JP6069940B2 - Plastic container - Google Patents

Description

  The present invention relates to a synthetic resin container having a bottom shape capable of suppressing the occurrence of problems due to a load applied to a container bottom.

  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.

  In recent years, such synthetic resin containers have been rapidly and widely spread, and accordingly, it is strongly demanded to make the containers thinner. In particular, for those used for relatively large capacity applications, the weight of the container accompanying the increase in size has become a problem, and the cost disadvantage caused by the amount of material resin used. Improvements are also required for resource conservation as environmental measures.

  Then, the present inventor proposed a synthetic resin container in which deformation on the bottom side of the container is suppressed in Patent Document 1 under the demand for such a thin container.

JP 2011-152952 A

The synthetic resin container proposed in Patent Document 1 is such that the bottom side of the container is deformed due to the weight of the contents or the like when filling the contents, and it becomes difficult to erect the container. This is to prevent the occurrence of a serious situation.
However, as a result of further intensive studies by the inventor, it is said that further improvements at the bottom of the container are necessary in order to fully meet the demand for thinning of today's containers that are becoming increasingly severe. I came up with an idea.

  For example, Patent Document 1 shows an example in which legs are provided at the four corners of the bottom of the container. However, in a container having such a configuration, a load applied from the vertical direction is applied to the bottom through the legs provided at the four corners. It is transmitted to the bottom side of the leg and tries to bend the periphery of the leg part greatly. Then, the bottom surface side of the bottom portion is compressed in the circumferential direction and worries such as wrinkles are concerned, especially when the container is boxed and transported, when the wrinkles occur repeatedly on the bottom surface side of the bottom portion due to the vibration, It is also conceivable that the ridges are woven and a protruding part is formed at the bottom, and the container is tilted when the container is erected, and further, a pinhole is generated in the protruding part and the contents leak out.

Therefore, as a result of further studies focusing on the shape of the ground contact portion that receives the load applied to the bottom of the container, the present inventor has completed the present invention.
That is, an object of the present invention is to provide a synthetic resin container provided with a grounding portion that can suppress the occurrence of problems due to the load applied to the bottom of the container under the demand for thinning the container.

A synthetic resin container according to the present invention is a bottle-shaped synthetic resin container provided with a mouth, a shoulder, a trunk, and a bottom, and the trunk is chamfered on a side surface and a corner. together are square tube shape having a chamfered portion comprising, on the bottom side of the bottom portion, the ground portion outer peripheral edge is a polygonal shape similar to the cross-sectional shape perpendicular to the height direction of the lower end of the body portion has, in a position the sides forming the outer edge of the ground portion intersects, overlaps the position, and a first groove which is disposed so as to extend radially outwardly of said bottom, said side It is set as the structure currently formed on the extended line of the ridgeline part formed in the boundary along the height direction of a part and the said chamfering part .

  According to this invention, generation | occurrence | production of the malfunction by the load added to a container bottom part can be suppressed.

It is a front view which shows the synthetic resin container which concerns on embodiment of this invention. It is a bottom view showing a synthetic resin container according to an embodiment of the present invention. It is a principal part perspective view which shows the synthetic resin container which concerns on embodiment of this invention. It is AA sectional drawing of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. It is a bottom view which shows the modification of the synthetic resin containers which concern on embodiment of this invention. It is a principal part enlarged view of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a synthetic resin container according to the present embodiment, FIG. 2 is a bottom view thereof, and FIG. 3 is a perspective view of an essential part thereof.

  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, as shown in FIG. 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 provided in the container 1 is a cylindrical portion in which a screw portion 21 for attaching a lid (not shown) is formed. Further, the mouth portion 2 includes a portion having a substantially the same diameter immediately below a support ring 22 generally formed in this type of container, and a shoulder formed in a truncated pyramid shape whose diameter increases toward the body portion 4. It is connected to part 3.

  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 cross-sectional shape orthogonal to the height direction is substantially the same shape. And it is set as the square shape which chamfered the corner | angular part. Thereby, the trunk | drum 4 is comprised by the two sets of side parts 41 which oppose, and the chamfering part 42 located between each side part 41, and the container 1 is made into what is called a square bottle-shaped container shape. .

  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.

  Moreover, the trunk | drum 4 is divided into the upper trunk | drum 4a and the lower trunk | drum 4b by the waist part 40 formed so that a part of trunk | drum 4 might be narrowed inside a container. Such a waist portion 40 is formed along the circumferential direction of the trunk portion 4 in order to increase the rigidity near the center in the height direction of the container 1. The upper body part 4a and the lower body part 4b divided by the waist part 40 are provided with reduced pressure absorption panels 45a and 45b on the side surface parts 41 respectively. The vacuum absorption panels 45a and 45b are for preventing uneven change in the shape of the container 1 due to a decrease in internal pressure after filling and sealing the contents in the container 1, and according to the required vacuum absorption performance. Various panel shapes can be employed.

  Further, in any of the upper body portion 4a and the lower body portion 4b, the ridge line portion formed at the boundary along the height direction between the adjacent side surface portion 41 and the chamfered portion 42 has a longitudinal groove along the ridge line portion. A ridge line groove 43 is formed. Although the specific form of the ridge line groove portion 43 is not limited, for example, in addition to a groove shape having a V-shaped cross section where the groove side surface intersects at the straight groove bottom portion, the groove bottom portion has a predetermined width, and the groove bottom portion A groove shape having a trapezoidal cross section in which the groove side surface rises from both side edges in the width direction may be used.

  When the corner portion is deformed so that the corner portion is pushed into the container by applying an external force to the corner portion of the body portion 4, the body portion 4 is deformed so that a broken line is generated in a direction perpendicular to the height direction. By forming the ridge line groove portion 43 at the ridge line portion formed at the boundary along the height direction between the adjacent side surface portion 41 and the chamfered portion 42 so as to be orthogonal to the broken line, a restoring force against such a shape change is obtained. It can be exhibited satisfactorily and permanent deformation of the container 1 can be suppressed.

  The bottom portion 5 provided in the container 1 is located on the lower end side of the body portion 4. In the example shown in FIG. 1 and the like, the chamfered portion 42 located between the side portions 41 that are flat is formed inward of the container. The bottom portion 5 is connected to the bottom portion 5 so as to be narrowed down, and a dome-shaped raised bottom portion 50 is formed in the center of the bottom portion 5 on the bottom surface side. Further, the outer periphery of the bottom portion 5 is a polygonal shape (an octagonal shape in the illustrated example) so as to resemble a cross-sectional shape perpendicular to the height direction of the lower end of the body portion 4 at a position surrounding the raised bottom portion 50. More specifically, at the position where the sides forming the outer peripheral edge of the grounding portion 54 intersect, the grounding portion 54 overlaps with the position and extends toward the outside in the radial direction of the bottom portion 5. Specifically, a first groove portion 55 is formed so as to extend on a connecting surface 53 formed between the lower end of the body portion 4 and the grounding portion 54.

  FIG. 4 shows the AA cross section of FIG. 3, and the first groove 55 has an angle α with respect to the horizontal plane of preferably 5 to 40 ° when the container 1 is erected on the horizontal plane. It has a groove bottom portion 55a that rises obliquely, and has a groove side surface 55b that rises from both side edges of the groove bottom portion 55a. The angle formed by the groove bottom 55a and the groove side surface 55b can be 10 to 80 °, and is preferably 30 to 60 ° in consideration of mold opening. Although not particularly illustrated, the first groove portion 55 may have a groove shape with a V-shaped cross section with the groove bottom portion 55a being linear, and the width of the first groove portion 55 can be appropriately changed.

  In addition, the container 1 filled and sealed with the contents is provided with a band-like label made of a heat-shrinkable shrink film and is sold. When the label is attached to the container 1, the bottom surface of the bottom portion 5 is used. It is known to attach a label after the container 1 is centered by negative pressure suction on the side. At this time, the portion in which the first groove portion 55 is formed so as to enhance the stability when the container 1 is erected and to ensure the suction of the negative pressure so that the label can be easily attached. Then, it is preferable that the inner peripheral edge side of the grounding portion 54 is continuous in the circumferential direction without the grounding portion 54 being divided by the first groove portion 55.

  Here, the part surrounded by the alternate long and short dash line in FIG. 2 is enlarged and shown in FIG. 5, and when the container 1 is erected on the horizontal plane, the part that comes into contact with the horizontal plane is shaded. The shaded portion is the grounding portion 54. In the container 1 shown in FIG. 1 and the like, the grounding portion 54 is partly cut away by the first groove portion 55, and the inner periphery of the grounding portion 54 of the portion. On the edge side, the container 1 is formed so as to be in line contact with a horizontal plane in which the container 1 is upright.

  The load applied to the container 1 from the vertical direction is transmitted to the bottom surface side of the bottom portion 5 through the side surface portion 41 and the chamfered portion 42 of the trunk portion 4 and is received by the grounding portion 54. At this time, a force acts to bend the periphery of the grounding portion 54, and there is a concern that this force may cause defects such as compression of the bottom surface side of the bottom portion 5 in the circumferential direction to cause wrinkles. In particular, when the container 1 is packed and transported, if the wrinkles are repeatedly generated on the bottom surface side of the bottom portion 5 due to the vibration, the wrinkles are woven and a protruding portion is generated in the bottom portion 5, and the container 1 is tilted upright. Furthermore, it is conceivable that pinholes are generated in the protruding portion and the contents leak out, and countermeasures against such problems are increasingly required as the container becomes thinner.

  For this reason, in the container 1 shown in FIG. 1 and the like, the grounding portion 54 provided on the bottom surface side of the bottom portion 5 is formed so that the outer peripheral edge has a polygonal shape, and the sides forming the outer peripheral edge of the grounding portion 54 intersect each other. The first groove portion 55 is formed so as to overlap the position and to extend outward in the radial direction of the bottom portion. By doing so, the periphery of the grounding portion 54 that has received the load is deformed so as to be more greatly bent along the height direction, and the force to compress the bottom surface side of the bottom portion 5 in the circumferential direction is reduced. It is possible to prevent defects such as wrinkles on the bottom surface side of the bottom portion 5 by being transmitted through each side forming the outer periphery of the bottom portion 5 and being absorbed by the first groove portion 55.

  At this time, the load transmitted to the bottom surface side of the bottom portion 5 is transmitted through the ridge line portion formed at the boundary along the height direction between the side surface portion 41 and the chamfered portion 42 in particular, so that the first groove portion 55 passes through the ridge line portion. By forming it on the extended line, it is possible to suppress the concentration of the load at the position where the sides forming the outer peripheral edge of the grounding portion 54 intersect.

  Further, when the ridge line groove portion 43 as described above is formed at the ridge line portion formed at the boundary along the height direction between the side surface portion 41 and the chamfered portion 42, the ridge line groove portion 43 and the first groove portion 55 are connected. When the load from the vertical direction is applied to the container 1 and the periphery of the grounding portion 54 is deformed so as to bend along the height direction, the groove bottom of the ridge line groove portion 43 or the first groove portion 55 is outward. There is concern that it will deform so as to protrude and become the starting point of buckling. For this reason, in the container 1 shown in FIG. 1 etc., the discontinuous part 44 is formed between the ridge line groove part 43 and the first groove part 55, and the ridge line groove part 43 and the first groove part 55 are not connected. I am doing so.

  The container 1 shown in FIG. 1 and the like is an example of a container having a capacity of 1 L. In many cases, after filling and sealing contents such as beverages, the container 1 is usually packed in a box of 12 bottles in an A-type carton. Stacked. At this time, the six containers 1 positioned under the inner flaps of the carton are pressed by the inner flaps and receive an axial load. However, the container 1 according to the present embodiment having the grounding portion 54 as described above largely deforms the periphery of the grounding portion 54 along the height direction and deforms to the extent that the connecting surface 53 is grounded to absorb the axial load. It becomes possible, and it can suppress that a wrinkle etc. arise in the bottom part 5 of the container 1 under an inner flap. Further, since the axial load is received in all the containers 1 accommodated after the deformation, the axial load received by each container 1 in the carton is reduced, and as a result, the carton strength is improved.

Further, when the periphery of the grounding portion 54 is deformed so as to bend along the height direction and the force to compress the bottom surface side of the bottom portion 5 in the circumferential direction is dispersed, a part of the dispersed load is Concentrating on each side forming the outer peripheral edge of the grounding portion 54 and between the first groove portions 55 formed at both ends of the side, particularly between the first groove portions 55, thereby A dent may occur in the part.
In order to avoid the occurrence of such a dent, as shown in FIG. 6 between the first grooves 55 formed on both sides of the outer edge of the grounding portion 54 and at both ends of the side. It is preferable to form the second groove 56.
FIG. 6 is a bottom view showing a modification of the synthetic resin container according to the present embodiment.

  Such a second groove portion 56 is formed on at least one side of each side forming the outer peripheral edge of the grounding portion 54 and at both ends of the side, depending on a portion where the dent easily occurs in the grounding portion 54. It can be formed between the first grooves 55 formed. That is, in the example shown in FIG. 6, the four second groove portions 56 on the side surface portion 41 side, together with the first groove portion 55, toward the radially outer side of the bottom portion 5, Although arranged so as to extend on the connecting surface 53 formed therebetween, the arrangement and number of the second groove portions 56 are deformed so that the periphery of the grounding portion 54 is bent along the height direction, When the load applied to the container 1 from the vertical direction is dispersed, as long as the intended purpose of preventing a part of the dispersed load from concentrating and generating a dent in the ground contact portion 54 can be appropriately achieved. Can be changed.

In forming the second groove portion 56, the specific form thereof can be the same as that of the first groove portion 55. Therefore, although not particularly illustrated, the second groove portion 56 allows the container 1 to stand upright on a horizontal plane. The groove bottom portion that rises obliquely at an angle of preferably 5 to 40 ° with respect to the horizontal plane, and the groove side surface that rises from both side edges of the groove bottom portion can be formed. Similarly, the angle formed between the groove bottom and the groove side surface can be set to 10 to 80 °, and is preferably set to 30 to 60 ° in consideration of mold opening. The groove bottom is linear and has a V-shaped cross section. The width of the second groove portion 56 can be changed as appropriate.
Further, when the label is attached to the container 1 as described above, in the portion where the second groove portion 56 is formed, the negative pressure suction can be ensured and the label can be easily attached. Similarly to the first groove portion 55, the inner peripheral edge side of the grounding portion 54 is preferably continuous along the circumferential direction without being divided by the second groove portion 56.

  Here, while enlarging the part surrounded by the alternate long and short dash line in FIG. 6 and showing it in FIG. 7, in this aspect, when the container 1 is erected on the horizontal plane, the part in contact with the horizontal plane is shaded, In the case of forming the second groove portion 56, similarly to the first groove portion 55 described above, a part of the grounding portion 54 is notched by the second groove portion 56, and the container 1 is placed on the inner peripheral side of the grounding portion 54. It is preferable to form such that it is in line contact with an upright horizontal plane.

  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, the container 1 has a cross-sectional shape of the body portion 4 that is a square shape with chamfered corner portions, but the cross-sectional shape of the body portion 4 is a rectangular shape with chamfered corner portions. In addition, it is good also as a container form which has polygonal cross-sectional shapes, such as a regular hexagon and a regular octagon, and various container forms can be employ | adopted in the range which does not impair the effect of this invention.

  The present invention as described above can be applied to a bottle-shaped synthetic resin container to suppress the occurrence of problems due to the load applied to the bottom of the container.

DESCRIPTION OF SYMBOLS 1 Container 2 Mouth part 3 Shoulder part 4 Trunk part 41 Side part 42 Chamfering part 43 Edge line groove part 5 Bottom part 54 Grounding part 55 1st groove part 55a Groove bottom part 55b Groove side part 56 2nd groove part

Claims (6)

A bottle-shaped synthetic resin container having a mouth, a shoulder, a trunk, and a bottom,
The body portion is formed into a rectangular tube shape having a side surface portion and a chamfered portion formed by chamfering the corner portion,
On the bottom surface side of the bottom portion , the outer peripheral edge has a polygonal shape similar to a cross-sectional shape perpendicular to the height direction of the lower end of the body portion ,
A first groove portion disposed at a position where the sides forming the outer peripheral edge of the ground contact portion intersect with each other and extending toward the radially outer side of the bottom portion includes the side surface portion and the side portion. A synthetic resin container formed on an extended line of a ridge line portion formed at a boundary along a height direction with a chamfered portion .   The site | part in which the said 1st groove part was formed WHEREIN: The said grounding part is not parted by the said 1st groove part, but the inner periphery side of the said grounding part is continuing along the circumferential direction. Synthetic resin container. The synthetic resin container according to claim 1 or 2 , wherein a longitudinal groove-shaped ridge line groove portion is formed in the ridge line portion, and a discontinuous portion is formed between the ridge line groove portion and the first groove portion. Said first groove, the synthetic resin container when brought into erected in the horizontal plane, made of a synthetic resin according to claim 1 to 3 having a groove bottom portion inclined at an angle of 5 to 40 ° to the horizontal plane container. A on at least one side among the sides forming the outer edge of the ground portion, according to claim 1 to 4 between the first grooves formed on both ends of the sides, to form a second trench The synthetic resin container described in 1. Wherein in the second portion the groove is formed of, without being separated by the ground portion is the second groove portion, according to claim 5, the inner peripheral edge side of the ground portion is continuous along the circumferential direction Synthetic resin container.

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