JP2018104062A - Plastic bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic bottle which maintains high strength against decompression while increasing a neck ratio of a neck portion.SOLUTION: A plastic bottle (1) comprises a drum portion (4) including a neck portion (6) having contracting diameter portions (61) with its diameter contracting toward inner sides of its axial direction disposed on both axial ends of the neck portion, as well as a straight portion (62) formed between the contracting diameter portions (61) and extending in parallel to the axial direction. The neck portion (6) is formed with a plurality of radially recessed elongated oval portions (63) aligned along the peripheral direction of the drum portion (4). When each of diameters at both ends of the neck portion (6) is represented as a first diameter, and a diameter of the straight portion (62) is represented as a second diameter, (the first diameter-the second diameter)/(the first diameter)≥0.1 is to be satisfied. The contracting diameter portion (61) has an arc-shape, and a length of each of the contracting diameter portions (61) satisfies an equation: 0.25≤(the first diameter-the second diameter)/(the length of the contracting diameter portion (61))≤0.50. The length of the axial direction of the straight portion (62) is to be a half or less of an axial length of the neck portion (6).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plastic bottle having a cylindrical body.

  In recent years, aiming at a design effect, for example, as in Design Registration No. 1216509 (Patent Document 1), a diameter-reduced portion that is reduced in diameter toward the inner side in the axial direction is formed on both sides in the axial direction. A plastic bottle in which a constricted portion simulating a bamboo is provided in a trunk portion by forming a straight portion extending in parallel with the axial direction between the portions is used.

Design registration No. 1216509

  In such a bottle having a constricted portion, the larger the constriction ratio ((maximum diameter−minimum diameter) / maximum diameter) of the constricted portion, the more characteristic the bottle as a whole, and the more easily a user's eyes are drawn. However, if the squeezing rate is increased aiming at the design effect, the rate of change of the diameter at the reduced diameter portion increases, stress tends to concentrate on the boundary portion between the reduced diameter portion and the straight portion, and against the vertical load. There was a problem that the strength of the constricted portion was lowered.

  In addition, bottles having such a constricted portion have been mainly used in a volume of 500 ml, but in recent years, attempts have been made to provide the constricted portion as described above even for a relatively small-capacity bottle of 400 ml or less. . And, when trying to increase the constriction rate with such a relatively small capacity bottle, the diameter change rate at the reduced diameter portion is large because the axial length is smaller than the large capacity bottle. The strength of the constricted part against the vertical load is further reduced.

  Therefore, it is desired to realize a plastic bottle that can be suitably used for a small-capacity bottle and can maintain a high strength against a vertical load while increasing the constriction rate of the constricted portion.

The plastic bottle according to the present invention is
A plastic bottle having a cylindrical body,
The body portion is provided with a reduced diameter portion that decreases in diameter toward the inner side in the axial direction on both sides in the axial direction, and a constriction is formed between the reduced diameter portions that extends in parallel with the axial direction. Part is provided,
A plurality of radially recessed panels are formed side by side in the circumferential direction of the body portion in the constricted portion,
When the diameter at both ends of the constricted portion is the first diameter and the diameter at the straight portion is the second diameter, (first diameter−second diameter) / first diameter ≧ 0.1 is satisfied,
The reduced diameter portion is arcuate, and the length of each reduced diameter portion satisfies 0.25 ≦ (first diameter−second diameter) / the length of the reduced diameter portion ≦ 0.50,
The length of the straight portion in the axial direction is not more than half of the length of the constricted portion in the axial direction.

  According to this configuration, first, a plurality of panels are formed in the circumferential direction so as to absorb reduced pressure by the panels. And since the reduced diameter part is lengthened by making the length in the axial direction of the straight part half or less of the length in the axial direction of the constricted part, the constriction rate ((first diameter−second diameter) / first 1 diameter) is set to a large value of 0.1 or more, but the constriction degree ((first diameter−second diameter) / length of the reduced diameter portion) is reduced to 0.25 to 0.50 in each reduced diameter portion. The change in diameter at the diameter portion can be moderated. Thereby, stress concentration at the boundary portion between the reduced diameter portion and the straight portion can be effectively suppressed. As described above, the panel concentrates the stress at the boundary between the reduced diameter portion and the straight portion while absorbing the reduced pressure, so that the overall narrowness is achieved while increasing the constriction rate of the constricted portion. High strength against load can be maintained. In addition, according to this configuration, a small-diameter bottle with a small axial length can have a long diameter-reduced portion, and the diameter change at the reduced-diameter portion can be moderated. However, it can be suitably used.

  Hereinafter, the suitable aspect of the plastic bottle which concerns on this invention is demonstrated. However, the scope of the present invention is not limited by the preferred embodiments described below.

  As one aspect, it is preferable that the ratio of the length of the panel in the vertical direction with respect to the total length of the bottle is 0.20 to 0.50.

  According to this structure, the effect of the reduced pressure absorption by a panel can be suitably acquired because the ratio of the length of the panel in the up-down direction is 0.20 to 0.50.

  As one aspect, it is preferable that one or more concave peripheral ribs are provided above and below the constricted portion.

  According to this configuration, the vacuum absorption by the panel unit is performed by the movement of the panel unit, but the panel unit is more easily moved by providing the peripheral ribs that are difficult to move above and below the panel unit. Thereby, reduced pressure can be absorbed more effectively by the panel part.

  As one aspect, provided with a shoulder portion that expands toward the lower side in the axial direction on the upper side of the body portion, and a protruding portion that protrudes toward the outside of the bottle is formed on the shoulder portion. Is preferred.

  According to this configuration, the strength of the bottle can be increased by the protruding portion.

  As one aspect, it is preferable that the protrusion has an arc shape and an average curvature is 10 or more.

  According to this structure, the intensity | strength of a protrusion part can be effectively raised because a protrusion part is arc-shaped and an average curvature shall be 10 or more.

  As one aspect, the capacity is preferably 200 to 500 milliliters.

  If the bottle has a capacity of 200 to 500 ml, the design effect obtained by the present invention can be obtained more effectively.

  As one aspect, it is suitable that it is thin.

  That is, in a thin plastic bottle, a decrease in strength becomes a problem. However, the plastic bottle according to the present invention that can maintain high strength can be suitably used for a thin plastic bottle.

Front view of plastic bottle

  An embodiment of a plastic bottle according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the plastic bottle 1 according to the present embodiment includes a mouth 2 as a liquid spout, a shoulder 3 that is continuous with the mouth 2 and gradually increases in diameter toward the bottom surface, The cylindrical body 4 is continuous with the shoulder 3, and the bottom 5 is the bottom of the plastic bottle 1. And the plastic bottle 1 which concerns on this embodiment is provided with the constriction part 6 made into the shape which simulated the bamboo in the trunk | drum 4 in order to aim at the design effect. Specifically, the constricted portion 6 includes reduced-diameter portions 61 that are reduced in diameter toward the inner side (vertical direction intermediate portion) in the axial direction (vertical direction in FIG. 1) on both sides in the axial direction. A straight portion 62 extending in parallel with the axial direction is formed between 61. Hereinafter, the plastic bottle 1 according to the present embodiment will be described in detail.

  First, the plastic bottle 1 of this embodiment can be integrally molded by a stretch molding method such as biaxial stretch blow molding, using, for example, a thermoplastic resin such as polyethylene, polypropylene, or polyethylene terephthalate as a main material. The capacity of the plastic bottle 1 is not particularly limited, and can be about 200 ml to 2 liters that are generally distributed. In particular, the plastic bottle 1 has a relatively small capacity of 200 to 500 ml, preferably 200 to 400 ml. In this embodiment, the capacity is 350 ml. Moreover, the liquid with which the bottle 1 is filled is not particularly limited. For example, beverages such as drinking water, tea, fruit juice, coffee, cocoa, soft drinks, alcoholic beverages, milk beverages, soups, and liquid seasonings such as sauces and soy sauces. Fees.

  Further, the plastic bottle 1 of the present embodiment is made thinner than that for general beverages in order to save resources and costs. For example, in the present embodiment, the amount of resin in the plastic bottle 1 is preferably 20 g or less, more preferably 15 g or less with respect to a capacity of 350 ml (367.1 ml in a full capacity) (in other words, plastic The ratio of the resin amount (g) of the plastic bottle 1 to the full injection capacity (ml) of the bottle 1 is preferably 0.054 (g / ml) or less, and more preferably 0.041 or less.

  Next, the constricted part 6 of the plastic bottle 1 according to the present embodiment will be described. First, in the present embodiment, the constricted portion 6 is formed with a plurality of (63 in the present embodiment) equidistantly arranged panels 63 recessed in the radial direction along the circumferential direction of the body portion 4. To absorb. Further, a concave groove 63a extending in the axial direction is provided at the center portion in the circumferential direction of each panel 63 in order to increase the strength of the panel 63. Further, the ratio of the length of the panel 63 in the vertical direction with respect to the total length of the bottle is 0.20 to 0.50 (for example, in this embodiment, the length of the panel 63 is 50 mm and the total length of the bottle is 159 mm. The ratio is approximately 0.31). If this ratio is less than 0.20, the panel is too short to obtain a sufficient effect of absorbing vacuum, and if this ratio exceeds 0.50, the panel 63 is too long and the constricted portion 6 This is because the strength decreases.

  In the present embodiment, when the constricted portion 6 has a diameter at both ends of the constricted portion 6 (that is, a maximum diameter of the constricted portion 6) as a first diameter and a diameter at the straight portion 62 as a second diameter ( (First diameter−second diameter) / first diameter ≧ 0.1. For example, in this embodiment, the first diameter is 67.5 mm, the second diameter is 60.7 mm, and (first diameter−second diameter) / first diameter is approximately 0.101.

  In the present embodiment, the length of the straight portion 62 in the axial direction is not more than half the length of the constricted portion 6 in the axial direction (for example, in the present embodiment, the length of the constricted portion 6 is about 67 mm. Yes, the length of the straight portion 62 is about 20 mm, which is half or less of that).

  Furthermore, in the present embodiment, the reduced diameter portion 61 is arcuate, and the length of the straight portion 62 in the axial direction is not more than half the length of the constricted portion 6, so that the axis of each reduced diameter portion 61 is reduced. Each of the lengths in the direction satisfies 0.25 ≦ (first diameter−second diameter) / length of the reduced diameter portion ≦ 0.50. Note that the length of the reduced diameter portion 61 is 18 mm to 35 mm, and preferably 20 mm to 30 mm. For example, in this embodiment, the length of the lower reduced diameter portion 61 in the axial direction is about 21 mm. The length of the upper reduced diameter portion 61 in the axial direction is about 26 mm. In this case, the length of the (first diameter−second diameter) / reduced diameter portion is approximately 0.32 in the lower reduced diameter portion 61 and approximately 0.26 in the upper reduced diameter portion 61. Yes.

  As described above, since the reduced diameter portion 61 is lengthened so that the length of the straight portion 62 in the axial direction is equal to or less than half of the length of the constricted portion 6 in the axial direction, the constriction rate ((first diameter−second diameter)). / First diameter) is set to a large value of 0.1 or more, but the constriction degree ((first diameter−second diameter) / length of the reduced diameter portion) is 0.25-0. 50, the change in diameter at the reduced diameter portion 61 is moderated. Thereby, stress concentration at the boundary portion between the reduced diameter portion 61 and the straight portion 62 can be effectively suppressed while increasing the constriction rate of the constricted portion 6.

  As described above, according to the plastic bottle 1 of the present embodiment, stress concentration at the boundary portion between the reduced diameter portion 61 and the straight portion 62 is effectively suppressed while absorbing reduced pressure by the panel 63. The strength against the vertical load as a whole can be maintained high while increasing the constriction rate of the constricted portion 6. In particular, since the diameter-reduced portion 61 can be made longer even in a small-capacity bottle with a small axial length, and the diameter change at the reduced-diameter portion 61 can be moderated, it is extremely effective for a small-capacity bottle. is there.

  Next, features other than the constricted portion 6 in the plastic bottle 1 of the present embodiment will be described. First, in the present embodiment, one or more concave peripheral ribs 7 are provided on the upper and lower sides of the constricted portion 6 (one in the upper side and two in the lower side in the present embodiment). The vacuum absorption by the panel 63 is performed by the movement of the panel 63, but by providing the peripheral ribs 7 that are difficult to move above and below the constricted portion 6, the panel 63 becomes easier to move. As a result, the panel 63 can absorb the reduced pressure more effectively. In the present embodiment, each of the peripheral ribs 7 has a depth of 1.2 mm.

  In addition, the shoulder 3 is formed with a protruding portion 31 that protrudes toward the outside of the bottle over the circumferential direction. And in this embodiment, the protrusion part 31 is circular and the average curvature is 10 or more. The average curvature of the protrusion 31 is more preferably 20 or more. In this embodiment, the average curvature is 20. By providing such a protrusion 31, the strength of the bottle 1 is increased.

[Other Embodiments]
Finally, other embodiments of the plastic bottle according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) The ratio of the length of the panel 63 in the vertical direction with respect to the total length of the bottle shown in the above embodiment is merely an example, and can be changed as appropriate.

(2) In the above-described embodiment, the configuration in which one or more concave peripheral ribs 7 are provided on the top and bottom of the constricted portion 6 has been described as an example. However, the embodiment of the present invention is not limited to this, and the peripheral rib 7 may not be provided.

(3) In the above-described embodiment, the configuration in which the protrusion 31 is provided on the shoulder 3 has been described as an example. However, the embodiment of the present invention is not limited to this, and the protrusion 31 may not be provided. Moreover, the shape of the protrusion part 31 is not restricted to the thing of the above-mentioned embodiment, It can change suitably.

(4) The shape of the reduced diameter portion 61 is not limited to that of the above-described embodiment, and may be an arc shape as a whole, and a part of the reduced diameter portion 61 may be linear or different. For example, a combination of a plurality of curved shapes having curvature can be appropriately changed without departing from the spirit of the present invention.

(5) Regarding other configurations, it should be understood that the embodiments disclosed herein are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Accordingly, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

  The present invention can be used for a thin plastic bottle, for example.

DESCRIPTION OF SYMBOLS 1 Plastic bottle 3 Shoulder part 31 Projection part 4 Trunk part 6 Constriction part 61 Reduced diameter part 62 Straight part 63 Panel 7 Circumferential rib

Claims (7)

A plastic bottle having a cylindrical body,
The body portion is provided with a reduced diameter portion that decreases in diameter toward the inner side in the axial direction on both sides in the axial direction, and a constriction is formed between the reduced diameter portions that extends in parallel with the axial direction. Part is provided,
A plurality of radially recessed panels are formed side by side in the circumferential direction of the body portion in the constricted portion,
When the diameter at both ends of the constricted portion is the first diameter and the diameter at the straight portion is the second diameter, (first diameter−second diameter) / first diameter ≧ 0.1 is satisfied,
The reduced diameter portion is arcuate, and the length of each reduced diameter portion satisfies 0.25 ≦ (first diameter−second diameter) / the length of the reduced diameter portion ≦ 0.50,
The plastic bottle in which the length of the straight portion in the axial direction is not more than half of the length of the constricted portion in the axial direction.   The plastic bottle according to claim 1, wherein the ratio of the length of the panel in the vertical direction with respect to the total length of the bottle is 0.20 to 0.50.   The plastic bottle according to claim 1 or 2, wherein at least one concave peripheral rib is provided on each of the upper and lower sides of the constricted portion. On the upper side of the trunk portion, a shoulder portion that expands toward the lower side in the axial direction is provided,
The plastic bottle as described in any one of Claims 1-3 in which the protrusion part which protrudes toward the bottle outer side is formed in the said shoulder part.   The plastic bottle according to claim 4, wherein the protrusion has an arc shape and an average curvature is 10 or more.   The plastic bottle according to any one of claims 1 to 5, which has a capacity of 200 to 500 milliliters. The plastic bottle according to any one of claims 1 to 6, wherein the plastic bottle is thin.

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