JP6415347B2 - Plastic container - Google Patents

Description

  The present invention relates to a synthetic resin container capable of exhibiting high axial load strength.

  Conventionally, various types of synthetic resin containers are 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 beverage container containing a beverage.

And, 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 cost by reducing the amount of resin used, In recent years, so-called aseptic filling, in which the contents are filled in an aseptic state, has been attracting attention instead of the conventional hot filling in which the contents are sterilized by heating (see, for example, Patent Document 1). ).
If aseptic filling is employed as the filling means for the contents, the container is not required to have heat resistance as in the case of hot filling, and therefore it is possible to further reduce the weight and thickness.

JP 2011-230815 A

  However, even if aseptic filling is employed to reduce the weight and thickness of the container, there are concerns about strength problems such as a decrease in axial compressive strength (axial load strength). For this reason, various types of containers have been proposed that reduce the weight and thickness of the container and make it difficult to deform with respect to the load applied from the axial direction. However, the demand for thinner containers today is becoming increasingly severe. There was still room for improvement in order to meet the requirements.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a synthetic resin container capable of exhibiting high axial load strength under the demand for weight reduction and thinning of the container.

  A synthetic resin container according to the present invention includes a mouth, a shoulder, a body, and a bottom, and the body includes a side surface and a chamfered corner that is chamfered so that the cross section is arcuate. A bottle-shaped synthetic resin container formed into a rectangular tube shape having an annular recess formed in the barrel so that the groove depth in the chamfered corner is deeper than the groove depth in the side surface. A cushion portion made of a groove is provided, and longitudinal groove-like vertical ribs extending along the height direction are formed on both edge sides of the chamfered corner portion so as to be separated from the annular concave groove, and in the chamfered corner portion A horizontal groove-like horizontal rib extending along the circumferential direction and having a constant groove depth is formed between the vertical ribs so as to be separated from the vertical rib.

  According to the present invention, while suppressing the deformation of the chamfered corner, the annular groove formed in the body functions as a cushion portion and absorbs the load applied from the axial direction, thereby exhibiting high axial load strength. Can do.

It is a front view showing an outline of a synthetic resin container according to an embodiment of the present invention. It is a top view which shows the outline of the synthetic resin containers which concern on embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. FIG. 6 is an enlarged view of a portion surrounded by a two-dot chain line in FIG. 5. It is an enlarged view of the part enclosed with a dashed-two dotted line in FIG. It is EE sectional drawing of FIG.

  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 using a thermoplastic resin to form a bottomed cylindrical preform by injection molding, compression 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 manufacturing such a container 1, as a thermoplastic resin to be used, any resin capable of forming the container 1 as described above 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.

  The mouth portion 2 is a cylindrical portion in which a screw portion 21 for attaching a lid (not shown) is formed. The mouth portion 2 includes a portion having substantially the same diameter immediately below a support ring 22 generally formed in this type of container, and a shoulder portion formed in a truncated pyramid shape whose diameter increases toward the body portion 4. 3 is connected.

The body part 4 located on the lower end side of the shoulder part 3 is a part formed in a rectangular tube shape that occupies most of the height direction of the container 1, and the corner part in the cross section orthogonal to the height direction is an arc shape. It is chamfered so that it becomes (refer FIG.2 and FIG.3). Thereby, the trunk | drum 4 is formed in the square cylinder shape which has the two sets of side parts 41 which oppose, and the chamfering corner part 42 located between each side part 41, and the container 1 is what is called a square bottle shape. It is a container shape.
The container 1 shown in FIG. 1 is a rectangular bottle-shaped container having a capacity of 500 mL, having an overall height of about 206 mm and a distance between opposing side surface parts 41 of about 60 mm.

  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.

  In the present embodiment, the three annular grooves 6 are formed so as to be substantially evenly arranged along the height direction in the range from the upper end side to the lower end side of the body portion 4. The annular groove 6 is formed such that the groove side surface rises in a V shape from the groove bottom at a predetermined angle θ, and the angle θ formed by the groove side surface is constant (or substantially constant) along the circumferential direction. (See FIGS. 4 to 6).

  Further, in forming the annular groove 6, as shown in FIG. 3, the chamfered corner portion 42 of the body portion 4 is chamfered so that the cross-sectional shape thereof becomes an arc shape with a predetermined radius of curvature. The radius of curvature of the groove bottom of the annular groove 6 in the chamfered corner 42 is made larger than this. Thereby, the annular concave groove 6 is formed so that the groove depth in the chamfered corner portion 42 is deeper than the groove depth in the side surface portion 41.

When a load is applied to the container 1 from the axial direction, such an annular groove 6 functions as a cushion part that elastically deforms so that the angle formed by the groove side surface is narrowed and absorbs the load. It suffices that at least one annular groove 6 is provided in the body portion 4, and the number thereof can be appropriately set according to the required axial load strength. In order to better absorb the load from the axial direction, it is preferable to provide a plurality of annular grooves 6. The annular grooves 6 are provided on each of the upper end side and the lower end side of the body portion 4. It is more preferable to provide one or a plurality of annular grooves 6 between them, and to arrange each of these annular grooves 6 equally (or substantially equally) along the height direction.
Moreover, in order to absorb the load from an axial direction favorably, it is preferable that angle (theta) which the groove | channel side surface of the annular groove 6 makes is 40-65 degrees.
Moreover, it is preferable that the curvature radius of the chamfered corner part 42 in a cross section is 15-21 mm, More preferably, it is 17-21 mm. The radius of curvature of the groove bottom of the annular concave groove 6 at the chamfered corner 42 is preferably 21.5 to 25.0 mm, more preferably 21.5 to 23.5 mm. If the above range is not satisfied, there is a risk that the function as the cushion portion may not be sufficiently exhibited when a load is applied to the container 1 from the axial direction. There is a possibility that it becomes difficult to shape the groove 6 into a desired shape.

In addition, the height of the chamfered corner portion 42 at the both ends in the circumferential direction (in other words, the chamfered corner portion 42 near the boundary between the chamfered corner portion 42 and the side surface portion 41 adjacent in the circumferential direction) is high. Vertical groove-shaped vertical ribs 7 extending along the direction are formed. The vertical rib 7 is formed so that the end thereof is separated from the annular groove 6 without intersecting with the annular groove 6.
Further, between the two vertical ribs 7 formed on the circumferential end edges of the chamfered corner portion 42, a horizontal groove-like horizontal rib 8 extending along the circumferential direction and having a constant groove depth is provided as the vertical rib. In the example shown in the figure, three horizontal ribs 8 arranged at substantially equal intervals along the height direction are formed.

When the load applied to the container 1 from the axial direction is absorbed by the elastic deformation of the annular groove 6, the chamfered corner 42 adjacent to the annular recess 6 is subjected to a stress that causes the container 1 to bulge outward. By forming such vertical ribs 7 and horizontal ribs 8 in the chamfered corner portion 42, the annular concave groove 6 functions as a cushion portion and resists the stress when absorbing the load from the axial direction. Further, it is possible to prevent the chamfered corner portion 42 from being deformed so as to bulge outward from the container.
In order to suppress the deformation of the chamfered portion 42 by forming the vertical rib 7 and the horizontal rib 8 at the chamfered corner portion 42, the separation distance between the vertical rib 7 and the annular groove 6 is 3.0 to 6.0 mm. It is preferable to do this. If the above range is exceeded, deformation of the chamfered corner 42 may not be sufficiently suppressed, and if it is less than the above range, it becomes difficult to shape the vertical rib 7 and the annular groove 6 into a desired shape. There is a risk of it. Moreover, it is preferable that the separation distance of the vertical rib 7 and the horizontal rib 8 shall be 2.5-3.5 mm. If the range is exceeded, deformation of the chamfered corner 42 may not be sufficiently suppressed. If the range is not exceeded, it becomes difficult to shape the vertical rib 7 and the horizontal rib 8 into a desired shape. There is a fear.

In the present embodiment, the vertical rib 7 has a V-shaped groove shape in which the groove side surfaces intersect at the straight groove bottom as shown in the figure in order to better suppress the deformation of the chamfered corner 42. However, it may have a groove shape with a trapezoidal cross section that has a groove bottom portion with a predetermined width and the groove side surface rises from both side edges in the width direction of the groove bottom portion. In order to satisfactorily suppress the deformation of the chamfered corner 42 without impairing the shapeability of the groove shape, the vertical rib 7 has a width w ₁ 2.0 to 4.0 mm and a depth d ₁ . It is preferable to form so that it may become 3-0.6 mm.
On the other hand, as long as the groove depth is constant, the lateral rib 8 may have a groove shape with a V-shaped cross section like the longitudinal rib 7. As described above, it is preferable to have a groove shape with a trapezoidal cross section in which the groove bottom portion has a predetermined width and the groove side surface rises from both side edges in the width direction. In order to satisfactorily suppress the deformation of the chamfered corner 42 without impairing the shapeability of the groove shape, the lateral rib 8 has a width w ₂ 3.0 to 5.0 mm and a depth d ₂ 0. is preferably formed to have a 5～1.5Mm, the width _{w 3} of the groove bottom of the lateral rib 8 is preferably 0.5 to 1.0 mm.
In addition, the number of the horizontal ribs 8 formed between the two vertical ribs 7 is not limited to three, and may be at least one according to the required axial load strength.

  In such a container 1 according to this embodiment, even when a load is applied from the axial direction, the annular concave groove formed in the trunk portion functions as a cushion portion and absorbs the load while suppressing the deformation of the chamfered corner portion. By doing so, a high axial load strength can be exhibited.

  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.

  The present invention as described above can be applied to a bottle-shaped synthetic resin container to increase its axial load strength.

DESCRIPTION OF SYMBOLS 1 Container 2 Mouth part 3 Shoulder part 4 Trunk part 41 Side part 42 Chamfering corner part 5 Bottom part 6 Annular groove 7 Vertical rib 8 Horizontal rib

Claims (6)

A bottle having a mouth part, a shoulder part, a body part, and a bottom part, and the body part is formed in a rectangular tube shape having a side surface part and a chamfered corner part chamfered so as to have a circular cross section. A synthetic resin container of
The body portion is provided with a cushion portion formed of an annular concave groove formed so that the groove depth at the chamfered corner portion is deeper than the groove depth at the side surface portion,
While forming the longitudinal groove-shaped longitudinal rib extending along the height direction on the both edge sides of the chamfered corner portion apart from the annular concave groove,
A synthetic resin characterized in that a transverse groove-shaped transverse rib extending in the circumferential direction and having a constant groove depth is formed between the longitudinal ribs at the chamfered corners and spaced apart from the longitudinal rib. Made container. The synthetic resin container according to claim 1, wherein the annular groove is formed such that a groove side surface rises in a V shape from the groove bottom. A plurality of the cushion portions are provided on the trunk portion,
The synthetic resin container according to claim 1 or 2 , wherein the vertical rib and the horizontal rib are formed between the cushion portions adjacent to each other in the height direction at the chamfered corner portion. While providing the said annular groove on each of the upper end side and lower end side of the said trunk | drum, providing one or some said annular groove between the said annular grooves, Each of the said annular groove is along a height direction. The synthetic resin container according to claim 3 arranged evenly. The synthetic rib container according to any one of claims 1 to 4 , wherein the vertical rib has a width of 2.0 to 4.0 mm and a depth of 0.3 to 0.6 mm. The synthetic rib container according to any one of claims 1 to 5 , wherein the lateral rib has a width of 3.0 to 5.0 mm and a depth of 0.5 to 1.5 mm.

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