JP2017109785A - Synthetic resin container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin container which has improved vertical load of a container body portion on which a pressure reduction absorbing panel is formed under a request for reduction in weight and thickness of the container.SOLUTION: A pressure reduction absorbing panel 6 is arranged on a cylindrical panel formation section 40 of a container body portion 4, and a convex rib 8, projects outward of the container along a contour of the pressure reduction absorbing panel 6, is provided on the outer peripheral side of a corner portion positioned on at least one of an upper end or a lower end of the pressure reduction absorbing panel 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a synthetic resin container including a reduced pressure absorption panel that absorbs a pressure change in a container after filling and sealing the contents.

  Conventionally, a synthetic resin container formed by forming a bottomed cylindrical preform using a thermoplastic resin such as polyethylene terephthalate, and then molding the preform into a bottle shape by biaxial stretch blow molding or the like, It is generally used in a wide field as a container containing various beverages.

In addition, when filling a synthetic resin container of this type with a content, a so-called hot pack is also known in which a heat-sterilized content is filled and sealed at a high temperature.
After filling and sealing the contents with a hot pack, the container cooled to room temperature is in a reduced pressure state. Therefore, in the case of a container provided for a hot pack, it generally deforms inside the container with cooling. A plurality of reduced-pressure absorption panels that reduce the volume of the container and absorb the decrease in internal pressure are disposed in the container body along the circumferential direction (see Patent Document 1).

JP 2011-93556 A

  However, in this type of synthetic resin container, attempts have been made to make the container as thin as possible in order to reduce its weight and reduce the cost by reducing the amount of resin used. In recent years, the demand for such thinning has become increasingly severe. And as the container becomes thinner, it has become difficult to ensure the strength of the container. For example, when a load is applied from the vertical direction, it is formed between the vacuum absorption panels adjacent to the circumferential direction of the container body. Buckling deformation is likely to occur on the upper and lower end sides of the column portion (see paragraph [0044] of FIG. 1 and FIG. 1).

  The present invention has been made in view of the above-described circumstances, and in recent years, under the demand for lighter and thinner containers, which have become increasingly severe, the vertical direction of the container body in which the vacuum absorption panel is formed. The object is to provide a synthetic resin container with improved load strength.

  A synthetic resin container according to the present invention is a synthetic resin container having a mouth portion, a shoulder portion, a trunk portion, and a bottom portion, and the trunk portion is provided with a plurality of reduced pressure absorption panels along a circumferential direction. A cylindrical panel forming portion, corner portions at the upper and lower ends of the reduced pressure absorption panel, and the reduced pressure on the outer peripheral side of the corner portion located at least one of the upper end or the lower end of the reduced pressure absorption panel. It is set as the structure which provided the convex-shaped rib which protrudes outside a container along the outline of an absorption panel.

  According to the present invention, sufficient longitudinal load strength can be secured while reducing the weight and thickness of the container.

It is a front view showing an outline of a synthetic resin container according to an embodiment of the present invention. It is an AA end view of FIG. It is a front view which shows the outline of the modification of the synthetic resin containers which concern on embodiment of this invention. It is explanatory drawing which shows the projection of the outline of the decompression absorption panel of the synthetic resin containers which concern on embodiment of this invention. It is a front view which shows the outline of the other modification of the synthetic resin containers which concern on embodiment of this invention. It is explanatory drawing which shows the projection of the outline of the decompression absorption panel of the other modification of the synthetic resin containers which concern on embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  In the present embodiment, the container 1 is formed, for example, by molding a bottomed cylindrical preform by injection molding or compression molding using a thermoplastic resin, and the preform is formed by biaxial stretch blow molding or the like. As shown in FIG. 4, the container is manufactured by molding into a predetermined container shape having a mouth portion 2, a shoulder portion 3, a trunk portion 4, and a bottom portion 5.

  In producing such a container 1, as a thermoplastic resin to be used, any resin capable of blow molding can be used. Specifically, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polylactic acid or copolymers thereof, those blended with these resins or other resins are suitable. It is. In particular, an ethylene terephthalate thermoplastic polyester such as polyethylene terephthalate is preferably used. Further, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene and the like can be used.

  In the example shown in FIG. 1, a screw portion 21 for attaching a lid (not shown) is formed in the mouth portion 2, and the lower end side of the mouth portion 2 is a truncated cone whose diameter increases toward the body portion 4. It is connected to the shoulder 3 of the shape.

  Moreover, the trunk | drum 4 is a site | part which occupies most of the height direction of the container 1, and the six-sided decompression absorption panel 6 is arrange | positioned by the predetermined interval along the circumferential direction at the cylindrical panel formation part 40. FIG. In addition, column portions 7 are formed between the vacuum absorption panels 6 adjacent to each other in the circumferential direction. The container 1 provided with such a body part 4 has a so-called round bottle-like container shape whose cross-sectional shape is rounded as a whole.

  Here, the height direction means a direction orthogonal to the horizontal plane when the container 1 is erected on the horizontal plane with the mouth portion 2 up, and in this state, the vertical, horizontal, vertical and horizontal directions of the container 1 are defined. Shall be defined.

  The panel forming portion 40 may be formed such that its outermost peripheral diameter is constant along the height direction. For example, the outermost peripheral diameter is such that the central portion in the height direction is expanded or recessed. May be formed so as to change along the height direction.

  In the example shown in FIG. 1, bead-shaped annular portions 41 and 42 are provided on the upper end side of the body portion 4 connected to the shoulder portion 3 and the lower end side of the body portion 4 connected to the bottom portion 5. Although the load bearing strength against the load from the lateral direction (the direction perpendicular to the height direction) is increased, these annular portions 41 and 42 can be omitted as appropriate. That is, the trunk | drum 4 should just have the cylindrical panel formation part 40 by which the some decompression absorption panel 6 was arrange | positioned along the circumferential direction.

  In the present embodiment, the reduced pressure absorption panel 6 is bordered by a stepped portion 60 that is recessed from the cylindrical surface of the panel forming portion 40 to form a step along the contour thereof. The panel main body 61 is connected.

  In the present embodiment, the specific shape of the panel body 61 is not particularly limited as long as the reduced pressure absorption panel 6 can exhibit a desired reduced pressure absorption performance. For this reason, in the example shown in FIG. 1, illustration of the specific shape of the panel main body 61 is abbreviate | omitted.

  In the round bottle-shaped container 1 in which a plurality of reduced pressure absorption panels 6 are disposed in the body portion 4 along the circumferential direction, a load is applied to the container 1 from the vertical direction as the container becomes lighter and thinner. And stress concentrates on the upper and lower end side portions of the column portion 7 formed between the decompression absorption panels 6 adjacent to each other in the circumferential direction, that is, the portion connected to the corner portion of the decompression absorption panel 6 of the column portion 7. It tends to be easy to cause the part to become the starting point of buckling deformation.

  Further, in the present embodiment, the reduced pressure absorption panel 6 has a contour with rounded corners at the upper end and the lower end (in the illustrated example, a rounded rectangular contour). When the part is rounded, the lateral width on the upper and lower end sides of the column part 7 formed between the adjacent reduced pressure absorption panels 6 is increased, and the area of the part is increased. For this reason, when molding the container 1, there is a concern that the upper and lower end portions of the column portion 7 are likely to stick to the molding surface of the mold.

  When such sticking to the molding surface occurs, the part that sticks to the molding surface is subjected to a load to peel it off at the time of release, and distortion called sink is generated. Sometimes. Such sinks tend to occur more easily as the container 1 becomes thinner. When sinks occur, not only the appearance of the container 1 is impaired, but also the strength is reduced.

In the present embodiment, in order to avoid these problems, a convex shape that is located on the outer peripheral side of the reduced pressure absorption panel 6 at the corner portion of the reduced pressure absorption panel 6 and projects outward from the container along the outline of the reduced pressure absorption panel 6. Ribs 8 are provided (see FIGS. 1 and 2). By doing in this way, the upper-lower-end part side of the column part 7 becomes difficult to stick to the molding surface of a shaping | molding die, generation | occurrence | production of sink marks can be suppressed, and the strength reduction can be prevented. Furthermore, by providing such convex ribs 8, the strength of the upper and lower ends of the column portion 7 can be improved, and the upper and lower end portions of the column portion 7 when a vertical load is applied to the container 1. The occurrence of buckling deformation on the side can be suppressed, and sufficient longitudinal load strength can be ensured while reducing the weight and thickness of the container 1.
1 is shown in FIG. 2. In FIG. 2, the thickness of the container 1 is omitted, and the cylindrical surface of the panel forming portion 40 is overlapped with the end surface in the circumferential direction. The imaginary line extended to is indicated by a chain line.

  Further, as shown in FIG. 3, such a convex rib 8 is formed from a corner portion located at the upper end of the reduced pressure absorbing panel 6 to a corner portion located at the lower end so that a sufficient longitudinal load strength can be secured. It may be provided so as to extend over the entire range. In such an embodiment, a portion where the convex rib 8 of the mold used for molding the container 1 is molded as a nested structure, and air bleeding during molding is satisfactorily performed from the gap of the nested along the contour of the reduced pressure absorption panel 6. Thus, it is also preferable to make it difficult for molding defects to occur due to air trapped in the mold.

Further, when the contour of the corner of the reduced pressure absorption panel 6 is vertically projected on a plane including the center line S along the height direction passing through the center of the reduced pressure absorption panel 6 and the center axis C of the container 1, The projection has an arc shape curved with a radius of curvature r as shown in FIG. The projection is also a projection of the contour of the part connected to the corner portion of the column portion 7, and the corner portion of the column portion 7 is configured such that the projection has an arc shape curved with a larger radius of curvature. It is possible to alleviate the concentration of stress on the part connected to.
In FIG. 4, the outline of the container 1 is shown by a chain line, and the projection of the outline of the reduced pressure absorption panel 6 is shown by a thick line so as to overlap this, and the arc shape is superimposed on the projection of the outline of the corner of the reduced pressure absorption panel 6. The auxiliary lines are indicated by thin lines.

In order for the projection to have an arc shape that curves with a larger radius of curvature, for example, the corner portion of the reduced pressure absorption panel 6 may be formed as follows.
That is, as shown in FIG. 5, the lateral width of the reduced pressure absorption panel 6 is reduced in the vertical direction by rounding the corner portion, and the position where the lateral width of the reduced pressure absorption panel 6 begins to decrease is defined as the starting edge IP of the corner portion. And the other end of the rounded section of the corner is defined as the end EP. And the corner part of the decompression absorption panel 6 from the reference point RP located in the center of the widthwise direction of the decompression absorption panel 6 on the line segment L orthogonal to the height direction passing through the starting end IP of the corner part, What is necessary is just to form so that the distance d to the periphery which forms an outline may become long gradually toward the terminal end EP from the start end IP of the said corner part, and the outline of the decompression absorption panel 6 corresponding to FIG. 4 at this time The projection of is shown in FIG.

  In addition, as an aspect in which the distance d from the reference point RP to the peripheral edge forming the contour of the corner portion is gradually increased from the start point IP to the end point EP of the corner portion, the distance d is constantly changed and gradually increased. There is also a mode in which the distance d gradually increases for each arbitrary section such that the distance d does not change in a certain section and becomes the same length and becomes longer in the section on the next terminal EP side. included. That is, when the distance d is expressed by a function F (θ) having an angle θ with respect to the line segment L as a variable, a relationship of F (θb) −F (θa) ≧ 0 (where θb> θa) is established. Just do it.

  By doing in this way, the projection of the outline of the corner portion of the reduced pressure absorption panel 6 becomes an arc shape curved with a larger curvature radius R (see FIG. 6), and starts from a portion connected to the corner portion of the column portion 7. It is possible to more effectively suppress the buckling deformation. In order to achieve such an effect satisfactorily, the length Lv of the perpendicular line extending from the end EP of the corner portion to the line segment L perpendicular to the height direction passing through the start end IP of the corner portion is The corner portion is formed by defining the start end IP and the end point EP so that Lv / Lh = 1.05-4 with respect to the length Lh from the start end IP of the corner portion to the reference point RP. Is preferred.

  In forming the corner portion of the reduced pressure absorption panel 6 as described above, in the modification shown in FIG. 5, the end points EP of the left and right corner portions overlap, and the upper end side and the lower end side of the reduced pressure absorption panel 6 are linear. However, the end portions EP of the left and right corner portions may be separated so that linear portions remain on the upper end side and the lower end side of the reduced pressure absorption panel 6. On the other hand, in the modification shown in FIG. 5, the start ends IP of the upper and lower corner portions are separated from each other, and a linear portion remains on the side of the reduced pressure absorption panel 6, but the start ends IP of the upper and lower corner portions overlap. In this way, a straight portion may not be left on the side of the reduced pressure absorption panel 6.

  Further, in the modification shown in FIG. 5, the distance d from the reference point RP to the peripheral edge forming the contour of the corner portion is the same as that of the corner portion of the reduced pressure absorption panel 6. Although it forms so that it may become long gradually toward EP, it can also form similarly only about the corner part located in one of the upper end of the decompression absorption panel 6, or a lower end as needed.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. Nor.

  For example, in the above-described embodiment, an example in which the six-sided vacuum absorption panel 6 is disposed in the trunk portion 4 has been described, but the present invention is not limited to this. The number of panels of the vacuum absorbing panel 6 disposed in the body portion 4 can be appropriately selected in the range of four to eight.

  Further, in the above-described embodiment, the example in which the outline of the vacuum absorbing panel 6 is formed in a rounded rectangular shape with the corners rounded with the rectangle as a base is illustrated and described. The base figure is not limited to a rectangle, but may be a square or an isosceles trapezoid. Further, the vacuum absorbing panel 6 is preferably formed in line symmetry having an axis of symmetry along the height direction, but may have a slight inclination with respect to the height direction. The figure that is the base of the contour of the panel 6 is a parallelogram.

  In the above-described embodiment, an example in which the convex ribs 8 are provided in each of the corner portions of the reduced pressure absorption panel 6 has been described. However, the reduced pressure may be selected according to the balance with the shape of other portions of the container 1. The convex ribs 8 may be provided only in the corner portion located at one of the upper end or the lower end of the absorption panel 6.

  That is, the present invention has corner portions at the upper end and the lower end of the reduced pressure absorption panel 6, and follows the outline of the reduced pressure absorption panel 6 on the outer peripheral side of the corner portion located at least one of the upper end or the lower end of the reduced pressure absorption panel 6. As long as the convex ribs 8 projecting outward from the container are provided, the detailed configuration other than this can be appropriately changed without being limited to the above-described embodiment. Further, the detailed configurations described in the above-described embodiments can be appropriately selected and combined.

  The present invention as described above can be applied to a synthetic resin container including a reduced pressure absorption panel that absorbs pressure changes in the container after filling and sealing the contents.

DESCRIPTION OF SYMBOLS 1 Container 2 Mouth part 3 Shoulder part 4 Trunk part 40 Panel formation part 5 Bottom part 6 Pressure-reduction absorption panel 60 Step part 8 Convex rib

Claims (2)

A synthetic resin container having a mouth, a shoulder, a trunk, and a bottom,
The trunk portion has a cylindrical panel forming portion in which a plurality of reduced pressure absorption panels are arranged along the circumferential direction,
Having a corner at the upper and lower ends of the vacuum absorbing panel;
A synthetic resin characterized in that a convex rib projecting outward of the container along the contour of the reduced pressure absorption panel is provided on the outer peripheral side of the corner portion located at at least one of the upper end and the lower end of the reduced pressure absorption panel. Made container.   The synthetic resin container according to claim 1, wherein the convex rib is provided so as to extend from the corner portion located at the upper end of the reduced pressure absorption panel to the corner portion located at the lower end.

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