JP7454914B2 - plastic bottle - Google Patents

Description

The present invention relates to a plastic bottle with a cylindrical bottom.

When storing a plastic bottle containing a beverage in a frozen state, a buckling phenomenon may occur in which the bottom of the plastic bottle protrudes outward and deforms as the beverage changes from liquid to solid and expands.

In order to prevent this buckling phenomenon, the bottom of conventional plastic bottles for freezing drinks is provided with a structure similar to a petaloid shape. This petaloid-shaped structure is used in pressure-resistant PET bottles for carbonated drinks, and prevents the bottle from deforming by withstanding the internal pressure caused by carbon dioxide gas.

The expansion rate of beverages due to freezing is higher for sugar-free beverages than for sugar-sweetened beverages. With conventional plastic bottles, it is possible to suppress the buckling phenomenon for sugar-sweetened beverages, but it is difficult to suppress the buckling phenomenon for sugar-free beverages. Of course, it is possible to suppress the buckling phenomenon by increasing the amount of resin used in plastic bottles and increasing the overall strength of the plastic bottle, but in line with the recent situation of saving resources and costs, plastic bottles The reality is that there is a need for lighter weight and thinner walls.

Therefore, it is desired to realize a plastic bottle that is less likely to cause buckling when a sugar-free beverage is frozen and stored, while also making the plastic bottle lighter and thinner.

The plastic bottle according to the present invention is a plastic bottle having a cylindrical bottom, and includes a plurality of troughs projecting inward from the side surfaces of the bottom to the bottom surface, and a plurality of grounding parts, and the bottom has a plurality of grounding parts, and has a plurality of grounding parts. The maximum length in the circumferential direction is set to be larger than the maximum length in the circumferential direction of the trough, and the deepest part of the trough is connected from the bottom surface upward to the side surface with an outwardly convex arc. The radius of curvature of the arc of the deepest part of the valley is in the range of 40 mm to 60 mm , the bottom surface is partially spherical inward, and the height from the ground contact part to the center of the bottom surface is in the range of 40 mm to 60 mm. It is characterized by having a diameter of 4 mm to 7 mm and being used for freezing .

By making the deepest part of the plurality of valleys provided at the bottom into a circular arc as in this configuration, the expansion pressure of the beverage during freezing can be easily distributed evenly, and the internal pressure at the time of expansion can be controlled by the plurality of valleys. Since the deepest part is supported as if by a partial spherical surface, the buckling phenomenon is less likely to occur even when freezing a sugar-free beverage with a high expansion rate. Furthermore, since the maximum circumferential length of the grounding part that makes contact with the installation surface such as a desk is set to be larger than the maximum circumferential length of the valley, it does not fall over when being transported by a conveyor etc. Hard to occur.
In addition, according to this configuration, there is no shape called a dome that protrudes into the inside of the bottle, which was provided at the center of the bottom of conventional plastic bottles, so there is no part where stress tends to concentrate, reducing stress concentration. Even if the plastic bottle is dropped, it can withstand the impact and prevents the bottom from cracking .
Further, according to this configuration, since it can be applied to a plastic bottle for freezing, deformation can be suppressed even when frozen, and it is convenient for the user to carry .

In the present invention, it is preferable that the three ground contact portions are provided at approximately equal intervals in the circumferential direction.

By having three ground contact parts as in this configuration, it is possible to secure a wider ground contact area than in the case of the conventional petaloid shape with five ground contact parts, and it is less likely to fall over when being transported by a conveyor etc. This becomes even more difficult to form, and it is also easier to ensure good moldability at the bottom.

In the present invention, it is preferable that a plurality of grooves extending from the side surface to the bottom surface through the grounding part are provided at approximately equal intervals in the circumferential direction in the grounding part.

According to this configuration, sink marks are less likely to occur during molding or sterilization of plastic bottles for the purpose of reducing weight and thinner walls, even when the plastic bottles are intended to be lighter and thinner. can do.

In the present invention, it is preferable that at least one of the plurality of grooves extends to near the center of the bottom surface.

According to this configuration, at least one of the plurality of grooves extends to the vicinity of the center portion of the bottom surface, so that the buckling phenomenon can be made more difficult to occur.

It is a front view of a plastic bottle. FIG. 3 is a bottom view of the bottom of the plastic bottle. FIG. 3 is a vertical cross-sectional view of the bottom taken along arrow line III-III in FIG. 2; FIG. 2 is a side view centered on the valley at the bottom of the plastic bottle. FIG. 3 is a side view centered on the groove at the bottom of the plastic bottle. FIG. 2 is a perspective view of the back side of the bottom of the plastic bottle.

Embodiments of the present invention will be described below based on the drawings.
As shown in FIG. 1, the plastic bottle 1 according to the present embodiment includes a spout 2 serving as a spout for pouring liquid, and a bottle main body 3 filled with liquid.

The bottle main body 3 includes a shoulder 4 that is continuous with the mouth 2 and gradually increases in diameter toward the bottom 60, a cylindrical body 5 that is continuous with the shoulder 4, and the bottom of the plastic bottle 1. It is composed of a cylindrical bottom part 6.

The upper part 50 of the body part 5 is a part that serves as a label pasting area where a roll label is pasted, and is provided with a plurality of reinforcing circumferential grooves 52. The lower portion 51 of the body 5 is formed with an uneven surface 53 having a plurality of curved circumferential grooves for reinforcement, ease of holding the bottle by the user, and design.

In this embodiment, the bottom 6 refers to the portion of the plastic bottle 1 excluding the mouth 2, shoulder 4, and body 5. In this embodiment, the bottom part 6 is from a part slightly above the starting position of the valley part 62 to the ground contact part 64, and the vertical length of the bottom part 6 (from the ground contact part 64 to the boundary between the side surface 61 and the body part 5) is the bottom part 6. For example, the height can be set to 20 mm to 22 mm.

As shown in FIGS. 2, 4, and 5, the bottom 6 has a plurality of valleys 62 that extend inward from the side surfaces 61 of the bottom 6 to near the center of the bottom 60, and is grounded against an installation surface such as a desk. A plurality of grounding portions 64 are provided. In the bottom portion 6 of this embodiment, three grounding portions 64 are provided at approximately equal intervals in the circumferential direction, and a valley portion 62 is provided between two neighboring grounding portions 64 in the circumferential direction.

As shown in FIG. 2, in the bottom portion 6, the plurality of grounding portions 64 are located on the same circumference of the outermost portion of the bottom surface 60. As shown in FIG. The maximum circumferential length L1 of the ground contact portion 64 varies depending on the maximum circumferential length L2 of the valley portion 62, but in this embodiment, as shown in FIG. The length L1 is set larger than the maximum circumferential length L2 of the valley portion 62 (L1>L2).

Note that the shape of the grounding portion 64 is not limited to the shapes shown in FIGS. 2 and 6, and the width in the radial direction thereof may be arbitrarily set as necessary.

As shown in FIG. 3, the deepest part of the valley 62 is connected upwardly from the center of the bottom surface 60 to the side surface 61 by an outwardly convex arc 63. Note that the "upper side" above the center portion of the bottom surface 60 means the side where the mouth portion 2, shoulder portion 4, and body portion 5 are located when viewed from the bottom surface 60 of the plastic bottle 1.

Although the deepest part of the valley part 62 in this embodiment extends to the center part of the bottom surface 60, it is not limited to this structure. The closer the deepest part of the valley part 62 is to the center of the bottom surface 60, the closer it becomes to a spherical shape suitable for dispersing stress, which increases the effect of suppressing the buckling phenomenon. It does not necessarily have to extend to the center of the bottom surface 60.

As shown in FIGS. 3 and 6, the bottom surface 60 in this embodiment has a partially spherical shape that protrudes inward. The deepest part of the valley part 62 is connected from the top of the bottom surface 60 to the side surface 61 of the bottom part 6 by a smooth circular arc 63.

The bottom surface 60 in this embodiment does not have a shape called a dome that protrudes into the inside of the bottle, which was provided at the center of the bottom surface of conventional plastic bottles, so there is no part where stress tends to concentrate, so stress concentration Even if the plastic bottle 1 is dropped, it can withstand the impact and prevents the bottom from cracking.

By making the deepest part of the plurality of troughs 62 provided in the bottom part 6 into an arc 63, the expansion pressure of the beverage during freezing can be easily distributed evenly, and the internal pressure at the time of expansion can be reduced to the deepest part of the plurality of troughs 62. Since it is supported as if by a partial spherical surface (see FIG. 5), the buckling phenomenon is less likely to occur even when freezing a sugar-free beverage with a high expansion rate. Furthermore, since the maximum length L1 in the circumferential direction of the grounding portion 64 that is grounded against the installation surface such as a desk is set larger than the maximum length L2 in the circumferential direction of the valley portion 62, it is difficult to convey the material by a conveyor or the like. It is also less likely to fall over when you move.

As shown in FIG. 3, the height H1 of the valley portion 62 can be set within a range of, for example, 12 mm to 25 mm. If the height H1 of the valley portion 62 is too high, the moldability will deteriorate and the area of the ground contact portion 64 will become small, making it more likely to fall, whereas if the height H1 of the valley portion 62 is too low, the buckling phenomenon will easily occur. , are set after taking these things into consideration. The height H1 of the trough portion 62, which exhibits better effects in terms of moldability, difficulty in tipping over, and the effect of suppressing the buckling phenomenon, is 15 mm to 22 mm, particularly preferably 15 mm to 18 mm.

The radius of curvature of the arc 63 at the deepest part of the trough 62 is in the range of approximately 40 mm (R40) to approximately 60 mm (R60), which is effective against internal pressure and ensures bottle formability. This is desirable.

In addition, by having three ground contact parts 64, it is possible to secure a wider ground contact area than in the conventional petaloid-shaped case where the ground contact parts 64 are five, and it is possible to further prevent the product from falling over when being transported by a conveyor or the like. This is less likely to occur, and it is also easier to ensure good moldability of the bottom portion 6. However, the number of ground-contacting parts 64 is not limited to this configuration, and may be changed as appropriate in consideration of moldability, difficulty in overturning, effect of suppressing buckling phenomenon, etc.

As shown in FIGS. 2 and 4 to 6, three groove portions 65 extending from the side surface 61 of the bottom portion 6 to the bottom surface 60 via the ground contact portion 64 are provided at approximately equal intervals in the circumferential direction in the ground contact portion 64. According to this configuration, when the plastic bottle 1 is molded or sterilized for the purpose of reducing weight and thinning, even if the plastic bottle 1 is intended for weight reduction and thinning, the occurrence of sink marks is prevented. You can make it less likely to happen. The number of grooves 65 is not limited to this configuration, and may be changed as appropriate in consideration of moldability, the effect of suppressing the generation of sink marks, etc., but especially in the case of this embodiment, the number of grooves 65 is In the case of two grooves 65, sink marks are likely to occur, and in the case of four grooves 65, it becomes difficult to obtain good moldability.

As shown in FIGS. 2 and 6, in this embodiment, three grooves 65 are provided at approximately equal intervals in the circumferential direction for one grounding portion 64, and only the middle groove 65 is located at the center of the bottom surface 60. It extends to the vicinity of the part. By extending the groove portion 65 to the vicinity of the center portion of the bottom surface 60, the buckling phenomenon can be made more difficult to occur. All of the plurality of grooves 65 may extend to the vicinity of the center portion of the bottom surface 60, but in consideration of moldability etc., at least one of the plurality of grooves 65 should extend to the vicinity of the center portion of the bottom surface 60. is desirable, and the number of grooves 65 extending to the vicinity of the center portion of the bottom surface 60 may be changed as appropriate while taking these points into consideration.

The circumferential length of the groove portion 65 in this embodiment is set smaller than the maximum length of the trough portion 62 in the circumferential direction.

As shown in FIG. 3, the height H2 of the bottom rise (the height from the ground contact part 64 to the center part of the bottom surface 60) suppresses the buckling phenomenon, provides good bottle formability, and also From the viewpoint of easily preventing cracks, the thickness is preferably 2 mm to 10 mm, and particularly preferably 4 mm to 7 mm.

The liquid to be filled into the plastic bottle 1 of this embodiment is not particularly limited, and examples thereof include beverages such as drinking water, tea, fruit juice, coffee, cocoa, soft drinks, alcoholic beverages, milk drinks, soup, sauce, soy sauce, etc. Examples include liquid seasonings. In particular, in the case of beverages, the plastic bottle 1 of this embodiment can be suitably used even when a sugar-sweetened beverage or a sugar-free beverage is used, and even when a sugar-free beverage is frozen.

Although the plastic bottle 1 of this embodiment can be used for any purpose such as room temperature use, refrigerated use, or frozen use, it is particularly suitable for use in frozen use.

The plastic bottle 1 of this embodiment can be integrally molded using a thermoplastic resin such as polyethylene, polypropylene, or polyethylene terephthalate as a main material by a stretch molding method such as biaxial stretch blow molding. The capacity of the plastic bottle 1 is not particularly limited, and can be approximately 200 ml to 2 liters, which is generally available, and is particularly preferably 250 ml to 1 liter.

In order to save resources and costs, the plastic bottle 1 of this embodiment may be made thinner than those for general beverages. Specifically, the ratio of the amount of resin (g) in the plastic bottle 1 to the full filling capacity (ml) of the plastic bottle 1 is 0.017 to 0.041 (g/ml), more preferably 0.023 to 0. 037 is preferable. If the ratio of the resin amount to the full filling capacity exceeds 0.041 (g/ml), it cannot be said that the bottle is thin and lightweight; ), the wall thickness becomes too thin and it becomes difficult to ensure strength.

It should be understood that the above-described embodiments disclosed in this specification are illustrative in all respects, and the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that modifications can be made as appropriate without departing from the spirit of the present invention.

INDUSTRIAL APPLICATION This invention can be utilized suitably for the plastic bottle for freezing.

1 Plastic bottle 2 Mouth 3 Bottle body 4 Shoulder 5 Body 50 Upper part 51 Lower part 52 Circumferential groove 53 Uneven surface 6 Bottom 60 Bottom 61 Side 62 Trough 63 Arc 64 Grounding part 65 Groove L1 Circumference of grounding part Maximum length in the direction L2 Maximum circumferential length of the trough H1 Height of the trough H2 Height of bottom rise

Claims (4)

A plastic bottle with a cylindrical bottom,
A plurality of troughs protruding inward from a side surface of the bottom portion to a bottom surface, and a plurality of grounding portions, wherein a maximum circumferential length of the grounding portion is set to be larger than a maximum length of the trough in the circumferential direction. and
The deepest part of the valley is connected from the bottom surface upward to the side surface by an outwardly convex arc,
The radius of curvature of the deepest circular arc of the valley is in the range of 40 mm to 60 mm,
A plastic bottle characterized in that the bottom surface has a partially spherical shape that protrudes inward, the height from the grounding part to the center of the bottom surface is 4 mm to 7 mm, and the bottle is for freezing . The plastic bottle according to claim 1, wherein the three ground contact portions are provided at approximately equal intervals in the circumferential direction. 3. The plastic bottle according to claim 1, wherein a plurality of grooves extending from the side surface to the bottom surface through the grounding part are provided at approximately equal intervals in the circumferential direction in the grounding part. 4. The plastic bottle according to claim 3, wherein at least one of the plurality of grooves extends to near a central portion of the bottom surface.

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