Plastic Bottles

Abstract

The plastic bottle 100 of the present invention is a plastic bottle having at least one concave circumferential rib 31 on the body 3, and the circumferential rib 31 has a wavy horizontal cross-sectional shape in which the depth from the surface of the plastic bottle 100 to the interior changes continuously along the circumferential direction of the plastic bottle 100, and the maximum depth of the circumferential rib is 4.5 to 6.0 mm and the minimum depth of the circumferential rib is 3.5 to 4.4 mm.

Description

[Technical field]

[0001] The present invention relates to a plastic bottle having at least one concave circumferential rib on its body. [Background technology]

[0002] During the manufacturing and distribution of beverages filled in plastic bottles, loads are applied to the plastic bottles, which may cause problems such as deformation of the plastic bottles. Examples of loads that can cause such deformation include horizontal loads caused by plastic bottles pushing against each other on a conveyor during the beverage manufacturing process, and vertical loads caused by stacking during the distribution process. In order to prevent deformation due to these loads, various efforts have been made to improve the strength of plastic bottles.

[0003] As an example of such an innovation, Patent Document 1 discloses a plastic bottle in which a reinforcing relief is provided to improve the structural strength of the bottle, which achieves good resistance to vertical compression without increasing the thickness of the wall.

[0004] Patent Document 2 discloses a plastic bottle that has a plurality of wavy recesses on the side surface thereof to ensure sufficient strength against impacts and loads applied to the side surface of the container. This plastic bottle has good resistance to horizontal loads without increasing the wall thickness. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2007 / 118966 [Patent Document 2] Japanese Patent Application Publication No. 2012-126448 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 may lack strength against horizontal loads. For example, in a process in which plastic bottles are placed on a conveyor and transported, the plastic bottles may collide with each other and be deformed. This problem is of particular concern in a transport process involving heating for sterilization, because the strength of the plastic bottles decreases due to heating.

[0007] Furthermore, in the technology disclosed in Patent Document 2, the strength against vertical loads may be insufficient. This makes it difficult to increase the number of vertical loads during the distribution process, which may reduce distribution efficiency.

[0008] Therefore, there is a need to develop a plastic bottle that can withstand both vertical and horizontal loads. [Means for solving the problem]

[0009] The plastic bottle according to the present invention has at least one concave peripheral rib on the body. , capacity 200mL~500mL A plastic bottle, wherein the circumferential rib has a wavy horizontal cross-sectional shape in which the depth from the surface of the plastic bottle to the inside changes continuously along the circumferential direction of the plastic bottle, the maximum depth of the circumferential rib is 4.5 to 6.0 mm, the minimum depth of the circumferential rib is 3.5 to 4.4 mm, and the vertical width of the circumferential rib is 7 to 9 mm at the point where the depth of the circumferential rib is at its minimum value.

[0010] According to this configuration, the peripheral rib has a wavy horizontal cross-sectional shape, which realizes a structure in which loads are less likely to concentrate, and the effect of making the plastic bottle less likely to deform in the horizontal direction is realized. Also, by having the peripheral rib dimensions within the above range, the effect of absorbing loads in the vertical direction is realized, and the effect of making the plastic bottle less likely to deform in the vertical direction is realized.

[0011] Preferred embodiments of the present invention will be described below. However, the scope of the present invention is not limited to the preferred embodiments described below.

[0014] In one aspect, the plastic bottle according to the present invention further comprises a vacuum absorption panel portion in the body portion, and the circumferential rib is preferably provided in a portion of the body portion above the vacuum absorption panel portion or below the vacuum absorption panel portion.

[0015] According to this configuration, deformation of the plastic bottle caused by an increase in internal pressure can be absorbed by the vacuum absorption panel.

[0016] In one embodiment, the plastic bottle according to the present invention preferably has only one circumferential rib.

[0017] According to this configuration, the effect of absorbing vertical loads can be further improved compared to a plastic bottle having a plurality of peripheral ribs each having a wavy horizontal cross-sectional shape.

[0018] In one embodiment, the plastic bottle of the present invention further comprises at least one concave secondary circumferential rib, the secondary rib having a circular horizontal cross-sectional shape, the depth of the secondary rib extending from the surface of the plastic bottle into the interior being smaller than the minimum value of the depth of the circumferential rib, and the vertical width of the secondary rib being smaller than the vertical width of the circumferential rib.

[0019] According to this configuration, the circumferential rib and the secondary circumferential rib work in cooperation with each other like a spring, and the effect of absorbing the load in the vertical direction can be further improved.

[0020] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which are given with reference to the drawings. [Brief description of the drawings]

[0021] [Figure 1]Front view of a plastic bottle. [Diagram 2] Front cross-sectional view of a plastic bottle. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] IV-IV cross-sectional view in FIG. 1. [Diagram 5] A close-up front view of the body of a plastic bottle. [Figure 6] Cross-sectional view taken along line VI-VI in FIG. [Figure 7] Cross-sectional view taken along line VII-VII in FIG. 5 . [Figure 8] A bottom view of the base of a plastic bottle. [Figure 9] 4 is an enlarged view of the bottom of a recess provided in the bottom of a plastic bottle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] 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 100 according to this embodiment is composed of a mouth 1 as a spout for pouring liquid, a shoulder 2 that is continuous with the mouth 1 and gradually expands in diameter toward the bottom, a cylindrical body 3 that is continuous with the shoulder 2, and a bottom 4 that is the bottom of the plastic bottle 100. In the following description, the direction of the straight line connecting the centers of the mouth 1 and the bottom 4 is referred to as the "vertical direction," and the direction of the plane perpendicular to the straight line is referred to as the "horizontal direction." The "depth" of each structure provided on the surface of the plastic bottle 100 is defined as the depth from the surface of the plastic bottle 100 to the inside.

[0023] The plastic bottle 100 according to this embodiment can be integrally molded by a stretch molding method such as biaxial stretch blow molding, using a thermoplastic resin such as polyethylene, polypropylene, or polyethylene terephthalate as the main material. The capacity of the plastic bottle 100 is not particularly limited, and can be about 200 mL to 2 L, such as 280 mL, 350 mL, or 500 mL, which are commonly distributed. The liquid to be filled in the plastic bottle 100 is not particularly limited, and examples thereof include beverages such as drinking water, tea, fruit juice, coffee, cocoa, soft drinks, alcoholic beverages, milk beverages, and soups, and liquid seasonings such as sauces and soy sauces.

[0024] [Rib structure] One concave main circumferential rib 31 (an example of a circumferential rib) is provided in the upper region 3a of the body 3. In addition, a plurality of concave sub-circumferential ribs 32 are provided in the upper region 3a and the lower region 3c of the body 3. As shown in Fig. 2, the main circumferential rib 31 is formed so as to be deeper and wider in the up-down direction than the sub-circumferential rib 32.

[0025] As shown in Fig. 3, the main circumferential rib 31 has a wavy horizontal cross-sectional shape whose depth changes continuously along the circumferential direction of the plastic bottle 100, and the depth has a maximum value of 4.5 mm and a minimum value of 3.5 mm. The main circumferential rib 31 has seven points 31a where the depth is maximum and seven points 31b where the depth is minimum, and the horizontal cross-sectional shape of the main circumferential rib 31 is a wavy shape that smoothly connects the points 31a where the depth is maximum and the points 31b where the depth is minimum alternately. That is, the horizontal cross-sectional shape is a closed curve that is convex toward the outside of the plastic bottle around the point 31a where the depth is maximum and that is convex toward the inside of the plastic bottle around the point 31b where the depth is minimum, and has an inflection point between the point 31a where the depth is maximum and the point 31b where the depth is minimum.

[0026] The vertical width of the main circumferential rib 31 is 8.0 mm at point 31a where the depth is at its maximum value, and 7.2 mm at point 31b where the depth is at its minimum value.

[0027] 1 and 2, a plurality of secondary circumferential ribs 32 may be provided, and in this embodiment, three secondary circumferential ribs 32 are provided in the upper region 3a and two secondary circumferential ribs 32 are provided in the lower region 3c. In this embodiment, the secondary circumferential rib 32 has a circular horizontal cross-sectional shape with a depth of 1.5 mm and a vertical width of 4.9 mm.

[0028] When a horizontal load is applied to plastic bottle 100, the load can cause the horizontal cross-sectional shape of plastic bottle 100 to deform into an ellipse. However, in plastic bottle 100 according to this embodiment, main circumferential rib 31 has a wavy horizontal cross-sectional shape, realizing a structure that makes it difficult for load to concentrate, so that plastic bottle 100 is less likely to deform.

[0029] Furthermore, when a load is applied in the vertical direction to plastic bottle 100, the plastic bottle may also deform in the vertical direction. However, plastic bottle 100 according to this embodiment is provided with main circumferential ribs 31 and secondary circumferential ribs 32 that are different in depth and width, and these ribs work together like a spring to reduce the load in the vertical direction, making plastic bottle 100 less likely to deform.

[0030] [Panel structure] In the central region 3b of the body 3, a plurality of (six in this embodiment) radially recessed panels 33 (an example of a vacuum absorption panel portion) are formed at equal intervals in the circumferential direction of the central region 3b. As shown in Fig. 5, the panels 33 extend in the vertical direction of the central region 3b and are provided in a shape twisted in the circumferential direction around the central axis of the plastic bottle 100. In addition, a body reference surface 34 is formed around the panel 33.

[0031] 5 to 7, the panel 33 has a panel first recess 33a, a panel second recess 33b, and a panel protrusion 33c. The panel first recess 33a has a planar shape and is provided so as to recess from the body reference surface 34 toward the inside of the plastic bottle 100. The panel second recess 33b is provided in the circumferential center of the panel first recess 33a, and is provided so as to recess further from the panel first recess 33a toward the inside of the plastic bottle 100.

[0032] The panel protrusion 33c is formed as a curved surface in which both ends in the up-down direction of the panel first recess 33a are convex from the panel first recess 33a toward the outside of the plastic bottle 100, over the entire circumferential width of the panel first recess 33a. The up-down width of the panel protrusion 33c is smallest at both ends in the circumferential direction of the panel protrusion 33c, and is largest at the circumferential center of the panel protrusion 33c.

[0033] A ridge-like portion 34a is formed at the portion where the two body reference surfaces 34 extending from the two panel first recesses 33a meet. The distance of the body reference surface 34 from the central axis of the plastic bottle 100 is greatest at the ridge-like portion 34a.

[0034] The vacuum absorption section provided in conventional plastic bottles had strength problems such as being easily deformed radially outward when pressurizing the bottle to fill it with a beverage, and being easily dented (so-called sink marks) due to shrinkage during bottle molding. Plastic bottle 100 according to this embodiment has panel protrusion 33c to reinforce panel 33, and is less likely to suffer from defects due to the above-mentioned deformation.

[0035] [Bottom structure] 5, 8, and 9, bottom 4 is formed with grounding portion 41 that is grounded to a placement surface such as a desk, and dome portion 42 that projects radially inward from grounding portion 41 into the inside of plastic bottle 100 (upward in FIG. 5). Dome portion 42 has flat dome center portion 421 in the center, and multiple bottom recesses 422 are provided from the outside of dome center portion 421 to the inside of grounding portion 41.

[0036] 9, bottom recess 422 has a concave hexagonal shape (so-called bowtie shape) with four convex vertices 422a with an interior angle of 70° and two concave vertices 422b with an interior angle of 220° in plan view. Here, the two vertices adjacent to convex vertex 422a are convex vertex 422a and concave vertex 422b, and the two vertices adjacent to concave vertex 422b are two convex vertices 422a. Each side of the concave hexagon is 3 mm, and the diagonal line with the longest length among the diagonals of the concave hexagon is 6 mm. The depth of bottom recess 422 is 1.2 mm.

[0037] 8 and 9, the bottom recesses 422 form a bottom recess row 423 in which a plurality of bottom recesses 422 are arranged in a row. In the bottom recess row 423, the plurality of bottom recesses 422 are arranged along a center line C L The central axis C is an extension of A along the central axis C A are arranged adjacent to each other so as to match.

[0038] As shown in FIGS. 8 and 9, the plurality of bottom recess rows 423 are aligned along the respective central axes C A The two adjacent bottom recess rows 423a and 423b are arranged so as to be parallel to each other. A are offset from one another along the center line C LThe term "offset" used here refers to the offset of the plurality of bottom recess rows 423 from the central axis C such that a straight line connecting two concave vertices 422b of the bottom recesses 422 belonging to one bottom recess row 423a does not coincide with a straight line connecting two concave vertices 422b of the bottom recesses 422 belonging to the other adjacent bottom recess row 423b. A The term "offset width" refers to the distance between the straight lines.

[0039] Furthermore, three adjacent bottom recesses 422 are arranged in such a manner that two convex vertices 422a and one concave vertex 422b are close to each other. In other words, each adjacent convex vertex 422a of two adjacent bottom recesses 422 belonging to the bottom recess row 423a is arranged so as to fit in a plan view outside the concave vertex 422b of the bottom recess 422 belonging to the bottom recess row 423b (part A in FIG. 9). Such a fitting structure is formed in all locations where the three bottom recesses 422 are adjacent to each other.

[0040] In conventional plastic bottles, when pressurizing the bottle to fill it with a beverage, the bottle may be deformed in such a manner that the bottom of the bottle is pushed downward by the internal pressure. In the plastic bottle 100 according to this embodiment, the bottom recesses 422 have a structure in which they fit into each other as described above, so that the movement of the bottom recesses 422 in the direction along the bottom surface is restricted, and as a result, deformation of the bottom 4 is prevented. This action gives the plastic bottle 100 resistance to loads that may cause deformation, and the effect of making the entire plastic bottle 100 less likely to deform is obtained.

[0041] 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 combined with the configurations disclosed in other embodiments as long as no contradiction occurs.

[0042] In the above embodiment, a configuration in which one main circumferential rib 31 is provided has been described as an example. However, the present invention is not limited to such a configuration, and the plastic bottle according to the present invention may have multiple circumferential ribs. However, from the viewpoint of effectively exerting the effect of reducing the load in the vertical direction, it is preferable to have one circumferential rib as in the above embodiment, and it is preferable to have at least one sub-circumferential rib in addition to the circumferential rib, and it is even more preferable to have at least five sub-circumferential ribs in addition to the circumferential rib.

[0043] In the above embodiment, the main circumferential rib 31 has seven points 31a where the depth is maximum and seven points 31b where the depth is minimum. However, the present invention is not limited to such a configuration, and the number of points where the depth of the circumferential rib is maximum and the number of points where the depth of the circumferential rib is minimum may be any number as long as they are equal and plural. However, it is preferable that the number of points where the depth of the circumferential rib is maximum and the number of points where the depth of the circumferential rib is minimum are 6 to 9 each, because this effectively avoids the concentration of horizontal load.

[0044] In the above embodiment, the maximum depth of the main circumferential rib 31 is 4.5 mm. However, the present invention is not limited to such a configuration, and the maximum depth of the circumferential rib may be 4.5 to 6.0 mm. The maximum depth of the circumferential rib is preferably 4.5 to 5.5 mm, and more preferably 4.5 to 5.1 mm.

[0045] In the above embodiment, the minimum depth of the main circumferential rib 31 is 3.5 mm. However, the present invention is not limited to such a configuration, and the minimum depth of the circumferential rib may be 3.5 to 4.4 mm.

[0046] In the above embodiment, the vertical width of the main circumferential rib 31 is 7.2 mm at point 31b where the depth is at its minimum. However, the present invention is not limited to such a configuration, and the vertical width of the circumferential rib may be 7 to 9 mm at the point where the depth of the circumferential rib is at its minimum. The vertical width of the circumferential rib is preferably 7.1 to 8.8 mm, more preferably 7.2 to 8.6 mm, and particularly preferably 7.2 to 8.4 mm at the point where the depth of the circumferential rib is at its minimum.

[0047] In the above embodiment, a configuration in which the ridge portion 34a is formed at the portion where the two body reference surfaces 34 extending from the two panel first recesses 33a meet has been described as an example. However, the present invention is not limited to such a configuration, and for example, a planar connection portion may be provided in the region where the two body reference surfaces meet.

[0048] In the above embodiment, the panel first recess 33a has a planar shape. However, the present invention is not limited to such a configuration, and the panel first recess may have a rib for absorbing reduced pressure.

[0049] In the above embodiment, an example has been described in which the interior angle of convex vertex 422a is 70° and the interior angle of concave vertex 422b is 220°. However, the present invention is not limited to such a configuration, and the interior angle of the convex vertex may be greater than 60° and less than or equal to 80°. Note that the interior angle of the convex vertex is preferably 63° or more and 87° or less, and more preferably 65° or more and 75° or less.

[0050] In the above embodiment, the longest diagonal among the diagonals of the recessed hexagon is 6 mm in length. However, the present invention is not limited to such a configuration, and the length of the diagonal may be 3 to 8 mm. The length of the diagonal is preferably 4 to 7 mm, and more preferably 5 to 7 mm.

[0051] In the above embodiment, the bottom recess 422 has a depth of 1.2 mm. However, the present invention is not limited to such a configuration, and the depth of the bottom recess may be 0.6 to 2.4 mm. The depth of the bottom recess is preferably 0.5 to 2.5 mm, and more preferably 0.7 to 2.3 mm.

[0052] In the above embodiment, the offset width between the two adjacent bottom recess rows 423a, 423b is 2.6 mm, and the center line C L In the above example, the offset width is half the length of the center line (5.2 mm). However, the present invention is not limited to such a configuration, and the offset width may be 40 to 60% of the length of the center line. The offset width is preferably 45 to 55% of the length of the center line, more preferably 48 to 52%, and particularly preferably 50%.

[0053] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereto. A person skilled in the art would easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. EXAMPLES

[0054] Examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples.

[0055] [Specification of Shapes in Examples and Comparative Examples] The outline shape of each bottle of the examples and comparative examples is the same as that shown in Fig. 1 to Fig. 9 except for the difference in the numerical values ​​of the dimensions of each part. In the following, the depth D of the main circumferential rib 31 at the point 31a where the depth of the main circumferential rib 31 is the maximum value is calculated. max , and the depth D of the main circumferential rib 31 at point 31b where the depth of the main circumferential rib 31 is maximum min and width W minThe dimensions of each bottle are shown in Table 1 below, together with the results of the evaluation tests described below.

[0056] [Vertical load resistance test] A known testing machine was used to apply a vertical stress to each bottle of the Examples and Comparative Examples, and a stress-strain curve was plotted. As a specification for enduring the environment during distribution and warehouse storage, bottles with a maximum stress value of 210N or more in the plot were judged as passing, and bottles with a maximum stress value of less than 210N were judged as failing. The bottle of the present invention preferably has a vertical load resistance of 210N or more, and particularly preferably 500N or more.

[0057] [Horizontal load resistance test] A known testing machine was used to apply a stress of 20 N from the outside of the body 3 of each bottle in the examples and comparative examples. With the stress applied, the horizontal width dimension of the body 3 of each bottle was measured in a direction parallel to the line of action of the stress and in a direction perpendicular to the line of action of the stress. Bottles with a difference between the two measurements of within 4 mm were deemed to have passed, and bottles with a difference exceeding 4 mm were deemed to have failed.

[0058] [Evaluation results] The dimensions of each bottle in the examples and comparative examples and the evaluation results of each bottle are shown in Table 1. [Table 1]

[0059] As shown in Table 1, all of the bottles of Examples 1 to 3 and Comparative Examples 1 and 2 passed the vertical load resistance test. All of the bottles exhibited a vertical load resistance of 500 N or more. From these results, it is considered that the main circumferential rib 31 and the secondary circumferential rib 32 exerted the effect of reducing the vertical load in all of the bottles.

[0060] However, while the bottles of Examples 1 to 3 passed the horizontal load resistance test, the bottles of Comparative Examples 1 and 2 did not pass the test. This is thought to be because the depth of the main circumferential rib 31 in Comparative Examples 1 and 2 is smaller than that in Examples 1 to 3, and therefore the effect of the main circumferential rib 31 in preventing the load from concentrating was not sufficiently obtained. [Industrial Applicability]

[0061] The present invention can be used, for example, in soft drink containers. [Explanation of symbols]

[0062] 100: Plastic bottles 1: Mouth 2:Shoulder 3: Torso 3a: Upper torso area 3b: Central region of the torso 3c: Lower torso area 31: Main rib 32: Secondary rib 33: Panel 33a: Panel first recess 33b: Panel second recess 33c: Panel protrusion 34: Torso reference plane 34a: Ridge-like part 4: Bottom 41: Grounding part 42: Dome section 421: Center of the dome 422: Bottom recess 422a: Convex apex of bottom concave 422b: Concave apex of bottom concave 423 (423a, 423b): Bottom recess row C A :Central axis C L :Center line A: Interfitting part of bottom recess

Claims

1. A plastic bottle having a capacity of 200 mL to 500 mL and having at least one concave peripheral rib on a body portion, The peripheral rib has a wavy horizontal cross-sectional shape in which the depth from the surface of the plastic bottle to the inside of the plastic bottle changes continuously along the circumferential direction of the plastic bottle, The maximum depth of the peripheral rib is 4.5 to 6.0 mm; The minimum depth of the circumferential rib is 3.5 to 4.4 mm; A plastic bottle in which the vertical width of the peripheral rib is 7 to 9 mm at the point where the depth of the peripheral rib is at its minimum value.

2. The body portion further includes a vacuum absorption panel portion, 2. The plastic bottle according to claim 1, wherein the circumferential rib is provided on a portion of the body portion above the vacuum absorption panel portion or below the vacuum absorption panel portion.

3. 3. The plastic bottle according to claim 1, further comprising only one peripheral rib.

4. Further comprising at least one concave secondary circumferential rib; The secondary rib has a circular horizontal cross-sectional shape, The depth of the secondary rib from the surface of the plastic bottle to the inside is less than the minimum value of the depth of the circumferential rib, 4. The plastic bottle according to claim 1, wherein the vertical width of the secondary circumferential rib is smaller than the vertical width of the circumferential rib.

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