JP7670964B2 - Pre-peeling method for double container - Google Patents

Description

The present invention relates to a method for preliminary peeling of a double-layered container.

Patent document 1 discloses a double container having an inner bag and an outer shell.

JP 2020-193023 A

An outside air intake is necessary for preliminary peeling of the inner bag. There is a cut in the bottom of the outer shell that is created during the manufacturing process, and if this cut is broken, an outside air intake can be formed. However, if force is applied to the bottom of the outer shell to break the cut, that force is also transmitted to the inner bag. While breaking the outer shell, we want to minimize damage to the inner bag.

The present invention was made in consideration of these circumstances, and provides a method for preliminary peeling of a double-layered container that can perform preliminary peeling while minimizing damage to the inner bag.

According to the present invention, a preliminary peeling method for a double container having an outer shell and an inner bag is provided, which includes a peeling step, in which the inner bag is peeled off from the outer shell by breaking a cutout provided at the bottom of the outer shell while the inside of the inner bag is under negative pressure.

In the present invention, the cut-out portion can be broken when the inner bag is shrinking due to negative pressure. The inner bag can shrink as the cut-out portion breaks and outside air is introduced, so preliminary peeling can be performed while minimizing damage to the inner bag.

Various embodiments of the present invention will be described below. The embodiments described below can be combined with each other.
Preferably, in the peeling step, the cut-out portion is broken by applying a force to a portion of the bottom portion shifted from the cut-out portion.
Preferably, the method further comprises an inspection step, in which the inspection step checks whether or not a pinhole is present in the inner bag based on data obtained when the inside of the inner bag is pressurized after the peeling step.
Preferably, the diameter of the base of the shell is between 14 and 25 mm.

FIG. 2 is a side view of an example of a double container. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. FIG. 2 is a block diagram showing a configuration of a preliminary peeling device. FIG. 2 is an exploded perspective view of an example of a suction head. 11 is a cross-sectional view showing a state in which a double container is set on the suction head and the amount of displacement of the contact portion is set. FIG. 10 is a cross-sectional view showing a state in which the tip surface of the contact portion comes into contact with the bottom of the double container in the peeling process. FIG. 8 is an enlarged cross-sectional view of the area indicated by the dashed line B near the bottom of the double container in FIG. 7. 10A to 10C are schematic cross-sectional views showing an example of how the inner bag shrinks in a peeling process. 11 is a cross-sectional view showing how the inner bag is replaced after the peeling step and a leak inspection step is performed. FIG. 13 is a graph showing a schematic representation of the relationship between time and flow rate measured when the pressure inside the inner bag is increased. 13 is a cross-sectional view showing a modified example of the position of the abutment portion (amount of deviation is zero). FIG. 13 is a cross-sectional view showing a modified example (concave curved surface) of the contact portion. FIG. 13 is a cross-sectional view showing a modified example (trapezoidal recess) of the abutment portion. FIG. 13 is a cross-sectional view showing a modified example of the contact portion (a small convex curved surface inside the recess). FIG. FIG. 13 is a cross-sectional view showing a modified example of the contact portion (a displaced convex curved surface within a recess). FIG. 11 is an exploded perspective view of another example of the suction head. FIG. 11 is a cross-sectional view showing a state in which a double container is set in another example of the suction head.

The following describes the embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. In addition, each feature can be an invention independently.

1. Example of a double container to be subjected to preliminary peeling A double container 1 to be subjected to preliminary peeling will be described with reference to Figures 1 to 3. As shown in Figure 1, the double container 1 is a cylindrical container with a bottom, and includes a storage section 7 for storing the contents, and a spout 9 for discharging the contents from the storage section 7. The storage section 7 includes a body section 7a and a bottom section 7b.

Figure 2 shows the A-A cross section of Figure 1. The double container 1 is a double-structure container having an outer shell 12 and an inner bag 14. The inner bag 14 is disposed within the outer shell 12 at a location other than the mouth end of the double container 1. The inner bag 14 is configured to be able to shrink away from the outer shell 12 as the contents are dispensed. At that time, outside air is introduced into the intermediate space between the inner bag 14 and the outer shell 12 through the outside air introduction section 15 (outside air introduction hole) described below, so that the outer shell 12 maintains its original shape without shrinking.

The double container 1 of this embodiment is, in one example, a resin container (cartridge) to which a nebulizer is attached as an aspirating device that aspirates and sprays the contents. In this embodiment, the contents are liquid (e.g., a medicinal liquid for treating asthma). After the contents are filled into the double container 1, a cap with a through hole is attached, and the through hole is sealed with a film. The nebulizer has a hollow puncture needle, which breaks through the film and is then inserted into the double container 1 through the through hole, and the contents are aspirated through the puncture needle.

The bottom 7b has a convex cross section that protrudes downward, and a cutout 7d is provided in the center of the bottom 7b. The cutout 7d closes the bottom of each of the outer shell 12 and the inner bag 14. This cutout 7d is formed when the parison is crushed between a pair of split molds when forming the double container 1 by direct blow molding. The bottom of the double container 1 is closed by welding the opposing surfaces of the parison together at the cutout 7d.

The notched portion 7d is also shown in the bottom view of Fig. 3. As shown in Fig. 3, the notched portion 7d passes through the center point _C0 of the bottom portion 7b and cuts the bottom portion 7b vertically.

The material of the outer shell 12 preferably contains homopolypropylene from the viewpoint of increasing rigidity, and preferably contains random polypropylene from the viewpoint of increasing impact resistance, and preferably contains both homopolypropylene and random polypropylene. The material of the inner bag 14 preferably contains at least one of LDPE and LLDPE, and preferably contains LDPE, from the viewpoint of increasing flexibility. An intermediate layer (not shown) may be provided between the outer shell 12 and the inner bag 14. The intermediate layer is composed of a resin that is peelable from one or both of the material of the outer shell 12 and the material of the inner bag 14. The intermediate layer is preferably an EVOH layer containing EVOH (ethylene-vinyl alcohol copolymer) resin.

The double container 1 has an internal volume of 1 to 20 mL, for example. The internal volume of the double container 1 is preferably 1 to 10 ml, and more preferably 3 to 5 ml. The internal volume of the double container 1 may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or 20, and may be within a range between any two of the numerical values exemplified here. The bottom diameter D ₀ of the double container 1 shown in FIG. 3 may be, for example, 14 to 25 mm, or 14 to 16 mm. The bottom diameter D ₀ may be, for example, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 mm, and may be within a range between any two of the numerical values exemplified here.

2. Configuration of the preliminary peeling device An example of the preliminary peeling device 2 used in the preliminary peeling method of the embodiment will be described with reference to Figures 4 to 6. Preliminary peeling refers to a process of peeling the inner bag 14 from the outer shell 12 before filling the inner bag 14 with the contents. By performing preliminary peeling, the inner bag 14 is easily separated from the outer shell 12 and shrinks after the inner bag 14 is filled with the contents.

2-1. Block diagram As shown in Fig. 4, the preliminary peeling device 2 includes a suction device 3, a solenoid valve 4, a pressure reduction system 5, a pressure increase system 6, and a pipe 8. The suction device 3 includes a suction head 3a (see Fig. 5) and a stage 3b (see Fig. 6). The pipe 8 includes a pipe 8a connecting the suction head 3a and the solenoid valve 4, a pipe 8b connecting the pressure reduction system 5 and the solenoid valve 4, and a pipe 8c connecting the pressure increase system 6 and the solenoid valve 4. By controlling the solenoid valve 4, it is possible to switch between the pressure reduction system 5 and the pressure increase system 6 to be connected to the suction head 3a. The pressure reduction system 5 allows air to be sucked through the suction head 3a. The pressure increase system 6 allows air to be blown through the suction head 3a.

The pressure reduction system 5 includes, in order from the solenoid valve 4 side, a regulator 53 and a vacuum pump 54. The vacuum pump 54 exhausts the air in the pipe 8b to reduce the pressure in the pipe 8b. The regulator 53 controls the flow rate of the air flowing through the pipe 8b or the air pressure in the pipe 8b.

The pressurizing system 6 includes, in order from the solenoid valve 4 side, a flowmeter 64, a pressure gauge 65, a speed controller 61, a regulator 62, and a compressor 63. The compressor 63 supplies compressed air into the pipe 8c. The regulator 62 controls the air pressure in the pipe 8c. The speed controller 61 controls the flow rate of air flowing through the pipe 8c. The pressure gauge 65 measures the air pressure in the pipe 8c. The flowmeter 64 measures the flow rate of air flowing through the pipe 8c. The order of the components included in the pressurizing system 6 may be changed or omitted as appropriate.

The preliminary peeling device 2 further includes a driving mechanism 71, a contact portion 72, and a control unit 73. One example of the driving mechanism 71 is an air cylinder. The contact portion 72 is disposed at a position facing the suction head 3a (see FIG. 6). The driving mechanism 71 drives the contact portion 72 to move toward and away from the suction device 3, and stops the contact portion 72 at any position. The control unit 73 controls the driving mechanism 71 to control the position of the contact portion 72 relative to the suction head 3a, the number of repeated movements of the contact portion 72 (i.e., the number of reciprocating movements), and the moving speed of the contact portion 72. This allows the magnitude of the impact force and pressing force applied to the contact portion 72.

2-2. Configuration of suction head 3a The suction head 3a shown in Fig. 5 comprises a head base 31, a packing 32, an insert member 33, and a packing 34. The head base 31 and the packing 32 are provided with through holes 31a and 32a, respectively, which communicate with the inside of the pipe 8a. The packing 32 is disposed in the accommodation recess 31b of the head base 31. The packing 32 is made of a material capable of increasing airtightness, such as an elastomer.

The insert member 33 has a rod-shaped portion 33a and a flange portion 33b that protrudes radially from the base end of the rod-shaped portion 33a. The packing 34 has a through hole 34a, and the rod-shaped portion 33a is inserted into the through hole 34a. The material of the packing 34 is the same as that of the packing 32. The rod-shaped portion 33a is a rod-shaped portion and is made thinner than the inner diameter of the mouth portion 9 of the double container 1.

2-3. Configuration of stage 3b and abutment portion 72 Fig. 6 shows the state in which the double container 1 is set in the preliminary peeling device 2. The suction head 3a is installed in the central recess 3b1 of the stage 3b. The mouth 9 of the double container 1 is placed over the suction head 3a, and the mouth 9 is accommodated in the central recess 3b1 of the stage 3b. The depth of the central recess 3b1 may be, for example, deep enough to surround the body 7a of the double container 1.

As shown in FIG. 6, a through hole 33c is provided inside the insertion member 33. The rod-shaped portion 33a is provided with a suction port 33d that communicates with the through hole 33c. The suction port 33d is provided at the tip 33a1 of the rod-shaped portion 33a.

Abutment portion 72 is disposed above suction head 3a in FIG. 6 (in other words, above bottom portion 7b). Abutment portion 72 is connected to a drive mechanism 71 (not shown in FIG. 6) installed near stage 3b. Abutment portion 72 has a tip surface 72a. Tip surface 72a is located above suction head 3a. In FIG. 6, tip surface 72a of abutment portion 72 is a dome-shaped convex curved surface (hemispherical surface). There are various other structural examples of abutment portion 72, including those shown in FIG. 13 to FIG. 16, and this point will be explained later in the modified examples.

In Fig. 6, the deviation amount _E1 is set in advance as an example. The deviation amount _E1 will be described with reference to Figs. 3 and 8. Fig. 3 is a plan view of the bottom 7b viewed along the central axis of the double container 1. The contact portion _F1 is a point where the tip surface 72a and the bottom 7b contact each other, shown within the plan view area of the bottom 7b. The deviation amount _E1 represents how far the contact portion _F1 is displaced from the center point _C0 in the plan view of Fig. 3. When the deviation amount _E1 is set, the tip surface 72a can be brought into contact with a portion displaced from the cutting portion 7d when the contact portion 72 is lowered, as shown in Fig. 8.

FIG. 3 illustrates the bottom radius R ₀ , which is 1/2 of D _0. The deviation amount E ₁ may be defined as E ₁ =k×R ₀ using the coefficient k with C ₀ as the origin. k may be _, for example, 0.1 or less, 0.2 or less, or 0.5 or less, for example, k=0.05 to 0.5. When k=0.5, the contact part F ₁ is shifted from the center point C ₀ in the outer radial direction by exactly half of R _0. The coefficient k may be, for example, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, 0.50, 0.60, or the like, or may be within a range between any two of the numerical values exemplified here. As described in a modified example below, the deviation amount E ₁ may be zero, in which case the coefficient k=0.

The contact site _F1 varies depending on the shape of the tip surface 72a and the degree of curvature. When the tip surface 72a and the bottom portion 7b can be regarded as being in point contact, the distance between the contact site _F1 , which is the contact point, and the center point _C0 can be regarded as the deviation amount _E1 . When the tip surface 72a and the bottom portion 7b are in surface contact over a relatively large range, for example, the center point of the contact surface area can be regarded as the contact site _F1 , and the distance between this center point and the center point _C0 can be regarded as the deviation amount _E1 .

3. Preliminary Peeling Method The preliminary peeling method according to the embodiment includes a peeling step and a leak inspection step.

6, the double container 1 is set in the preliminary peeling device 2. The head base 31, the flange portion 33b, and the end face of the mouth portion 9 are tightly attached via the packings 32 and 34. This tight attachment results in the inside of the inner bag 14 being in communication with the outside only through the through holes 31a, 32a, and 33c. It becomes possible to reduce or increase the pressure inside the inner bag 14 by the pressure reduction system 5 or the pressure increase system 6.

Next, suction by the suction head 3a is started by the pressure reduction system 5. The pressure inside the inner bag 14 is reduced by the suction. The pressure inside the inner bag 14 becomes negative, creating a state in which the inner bag 14 tries to shrink. The timing of starting suction is set so that the pressure inside the inner bag 14 becomes negative at the latest by the time the tip surface 72a hits the bottom 7b.

Next, the contact portion 72 is lowered so that the tip surface 72a comes into contact with the bottom portion 7b as shown in FIG. 7. In the embodiment, the amount of deviation _E1 is set as an example, so that the tip surface 72a comes into contact with the contact portion _F1 that is shifted from the cut-off portion 7d of the bottom portion 7b. In the enlarged cross-sectional view of FIG. 8, the original bottom surface position 7b1 is shown by a dashed line. When the tip surface 72a comes into contact, a vertically downward force acts on one side of the bottom portion 7b. As a result, the cut-off portion 7d is cracked, and the outside air intake portion 15 is formed.

The strength of the cutout portion 7d of the outer shell 12 is particularly weak. Therefore, by applying a force to the outer shell 12, the cutout portion 7d can be opened to form the outside air introduction portion 15 as shown in Fig. 8. As outside air is introduced from the outside air introduction portion 15, a force that causes the inner bag 14 to shrink (force represented by multiple arrows pointing downward in Fig. 8) acts, and a peel gap _G1 is generated between the inner bag 14 and the outer shell 12. Fig. 8 shows an example of the peel gap _G1 . Outside air can be introduced into the peel gap _G1 between the outer shell 12 and the inner bag 14 through the outside air introduction portion 15.

Here, there are various variations in the way the tip surface 72a applies force to the bottom 7b. The drive mechanism 71 may quickly lower the contact portion 72 to apply an impact force to the bottom 7b. The drive mechanism 71 may relatively gently lower the contact portion 72 to apply a pressing force to the bottom 7b. The contact portion 72 may be moved up and down multiple times to bring the tip surface 72a into contact with the bottom 7b multiple times. This "multiple times" may be, for example, two or three times, or four or more times, but may be, for example, three times in order to reliably break the biting portion 7d and to shorten the process time. In one to several times of contact (specifically, for example, the last time), the contact portion 72 may be stopped at the lowered position for a certain period of time to hold the bottom 7b pressed down. If the area of the bottom 7b is small in a small double container 1, it may be difficult to peel it off with only one contact. In this case, the impact force can be applied multiple times to ensure peeling.

Although not shown in FIG. 8, the force with which the double container 1 is pressed downward when the contact portion 72 contacts the bottom portion 7b may be absorbed to a certain extent by the packings 32 and 34. In this case, the packings 32 and 34 may shrink in the thickness direction when the contact portion 72 contacts the bottom portion 7b, causing the double container 1 to be displaced downward to a certain extent. This may adjust the impact force or pressing force applied to the outer shell 12.

Figure 9 shows a schematic example of how the inner bag 14 shrinks due to preliminary peeling. When the cut-off portion 7d is broken to form the outside air introduction portion 15, the inner bag 14 can quickly shrink accordingly, as shown in Figure 9. This is because the inside of the inner bag 14 is made negative pressure by suction, so the cut-off portion 7d can be broken while the inner bag 14 is about to shrink due to the negative pressure. This makes it possible to perform preliminary peeling while minimizing damage to the inner bag 14.

After preliminary peeling, air is blown into the inner bag 14 through the suction head 3a by the pressure system 6. This causes the inner bag 14 to expand until it returns to its original position, as shown in Figure 10.

In the embodiment, as an example, a leak inspection process is performed following the preliminary peeling process. In the leak inspection process, the presence or absence of pinholes in the inner bag 14 is inspected based on data obtained when the inside of the inner bag 14 is pressurized after the peeling process.

Specifically, when the inner bag 14 is inflated to its original state as shown in Figure 10, the presence or absence of a pinhole is checked using the flow meter 64. If a pinhole is present, a flow rate will occur due to air leakage.

As shown in FIG. 11, after the start of pressurization, the air flow rate measured by the flowmeter 64 increases rapidly, but the flow rate gradually decreases as the inner bag 14 expands. If there is no pinhole in the inner bag 14, the air flow rate becomes very small (almost zero) when the inner bag 14 is fully inflated. On the other hand, if there is a pinhole in the inner bag 14, air will flow out of the inner bag 14 through the pinhole even when the inner bag 14 is fully inflated, so the flow rate of air sucked out of the inner bag 14 will be greater than when there is no pinhole in the inner bag 14. Therefore, after a predetermined time T has elapsed, it can be determined whether or not there is a pinhole in the inner bag 14 based on the flow rate of air leaking out of the inner bag 14 (more specifically, by checking whether this flow rate exceeds a threshold value Th).

Furthermore, if a pinhole exists in the inner bag 14, the degree of sealing inside the inner bag 14 will be reduced, making it difficult to pressurize the inside of the inner bag 14. For this reason, with the set pressure of the compressor 63 set to a reference value, it may be determined whether or not a pinhole exists in the inner bag 14 based on the pressure detected by the pressure gauge 65 after a predetermined time has elapsed. Furthermore, in addition to the flow rate and pressure, the presence or absence of a pinhole may also be determined based on data such as the expansion state and expansion time of the inner bag 14. However, from the standpoint of accuracy, a determination based on the flow rate is preferable.

According to the preliminary peeling method of the embodiment described above, the inner bag 14 can be shrunk as the cutout portion 7d breaks and outside air is introduced. This allows preliminary peeling to be performed while minimizing damage to the inner bag 14. In addition, it is efficient because a leak test can be performed following the preliminary peeling. The double container 1 set in FIG. 6 may be one that has just been molded, for example. In other words, the peeling process may be performed immediately following the molding process for forming the double container 1.

The configuration of the embodiment can be modified in various ways. The following modifications may be applied alone or in combination.

For example, the leak inspection process in the embodiment may be omitted, or a leak inspection may be performed using another method after the peeling process.

As a modified example, the deviation amount _E1 may be set to zero as shown in Fig. 12. Specifically, the peeling process may be started by placing the center _C1 of the tip surface 72a vertically above the cutting portion 7d as shown in Fig. 12, or the center _C1 of the tip surface 72a may be placed against the center point _C0 of the bottom portion 7b. In this case, the center _C1 , center point _C0 , and contact portion _F1 are exactly aligned on a vertical line, so the deviation amount _E1 is zero.

The shape of the contact portion 72 may be modified in various ways. For example, the modified examples shown in Figs. 13 to 16 may be provided. As shown in Fig. 13, a concave (or inverted dome) tip surface 72b may be provided. As shown in Fig. 14, tip surfaces 72c1 and 72c2 constituting the side and bottom surfaces of the inverted trapezoid recess may be provided. In the example of Fig. 14, a force is applied to the bottom 7b by the planar tip surface 72c1. As shown in Fig. 15, the tip surface 72c1 of Fig. 14 may be replaced with a tip surface 72d of a convex curved surface that rises slightly in the recess. As shown in Fig. 16, a tip surface 72e2 of a convex curved surface that rises slightly in the recess and is offset may be provided in the tip surface 72e1 of the concave curved surface. As another modified example, the tip surface 72c2 of Fig. 14 may be removed to make the contact portion 72 simply a bottomed cylinder, and its bottom surface (i.e., tip surface 72c1) may be abutted against the bottom 7b. In the examples of FIGS. 13 to 15, the deviation amount _E1 is zero as in the example of FIG. 12, while in the example of FIG. 16, the deviation amount _E1 is provided due to the deviation of the tip end surface 72e2.

The three-dimensional shape of each of the abutment portions 72 in Fig. 6 and Figs. 12 to 15 can be rotationally symmetric about the central axis CL, but is not limited to this. As a modified example, an extruded shape in which the contour of the abutment portion 72 in these figures is extruded in the depth direction (thickness direction) of each figure may be applied. Note that the abutment portion 72 in Fig. 16 has an asymmetric shape with respect to the central axis CL, and an extruded shape extruded in the depth direction of Fig. 16 can be used.

The configuration of the bottom 7b of the double container 1 can also be modified in various ways. As one example, the bottom 7b may be modified to have a flat bottom surface. As another modification, the bottom 7b may be recessed toward the inside of the storage section 7, in which case the bottom 7b will have a concave curved surface. In these cases, it is preferable that the tip surface 72a has a convex shape. Also, the convex height of the bottom 7b, i.e., the degree to which the bottom 7b protrudes, may be smaller than that illustrated in FIG. 6.

According to the above modified example, it is understood that there are many combinations of shapes of the bottom 7b and the tip surface 72a. For convenience, when the shape combination is expressed as "(shape of the bottom 7b)/(shape of the tip surface 72a)", there are at least multiple combinations of "convex shape/convex shape (see FIG. 6)", "convex shape/concave shape (see FIG. 13)", "convex shape/flat shape (see FIG. 14)", "flat shape/convex shape", and "concave shape/convex shape".

When both the bottom 7b and the tip surface 72a are curved convexly or concavely, the degree of curvature of the two can be set to various degrees. As an example, the convex shape of the bottom 7b may have a gentler curvature (i.e., a smaller curvature) than the convex curved surface of the tip surface 72a, or vice versa. The degree of curvature may be compared in terms of the radius of curvature, but if the cross section is not circular, it may also be compared in terms of the radius of curvature of the circumscribed circle.

In the embodiment, the force is applied only to one point on the bottom 7b, but this is not limiting. As a modification, the force may be applied to multiple points simultaneously, or sequentially in any order. The multiple abutting portions 72 may have multiple convex tip surfaces 72a. The multiple areas to which the force is applied may be set on both sides of the cutting portion 7d.

In each of the above modified examples, the method of applying force to the bottom 7b (number of times, speed, strength) can be selected from a variety of methods as described in the embodiment.

The suction head 3a can be modified in various ways. The suction port 33d may be provided at a location other than the tip of the rod-shaped portion 33a. When the suction port 33d is provided on the peripheral surface of the rod-shaped portion 33a, it is preferable to provide it at a location where the inner bag 14 is unlikely to block the suction port 33d (e.g., near the base of the rod-shaped portion 33a). The number of suction ports 33d may be two or more. As another modification of the suction head 3a, the insert member 33 and the packing 34 may be omitted as shown in FIG. 17. In this case, suction is also possible with the double container 1 set as shown in FIG. 18.

The driving mechanism 71 is not limited to an air cylinder. Any other reciprocating mechanical element may be used instead of the air cylinder, and the abutment portion 72 may be driven by any electromagnetic actuator.

Table 1 below shows the results of a test of the peeling process using several types (No. 1 to No. 6) of the contact portion 72 in the preliminary peeling device 2 of the embodiment. The several types of contact portion 72 have different tip surface shapes (shapes of the contact surface with the bottom portion 7d). Each test condition No. 1 to No. 6 in Table 1 differs in tip surface shape (convex, concave, flat) and the presence or absence of deviation (presence or absence of deviation amount E ₁ ). An air cylinder was used as the driving mechanism 71, and the air cylinder pressing force was set to 0.2 MPa. When the force applied by the contact portion 72 to the contacted portion with this setting was measured with a push-pull gauge, it was 60 N. The double container 1 used as the sample under each test condition had the same shape. Since the sample double container 1 had cooled down due to the passage of time after molding, it was lightly warmed with hot air (about 5 seconds) before being used in the test. The number of samples of the double container 1 under each test condition No. 1 to No. 6 was N=3.

Table 1 shows three-level evaluation results (◎, ○, △) focusing on cracking of the cutting edge 7d. In all (three) samples under test conditions No. 1, 2, 5, and 6, the cutting edge 7d cracked well, and the inner bag 14 peeled well (result ◎). In the sample under test condition No. 4, the cutting edge 7d cracked, but the degree of peeling was poor, and peeling occurred to a certain extent in some samples (result ○). In the sample under test condition No. 3, the cutting edge 7d cracked, but peeling was insufficient (result △). When comparing the tip surface shapes, the convex shape was advantageous.

The fragility of the cutting portion 7d depends on the material and thickness of the outer shell 12 and the shape of the bottom portion 7b, so the shape of the tip surface may be selected according to the structural material of the double container 1. Other possible methods include, for example, applying the peeling process of the embodiment immediately after molding the double container 1, increasing the magnitude or number of times the force applied by the drive mechanism 71 is applied, or increasing the suction force of the suction device 3 to promote preliminary peeling.

1: Double container 2: Preliminary peeling device 3: Suction device 3a: Suction head 3b: Stage 3b1: Central recess 4: Solenoid valve 5: Decompression system 6: Pressurization system 7: Storage section 7a: Body section 7b: Bottom section 7b1: Original bottom surface position 7d: Cutting section 8, 8a, 8b, 8c: Pipe 9: Mouth section 12: Outer shell 14: Inner bag 15: Outside air introduction section 31: Head base 31a, 32a, 33c, 34a: Through hole 31b: Storage recess 32: Packing 33: Insertion member 33a: Rod-shaped section 33a1: Tip 33b: Flange section 33d: Suction port 34: Packing 53: Regulator 54: Vacuum pump 61: Speed controller 62: Regulator 63: Compressor 64: Flow meter 65: Pressure gauge 71 : Drive mechanism 72 : Contact parts 72a, 72b, 72c1, 72c2, 72d, 72e1, 72e2 : Tip surface 73 : Control part C ₀ : Center point C ₁ : Center part D ₀ : Bottom diameter R ₀ : Bottom radius E ₁ : Deflection amount F ₁ : Contact part G ₁ : Peeling gap T : Predetermined time Th : Threshold

Claims (3)

A method for pre-peeling a double-layered container having an outer shell and an inner bag, comprising the steps of:
A peeling step is provided,
The peeling step peels the inner bag from the outer shell by breaking a cutout portion provided at a bottom of the outer shell while maintaining a negative pressure inside the inner bag,
The peeling step is a method in which the cutting portion is broken by applying force to a portion of the bottom portion that is shifted from the cutting portion. 2. The method of claim 1 ,
Further comprising an inspection process;
The inspection step inspects whether or not there is a pinhole in the inner bag based on data obtained when the inside of the inner bag is pressurized after the peeling step. 3. The method of claim 1 or claim 2 ,
wherein the diameter of the base of the shell is between 14 and 25 mm.