JP6756100B2 - Synthetic resin container - Google Patents

Description

The present invention relates to a synthetic resin container in which a plurality of lateral grooves formed in an annular shape along the circumferential direction are provided in the container body.

Conventionally, a container made of synthetic resin, which is formed by forming a bottomed tubular preform using a thermoplastic resin such as polyethylene terephthalate and then molding this preform into a bottle shape by biaxial stretching blow molding or the like. It is generally used in a wide range of fields as a container containing various beverages and the like.

Further, in this type of synthetic resin container, the decrease in internal pressure after the contents are hot-packed is absorbed by providing a plurality of lateral grooves formed in an annular shape along the circumferential direction in the container body. It is also known that the container functions as a decompression absorption structure and prevents buckling deformation of the container against a load from the height direction (vertical load) (see, for example, Patent Documents 1 and 2). ..

Japanese Unexamined Patent Publication No. 2004-262500 JP-A-2009-214895

By the way, in 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 of the container progresses, it becomes difficult to secure the strength of the container.
Further, as the thickness of the container becomes thinner, the surface of the container after molding tends to be distorted, which is generally called sink mark, and when such sink mark occurs, not only the appearance of the container is impaired but also the appearance of the container is impaired. It also causes the strength of the container to decrease.

The present invention has been made in view of the above circumstances, and under the demand for weight reduction and thinning of the container, which has become more and more severe in recent years, the container body is annularly formed along the circumferential direction. In providing the formed plurality of lateral grooves, it is an object of the present invention to provide a synthetic resin container in which the strength thereof, particularly the load-bearing strength against a load from the lateral direction, is increased and the occurrence of sink marks is suppressed.

The synthetic resin container according to the present invention is a synthetic resin container provided with a mouth portion, a shoulder portion, a body portion, and a bottom portion, and is annularly convex along a connecting portion between the shoulder portion and the body portion. Along with providing the portion, a vertical groove that divides the convex portion in the circumferential direction is formed, and the trunk portion is formed in an annular shape along the circumferential direction, and the upper end edge side is formed along the upper end edge. A plurality of ribbed lateral grooves are provided which are connected to the ribs and whose lower end edge side is connected to the lower end side annular ribs formed along the lower end edge, and are higher in the portion partitioned by the ribbed lateral grooves adjacent in the height direction. It bulges continuously or intermittently along the circumferential direction between the lower end side annular rib on the ribbed lateral groove side located at the bottom and the upper end side annular rib on the ribbed lateral groove side located below. there a structure in which at least one of the bulge portion.

According to the present invention, when a plurality of lateral grooves formed in an annular shape along the circumferential direction are provided on the container body, the container body is made lighter and thinner, and the strength of the container, particularly resistance to a load from the lateral direction, is tolerated. It is possible to increase the load strength and suppress the occurrence of sink marks. Further, by providing an annular convex portion along the connecting portion between the shoulder portion and the body portion and forming a vertical groove that divides the convex portion in the circumferential direction, an impact is applied to the connecting portion and the joint portion is crushed. Even if it does, the convex portion exerts a restoring force and can suppress the deformation of the container.

It is a front view which shows the outline of the synthetic resin container which concerns on the reference form of this invention. It is an enlarged view of the main part of FIG. It is a front view which shows the outline of the modification of the synthetic resin container which concerns on the reference form of this invention. It is a front view which shows the outline of the synthetic resin container which concerns on embodiment of this invention.

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

[ Reference form ]
First, the reference form of the present invention will be described.
An example of the present reference form is shown in FIG. 1. The container 1 shown in FIG. 1 includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and the body portion 4 is generally formed in a cylindrical shape. , Has a container shape called a round bottle.
Note that FIG. 2 is an enlarged view of a main part showing an enlarged portion including the alternate long and short dash line in FIG.

In such a container 1, for example, a bottomed tubular preform is formed by injection molding or compression molding using a thermoplastic resin, and the preform is formed into a predetermined container shape by biaxial stretching blow molding or the like. Manufactured by molding.

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, polycarbonate, 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, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene and the like can also be used.

In the present reference embodiment , the body portion 4 is provided with a plurality of lateral grooves 41 (three in the example shown in FIG. 1) formed in an annular shape along the circumferential direction, and these lateral grooves 41 are provided with ribs. It is provided as a lateral groove 41a. In the ribbed lateral groove 41a, the upper end edge side is connected to the upper end side annular rib 41b formed along the upper end edge, and the lower end edge side is connected to the lower end side annular rib 41c formed along the lower end edge. It is formed.

Further, in the example shown in FIG. 1, the body portion 4 has ribs located higher in each of the first annular portion 40a and the second annular portion 40b, which are partitioned by the ribbed lateral grooves 41a adjacent to each other in the height direction. A bulging portion 42 that continuously bulges and extends along the circumferential direction is provided between the lower end side annular rib 41c on the lateral groove 41a side and the upper end side annular rib 41b on the lower ribbed lateral groove 41a side. It is provided.

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

When the contents are sterilized at a high temperature, filled at the same temperature, and sealed. For containers used for hot pack filling, when the contents are filled, sealed, and then cooled to room temperature to reduce the internal pressure of the container. As a decompression absorption structure in which a container is deformed (contracted) in the vertical direction to absorb a decrease in internal pressure, a structure in which a plurality of lateral grooves formed in an annular shape along the circumferential direction are provided in the body is known. There is. The lateral groove functions to suppress buckling deformation by elastically deforming with respect to a load from the height direction, and also functions to increase the load-bearing strength against a load from the lateral direction (lateral load). However, as the weight and wall thickness of the container progress, there is a concern that the strength of the container, particularly the load-bearing strength against a lateral load, cannot be sufficiently secured.
Therefore, in the present reference embodiment , when providing such a lateral groove in the body portion 4, the container 1 is provided with a ribbed lateral groove 41a that is connected to the upper end side annular rib 41b and the lower end side annular rib 41c as described above. Is made thinner so that the load-bearing strength against lateral load can be secured.

Further, as described above, the container 1 can be molded by blow molding, but if a part of the container 1 sticks to the molding surface of the molding mold at the time of molding, the portion is exposed to the molding surface at the time of mold release. A load that attempts to peel it off may be applied, causing distortion called sink marks. Such sink marks tend to occur as the thickness of the container 1 becomes thinner, and if sink marks occur, not only the appearance of the container 1 is impaired, but also the strength of the container 1 is lowered. ..
Therefore, in this reference embodiment , the ribs located higher in the portions (in the example shown in FIG. 1, the first annular portion 40a and the second annular portion 40b) partitioned by the ribbed lateral grooves 41a adjacent to each other in the height direction. A bulging portion 42 that continuously bulges and extends along the circumferential direction between the lower end side annular rib 41c on the side of the lateral groove 41a and the upper end side annular rib 41b on the lower side of the ribbed lateral groove 41a. By providing the above, the portion is prevented from sticking to the molded surface and the occurrence of sink marks is suppressed.

As described above, according to the present reference embodiment, when the plurality of lateral grooves 41 formed in an annular shape along the circumferential direction are provided on the body portion, the container is provided by adopting the above configuration with the lateral grooves 41 as the ribbed lateral grooves 41a. It is possible to increase the strength of the container 1, particularly the load-bearing strength against a load from the lateral direction, and suppress the occurrence of sink marks, while reducing the weight and thickness of 1.

In order to achieve such an effect satisfactorily, the ribbed lateral grooves 41a have a depth of Dg of 1.0 to 4.0 mm and a width of Wg of 2.0 to 12.0 mm at intervals of 7 to 30 mm along the height direction. It is preferable that P is provided, and the upper end side annular rib 41b and the lower end side annular rib 41c are preferably set to a height Hr 0.01 to 0.5 mm and a width Wr 0.5 to 5.0 mm, respectively. If it is less than the above range, the rigidity tends to decrease, and if it exceeds the above range, the shapeability at the time of blow molding tends to be inferior.

Further, in the example shown in FIG. 1, the groove shape of the lateral groove 41 of the ribbed lateral groove 41a is V-shaped, but the present invention is not limited to this. By making the groove shape V-shaped, more resin can be fed between the horizontal grooves 41 during blow molding, and the effect of suppressing the occurrence of sink marks can be enhanced, but it is U-shaped. , A trapezoidal groove shape may be used. Increasing the area of the groove bottom of the lateral groove 41 has the effect of improving the lateral load strength and preventing buckling that occurs at the groove bottom. Therefore, the width of the groove bottom of the lateral groove 41 is appropriately adjusted as necessary. It is also possible.

Further, in the example shown in FIG. 1, in each of the first annular portion 40a and the second annular portion 40b, the lower end side annular rib 41c on the ribbed lateral groove 41a side located at the upper side and the ribbed lateral groove 41a side located at the lower side. Two bulging portions 42 are provided between the bulging portion 42 and the annular rib 41b on the upper end side, but the number of bulging portions 42 provided is not limited to this.
The bulging portion 42 has a height Hb of 0.01 to 0.5 mm and a width of Wb of 0.5 to 5.0 mm, and has an annular rib 41c on the lower end side of the ribbed lateral groove 41a located on the upper side and a ribbed lateral groove located on the lower side. It is preferable to provide the annular rib 41b on the upper end side on the 41a side so as to be closely connected to the annular rib 41b on the upper end side without a gap in the height direction, but there may be a planar gap between the adjacent bulging portions 42. .. If it does not reach the above range, the rigidity tends to decrease and the effect of suppressing the occurrence of sink marks tends to be impaired, and if it exceeds the above range, the shapeability at the time of blow molding tends to be inferior.
Further, in the example shown in FIG. 1, the bulging portion 42 is provided so as to continuously bulge and extend along the circumferential direction, but it is intermittent along the circumferential direction as long as the above-mentioned effect is not impaired. It may be provided so as to bulge and extend.

Further, when the container 1 is filled with the contents, sealed and put on the market, the container 1 is usually attached with various labels indicating the contents. When the label is attached, the ribbed lateral groove 41a is periodically wavy (sinusoidal or cosine wavy) along the circumferential direction in order to prevent the label from biting into the ribbed lateral groove 41a, as shown in FIG. ) May be curved. In this case, it is preferable that each of the upper end side annular rib 41b, the lower end side annular rib 41c, and the bulging portion 42 is also formed by being curved in a wavy shape at the same cycle so as to follow the ribbed lateral groove 41a.

[ Embodiment ]
Next, an embodiment of the present invention will be described.
An example of the present embodiment is shown in FIG. 4. The container 1 shown in FIG. 4 includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and the body portion 4 is formed in a cylindrical shape. A waist portion 40 formed by narrowing a part of the body portion 4 in the radial direction is divided into an upper body portion 4a and a lower body portion 4b.
Note that FIG. 4A is a front view showing an example of the synthetic resin container according to the present embodiment, and FIG. 4B is a bottom view of the same.

In the present embodiment, both the upper body portion 4a and the lower body portion 4b are provided with a plurality of lateral grooves 41 formed in an annular shape along the circumferential direction, but the lateral grooves 41 provided in the lower body portion 4b are provided. The upper end edge side is connected to the upper end side annular rib 41b formed along the upper end edge, and the lower end edge side is provided as a ribbed lateral groove 41a connected to the lower end side annular rib 41c formed along the lower end edge. There is.

Then, in the example shown in FIG. 4, the lower body portion 4b has a first annular portion 40a, a second annular portion 40b, a third annular portion 40c, and a fourth annular portion, which are partitioned by a ribbed lateral groove 41a adjacent in the height direction. In each of the annular portion 40d and the fifth annular portion 40e, between the lower end side annular rib 41c on the ribbed lateral groove 41a side located above and the upper end side annular rib 41b on the lower ribbed lateral groove 41a side. A bulging portion 42 that continuously bulges and extends along the circumferential direction is provided.

In the example shown in FIG. 4, among the six lateral grooves 41 provided in the lower body portion 4b, the lateral groove 41 located at the uppermost position omits the upper end side annular rib 41b, but three. When the above lateral groove 41 is provided as the ribbed lateral groove 41a, either the upper end side annular rib 41b in the ribbed lateral groove 41a located at the highest position or the lower end side annular rib 41c in the ribbed lateral groove 41a located at the lowest position. One may be omitted if necessary. When four or more lateral grooves 41 are provided as the ribbed lateral grooves 41a, the upper end side annular rib 41b in the ribbed lateral groove 41a located at the uppermost position and the lower end side annular rib 41 in the ribbed lateral groove 41a located at the lowest position. Both of 41c may be omitted if necessary.

By doing so, the strength of the container 1, particularly the load-bearing strength against a load from the lateral direction, is increased while the weight and wall thickness of the container 1 are reduced as in the above-described reference form, and sink marks are generated. It can be deterred.
In particular, as in the present embodiment, the container 1 divided into the upper body portion 4a and the lower body portion 4b by the waist portion 40 has a relatively long length in the height direction, and the lower body portion 4b is formed during blow molding. Since the thickness is relatively thin and sink marks are likely to occur, it is preferable to adopt the above configuration with the lateral groove 41 provided in the lower body portion 4b as the ribbed horizontal groove 41a to suppress the occurrence of sink marks.

Further, in the example shown in FIG. 4, the diameter of the lower body portion 4b is larger than that of the upper body portion 4a, and the containers 1 to be conveyed are lower than each other in the manufacturing process of the container 1 and the filling process of the contents. It comes into contact with the body portion 4b, and a lateral load (line pressure) is easily applied to the lower body portion 4b. Even in such a case, it is preferable that the lateral groove 41 provided in the lower body portion 4b is used as the ribbed lateral groove 41a to adopt the above configuration so that the load-bearing strength of the lower body portion 4b with respect to the lateral load can be increased.

Further, in the example shown in FIG. 4, a convex portion 6 is provided along the connecting portion with the shoulder portion 3 on the upper end side of the upper body portion 4a, and the convex portion 6 is formed vertically. It is divided in the circumferential direction by a plurality of vertical grooves 60. By providing such a convex portion 6, for example, even if the container 1 is overturned when being conveyed and the joint portion between the shoulder portion 3 and the upper body portion 4a is impacted and crushed. , The convex portion 6 exerts a restoring force and can suppress the deformation of the container 1.

Further, in the example shown in FIG. 4, the bottom portion 5 has a bottom plate portion 51 located at the center thereof and a peripheral edge portion 52 located around the bottom plate portion 51. The peripheral edge portion 52 is formed with a ground contact portion 522 having an inner slope 522a that rises outward from the container starting from the outer peripheral edge 510 of the bottom plate portion 51 and an outer slope 522b that is continuous with the side surface of the bottom portion 5. Further, a plurality of groove portions 521 extending toward the side surface of the bottom portion 5 are formed in the peripheral edge portion 52 starting from the outer peripheral edge 510 of the bottom plate portion 51, and the ground contact portion 522 is rotated by these groove portions 521. It is divided into multiple parts along the direction. By doing so, for example, when a load from the height direction is applied to the container 1, the bottom portion can be reversibly deformed so that the bottom plate portion 51 is recessed inward of the container.

As a result, not only can the load from the height direction be absorbed to suppress buckling deformation, but also when the load from the height direction is applied while the contents are sealed in the container, the bottom plate portion 51 moves inside the container. Since the bottom portion 5 is deformed so as to be recessed into the container 1, the volume of the container 1 is reduced, and the pressure inside the container is increased accordingly, so that the rigidity against the external force can be secured. Further, such deformation of the bottom portion 5 can also function as a decompression absorption structure that absorbs a decrease in internal pressure after the contents are hot-packed.

Further, in forming the bottom portion 5 as described above and enabling its reversible deformation, sink marks tend to occur on the outer slope 522b of the ground contact portion 522. If sink marks occur on the outer slope 522b of the ground contact portion 522, there is a risk of hindering the reversible deformation of the bottom portion 5. Therefore, in the example shown in FIG. 4, a recess 50 is provided on the outer slope 522 b of the ground contact portion 522. It is formed to suppress the occurrence of sink marks.

Although the present embodiment has been mainly described in terms of differences from the above-described reference embodiment , since the other configurations are the same as those of the above-described reference embodiment , duplicate description will be omitted.

Although the present invention has been described above with reference to preferred embodiments, it goes without saying 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 present invention has been described by giving an example of applying the present invention to a round bottle-shaped synthetic resin container, but the present invention has a so-called square shape having a rectangular or rectangular cross-sectional shape. It can also be applied to bottle-shaped synthetic resin containers.

Further, the container is not limited to a container used for hot pack filling in which a plurality of lateral grooves formed in a ring shape along the circumferential direction are provided as a decompression absorption structure, and the sterilized content liquid is placed in a sterilized container at room temperature in a sterile environment. It can also be applied to a container to be filled aseptically at room temperature, and its capacity is not particularly limited.

That is, in the present invention, the body portion 4 is formed in an annular shape along the circumferential direction, the upper end edge side is connected to the upper end side annular rib 41b formed along the upper end edge, and the lower end edge side is along the lower end edge. A plurality of ribbed lateral grooves 41a connected to the lower end side annular rib 41c formed therein are provided, and in a portion partitioned by the ribbed lateral grooves 41a adjacent in the height direction, the lower end side of the ribbed lateral groove 41a side located above. At least one bulging portion 42 that bulges continuously or intermittently along the circumferential direction is provided between the annular rib 41c and the upper end side annular rib 41b on the lower ribbed lateral groove 41a side. If the convex portion 6 is provided in an annular shape along the connecting portion between the shoulder portion 3 and the body portion 4 and the vertical groove 60 for dividing the convex portion 6 in the circumferential direction is formed , the configuration of other details is configured. Can be appropriately changed without being limited to the above-described embodiment. In addition, the detailed configurations described in the above-described embodiments can be appropriately selected and combined.

The present invention can be applied to a synthetic resin container provided with a plurality of lateral grooves formed in an annular shape along the circumferential direction in the container body.

1 Container 2 Mouth 3 Shoulder 4 Body 40 Waist 40a 1st ring 40b 2nd ring 40c 3rd ring 40d 4th ring 40e 5th ring 41 Horizontal groove 41a Ribbed horizontal groove 41b Upper end side ring rib 41c Lower end side annular rib 5 Bottom 50 Recess 51 Bottom plate 510 Outer peripheral edge 52 Peripheral part 521 Groove part 522 Grounding part 522a Inner slope 522b Outer slope

Claims (5)

A synthetic resin container with a mouth, shoulders, torso, and bottom.
A convex portion is provided in an annular shape along the connecting portion between the shoulder portion and the body portion, and a vertical groove for dividing the convex portion in the circumferential direction is formed.
The trunk is annularly formed along the circumferential direction, the upper end edge side is connected to the upper end side annular rib formed along the upper end edge, and the lower end edge side is formed along the lower end edge. Multiple ribbed lateral grooves are provided to connect to the ribs.
In the portion partitioned by the ribbed lateral groove adjacent in the height direction,
It extends continuously or intermittently along the circumferential direction between the lower end-side annular rib on the ribbed lateral groove side located at the upper side and the upper end-side annular rib on the ribbed lateral groove side located at the lower position. At least one synthetic resin container, characterized in that a bulging portion for. The body portion is divided into an upper body portion and a lower body portion by a waist portion formed by narrowing a part of the body portion in the radial direction.
The synthetic resin container according to claim 1, wherein the ribbed lateral groove and the bulging portion are formed at least in the lower body portion. The synthetic resin container according to claim 2, wherein the upper body portion is provided with a lateral groove formed in an annular shape along the circumferential direction. The synthetic resin container according to any one of claims 1 to 3, wherein the ribbed lateral groove is periodically curved in a wavy shape along the circumferential direction. The bottom portion has a bottom plate portion located at the center of the bottom portion and a peripheral edge portion located around the bottom plate portion.
The peripheral edge portion is formed with a ground contact portion having an inner slope that rises outward from the container starting from the outer peripheral edge of the bottom plate portion and an outer slope that is continuous with the side surface of the bottom portion.
By forming a plurality of grooves extending toward the side surface of the bottom portion from the outer peripheral edge of the bottom plate portion on the peripheral edge portion, the ground contact portion is divided into a plurality of portions along the circumferential direction.
The synthetic resin container according to any one of claims 1 to 4, wherein a recess is formed on the outer slope of the ground contact portion.

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