JP7766982B2 - Extrusion blow molded containers - Google Patents

Description

The present invention relates to extrusion blow-molded containers.

Conventional extrusion blow-molded containers are known to have a lower body portion formed with a vacuum absorption panel and an upper body portion positioned above the lower body portion (see, for example, Patent Document 1).

JP 2015-143125 A

However, when the above-mentioned conventional extrusion blow-molded containers are made lighter (thinner-walled) for purposes such as reducing environmental impact, there is a problem in that the entire container deforms, for example, into an elliptical shape in the circumferential direction around the central axis of the container, before the vacuum absorption panel can function.

The object of the present invention is to provide an extrusion blow-molded container that suppresses deformation of the entire container.

The extrusion blow-molded container according to the present invention comprises a lower body portion having a vacuum absorption panel formed therein, and an upper body portion located above the lower body portion. The extrusion blow-molded container further comprises a convex rib between the lower body portion and the upper body portion, protruding radially outward and extending circumferentially, and a lower concave rib located below the convex rib, protruding radially inward and extending circumferentially. The lower concave rib has a bottom portion that extends axially and is formed flat in side view, an upper inclined portion that is continuous with the lower end of the convex rib and slopes linearly toward the upper end of the bottom portion in side view and is connected to the upper end of the bottom portion, and a lower inclined portion that is continuous with the upper end of the lower body portion and slopes linearly toward the lower end of the bottom portion in side view and is connected to the lower end of the bottom portion.

The extrusion blow-molded container according to the present invention preferably further comprises an upper concave rib located above the convex rib, protruding radially inward and extending circumferentially. The upper concave rib preferably has a bottom surface portion that extends axially and is formed flat in a side view, an upper inclined portion that connects to the lower end of the upper body portion, slopes linearly toward the upper end of the bottom surface portion in a side view, and is connected to the upper end of the bottom surface portion, and a lower inclined portion that connects to the upper end of the convex rib, slopes linearly toward the lower end of the bottom surface portion in a side view, and is connected to the lower end of the bottom surface portion.

In the extrusion blow-molded container according to the present invention, it is preferable that the upper body portion is formed with a curved concave rib that protrudes radially inward, extends circumferentially, and has an arc-shaped shape in side view.

In the extrusion blow-molded container according to the present invention, it is preferable that at least one pair of the vacuum absorption panels be formed in a direction perpendicular to the extension direction of the pinch-off portion.

The present invention provides an extrusion blow-molded container that suppresses deformation of the entire container.

1 is a side view schematically showing an extrusion blow molded container according to a first embodiment of the present invention. FIG. 2 is an enlarged view showing an area A in FIG. 1 . 2 is a bottom view schematically showing the bottom of the extrusion blow molded container of FIG. 1. FIG. FIG. 4 is a side view schematically showing an extrusion blow molded container according to a second embodiment of the present invention.

Below, an extrusion blow-molded container according to an exemplary embodiment of the present invention will be described with reference to the drawings.

In this disclosure, the term "upper side" also refers to the side on which the mouth of the extrusion blow-molded container is located, and the term "lower side" also refers to the side on which the bottom of the blow-molded container is located. Furthermore, the axis O is the central axis of the extrusion blow-molded container. In this disclosure, the term "axial direction" refers to the direction along the axis O. In this disclosure, the term "radial direction" refers to the direction perpendicular to the axis O. In this disclosure, the term "radially inner side" refers to the side on both radial sides that is closer to the axis O, and the term "radially outer side" refers to the side on both radial sides that is farther from the axis O.

Figure 1 shows an extrusion blow-molded container 1A according to a first embodiment of the present invention. Figure 2 shows an enlarged view of region A in Figure 1.

Referring to FIG. 1, the extrusion blow-molded container 1A comprises a lower body portion 8 on which a vacuum absorption panel 8a is formed, and an upper body portion 4 located above the lower body portion 8. The extrusion blow-molded container 1A further comprises, between the lower body portion 8 and the upper body portion 4, a convex rib 6 that protrudes radially outward and extends circumferentially, and a lower concave rib 7 that is located below the convex rib 6, protrudes radially inward, and extends circumferentially.

The convex rib 6 is an annular convex rib that extends circumferentially around the axis O. Specifically, the convex rib 6 is formed continuously around the entire circumferential direction around the axis O. Furthermore, the lower concave rib 7 is an annular concave rib that extends circumferentially around the axis O. Specifically, the lower concave rib 7 is formed continuously around the entire circumferential direction around the axis O.

Referring to FIG. 2, the lower concave rib 7 is formed with a bottom surface portion 71, an upper inclined portion 72, and a lower inclined portion 73. The bottom surface portion 71 extends axially and is flat in side view as shown in FIG. 2. However, "extending axially" here is interpreted to mean allowing for a slight inclination with respect to the axis O. The upper inclined portion 72 is formed continuous with the lower end of the convex rib 6 and, as shown in FIG. 2, is linearly inclined toward the upper end 7e1 of the bottom surface portion 71 and is connected to the upper end 7e1 of the bottom surface portion 7a in side view. The lower inclined portion 73 is connected to the upper end 8e1 of the lower body portion 8 and, as shown in FIG. 2, is linearly inclined toward the lower end 7e2 of the bottom surface portion 71 and is connected to the lower end 7e2 of the bottom surface portion 7a in side view. Additionally, "connected" here not only means that they are connected to each other in a straight line when viewed from the side, but also includes, as in the present disclosure, that they are connected in a curved line.

Also, referring to Figure 1, the extrusion blow-molded container 1A according to this embodiment further includes an upper concave rib 5 that is positioned above the convex rib 6, protrudes radially inward, and extends circumferentially.

Referring to FIG. 2, the upper concave rib 5 is formed with a bottom surface portion 51, an upper inclined portion 52, and a lower inclined portion 53. The bottom surface portion 51 extends axially and is flat in side view as shown in FIG. 2. However, here too, "extending axially" is interpreted to mean allowing for a slight inclination with respect to the axis O. The upper inclined portion 52 is continuous with the lower end 4e2 of the upper body portion 4 and, as shown in FIG. 2, is linearly inclined toward the upper end 5e1 of the bottom surface portion 51 in side view and is continuous with the upper end 5e1 of the bottom surface portion 51. The lower inclined portion 53 is formed continuous with the upper end of the convex rib 6 and, as shown in FIG. 2, is linearly inclined toward the lower end 5e2 of the bottom surface portion 51 and is continuous with the lower end 5e2 of the bottom surface portion 51. Also, here, "connected" not only means that they are connected to each other in a straight line when viewed from the side, but also includes, as in this disclosure, that they are connected in a curved line.

Referring to FIG. 1, in this disclosure, the extrusion blow-molded container 1A comprises a cylindrical mouth 2, a shoulder 3 connected to the lower end 2e2 of the mouth 2, an upper body 4 connected to the lower end of the shoulder 3 (the upper end 4e1 of the upper body 4), an upper concave rib 5 connected to the lower end 4e2 of the upper body 4, a convex rib 6 connected to the lower end of the upper concave rib 5, a lower concave rib 7 connected to the lower end of the convex rib 6, a lower body 8 connected to the lower end of the lower concave rib 7 (the upper end 8e1 of the lower body 8), and a bottom 9 connected to the lower end (recess 10) of the lower body 8. The bottom 9 closes the lower end of the lower body 8.

In this disclosure, the extrusion blow-molded container 1A is a round bottle formed into a cylindrical shape. The interior of the extrusion blow-molded container 1A forms a storage space capable of containing various contents. The mouth portion 2 is formed with an opening (not shown) that leads to the storage space.

In this disclosure, extrusion blow-molded container 1A is a heat-resistant extrusion blow-molded container. In this disclosure, extrusion blow-molded container 1A is made primarily from heat-resistant polypropylene (PP) and is molded by extrusion blow molding. However, the primary material is not limited to polypropylene.

In this disclosure, the shoulder portion 3 has a polyhedral shape consisting of multiple curved surfaces 3a. However, the shoulder portion 3 does not have to have a polyhedral shape, and various shapes such as a dome shape can be appropriately adopted.

In addition, in the present disclosure, a curved concave rib 4a is formed on the upper body portion 4. The curved concave rib 4a protrudes radially inward and extends circumferentially, and has an arc-shaped outline in side view as shown in FIG. 1. In the present disclosure, the curved concave rib 4a is an annular curved concave rib that extends circumferentially around the axis O. Specifically, the curved concave rib 4a is formed continuously around the entire circumferential direction around the axis O. In the present disclosure, the curved concave rib 4a has an arc-shaped outline with an arbitrary radius of curvature r. In addition, in the present disclosure, multiple curvature concave ribs 4a are formed at intervals in the axial direction. However, there may be at least one curvature concave rib 4a. Alternatively, the curvature concave rib 4a may be omitted.

In the present disclosure, the upper concave rib 5 is an annular concave rib extending circumferentially around the axis O. Specifically, the upper concave rib 5 is formed continuously around the entire circumferential direction around the axis O. Referring to FIG. 2, in the present disclosure, the upper end of the upper concave rib 5 coincides with the lower end 4e2 of the upper body portion 4. The upper concave rib 5 is located radially inward from the upper body portion 4. In the present disclosure, the upper inclined portion 52 of the upper concave rib 5 is inclined at an angle α1 with respect to the bottom surface portion 51 (axis O). In the present disclosure, the lower inclined portion 53 of the upper concave rib 5 is inclined at an angle α2 with respect to the bottom surface portion 51 (axis O). In the present disclosure, the bottom surface portion 51 of the upper concave rib 5 is located radially inward from the curvature concave rib 4a, as shown in FIG. 1.

In addition, in the present disclosure, the convex rib 6 is an annular convex rib extending circumferentially around the axis O. Referring to FIG. 2, in the present disclosure, the upper end of the convex rib 6 coincides with the lower inclined portion 53 of the upper concave rib 5. In addition, in the present disclosure, the lower end of the convex rib 6 coincides with the upper inclined portion 72 of the lower concave rib 7. In the present disclosure, the upper and lower ends of the convex rib 6 are connected by a peak extending along the axial direction in a side view as shown in FIG. 2. In addition, in the present disclosure, the convex rib 6 protrudes radially outward beyond both the upper body portion 4 and the lower body portion 8.

In addition, in the present disclosure, the lower concave rib 7 is an annular concave rib extending circumferentially around the axis O. It is an annular concave rib. In the present disclosure, the upper inclined portion 72 of the lower concave rib 7 coincides with the lower end of the convex rib 6, as described above. In addition, in the present disclosure, the upper inclined portion 72 of the lower concave rib 7 is inclined at an angle β1 with respect to the bottom surface portion 71 (axis O). In addition, in the present disclosure, the lower inclined portion 73 of the lower concave rib 7 is inclined at an angle β2 with respect to the bottom surface portion 71 (axis O). In the present disclosure, the lower end of the lower concave rib 7 coincides with the upper end 8e1 of the lower body portion 8. In the present disclosure, the lower concave rib 7 is located radially inward of the lower body portion 8. Referring to FIG. 2, in the present disclosure, the bottom surface portion 71 of the lower concave rib 7 is located radially inward of the bottom surface portion 51 of the upper concave rib 5.

Also, referring to FIG. 1, in the present disclosure, the lower body portion 8 expands radially outward as it approaches the bottom portion 9 along the axial direction. Also, in the present disclosure, a recess 10 is formed between the lower body portion 8 and the bottom portion 9. That is, in the present disclosure, the recess 10 connects the lower body portion 8 and the bottom portion 9 and is the boundary between the lower body portion 8 and the bottom portion 9. In the present disclosure, the recess 10 is an annular recess that extends circumferentially around the axis O.

In addition, in the present disclosure, the bottom portion 9 is formed with a bottom surface 9b that is raised from the annular ground portion 9a toward the center of the bottom portion. A pinch-off portion 9c is formed on the bottom surface 9b. In the present disclosure, the pinch-off portion 9c is formed in a direction that overlaps with the parting line of the blow molding die.

In the present disclosure, the lower body portion 8 is formed with multiple vacuum absorption panels 8a spaced circumferentially around the axis O. In the present disclosure, six vacuum absorption panels 8a are formed in the lower body portion 8. Note that in FIG. 1, three vacuum absorption panels 8a on the back side of the drawing are not visible. However, the number of vacuum absorption panels 8a is not limited to the present disclosure. For example, the number of vacuum absorption panels 8a can be at least one. When the internal pressure of the extrusion blow-molded container 1A is reduced, the vacuum absorption panel 8a deforms preferentially over other portions, thereby absorbing the reduced pressure inside the extrusion blow-molded container 1A. Furthermore, the vacuum absorption panel 8a is the portion of the entire extrusion blow-molded container 1A that is most susceptible to radial inward deformation. For this reason, the vacuum absorption panel 8a can be given the function of discharging the contents of the extrusion blow-molded container 1A from the mouth 2 by pressing (squeezing) the vacuum absorption panel 8a from the radially outward direction. In the present disclosure, the vacuum absorption panel 8a is composed of a bottom surface 8a1 and a peripheral surface 8a2 that surrounds the bottom surface 8a1. However, the shape of the vacuum absorption panel 8a can be set as appropriate. Also, in the present disclosure, a columnar reinforcement portion 8b is formed between adjacent vacuum absorption panels 8a in the circumferential direction, reinforcing the lower body portion 8.

Also, referring to FIG. 1, in the present disclosure, at least one pair of vacuum absorption panels 8a are formed in a direction perpendicular to the extension direction of the pinch-off portion 9c. In FIG. 1, one of the pair of vacuum absorption panels 8a among the multiple vacuum absorption panels 8a is designated by the reference symbol 8ax. Note that in the present disclosure, the shapes of the multiple vacuum absorption panels 8a arranged in the lower body portion 8 are identical. Also, in the present disclosure, the dimensions of the multiple vacuum absorption panels 8a arranged in the lower body portion 8 are identical. Furthermore, in the present disclosure, the multiple vacuum absorption panels 8a are arranged at equal intervals circumferentially around the axis O.

3, in the present disclosure, the pinch-off portion 9c extends along a radial extension line L that passes through the axis O and extends radially in a bottom view. Referring to FIG. 3, in the present disclosure, one of the pair of vacuum absorption panels 8a1 is disposed on one side in a direction perpendicular to the extension direction of the pinch-off portion 9c in a bottom view of FIG. 3, for example, in region R1 in FIG. 3. That is, one of the pair of vacuum absorption panels 8a1 is disposed on one of the two sides of the radial extension line L in a bottom view of FIG. 3. Also referring to FIG. 3, in the present disclosure, the other of the pair of vacuum absorption panels 8a1 is disposed on the other side in a direction perpendicular to the extension direction of the pinch-off portion 9c in a bottom view of FIG. 3, for example, in region R2 in FIG. That is, the other of the pair of vacuum absorption panels 8a1 is disposed on the other side of the radial extension line L in a bottom view of FIG. 3. In other words, in this disclosure, the vacuum absorption panels 8a1 are formed as a pair at 90 degrees to the extension direction of the pinch-off portion 9c when viewed from the bottom, as shown in Figure 3, and at positions facing each other across the pinch-off portion 9c.

As shown in FIG. 1, the extrusion blow-molded container 1A includes a convex rib 6 and a lower concave rib 7 located below the convex rib 6 between the lower body portion 8 and the upper body portion 4. As shown in FIG. 2, the lower concave rib 7 has a trapezoidal contour formed by a bottom surface portion 71, an upper inclined portion 72, and a lower inclined portion 73 in a side view. This configuration enhances the rigidity between the lower body portion 8 and the upper body portion 4. Therefore, even when the internal pressure of the extrusion blow-molded container 1A is reduced, the entire extrusion blow-molded container 1A can be prevented from deforming, for example, into an elliptical shape in the circumferential direction around the central axis of the container. Therefore, the extrusion blow-molded container 1A is prevented from deforming overall. Furthermore, this prevents portions other than the vacuum absorption panel 8a from deforming prior to the vacuum absorption panel 8a. Therefore, the extrusion blow molded container 1A allows the vacuum absorption panel 8a to function effectively.

In addition, the radial rigidity of the extrusion blow-molded container 1A is improved by forming inclined portions (72, 73) on the lower concave rib 7. This allows the extrusion blow-molded container 1A to exert a stronger resistance to radial deformation than, for example, a concave rib formed by curvature (e.g., curvature concave rib 4a). Furthermore, in the extrusion blow-molded container 1A, the convex rib 6 is formed to connect to the lower concave rib 7, which exerts a stronger resistance to stress that tends to cause elliptical deformation, thereby strengthening the entire body of the extrusion blow-molded container 1A.

In addition, in the present disclosure, the extrusion blow-molded container 1A further includes an upper concave rib 5 located above the convex rib 6, and as shown in FIG. 2, the upper concave rib 5 has a trapezoidal outline formed by a bottom surface portion 51, an upper inclined portion 52, and a lower inclined portion 53 in side view. In this case, the rigidity between the lower body portion 8 and the upper body portion 4 can be further increased. Therefore, the blow-molded container 1A further suppresses deformation of the entire extrusion blow-molded container 1A.

Also, referring to Figure 1, in the extrusion blow molded container 1A, a curved concave rib 4a is formed on the upper body 4. By forming a curved concave rib 4a formed only by curvature on the upper body 4 in this way, it is possible to prevent a decrease in buckling strength compared to when a concave rib formed by a flat bottom surface and an inclined portion is formed on the upper body 4.

Furthermore, in the extrusion blow-molded container 1A, at least one pair of vacuum absorption panels 8ax are formed in a direction perpendicular to the extension direction of the pinch-off portion 9c. Here, the pinch-off portion 9c is a portion that is held by being sandwiched between the mating surfaces of the mold. Therefore, referring to the bottom view of FIG. 3, the extension axis (radial extension line L) of the pinch-off portion 9c is less likely to stretch during extrusion blow molding than the direction perpendicular to the extension axis of the pinch-off portion 9c. Therefore, the thickness in the direction perpendicular to the extension axis of the pinch-off portion 9c (the thickness of the portion corresponding to regions R1 and R2 in FIG. 3) is thinner than the thickness along the extension axis of the pinch-off portion 9c (the thickness of the portion corresponding to region R3 in FIG. 3). Therefore, by forming the vacuum absorption panel 8ax in a direction perpendicular to the extension direction of the pinch-off portion 9c, as in the present disclosure, the vacuum absorption panel 8ax can be more easily deformed.

Furthermore, when considering the positional relationship with the pinch-off portion 9c, it is particularly preferable that the number of vacuum absorption panels 8a be two or a multiple of six. When considering the positional relationship between the vacuum absorption panels 8a and the pinch-off portion 9c, for the reasons described above, it is preferable that the vacuum absorption panels 8a not be formed in a position that includes the extension axis (radial extension line L) of the pinch-off portion 9c when viewed from the bottom in Figure 3, such as in the position of region R3 in Figure 3, as in the present disclosure. When the number of vacuum absorption panels 8a is two or a multiple of six, as in the present disclosure, the vacuum absorption panels 8a can be easily positioned in a position that avoids region R3 in Figure 3.

Figure 4 is a side view schematically showing an extrusion blow-molded container 1B according to a second embodiment of the present invention. In the following description, parts that are substantially the same as those in extrusion blow-molded container 1A will be designated by the same reference numerals, and their description will be omitted.

In extrusion blow molded container 1B, the upper concave rib 5 of extrusion blow molded container 1A is omitted. That is, in extrusion blow molded container 1B, the upper end of the convex rib 6 is continuous with the lower end 4e2 of the upper body portion 4. In the present disclosure, the upper end of the convex rib 6 is configured similarly to the lower inclined portion 53 of the upper concave rib 5 in extrusion blow molded container 1A. That is, in side view, the upper end of the convex rib 6 is linearly inclined toward the lower end 4e2 of the upper body portion 4 and is continuous with the lower end 4e2 of the upper body portion 4.

Blow-molded container 1B also has a convex rib 6 and a lower concave rib 7. In side view, lower concave rib 7 has a trapezoidal outline formed by a bottom surface portion 71, an upper inclined portion 72, and a lower inclined portion 73. This configuration also enhances the rigidity of blow-molded container 1B between the lower body portion 8 and the upper body portion 4. Therefore, similar to extrusion blow-molded container 1A, even when the internal pressure of extrusion blow-molded container 1B is reduced, blow-molded container 1B as a whole does not deform, for example, into an elliptical shape in the circumferential direction around the central axis of the container. Therefore, extrusion blow-molded container 1A suppresses deformation of the entire extrusion blow-molded container 1A.

The foregoing describes exemplary embodiments of the present invention, and various modifications may be made without departing from the scope of the claims. For example, the various configurations employed in the above-described embodiments may be substituted for or combined with each other as appropriate.

1A: Extrusion blow molded container (first embodiment), 1B: Extrusion blow molded container (second embodiment), 2: Mouth portion, 3: Shoulder portion, 4: Upper body portion, 4e2: Lower end of upper body portion, 4a: Curved concave rib, 5: Upper concave rib, 51: Bottom surface portion of upper concave rib, 5e1: Upper end of bottom surface portion of upper concave rib, 5e2: Lower end of bottom surface portion of upper concave rib, 52: Upper inclined portion of upper concave rib, 53: Lower inclined portion of upper concave rib, 6: Convex rib, 7: Lower concave rib, 71: Bottom surface portion of lower concave rib, 7e1: Upper end of bottom surface portion of lower concave rib, 7e2: Lower end of bottom surface portion of lower concave rib, 72: Upper inclined portion of lower concave rib, 73: Lower inclined portion of lower concave rib, 8: Lower body portion, 8a: vacuum absorption panel, 8a1: pair of vacuum absorption panels, 8e1: upper end of lower body, 9: bottom, 9a: ground contact portion, 9b: raised bottom surface, 9c: pinch-off portion

Claims (3)

1. An extrusion blow-molded container comprising: a lower body portion having a plurality of vacuum absorption panels formed at intervals in the circumferential direction; and an upper body portion disposed above the lower body portion,
The extrusion blow-molded container further includes, between the lower body portion and the upper body portion, a convex rib that protrudes radially outward and extends circumferentially, and a lower concave rib that is disposed below the convex rib, protrudes radially inward, and extends circumferentially,
The lower concave rib is formed with a bottom surface portion that extends along the axial direction in side view and is formed flat, an upper inclined portion that is formed continuously with the lower end of the convex rib and that is linearly inclined toward the upper end of the bottom surface portion in side view and is connected to the upper end of the bottom surface portion, and a lower inclined portion that is connected to the upper end of a columnar reinforcing portion formed between the plurality of vacuum absorption panels in the lower body portion and that is linearly inclined toward the lower end of the bottom surface portion in side view and is connected to the lower end of the bottom surface portion ,
The extrusion blow molded container has at least one pair of vacuum absorption panels formed in a direction perpendicular to the extending direction of the pinch-off portion . the extrusion blow-molded container further includes an upper concave rib disposed above the convex rib, protruding radially inward, and extending circumferentially;
2. The extrusion blow molded container according to claim 1, wherein the upper concave rib is formed of: a bottom portion that extends along the axial direction in a side view and is formed flat; an upper inclined portion that is connected to the lower end of the upper body portion, that is linearly inclined toward the upper end of the bottom portion in a side view, and that is connected to the upper end of the bottom portion; and a lower inclined portion that is formed continuously with the upper end of the convex rib, that is linearly inclined toward the lower end of the bottom portion in a side view, and that is connected to the lower end of the bottom portion. 3. The extrusion blow molded container according to claim 1, wherein the upper body portion is formed with a curved concave rib that protrudes radially inward, extends circumferentially, and has an arc-shaped shape in side view.