JP7069553B2 - Synthetic resin container - Google Patents

Description

The present invention relates to a synthetic resin container having improved impact resistance against a lateral impact of the shoulder of the container.

Conventionally, using a thermoplastic resin such as polyethylene terephthalate, a bottomed tubular preform is produced by injection molding or compression molding, and this preform is molded into a bottle shape by biaxial stretching blow molding. The manufacturing container is used in a wide range of fields as a container containing various beverages, various seasonings and the like as a content liquid.

For this type of synthetic resin container, attempts have been made to make the container as thin as possible in order to reduce the weight and cost by reducing the amount of resin used. In recent years, the demand for such thinning has become more and more strict, and as the thinning progresses, the rigidity of the container decreases, and the shape of the container becomes indefinite due to the collapse due to the impact applied from the outside. Appearance defects are likely to occur due to deformation.

Under such circumstances, for example, according to Patent Document 1, by providing the shoulder portion with a wall surface formed by a plurality of curved surfaces, the tangents of the curved surfaces play the role of vertical ribs to form a thin-walled bottle. It is said that the strength of the shoulder can be maintained even in some cases.

Japanese Patent Application Laid-Open No. 2003-104343

By the way, when the molded container is filled with the content liquid, for example, air may be blown onto the container suspended from the guide rail so that the container is slid in a forward leaning posture. In this case, the container transported later collides with the container transported first and stands by, and stops, but at that time, a lateral impact is applied to the shoulder of the container (see FIG. 8). ..
In addition, when a container filled with beverages is packed in a box and loaded on a loading platform such as a truck for transportation, the vibration causes the adjacent containers to collide with each other in the box. Impact from the lateral direction is applied.

With respect to such an impact from the lateral direction, sufficient impact resistance cannot be obtained simply by providing the shoulder with a wall surface formed by a plurality of curved surfaces as in Patent Document 1, and further thinning is promoted. There was still room for improvement in order to prevent the shoulder of the container from collapsing due to lateral impact.

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 having improved impact resistance against an impact applied laterally to the shoulder of the container.

The synthetic resin container according to the present invention includes a mouth portion, a shoulder portion, a body portion, and a bottom portion, the shoulder portion includes a hem portion on the lower end side of the shoulder portion, and the hem portion has a vertical cross section. It curves outward in a convex arc shape and is connected to the body, and the shoulder is continuous with the hem while expanding its diameter toward the body, and the vertical cross section of the shoulder is the hem. The position where the arc-shaped vertical cross section of the portion begins to bend with the radius of curvature is defined as the upper end edge of the hem portion, and a plurality of grooves extending radially from the center side of the container toward the outer peripheral edge side are formed on the shoulder portion. The end of the groove portion protrudes beyond the upper end edge of the hem portion and does not exceed the outer peripheral edge of the hem portion.

According to the present invention, even if an impact from the lateral direction is applied to the shoulder portion of the container, the shoulder portion of the container does not collapse and its deformation can be suppressed.

It is a front view which shows the outline of embodiment of the synthetic resin container which concerns on this invention. It is a top view which shows the outline of the embodiment of the synthetic resin container which concerns on this invention. It is sectional drawing of the main part of the embodiment shown in FIG. It is explanatory drawing which shows the cross section orthogonal to the extending direction of the groove part in embodiment of the synthetic resin container which concerns on this invention. It is a front view which shows the outline of the modification of the embodiment of the synthetic resin container which concerns on this invention. It is a top view which shows the outline of the modification of the embodiment of the synthetic resin container which concerns on this invention. It is explanatory drawing which shows the cross section orthogonal to the extending direction of the groove part in the modification of the embodiment of the synthetic resin container which concerns on this invention. It is explanatory drawing which shows an example of the transport method of a container.

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

The container 1 according to the present invention includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5. In the container 1 illustrated as an embodiment of the present invention, the body portion 4 is formed in a cylindrical shape. , Generally, it has a container shape called a round bottle.
Note that FIG. 1 is a front view showing an outline of the container 1 according to the present embodiment, and FIG. 2 is a plan view of the same.

Here, in the present invention, when the container 1 is erected on a horizontal plane with the mouth portion 2 facing up, the direction orthogonal to the horizontal plane is defined as the height direction, and in this state, the container 1 is up, down, left, and right. And specify the vertical and horizontal directions.

The container 1 is manufactured by molding a bottomed tubular preform by injection molding or compression molding using a thermoplastic resin, and molding this preform into a predetermined container shape by biaxial stretch blow molding or the like. Will be done.

As the thermoplastic resin used in manufacturing the container 1, any resin capable of blow molding can be used. Specifically, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, acrylic polyarylate, polylactic acid or copolymers thereof, and those blended with these resins or other resins are preferable. Is. In particular, ethylene terephthalate-based thermoplastic polyesters such as polyethylene terephthalate are preferably used. Further, polycarbonate, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene and the like can also be used.

The mouth portion 2 is a cylindrical portion that serves as an injection outlet for the content liquid. A screw thread 21 for attaching a lid (not shown) is provided on the side surface of the mouth portion 2 on the opening end side, and a neck ring 22 projecting in an annular shape along the circumferential direction is provided below the screw thread 21. ing. Then, the mouth portion 2 includes a portion that hangs down in a cylindrical shape with substantially the same diameter from directly below the neck ring 22.

The shoulder portion 3 is a portion that is connected to the lower end of the mouth portion 2 and expands in diameter toward the body portion 4 to connect between the mouth portion 2 and the body portion 4, and begins to expand in diameter toward the body portion 4. The position is the upper end edge UE3 of the shoulder portion 3, and is shown by a chain line in FIG.
Further, the shoulder portion 3 includes a hem portion 30 having a vertical cross section curved outward in a circular arc shape and connected to the body portion 4 on the lower end side thereof, and gradually expands in diameter toward the body portion 4. However, it is continuous with the hem 30.

3 is a cross-sectional view of a main part of the container 1 shown in FIG. 2, in which the main part of the AA cross section of FIG. 2 is on the right side of the figure and the main part of the BB cross section of FIG. 2 is on the left side of the figure. In FIG. 3, the wall thickness of the portion located below the neck ring 22 is omitted.

In the present embodiment, the shoulder portion 3 is formed in a substantially truncated cone shape. Then, the diameter of the generatrix is expanded so as to change in the middle and is continuous with the hem portion 30, but the diameter of the generatrix is increased so as to be continuous with the hem portion 30 so that no significant change is observed. You may do so. Further, the diameter of the generatrix may be expanded so as to be linear so as to be continuous with the hem portion 30, or the generatrix may be expanded so as to draw a gentle arc so as to be continuous with the hem portion 30. However, it is preferable that the inclination angle (angle with respect to the horizontal plane in which the container 1 is upright) is in the range of 40 ° to 55 ° at least in the portion immediately before continuing to the hem portion 30.

Further, the hem portion 30 is preferably formed so that the radius of curvature R of the vertical cross section thereof is substantially constant, and the vertical cross section of the shoulder portion 3 begins to bend with the radius of curvature R of the vertical cross section of the hem portion 30. The position is the upper end edge UE 30 of the hem portion 30, and is shown by a chain line in FIGS. 2 and 3. The radius of curvature R of the vertical cross section of the hem portion 30 is preferably 4 mm to 10 mm in order to enhance the impact resistance of the shoulder portion 3 from the lateral direction, and in the present embodiment, the vertical cross section of the hem portion 30. The radius of curvature R of is 7 mm.

The body portion 4 occupies most of the height direction of the container 1, and the lower end thereof is connected to the bottom portion 5. Since the specific forms of the body portion 4 and the bottom portion 5 are not particularly limited, detailed description thereof will be omitted.

In the present embodiment, the shoulder portion 3 is formed with a plurality of groove portions 31 extending radially from the container center side to the outer peripheral edge side, and each groove portion 31 is close to the upper end edge UE 3 of the shoulder portion 3. It is formed so as to extend to the surface of the shoulder portion 3 starting from the position where the shoulder portion 3 is formed. By locating the start end of the groove portion 31 above the shoulder portion 3, the vertical compressive strength of the shoulder portion 3 can be increased, but if the portion that becomes the starting point of deformation due to the vertical compression can be reinforced, the position of the start end of the groove portion 31 will be. Not particularly limited.

Further, in the present embodiment, the end of the groove portion 31 is located at a position protruding beyond the upper end edge UE 30 of the hem portion 30. Then, each groove portion 31 is formed so as to extend to such a position along the inclination of the portion immediately before the hem portion 30 and project from the upper end edge UE 30 of the hem portion 30 . At the same time , the end of the groove portion 31 protruding beyond the upper end edge UE 30 of the hem portion 30 does not exceed the outer peripheral edge of the hem portion 30 in order to prevent deformation such that the groove portion 30 is bent due to a direct impact. I am trying to be in .

By doing so, when an impact from the lateral direction is applied to the shoulder portion 3, the groove portion 31 formed in the shoulder portion 3 acts to suppress deformation due to the impact, and the vertical cross section of the hem portion 30. Due to the synergistic effect of forming the shoulder portion 3 so as to be curved outward in a convex arc shape, the impact resistance to the lateral impact of the shoulder portion 3 is enhanced, and the impact from the lateral direction is applied to the shoulder portion 3. Even if it is added, the deformation of the shoulder portion 3 can be suppressed without being depressed.

In order to ensure sufficient strength against impact in order to achieve such an effect more effectively, the groove width w of the groove portion 31 is 1.5 mm to 2.5 mm on the terminal side thereof. The groove depth d of the groove portion 31 is preferably 0.25 mm to 0.65 mm on the terminal side thereof.
Further, a cross section orthogonal to the extending direction of the groove portion 31 is shown in FIG. 4, but as shown in the drawing, the cross section orthogonal to the extending direction of the groove portion 31 may be formed in a V shape, and is necessary. Depending on the situation, the cross section may be formed into a U-shape, a U-shape, or the like.

In forming the plurality of groove portions 31 radially on the shoulder portion 3, it is preferable that the grooves 31 adjacent to each other in the circumferential direction are closely spaced within a range in which the shapeability is not impaired, and the examples shown in FIGS. 1 and 2 are shown. Then, the groove portions 31 are formed so as to be closely adjacent to each other, with the angle θ formed by the center lines of the groove portions 31 adjacent to each other in the circumferential direction being about 4.5 °.

Further, the groove portions 31 can be formed at regular intervals in the circumferential direction, and in the examples shown in FIGS. 5 and 6, the angle θ formed by the center line of the groove portions 31 adjacent in the circumferential direction is set to about 7.2 °. However, the spacing between the groove portions 31 adjacent to each other in the circumferential direction is preferably formed so that at least two groove portions 31 are present in a range in which the impact from the lateral direction is concentrated and received.
Note that FIG. 5 is a front view showing an outline of a container 1 according to a modified example of the present embodiment, and FIG. 6 is a plan view of the same. Further, FIG. 7 is an explanatory view showing a cross section orthogonal to the extending direction of the groove portion 31 in this modified example.

For example, in the present embodiment, assuming that the internal volume of the container is 500 ml, the peripheral length of the maximum outer diameter portion of the shoulder portion 3 is about 217 mm, and the length along the circumferential direction of the portion that receives the impact from the lateral direction in a concentrated manner. Assuming that the diameter is about 24 mm, the central angle of the portion is about 40 °.
In consideration of these facts, the angle θ formed by the center lines of the groove portions 31 adjacent to each other in the circumferential direction is preferably 2.5 ° to 20 °.

Further, in forming the plurality of groove portions 31 radially, in the present embodiment, the groove portions 31 are formed at equal angular intervals, but the intervals may be different as necessary. In this case, the intervals of the groove portions 31 adjacent to each other in the circumferential direction may be alternately sparse and dense along the circumferential direction, and some of the groove portions 31 are sparsely formed from the densely formed portion. It may be mixed with the existing part. Further, the angle θ formed by the groove portions 31 adjacent to each other in the circumferential direction may be periodically changed along the circumferential direction, but in any of the embodiments, the balance with the overall shape of the container 1 is taken into consideration. Therefore, it is preferable to appropriately adjust the angle θ formed by the center lines of the groove portions 31 adjacent in the circumferential direction within the above-mentioned range so that the groove portions 31 are formed in a rotationally symmetric arrangement with the center of the container as the axis of symmetry.

Although the present invention has been described above with reference to preferred embodiments, it is needless to say that 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, the container 1 having a container shape called a round bottle is illustrated and described, but the illustrated example merely shows a preferred embodiment of the present invention. The container shape to which the present invention is applied is not limited to the one shown in the figure. INDUSTRIAL APPLICABILITY The present invention has a technical feature in the form of the shoulder portion 3 in a synthetic resin container provided with a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and a specific form of a portion other than the mouth portion 3. Can be changed as needed.

That is, the present invention includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and the shoulder portion 3 is connected to the body portion 4 with a vertical cross section curved in an arc shape in which the vertical cross section is convex outward of the container. A plurality of groove portions 31 including the hem portion 30 and extending radially from the container center side to the outer peripheral edge side are formed on the shoulder portion 3 extending at least to a position reaching the upper end edge UE 30 of the hem portion 30. Therefore, the configuration of other details can be appropriately changed without being limited to the above-described embodiment. Further, it is also possible to appropriately select and combine the detailed configurations described in the above-described embodiment.

1 Container 2 Mouth 3 Shoulder 30 Hem 31 Groove 4 Body 5 Bottom UE30 Hem top edge

Claims (3)

With mouth, shoulders, torso, and bottom,
The shoulder includes a hem on the lower end side of the shoulder .
The hem portion is curved in an arc shape whose vertical cross section is convex outward of the container and is connected to the body portion.
The hem is a position where the shoulder portion continues to the hem portion while expanding its diameter toward the body portion, and the vertical cross section of the shoulder portion begins to bend with the radius of curvature of the arcuate vertical cross section of the hem portion. As the upper edge of the part
A plurality of grooves extending radially from the center side of the container to the outer peripheral edge side are formed on the shoulder portion.
A container made of synthetic resin, wherein the end of the groove portion protrudes beyond the upper end edge of the hem portion and does not exceed the outer peripheral edge of the hem portion. The synthetic resin container according to claim 1, wherein the starting end of the groove portion is close to the upper end edge of the shoulder portion. The synthetic resin container according to claim 1 or 2, wherein the angle formed by the center line of the groove adjacent to the circumferential direction is 2.5 ° to 20 °.

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