preform 201, and runs down the inner surface of the side wall. Adheres to a wide range in the recess, enhancing the sterilization effect.

The liquid amount discriminating device 209 is for imaging the sterilizing liquid injected from the injection device 208 and judging whether or not the injection amount is appropriate. A lamp 243 for illuminating the sterilizing liquid discharged and a camera 244 for capturing an image of the discharged sterilizing liquid are provided.

The camera 244 is, for example, a CCD camera, and is designed to capture an image of the sterilizing liquid illuminated by the lamp 243 . Images captured by camera 244 are displayed on monitor 246 via image controller 245 . As shown in FIG. 38(A), on the screen 246a of the monitor 246, an image 239d of the nozzle 239a of the injection device 208, an image 247 of the sterilizing liquid linearly injected from the nozzle 239a, and the plug of the preform 201 are displayed. An image 203b of the portion 203 is displayed.

The liquid volume discriminating device 209 cuts out the portion of the sterilizing liquid image 247 with a window 248, discriminates the presence or absence of the sterilizing liquid at the timing when the preform 201 comes under the injection device 208, and sterilizes when it detects that the sterilizing liquid does not exist. A signal indicating a defect is issued. In addition, the liquid volume discriminating device 209 counts the number of pixels in the image 247 of the sterilizing liquid within the window 248, and outputs a sterilization failure signal when the count value is too large or too small than a predetermined number of pixels set in advance. emit.

As shown in FIG. 33, the turntable 207b is provided with a removal device 249 for removing preforms 201 that are defective in sterilization. remove from The removing device 249 is a device for opening the clamp 210 on the turntable 207b to drop the preform 201 under the turntable 207b. It may be something like removing a trap plate that catches from.

In addition, the liquid volume determination device 209 detects the presence of the image 247 of the sterilizing liquid when the turntables 207a and 207b, which are the transporting device 207, are not at the timing of transporting the preform 201, which is a concave body. In this case, a signal for stopping the turntables 207a and 207b is output assuming that the sterilizing liquid is dripping. That is, as shown in FIG. 38B, when the image 247 of the sterilizing liquid is detected between the transported preforms 201, the liquid amount determination device 209 causes the sterilizing liquid to drip from the injection device 208. is generated, and a transport stop signal is output. As a result, the supply state of the sterilizing liquid is restored, and excessive adhesion of the sterilizing liquid to the preform 201 and contamination of the transfer line due to the sterilizing liquid are prevented.

Further, when the number of pixels of the image 247 of the sterilizing liquid is outside the preset range at the timing when the turntables 207a and 207b serving as the transporting device 207 transport the preform 201, which is a concave body, the liquid volume determining device 209 A sterilization failure signal is generated assuming that the sterilization liquid was not sprayed. The turntables 207a, 207b continue to drive and the remover 249 removes the appropriate preform 201 from the turntable 207b. As a result, the preforms 201 with poor sterilization can be prevented from being stored in the storage body together with the non-defective preforms 201 .

The container is configured as, for example, a container 206 with a lid, into which the preforms 201 attached with the appropriate amount and concentration of sterilizing liquid discharged from the discharge conveyor 207d are put. A synthetic resin bag is placed in the container 206 in an inflated state, and the preform 201 is put into the bag. When the preforms 201 accumulate a predetermined amount, the bag is closed and the container 206 is carried out from the sterilization apparatus. The sealed container 206 is then transported and stored, during which time the sterilizing liquid evaporates within each preform 201 within the bag of the container 206 to sterilize the inside of the preform 201 . After such aging, the container 206 is opened and the sterilized preforms 201 are removed from the bags within the container 206 and sent to a blow molding machine (not shown) to be molded into bottles 202. . As a storage body, a single box such as the container 206 or a single bag may be used as long as it can be enclosed. Various methods such as folding the mouth of the bag, heat-sealing it, or clipping it can be used as the method of encapsulation.

Next, the operation of the sterilization device having the above configuration will be described.
The preforms 201 injection-molded by the injection molding machine 211 are supplied from the supply conveyor 207c to the turntable 207b on the downstream side through the turntable 207a on the upstream side, and the turntable 207b sequentially receives and injects the preforms 201 while rotating. It is transported directly below the device 208 .

A sterilizing liquid having a constant concentration is supplied from the sterilizing liquid supply device 212 into the cylinder 239 of the injection device 208 through the cushion tank 213 . The sterilizing liquid is obtained by blending the hydrogen peroxide solution and the volatile solvent at a given ratio by the blending device 231 . The concentration of the sterilizing liquid is constantly monitored by the densitometer 228 in the sterilizing liquid supply device 212 , so that a constant concentration of sterilizing liquid is always supplied to the injection device 208 .

The sterilizing liquid is stored in the cushion tank 213 so that the liquid surface 218 is always at a predetermined liquid height, and the sterilizing liquid is also stored in the cylinder 239 of the injection device 208 at the same liquid level as in the cushion tank 213 . The injection device 208 takes in a certain volume of sterilizing liquid through the sump valve 240 in the cylinder 239. When the preform 201 arrives under the nozzle 239a, the needle valve 242 opens the nozzle 239a, and the plunger 241 dispenses the sterilizing liquid from the nozzle 239a. inject.

The sterilizing liquid ejected from the nozzle 239 a of the injection device 208 straightly enters the recess of the preform 201 . The sterilizing liquid adheres to the inner surface of the side wall of the preform 201, runs down the side wall, and adheres to the recess of the preform 201 over a wide area.

The liquid amount determination device 209 uses a camera 244 to capture an image of the sterilizing liquid ejected from the ejection device 208 and determines whether or not the ejection amount is appropriate. Images captured by camera 244 are displayed on monitor 246 via image controller 245 .

The liquid amount discriminating device 209 cuts out the image 247 of the sterilizing liquid on the screen of the monitor 246 by the window 248, determines the presence or absence of the sterilizing liquid at the timing when the preform 201 comes under the injection device 208, and confirms that the sterilizing liquid is not injected. is detected, a signal indicating sterilization failure is emitted.

In addition, the liquid volume discriminating device 209 counts the number of pixels in the image of the sterilizing liquid within the window 248, and if the count value is too large or too small than the predetermined number of pixels set in advance, a sterilization failure signal is generated. emitted.

The preforms 201 that are determined to be sterilized poorly by the liquid amount determination device 209 are removed from the turntable 207b when they are conveyed to the removal device 249 by the turntable 207b.

If the liquid amount discriminating device 209 detects the existence of the image 247 of the sterilizing liquid when the turntable 207b is not at the timing of conveying the preform 201, the turntables 207a and 207b are stopped on the assumption that the sterilizing liquid is dripping. output a signal to This prevents the preform 201 and the transfer line from being contaminated with the sterilizing liquid.

On the other hand, during operation of the sterilizer, the concentration of the sterilizing liquid is constantly monitored by the densitometer 228 . A signal from the densitometer 228 provides an alarm when the concentration of the sterilizing solution is outside the set range. When the concentration abnormality is detected, the turntables 207a and 207b are stopped, and the sterilization process is resumed after the sterilization liquid is prepared again.

The preform 201 sprayed with the appropriate concentration and amount of sterilizing liquid is put into the bag in the container 206 via the turntable 207b and the discharge conveyor 207d.

When a predetermined amount of preforms 201 are accumulated in the container 206, the bag inside the container 206 is closed and the container 206 is carried out from the sterilizer.

This container 206 is then transported to a user or the like of the preform 201 and stored. The sterilizing solution evaporates in each preform 201 in the bag of the container 206 during transportation, storage, etc., and the vapor of hydrogen peroxide sterilizes the inside of the preform 201 . After such sterilization aging is performed, the bag in the container 206 is opened and the sterilized preform 201 is removed from the container 206 .

A sterilized preform 201 is molded into a bottle 202 by a blow molding machine, filled with contents in a sterilized atmosphere, capped, and transported as a product.

<Embodiment 2>
As shown in FIG. 39, in the second embodiment, a screw conveyor 250 is used as the conveying means while the turntables 207a and 207b are used as the conveying means in the first embodiment. The screw conveyor 250 has a pair of screws arranged in parallel, and conveys the preform 201 while sandwiching the body 204 of the preform 201 between the screws. A pair of guide rails 251 that abut on the flange portion 205 of the preform 201 are installed in parallel above the screw.

An injection device 208 is installed above the screw conveyor 250 in an orientation as shown in FIG. The preforms 201 are arranged vertically on the screw conveyor 250, whereas the injectors 208 are installed obliquely. Alternatively, the sterilizing liquid may be sprayed from a vertically arranged injector 208 onto the inner surface of the side wall of the preform 201 arranged at an angle as shown in FIG. 37(B).

According to the present invention, the sterilizing liquid is measured, the measured sterilizing liquid is sprayed into the recess of the concave body, the amount of the sterilizing liquid is determined from the amount of the sprayed sterilizing liquid, and an appropriate amount of the sterilizing liquid is attached to the concave body. Since it is a sterilization method in which only the only is stored in the storage body, and then the storage body is closed and held for a predetermined time, the sterilization liquid is measured and sprayed into the recess of the concave body, and the amount of sterilization liquid that is sprayed is Since the quantity is also discriminated, an appropriate amount of the sterilizing liquid can be adhered to a concave body such as a container, a preform, etc., so that the container can be efficiently sterilized, and the problem of sterilization failure does not occur.

According to the present invention, since it is a sterilization method for judging the appropriateness of the injection amount of the sterilizing liquid by imaging the injected sterilizing liquid, the injected sterilizing liquid is imaged, and the injection amount of the sterilizing liquid is determined from the image. The appropriateness is determined, and the injection amount can be properly detected without disturbing the injection of the sterilizing liquid.

According to the present invention, the sterilizing method is such that the sterilizing liquid is sprayed toward the inner surface of the side wall of the concave body. The liquid adheres to the recesses of the recessed body over a wide range, enhancing the sterilization effect.

According to the present invention, conveying means for conveying a concave body, injection means for measuring and injecting a sterilizing liquid into the concave portion of the concave body being conveyed, sterilizing liquid supply means for supplying the sterilizing liquid to the injection means, Since the sterilization device comprises a liquid amount discriminating means for judging whether or not the amount of the liquid is appropriate by imaging the sterilizing liquid jetted from the jetting means, and a container for enclosing the recessed body to which the sterilizing liquid is adhered, the sterilizing liquid is supplied. After weighing the sterilizing liquid supplied from the apparatus, it is injected into the concave portion of the concave body by the injection means, and the sterilizing liquid is continuously adhered to the concave body conveyed by the conveying means at a time and put into the container. be able to.
In addition, since the sterilizing liquid after spraying is imaged to determine whether or not the amount of liquid is appropriate, the adhered amount of sterilizing liquid can be managed more strictly, and only concave bodies to which an appropriate amount of sterilizing liquid has adhered can be put into the container. can be done. Therefore, a large number of concave bodies can be sterilized efficiently, and problems such as poor sterilization and residual sterilizing liquid do not occur.

According to the present invention, since the sterilization device stops the conveyance of the concave body by the conveying means when the liquid amount determination means detects the dripping of the sterilizing liquid, excessive adhesion of the sterilizing liquid to the concave body and the transfer line The occurrence of contamination, etc. due to the sterilizing solution is prevented.

According to the present invention, since the sterilization device removes the recessed body from the conveying means when the liquid amount determination means detects that the sterilizing liquid is not sprayed onto the recessed body, the sterilized recessed body is not supplied with the sterilizing liquid. A body is removed from the carrier. Therefore, it is possible to prevent inadequately sterilized recessed objects from being mixed into the container. Moreover, since the conveying means operates as it is, the sterilization treatment can be continued.

According to the present invention, since the sterilization apparatus is provided with the concentration determining means for determining whether the concentration of the sterilizing liquid is appropriate, the sterilizing liquid having the concentration required for sterilization can be sprayed onto the concave-shaped body, and proper sterilization can be performed. can be maintained.

According to the present invention, since the sterilization apparatus stops the transportation of the recessed bodies by the transporting means when the density determination means detects that the concentration of the sterilizing liquid is insufficient, it is possible to prevent the generation of a large number of defectively sterilized recessed bodies. can.

<Fifth Embodiment>
Next, a method of applying the container sterilization method of the present invention to a preform, molding the sterilized preform into a bottle with a blow molding machine, and subjecting the bottle to aseptic filling will be described.
First, an injection molding machine is used to produce a preform 301 as shown in FIG. 40(A).

In the case of a PET bottle, the preform 301 is molded using polyethylene terephthalate resin (hereinafter referred to as PET resin), but it is not limited to PET resin and may be manufactured using nylon or other thermoplastic resins.

Next, as shown in FIG. 40(B), a solution obtained by diluting a 35% hydrogen peroxide aqueous solution with a volatile solvent such as ethyl alcohol, that is, an H ₂ O ₂ solution 311 is placed in the preform 301 . As shown in FIG. 40(C), the preform 301 to which the H ₂ O ₂ solution 311 has been dropped is put into a container (storage body) 303 through the opening, and the opening is closed with a lid 304 . Then, a storage body containing preforms is produced.

A container 303 containing preforms 301 is transported to a user (food manufacturer, etc.).
_The H ₂ O ₂ solution diluted with a volatile solvent has a hydrogen peroxide (H ₂ O ₂ ) concentration of 0.1 to ₁₀ %. The concentration is preferably about 0.5-5%.

The H ₂ O ₂ solution to be dropped onto the preform 301 varies depending on the dilution solvent, and is dropped in the range of 0.1 to 100 μl, and preferably 1 to 30 μl when diluted with ethyl alcohol.

As the hydrogen peroxide used in the present invention, a commercially available hydrogen peroxide aqueous solution having a hydrogen peroxide concentration of 30 to 35% by weight is usually used.

A 3% by weight aqueous hydrogen peroxide solution commercially available as Oxidol can also be used.
The 30 to 35% hydrogen peroxide aqueous solution (hereinafter the weight percent of the hydrogen peroxide concentration is simply described as %) includes industrial use and food additive use, and both can be used in the present invention. For industrial use, a stabilizer or the like is added to prevent the decomposition of hydrogen peroxide, so an aqueous hydrogen peroxide solution for food additives containing few additives is suitable.

In the present invention, a 30-35% aqueous hydrogen peroxide solution for food additives is used, diluted with the following volatile solvent, and used as a 0.1-10% solution.

The concentration and dropping amount of the H ₂ O ₂ solution vary depending on the size of the container to be sterilized, but usually a 0.5 to 5% solution is used, and the dropping amount is 0.05 to 0.05 as the H ₂ O ₂ solution. It is used in the range of 100 μl, preferably about 1 to 30 μl.

As the volatile solvent used in the present invention, hydrogen peroxide or an aqueous solution of hydrogen peroxide can be dissolved and any volatile solvent can be used, but ethyl alcohol, methyl alcohol, isopropyl alcohol, Acetone is preferred.

In particular, ethyl alcohol is more preferable because of its compatibility with the aqueous hydrogen peroxide solution, wettability to plastic materials, permeability, evaporation rate, and other points of handling.

By using a volatile solvent as a diluting solvent for the aqueous hydrogen peroxide solution, the hydrogen peroxide solution dripped into the container forms a thin film on the inner surface of the container and spreads and spreads, and the evaporation rate is accelerated. The steam pressure is increased, the sterilization efficiency is improved, and the container sterilization time can be shortened.

That is, since the boiling point of hydrogen peroxide is 151.4°C, if the container in which the aqueous hydrogen peroxide solution is dripped is stored at a room temperature of 15°C or less, the evaporation rate of the aqueous hydrogen peroxide solution slows down, which significantly affects sterilization. In addition, sufficient hydrogen peroxide vapor pressure necessary for sterilization cannot be obtained, and sterilization of the inner surface of the container may become insufficient.

Therefore, in the present invention, a 35% hydrogen peroxide aqueous solution is diluted with a volatile solvent such as ethyl alcohol, and the diluted solvent is dripped onto the inner surface of the container to form a thin film of the hydrogen peroxide solution on the inner surface of the container. As it forms and spreads, the evaporation rate of hydrogen peroxide in the container is accelerated to increase the vapor pressure of H ₂ O ₂ , thereby sterilizing the container more efficiently and shortening the sterilization time.

As shown in FIG. 40(C), the preform 301 to which the H ₂ O ₂ solution has been dropped is temporarily stored in a container 303 in a sealed state, transported to the user, and then stored again by the user. After that, it is molded into a bottle by a blow molding machine.

The H ₂ O ₂ solution dripped onto the preform 301 vaporizes in the container during storage or transportation, and the vaporized H ₂ O ₂ vapor 311a sterilizes the inner surface of the preform.

That is, the H ₂ O ₂ solution 311 dropped onto the preform 301 evaporates quickly after being dropped onto the preform 301 and fills the inside of the preform 301 because the dilution solvent is a volatile solvent. .

H ₂ O ₂ also evaporates at the same time as the dilution solvent, and becomes H ₂ O ₂ vapor 311a, which comes into contact with the inner surface of the preform 301 and sterilizes the inner surface of the preform 301 .

Since the diluting solvent for H ₂ O ₂ is a volatile solvent, the evaporation rate of H ₂ O ₂ is accelerated to become H ₂ O ₂ vapor 311a in a short time, and the H ₂ O ₂ vapor 311a in the preform is reduced. Since the density increases, the sterilization effect on the inner surface of the preform 301 increases.

Further, since the opening plug portion of the preform 301 stored in the container 303 remains open, the H ₂ O ₂ vapor 311a evaporated inside the preform 301 flows out of the preform 301 as time passes. However, since the container 303 is closed with the lid 304, the H ₂ O ₂ vapor 311a stays inside the container and also sterilizes the outside of the preform.

When preforms are injection molded using PET resin, the molding temperature is 260 to 280°C. Since the outside of the remodel is fairly clean and has little microbial contamination, it is sterilized by the H ₂ O ₂ vapor 311a, leaving almost no viable bacteria.

However, since the density of the H ₂ O ₂ vapor 311a inside the container 303 is much lower than inside the preform 301, complete sterilization cannot be expected if the outside of the preform is heavily contaminated with microorganisms.

The preform 301, which has been sterilized on its inner and outer surfaces, is then placed in a container, brought to the user, and supplied to a blow molding machine to be molded into a blow bottle.

That is, as shown in FIG. 41(A), a sterilized preform 301 is blow-molded by a blow molding machine (not shown) to form a bottle 302 as shown in FIG. 41(B).

Next, the bottle 302 is supplied to the aseptic filling machine, and as shown in FIG. 41(C), in the aseptic chamber, an aqueous hydrogen peroxide solution is sprayed to adhere H ₂ O ₂ mist 311b to the inner surface of the bottle. is dried with hot air to _sterilize the inner surface of the bottle, and further, as shown in _FIG . Sterilize.

In the above process, when the sterilized preform 301 is used to mold a bottle with a blow molding machine, an ordinary blow molding machine can be operated in a clean state without using an expensive aseptic blow molding machine. For example, since the molded bottle has very little microbial contamination, the sterilization load in the next sterilization process can be reduced, and the sterilization efficiency can be improved.

That is, since the microbial contamination of the bottles is very low, the amount of H ₂ O ₂ mist adhering to the bottles can be reduced in the bottle sterilization process.

Therefore, the drying time is shortened, and the sterilization process time is also shortened, so that the sterilization capacity of the aseptic filling machine is increased and the production capacity is improved.

In addition, when the microbial contamination of the bottles is greatly reduced, the sterilization failure of the bottles is eliminated and the sterilization effect of the bottles is enhanced.

The sterilized bottle 302 is turned upside down in the aseptic chamber as shown in FIG. 41(E), and aseptic water 313 is jetted from the washing nozzle 312 into the inside of the bottle to wash the inside of the bottle.

This washing step cleans the inside of the bottle by washing away the dust adhering to the inside of the bottle and the slightly remaining H ₂ O ₂ .

Next, the washed bottle is moved to the filling process with the mouth stopper facing upward, and the bottle is placed under the filling nozzle 314 as shown in FIG. It is filled and then moved to the capping step to create an aseptically filled product 306 with a separately sterilized cap 305 as shown in FIG. 41(G).

In addition, when aseptic filling of a bottle is performed using a preform sterilized by the sterilization method of the present invention, depending on the content, aseptic filling can be performed without sterilizing the inner and outer surfaces of the bottle. As well as being able to improve the production capacity, it is possible to reduce the cost of the product.

That is, in the case of acidic foods such as orange juice and mineral water, as shown in FIG. to produce a bottle 302 as shown in FIG. 42(B).

Next, the bottle 302 is supplied to the aseptic filling machine, and in the aseptic chamber, as shown in FIG. ) to sterilize the closure of the bottle.

As a germicidal lamp, a low-pressure mercury lamp that emits germicidal radiation with a wavelength of 253.7 nm is generally used, but a high-pressure mercury lamp may be used as a high-output germicidal lamp.

In the process of molding the sterilized preform 301 into a bottle with a blow molding machine and supplying it to an aseptic filling machine, the mouth plug of the bottle is highly likely to be contaminated with microorganisms from the outside and comes into direct contact with the contents. By sterilizing the mouthpiece of the product, the defect rate of aseptically filled products can be reduced.

The bottle 302 whose spout has been sterilized is washed with sterilized water in an inverted state as shown in FIG. Contents 315 are filled in the filling process and capped 305 in the capping process to produce an aseptic filled product 306 .

Using a polyethylene terephthalate resin (manufactured by Teijin Limited), a preform 301 (inner diameter: 21 mmφ, height: 155 mm) for a PET bottle (volume: 2 liters) was produced using an injection molding machine, as shown in Fig. 43(A). bottom.

Next, a suspension of spores of Bacillus subtilus, which is resistant to hydrogen peroxide, is sprayed on the inner surface of the preform and dried at room temperature to form a preform as shown in FIG. 43(B). 10 ³ or 10 ⁴ Bacillus subtilis spores 307 were adhered to the inner surface of each reform 301, and 200 of each were produced.

Next, the 35% aqueous hydrogen peroxide solution was diluted with 99.5% ethyl alcohol to prepare solutions with H ₂ O ₂ concentrations of ₁ % and _2.5 %. As shown in 43(C), 20 μl was dropped on the inner surface of the preform 301 to which the Bacillus subtilis spores 307 were attached, and 1% H ₂ O ₂ was added to the preform 301 to which 10 ³ Bacillus subtilis spores 307 were attached. 100 tubes to which the solution was dropped and 100 tubes to which the 2.5% H ₂ O ₂ solution was dropped were prepared.

Similarly, with respect to the preforms 301 to which 10 ⁴ spores 307 of Bacillus subtilis are attached, 100 preforms to which the 1% H ₂ O ₂ solution was dropped and 100 preforms to which the 2.5% H ₂ O ₂ solution was dropped were prepared. 100 were made.

The 100 preforms onto which the H ₂ O ₂ solution 311 was dropped as described above were placed in a polyethylene bag (hereafter referred to as a PE bag) as shown in FIG. The preform 301 was sterilized by filling, packing, and storing at room temperature (15-20° C.) for 2 days.

After storage, the preforms are opened and taken out, and 20 ml of tryptic soy broth is aseptically dispensed into 10 preforms 301 out of the 100, sealed with a sterilized cap, and cultured at 35° C. for 5 days. bottom.

As a comparative example, 10 preforms to which 10 ³ and 10 ⁴ spores of Bacillus subtilis were attached were each dispensed with a tryptic soy broth medium in the same manner as described above and cultured at 35° C. for 5 days.

After culturing, the state of turbidity of the medium in the preform was observed, and it was determined that sterilization was complete if there was no turbidity, and that sterilization was incomplete if there was turbidity.

0/10 in Table 5 indicates that 0 out of 10 preforms 301 are cloudy, and 10/10 indicates that 10 out of 10 are cloudy.

The results are shown in Table 5. Both preforms 301 with 10 ³ and 10 ⁴ Bacillus subtilis spores were completely removed by dropping H ₂ O ₂ solutions (1% and 2.5%). had been sterilized.

That is, since the sterilization method of the present invention can completely sterilize up to 10 ⁴ spores of Bacillus subtilus, it can be said that the sterilization effect is 4 or more.

Generally, the number of bacteria adhering to a preform ranges from several to several tens at most, so it can be expected that a normal preform will be completely sterilized by using the sterilization method of the present invention.

As in Example 1, a preform for a PET bottle (volume 2 l) was produced.

A 1% H ₂ O ₂ solution of ethyl alcohol was prepared in the same manner as in Example 1, and 20 μl of the 1% H ₂ O ₂ solution was dropped on the above 200 preforms. It was packed in cardboard and stored at room temperature for 2 days.

As a comparative example, 200 preforms to which the H ₂ O ₂ solution was not dropped were similarly packed with cardboard and stored at room temperature for 2 days.

All of the preforms stored at room temperature for 2 days were filled with tryptic soy broth as in Example 1, capped, and cultured at 35°C for 2 days.

After culturing for 2 days, the turbidity of the medium was observed in the same manner as in Example 1 to determine the presence or absence of sterilization of the preform.

As a result, none of the 200 preforms onto which the H ₂ O ₂ solution was dropped became turbid, but in the case of the comparative example, 3 out of 200 preforms became turbid.

That is, three out of 200 preforms molded by injection molding were contaminated with microorganisms, but the contaminated preforms were completely sterilized by dripping a 1% H ₂ O ₂ solution. We were able to.

Preforms for PET bottles (volume: 2 l) were prepared in the same manner as in Example 1, and 20 μl of a 1% H ₂ O ₂ ethyl alcohol solution was dropped onto 1,000 preforms just before putting the preforms into a container. Then, as shown in FIG. 40(C), it was placed in a container and transported to a food manufacturer (user).

The above preform is molded into a 2-liter bottle by a blow molding machine at a food manufacturer, and the bottle is supplied to an aseptic filling machine. Then, 2 liters of a sterilized liquid medium (tryptic soy broth medium) was filled according to a conventional method to produce 1,000 aseptic filled bottles.

As a comparative example, a preform to which no H ₂ O ₂ solution was added was used, molded into a bottle with a blow molding machine, filled with a liquid medium sterilized with an aseptic filling machine in the same manner as described above, and filled with 1000 bottles of medium. made a bottle.

After culturing the medium-filled bottle prepared as described above at 35° C. for 5 days in the same manner as in Example 1, the turbidity of the medium was observed in the same manner as in Example 1 to determine whether the bottle was sterilized. .

As a result, none of the bottles using the preforms to which the H ₂ O ₂ solution was dripped produced turbidity, but in the case of the bottles using the preforms to which the H ₂ O ₂ solution was not dripped, 30 bottles out of 1000 had turbidity. Turbidity occurred and microbial contamination was observed.

That is, by dropping a 1% H ₂ O ₂ solution onto the preform to sterilize the preform, only the mouth portion of the bottle molded using it is sterilized, and even if the inner surface of the bottle is not sterilized, microorganisms found to be uncontaminated.

In addition, a bottle was formed using a preform in which the H ₂ O ₂ solution was dropped, distilled water was filled in the bottle, and the concentration of hydrogen peroxide therein was measured. , it was found that the H ₂ O ₂ dripped onto the preform did not remain in the bottle.

REFERENCE SIGNS LIST 10 plastic bottle 11 bottle main body 11a neck 11b shoulder 11c body 11d bottom 13 external screw 13a upper end 13b lower end 14 vent slot 15 mouth plug 15a top surface 15b outer peripheral surface 15c inner peripheral surface 15d chamfered portion 16 turnip 17 support ring 18 Annular surface 21 Step 22 Outside area 23 Inside area 25 Sanding part 26 Annular groove 30 Preform 31 Preform body 31a Body part 31b Bottom part 31c Minimum thickness part 31d Gate part 60 Cap 100 Preform 111 Mouth plug part 120 Preform body 121 Large-diameter portion 122 Constricted portion 123 Small-diameter portion 124 Bottom portion 125 Minimum thickness portion 126 Increased thickness portion 127 Predetermined thickness portion 128 Bottom center 201 Preform 202 Bottle 206 Container 207 Transfer device 207a, 207b Turntable 208 Injection device 210 Clamp ₂₁₁ Injection molding machine 301 Preform 302 Bottle 303 Container 304 Lid 306 Aseptically filled product 307 Spore 311 _H2O2 solution 312 Washing nozzle 313 Sterile water 315 Contents

Claims (9)

supplying a sterilizing solution to a plurality of preforms;
A step of storing the preform to which the sterilizing liquid is attached in a storage body having an opening;
and a step of closing the opening with a lid ,
The sterilizing liquid is weighed, the measured sterilizing liquid is sprayed onto each preform as a linearly continuous liquid, and the suitability of the injection amount of the sterilizing liquid is determined by imaging the linearly continuous sterilizing liquid. A method for sterilizing preforms, wherein only preforms to which an appropriate amount of sterilizing liquid has adhered are stored in said container, and then said container is closed and held for a predetermined period of time . 2. The preform sterilization method according to claim 1 , wherein the sterilization liquid is sprayed toward the side surface of each preform. In each preform, 30 to 35% by weight aqueous hydrogen peroxide solution is added as the sterilizing liquid, and ethyl alcohol, methyl alcohol, and isopropyl, which are volatile solvents in which hydrogen oxide water or hydrogen peroxide aqueous solution is soluble, are volatile. Add dropwise a 0.1 to 10% hydrogen peroxide aqueous solution diluted with a volatile solvent consisting of alcohol or acetone,
The preform to which the aqueous hydrogen peroxide solution has been dripped is placed in a storage body and sealed with a lid, and the inner surface of the preform is sterilized by the vaporized hydrogen peroxide in the storage body, and the outer surface of the preform is also sterilized. The preform sterilization method according to claim 1 , characterized in that: 4. The preform sterilization method according to claim 3 , wherein the amount of the aqueous hydrogen peroxide solution dropped per preform is 0.05 to 100 μl as hydrogen peroxide. Each preform is
a plug portion having an outer thread, a turnip located below the outer thread, and a support ring located below the turnip;
a preform body provided below the plug portion and having a minimum thickness portion below the support ring, a trunk portion, and a bottom portion;
a concave annular surface is formed on the outer surface of the plug portion between the turnip and the support ring;
The surface of the support ring on the side of the concave annular surface is formed in multiple stages with steps,
the support ring includes an outer region positioned radially outward of the step and an inner region positioned radially inward of the step;
In the preform body, the thickness of the minimum thickness portion below the support ring, the thickness of the body portion, and the thickness of the bottom portion are
5. The preform sterilization method according to any one of claims 1 to 4 , wherein the thickness of the minimum thickness portion<thickness of the bottom portion<thickness of the trunk portion. A preform for molding a plastic bottle having a resin weight of 21.0 g or less and a capacity of 600 ml or less,
The total length of the preform is less than 92.5 mm,
The outer diameter of the trunk portion of the preform is smaller than 24.0 mm,
the minimum thickness portion below the support ring has a length of 3.0 to 10.0 mm;
The thickness of the trunk portion is formed in a range of 1.19 to 1.9 times the thickness of the minimum thickness portion below the support ring,
The thickness of the bottom portion gradually decreases toward the gate portion, and the thickness of the bottom portion is formed in a range of 1.11 to 1.19 times the thickness of the minimum thickness portion below the support ring. to be
The preform sterilization method according to claim 5 , characterized in that: 7. The preform sterilization method according to claim 6 , wherein the preform has a total length of 80.0 to 85.0 mm and a barrel diameter of 22.0 to 23.0 mm. 8. The preform sterilization method according to claim 6 , wherein said minimum thickness portion below said support ring has a length of 3.0 to 7.5 mm. a storage body having an opening;
a plurality of preforms arranged in the container;
and a lid that closes the opening,
Each preform is coated with a pre-supplied sterilizing solution ,
Furthermore, injection means for measuring the sterilizing liquid and injecting the measured sterilizing liquid to each preform as a linearly continuous liquid;
Imaging means for imaging the linearly continuous sterilizing solution;
a liquid volume determination means for determining whether the injection amount of the sterilizing liquid imaged by the imaging means is appropriate;
a loading means for storing only preforms to which an appropriate amount of sterilizing liquid adhered as determined by the liquid volume determination means is stored in the storage body,
A container containing preforms, characterized in that the container containing the preforms is closed and held for a predetermined period of time .

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