JP5463503B2 - Synthetic resin container and manufacturing method thereof - Google Patents

Description

The present invention, for example when the container interior with the cooling of the hot filling (hot pack) after contents became reduced pressure, synthetic resin container and manufacturing can prevent the appearance defect occurs in the container body Regarding the method .

  In conventional biaxially stretched blow molded containers, after filling the contents such as beverages heated for sterilization, a decompression occurs inside the container as the contents cool down, and the wall of the container body deforms abnormally. There was a case.

  Therefore, in order to prevent abnormal deformation of the container main body due to the decompression, a decompression panel portion recessed toward the inside of the container is provided on the wall portion of the container main body.

JP 2005-173611 A JP 2005-8157 A

  However, in a container having the above conventional decompression panel part, the shrink label covering the decompression panel part causes the label to press the concave bottom surface of the decompression panel at the time of thermal contraction. There is a problem that the surface rises or the contents leak. And this problem arises more notably in containers with a small wall thickness that have been increasing in recent years.

  In order to solve the above problems, it has been proposed to use a polyester shrink label having a specific heat shrinkability (see Patent Document 1) or to provide a rib on the decompression panel (see Patent Document 2). In any case, the area ratio of the decompression panel portion occupying the outer surface of the container main body is large, and the problem remains that the appearance is easily damaged when the label is provided along the unevenness of the decompression panel portion.

The present invention has been made in view of the above circumstances, and its purpose is to make it possible to reliably prevent abnormal deformation of the container body due to reduced pressure generated inside the container and to improve the appearance of the container. It is in providing a container and its manufacturing method .

In order to achieve the above object, the synthetic resin container according to the present invention changes to a buckling pattern that goes around the outer peripheral surface of the container body when decompression occurs inside the container body, and the container body is moved to the container body. At least one step of a buckling pattern preliminary body that contracts in the axial direction of the main body is provided in the container main body, and after the contents are filled and capped, the contents are generated inside the container main body as the contents are cooled. Due to the reduced pressure, the pre-buckling pattern body is changed to the buckling pattern, thereby forming a synthetic resin container by a biaxial stretch blow molding method (Claim 1).

  In the synthetic resin container, the buckling pattern preliminary body includes a valley line, a ridge line, and a convex surface and a concave surface or a convex surface formed between one and the other of the valley line and the ridge line, respectively. (Claim 2), more specifically, between the upper and lower edges of the container body that are parallel to each other in the axial direction, from the upper edge to the lower edge. A plurality of obliquely extending valley lines and ridge lines are equally spaced in the circumferential direction of the container body, and are separated from the upper end of the upper end of the ridge line and the lower ends of two ridge lines adjacent to the ridge line. The valley line is provided so as to connect the lower end of the existing one, and the surface surrounded by the adjacent valley line, the peak line and the upper edge, and the surface surrounded by the adjacent valley line, the peak line and the lower edge. Of these, one can be convex and the other can be concave or convex ( Motomeko 3). Furthermore, in this case, the two steps of the buckling pattern preliminary bodies in which the direction of the valley line and the peak line are symmetric may be arranged side by side (Claim 4).

In the synthetic resin container, the pre-buckling pattern body may be a bellows (Claim 5).
A synthetic resin container manufacturing method according to the present invention is a synthetic resin container manufacturing method for manufacturing a synthetic resin container according to any one of claims 1 to 5, wherein the container body is Forming the buckling pattern preform of the container body in a state in which the contents are filled and capped by biaxial stretch blow molding, to generate a reduced pressure inside the container body as the contents are cooled. The method for manufacturing a synthetic resin container to be changed to the buckling pattern.

In the inventions according to claims 1 to 6 , a synthetic resin container and a method for manufacturing the same that can reliably prevent abnormal deformation of the container body due to the reduced pressure generated inside the container and can improve the appearance of the container can be obtained. .

  That is, in the inventions according to claims 1 to 4, the abnormal deformation of the container main body due to the reduced pressure generated inside the container means that the pre-buckling pattern body changes to a predetermined buckling pattern and the internal volume of the container main body is reduced. Therefore, it can be surely prevented. In addition, the area occupied by the pre-buckling pattern body on the outer surface of the container body is very small compared to the conventional decompression panel, so the shape of the container body can be simplified and fits the outer surface of the container body. Even if a label is provided in such a state, the appearance is hardly damaged.

  In particular, in the invention according to claim 4, since the two-stage buckling pattern preliminary bodies are buckled and deformed symmetrically with each other, the upper portion of the two-stage buckling pattern preliminary body in the container body before and after the buckling deformation. And the lower portion can be matched in phase, and can be applied to a container having a non-circular cross section such as a square bottle.

  Moreover, in the invention which concerns on Claim 5, a buckling pattern prior body can be made into a simpler shape.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a front view schematically showing the configuration of a synthetic resin container (hereinafter abbreviated as “container”) according to an embodiment of the present invention, and FIGS. 2 and 3 show the configuration of the container. FIG. 4 is a sectional view taken along the line AA in FIG. 1, FIG. 5 is a sectional view taken along the line BB in FIG. 2, and FIG. 6 is a schematic diagram of the main part of the container. FIG. 7 is a front view schematically showing the configuration of the container in a reduced pressure state.

  The container according to this embodiment is, for example, filled with soft drinks in a hot pack and has an inner volume of 500 ml, and includes a container body 1 formed by biaxial stretch blow molding. And this container main body 1 consists of a polyethylene terephthalate, and as shown in FIGS. 1-3 and FIG. 5, the container main body 1 is the mouth part 2, the shoulder part 3, and the substantially cylindrical trunk | drum in order from the top. It has a part 4 and a bottom part 5. The wall thickness of the container body 1 is set to 0.2 to 0.6 mm. Although not shown in detail, the mouth portion 2 is configured such that a cap made of polypropylene, for example, is detachably attached. Moreover, although the front view of the container main body 1 is shown in FIG. 1, the side view and rear view of the container main body 1 are also shown as the same shape.

  Here, when the decompression occurs inside the container body 1, the body part 4 changes to a buckling pattern that goes around the outer peripheral surface of the body part 4, and the container body 1 is moved in the axial direction of the container body 1. A pre-buckling pattern body 6 to be contracted is provided.

  As shown in FIGS. 1, 4, and 6, the buckling pattern preliminary body 6 has an upper edge between an annular upper edge 7 and a lower edge 8 that are parallel to each other in the axial direction of the container body 1. A plurality of valley lines (valley fold lines) 9 and ridge lines (ridge fold lines) 10 extending obliquely from the portion 7 to the lower edge portion 8 are provided at equal intervals in the circumferential direction of the container body 1. A trough line 9 is provided so as to connect the upper end of the ridge line 10 and the lower end of the two ridge lines 10 adjacent to the ridge line 10 away from the upper end.

  As shown in FIGS. 1 and 4, the surface 11 is surrounded by the adjacent valley line 9, the peak line 10 and the upper edge portion 7, and is surrounded by the adjacent valley line 9, the peak line 10 and the lower edge portion 8. One of the surfaces 12 (surface 11 in this embodiment) is a convex surface that is convex outward of the container body 1, and the other (surface 12 in this embodiment) is concave outward of the container body 1. It is a concave surface or a convex surface (in the illustrated example, the surface 12 is a concave surface, but the surface 12 may be a convex surface).

  Here, when the buckling pattern preliminary body 6 is deployed, the angle α (see FIG. 1) formed by the lower edge portion 8 and the valley line 9 is 40 to 50 °, and the angle formed by the lower edge portion 8 and the peak line 10. (beta) (refer FIG. 1) is 60-70 degrees, and the width | variety (distance from the upper edge part 7 to the lower edge part 8) of the buckling pattern preliminary body 6 is 10-20 mm. Further, the maximum protrusion amount a of the convex surface 11 (see FIG. 4) and the maximum depression amount b of the concave surface 12 (see FIG. 4, the maximum protrusion amount when the surface 12 is convex) are the buckling pattern preliminary body 6 Although it varies depending on the buckling wave number and the thickness of the container body 1, it is about 0.5 to 1.0 mm.

  Although not shown, the outer periphery of the container body 1 is shrink-sealed, and the pre-buckling pattern body 6 is not visible from the outside by the shrink label used for the seal.

  In the container according to this embodiment having the above-described configuration, after the contents heated to a high temperature (for example, 87 ° C.) are filled and capped, the contents of the container are cooled. A decompression occurs inside. However, as shown in FIG. 7, the buckling pattern preliminary body 6 changes to a buckling pattern that goes around the outer peripheral surface of the body 4 of the container body 1, so that the container body 1 is moved in the axial direction of the container body 1. By contracting and reducing the volume of the container body 1, the reduced pressure is absorbed.

  In addition, because of the configuration of the pre-buckling pattern body 6, when this becomes a predetermined buckling pattern, the upper portion 4 a and the lower portion 4 b of the pre-buckling pattern body 6 are twisted in the body portion 4 of the container body 1. Twisting deformation occurs. That is, before and after the deformation of the buckling pattern preliminary body 6, the phases of the upper portion 4a and the lower portion 4b are relatively different.

  Here, for example, in the case of a PET bottle having an internal volume of 500 ml, it is necessary to reduce the volume of the container body 1 by about 30 cc at the maximum in order to cope with the decompression, and if the volume reduction amount of the container body 1 is small Parts other than the buckling pattern preliminary body 6 of the container main body 1 will be abnormally deformed. Therefore, the configuration of the width of the buckling pattern preliminary body 6, the interval between the valley line 9 and the peak line 10, the angles α, β, and the like can be obtained when the buckling pattern preliminary body 6 changes to a predetermined buckling pattern. What is necessary is just to set suitably so that the volume of the main body 1 can reduce required amount.

  In the container having the above-described configuration, the abnormal deformation of the container body 1 due to the decompression generated inside the container is reliably performed because the buckling pattern preliminary body 6 is changed to the buckling pattern and the internal volume of the container body 1 is reduced. Can be prevented. In addition, the area occupied by the pre-buckling pattern body 6 on the outer surface of the container main body 1 is much smaller than that of the conventional decompression panel, so that the shape of the container main body 1 can be simplified, and the container main body 1 Even if a label is provided in a state that fits the outer surface, the appearance is hardly damaged.

  In addition, the above effect is exhibited not only when hot pack filling is performed, but also when cooling after aseptic filling, for example.

  In addition, the container of this invention is not restricted to said embodiment, It can implement in various deformation | transformation. Therefore, the modified example will be described below.

  For example, the contents of the container are not limited to soft drinks, but may be other contents suitable for hot packs, and the content is not limited to 500 ml.

In addition, the container body 1 may be made of a synthetic resin other than polyethylene terephthalate, and the shape of the container body 1 only needs to have a cylindrical portion that can be provided with the buckling pattern preliminary body 6. it may have a shape other than that is Ru of course der.

  Further, the buckling pattern preliminary body 6 may be provided obliquely so as to go around the outer peripheral surface of the trunk part 4 instead of in the circumferential direction of the trunk part 4, and the position of the pre-buckling pattern preliminary body 6 is also the same as that of the trunk part 4. Not only the central part, but also the upper part and the lower part of the body part 4 and the shoulder part 3 may be used.

  A plurality of buckling pattern preliminary bodies 6 may be provided. In this case, since the necessary reduction amount of the volume of the container body 1 is constant, the amount of contraction of each of the buckling pattern preliminary bodies 6 may be small compared to the case where there is only one buckling pattern preliminary body 6, Therefore, the width (distance from the upper edge portion 7 to the lower edge portion 8) of each buckling pattern preliminary body 6 can be reduced to make it less noticeable.

  And, for example, as shown in FIG. 8, two-stage buckling pattern preliminary bodies 6 in which the direction of the valley line 9 and the peak line 10 are symmetric can be arranged side by side. When each of the bodies 6 has a predetermined buckling pattern, deformations that twist the upper portion 4a and the lower portion 4b of the buckling pattern preliminary body 6 in the body portion 4 of the container body 1 cancel each other. The phase of the upper portion 4a and the lower portion 4b does not change relatively before and after the deformation of the buckling pattern preliminary bodies 6 and 6.

  Moreover, the said buckling pattern preliminary body 6 may be a bellows as shown in FIG. 9, and may be made into another shape.

It is a front view which shows roughly the structure of the container which concerns on one embodiment of this invention. It is a top view which shows the structure of the said container roughly. It is a bottom view which shows the structure of the said container roughly. FIG. 2 is an end view taken along line AA in FIG. 1. FIG. 3 is an end view taken along line B-B in FIG. 2. It is a partially cut perspective view which shows the structure of the principal part of the said container roughly. It is a front view which shows roughly the structure of the said container of a pressure reduction state. It is a front view which shows roughly the structure of the modification of the said container. It is a front view which shows roughly the structure of the other modification of the said container.

DESCRIPTION OF SYMBOLS 1 Container body 6 Buckling pattern prior body 7 Upper edge part 8 Lower edge part 9 Valley line 10 Peak line 11 Convex surface 12 Concave surface

Claims (6)

When pressure reduction occurs inside the container body, a buckling pattern preliminary body that changes to a buckling pattern that goes around the outer peripheral surface of the container body and contracts the container body in the axial direction of the container body is provided in the container body. At least one stage is provided , and after the contents are filled and capped, the buckling pattern preliminary body is changed to the buckling pattern due to the reduced pressure generated inside the container body as the contents are cooled. , A synthetic resin container by a biaxial stretch blow molding method .   The buckling pattern preliminary body has a valley line, a peak line, and a convex surface and a concave surface or a convex surface formed between one and the other of the valley line and the peak line, respectively, on the entire circumference of the container. Item 8. A synthetic resin container according to Item 1.   The pre-buckling pattern body includes a plurality of valley lines and ridge lines extending obliquely from the upper edge portion to the lower edge portion between the annular upper and lower edge portions parallel to each other in the axial direction of the container body. Each of the container bodies has an equal interval in the circumferential direction, and the valley line connects the upper end of the ridgeline and the lower end of the two ridgelines adjacent to the ridgeline that is far from the upper end. In addition, one of the surface surrounded by the adjacent valley line, the peak line and the upper edge and the surface surrounded by the adjacent valley line, the peak line and the lower edge becomes a convex surface, and the other is a concave surface. The synthetic resin container according to claim 1, wherein the container is a convex surface.   The synthetic resin container according to claim 3, wherein the two steps of the buckling pattern preliminary bodies in which the direction of the valley line and the peak line are symmetrical are arranged side by side.   The synthetic resin container according to claim 1, wherein the pre-buckling pattern body is a bellows. It is a manufacturing method of the synthetic resin container for manufacturing the synthetic resin container as described in any one of Claims 1-5, Comprising: The said container main body is shape | molded by biaxial stretch blow molding, and the content is filled. A synthetic resin container that changes the buckling pattern preliminary body of the container body in the capped state to the buckling pattern by generating a reduced pressure inside the container body as the contents cool down. Manufacturing method.

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