Plastic bottle

Abstract

A plastic bottle is provided with a recess (422) in the bottom (4) which projects from the bottom (4) toward the inside of the plastic bottle, and the planar shape of the recess (422) is a concave hexagon having four convex vertices with acute angles and two concave vertices with angles greater than 180° and less than 360°, two vertices adjacent to a convex vertex are one convex vertex and one concave vertex, and two vertices adjacent to a concave vertex are two convex vertices.

Description

Technical Field

[0001] The present invention relates to a plastic bottle having a bottom having at least two plurality of recesses arranged in a row. Background Technology

[0002] During the manufacturing and distribution of beverages filled into plastic bottles, there is a risk of deformation due to pressure variations within the bottles. Examples of pressure variations that can cause such deformation include: internal pressure changes caused by expansion and contraction due to temperature changes, and the application of hydraulic pressure higher than atmospheric pressure during beverage filling. To prevent deformation caused by these pressure variations, various studies have been conducted to improve the strength of the bottom of plastic bottles.

[0003] As an example of this research, Patent Document 1 discloses a plastic bottle having a recessed portion extending from the bottom of the bottle towards the inside of the bottle, and a plurality of generally spherical ribs radially arranged extending from the recessed portion further towards the inside of the bottle. This plastic bottle, by having generally spherical ribs, achieves resistance to thermal shrinkage and deformation of the bottom due to the weight of the contents.

[0004] Furthermore, Patent Document 2 discloses a plastic bottle with a movable wall having multiple ribs at the bottom. This plastic bottle achieves the effect of preventing deformation of other parts of the bottle by rapidly deforming the movable wall in response to changes in internal pressure. In this plastic bottle, the movable wall, by having multiple ribs, successfully improves its pressure change absorption performance.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 7-112729

[0008] Patent Document 2: International Publication No. 2012 / 43362

[0009] However, while technologies like those in Patent Documents 1 and 2 achieve sufficient resistance to deformation caused by natural pressure changes such as temperature variations and the bottle's own weight, they lack sufficient resistance to larger pressure changes, such as those caused by mechanically applied hydraulic pressure during beverage filling. The bottom of the bottle may deform downwards due to internal pressure. Therefore, it is necessary to limit the hydraulic pressure applied to the beverage during the filling process to a level that prevents the plastic bottle from deforming; however, such limitations may impair the manufacturability of the beverage product. Summary of the Invention

[0010] Therefore, it is desirable to develop a plastic bottle that improves its resistance to deformation caused by changes in internal pressure.

[0011] Means for solving technical problems

[0012] The plastic bottle of the present invention has a recess at the bottom, wherein the recess protrudes from the bottom toward the inside of the plastic bottle, and the planar shape of the recess is a concave hexagon, which has four convex vertices with acute interior angles and two concave vertices with interior angles greater than 180° and less than 360°. The two vertices adjacent to the convex vertices are one convex vertex and one concave vertex, and the two vertices adjacent to the concave vertex are two convex vertices.

[0013] According to this structure, the recess can deform accordingly regardless of whether the load is along the central axis or in a direction orthogonal to the central axis, thus achieving good pressure change absorption performance.

[0014] The preferred embodiments of the present invention will now be described. However, the preferred embodiments described below do not limit the scope of the present invention.

[0015] As one embodiment of the plastic bottle of the present invention, it is preferable that the interior angles of the four convex vertices are all equal, and the interior angles of the two concave vertices are mutually equal.

[0016] According to this structure, the recess has a highly symmetrical planar shape, so it can deform symmetrically when deforming according to the load, thereby improving the pressure change absorption performance.

[0017] As one embodiment of the plastic bottle of the present invention, it is preferable that the plurality of recesses in the bottom are arranged in a row.

[0018] According to this structure, the pressure change absorption performance is improved by the synergistic action of multiple recesses.

[0019] As one embodiment of the plastic bottle of the present invention, preferably in the recessed columns, a plurality of the recesses are arranged adjacent to each other along a central axis and in a manner consistent with the central axis, which is an extension of the center line connecting the center points of the two sides sandwiched by the two convex vertices of the concave hexagon, and at least two of the recessed columns are arranged parallel to each other along the central axis.

[0020] According to this structure, the pressure change absorption performance is further improved by the synergistic action of multiple recesses belonging to multiple rows of recesses.

[0021] As one embodiment of the plastic bottle of the present invention, preferably at least two of the recessed columns contain a first recessed column and a second recessed column that are adjacent to each other. The first recessed column and the second recessed column are offset from each other in a direction along the central axis, the width of the offset being equivalent to 40 to 60% of the length of the central axis. The adjacent convex vertices of two adjacent recesses belonging to the first recessed column are configured to be embedded, in view from above, into the outer side of the concave vertices of the recesses belonging to the second recessed column.

[0022] According to this structure, by having adjacent recesses that interlock with each other, movement along the bottom surface of the recesses is restricted. As a result, deformation of the bottom is hindered, and thus the plastic bottle gains resistance to loads that could cause deformation, achieving the effect of preventing overall deformation of the plastic bottle.

[0023] As one embodiment of the plastic bottle of the present invention, it is preferred that the interior angle of the convex vertex is greater than 60° and less than 80°.

[0024] When the planar shape of the concave portion meets the above-mentioned range, the pressure change absorption performance can be further improved.

[0025] As one embodiment of the plastic bottle of the present invention, it is preferred that the recess protrudes 0.5 to 2.5 mm from the bottom toward the inside of the plastic bottle.

[0026] When the depth of the recess meets the above-mentioned range, the pressure change absorption performance can be further improved.

[0027] As one embodiment of the plastic bottle of the present invention, it is preferred that the length of the longest diagonal of the concave hexagon is 3 to 8 mm.

[0028] When the planar shape of the concave portion meets the above-mentioned range, the pressure change absorption performance can be further improved.

[0029] As one embodiment of the plastic bottle of the present invention, the bottom preferably has a rounded top that protrudes into the inside of the plastic bottle from the ground portion toward the radially inward side of the plastic bottle, and the recess is configured to protrude further into the inside of the plastic bottle from the rounded top.

[0030] According to this structure, the pressure resistance based on the dome and the pressure change absorption performance based on the concave part can be utilized simultaneously, thus further improving the pressure resistance of the plastic bottle.

[0031] Other features and advantages of the invention will become more apparent from the following description of exemplary and non-limiting embodiments with reference to the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is the front view of the plastic bottle.

[0033] Figure 2 This is a front cross-sectional view of a plastic bottle.

[0034] Figure 3 yes Figure 1 Sectional view III-III.

[0035] Figure 4 yes Figure 1 Sectional view IV-IV in the diagram.

[0036] Figure 5 This is a magnified view of the front of the main body of the plastic bottle.

[0037] Figure 6 yes Figure 5 Sectional view VI-VI in the middle.

[0038] Figure 7 yes Figure 5 Sectional view VII-VII in the figure.

[0039] Figure 8 This is a bottom view of the bottom of a plastic bottle.

[0040] Figure 9 This is an enlarged view of the bottom of the recessed part located at the bottom of the plastic bottle. Detailed Implementation

[0041] Embodiments of the plastic bottle of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, the plastic bottle 100 of this embodiment includes: an opening 1 serving as a liquid inlet; a shoulder 2 continuous with the opening 1 and gradually widening in diameter toward the bottom surface; a cylindrical main body 3 continuous with the shoulder 2; and a bottom 4 forming the bottom of the plastic bottle 100. Furthermore, in the following description, the "depth" of each structure provided on the surface of the plastic bottle 100 is defined as the depth to which it protrudes from the surface of the plastic bottle 100 inwards.

[0042] Furthermore, the plastic bottle 100 of this embodiment uses thermoplastic resins such as polyethylene, polypropylene, and polyethylene terephthalate as the main material, and can be integrally formed by biaxial stretching blow molding or other stretching molding methods. The capacity of the plastic bottle 100 is not particularly limited, and can be of commonly available sizes such as 280mL, 350mL, 500mL, or between 200mL and 2L. Additionally, the liquid filled into the plastic bottle 100 is not particularly limited, and examples include beverages such as water, tea, juice, coffee, cocoa, soft drinks, alcoholic beverages, dairy drinks, soups, condiments, and liquid seasonings such as soy sauce.

[0043] [Rib structure]

[0044] A concave main peripheral rib 31 is provided in the upper region 3a of the main body 3. Additionally, concave secondary peripheral ribs 32 are provided in both the upper region 3a and the lower region 3c of the main body 3. Figure 2 As shown, the main peripheral rib 31 is formed such that it has a greater depth and a larger width in the vertical direction compared to the secondary peripheral rib 32.

[0045] like Figure 3 As shown, the main circumferential rib 31 has a wavy horizontal cross-sectional shape with a depth that continuously varies along the circumference of the plastic bottle 100, with a maximum depth of 4.5 mm and a minimum depth of 3.5 mm. There are seven points 31a where the depth reaches its maximum and seven points 31b where the depth reaches its minimum on the main circumferential rib 31. The horizontal cross-sectional shape of the main circumferential rib 31 is a wavy shape that smoothly connects the points 31a and 31b alternately. That is, the horizontal cross-sectional shape is a closed curve: it bulges outward from the periphery of the point 31a where the depth reaches its maximum, and bulges inward from the periphery of the point 31b where the depth reaches its minimum, with a point of curvature between the points 31a and 31b.

[0046] The width of the main circumferential rib 31 in the vertical direction 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.

[0047] like Figure 1 , 2 As shown, multiple secondary peripheral ribs 32 can be provided. In this embodiment, three secondary peripheral ribs 32 are provided in the upper region 3a and two are provided in the lower region 3c. In addition, in this embodiment, the secondary peripheral ribs 32 have a circular horizontal cross-sectional shape, a depth of 1.5 mm, and a width of 4.9 mm in the vertical direction.

[0048] When a horizontal load is applied to the plastic bottle 100, the load can deform the horizontal cross-sectional shape of the plastic bottle 100 into an elliptical shape. However, the plastic bottle 100 of this embodiment achieves a structure in which the load is difficult to concentrate by having a wavy horizontal cross-sectional shape for the main peripheral rib 31, thus making it difficult to cause deformation of the plastic bottle 100.

[0049] Furthermore, even when a vertical load is applied to the plastic bottle 100, the plastic bottle can deform in the vertical direction. However, the plastic bottle 100 of this embodiment has main peripheral ribs 31 and secondary peripheral ribs 32 with different depths and widths. These ribs work together in a spring-like manner, exhibiting a function of mitigating the vertical load, thus making it difficult to cause deformation of the plastic bottle 100.

[0050] [Plate Structure]

[0051] In the central region 3b of the main body 3, multiple radially recessed plates 33 are formed side-by-side and at equal intervals in the circumferential direction of the central region 3b (six in this embodiment). Figure 5 As shown, plate 33 is shaped to extend vertically along the central region 3b, and is configured to be circumferentially twisted around the central axis of the plastic bottle 100. Furthermore, a main body reference surface 34 is formed around plate 33.

[0052] like Figures 5-7 As shown, plate 33 has a first recess 33a, a second recess 33b, and a protrusion 33c. The first recess 33a has a planar shape and is configured to recess from the reference surface 34 of the main body toward the inside of the plastic bottle 100. The second recess 33b is configured to recess further toward the inside of the plastic bottle 100 from the center of the first recess 33a in the circumferential direction.

[0053] The plate protrusion 33c is formed as a curved surface such that both ends of the plate first recess 33a in the vertical direction protrude from the plate first recess 33a toward the outside of the plastic bottle 100, covering the entire circumferential width of the plate first recess 33a. Furthermore, the vertical width of the plate protrusion 33c is smallest at both ends of the plate protrusion 33c and largest at the center of the plate protrusion 33c in the circumferential direction.

[0054] A peak-shaped portion 34a is formed at the point where the two main body reference surfaces 34, which extend from the first recess 33a of the two plates, meet. The distance from the main body reference surface 34 to the central axis of the plastic bottle 100 is greatest at the peak-shaped portion 34a.

[0055] The pressure-absorbing portion of existing plastic bottles has the following technical problems regarding strength: it is prone to radial outward deformation when pressure is applied to fill the bottle with beverage, and it is prone to dents (so-called shrinkage marks) due to shrinkage during bottle forming. The plastic bottle 100 of this embodiment achieves reinforcement of the plate 33 by having a plate protrusion 33c, thereby making it difficult to cause the above-mentioned adverse conditions.

[0056] [Bottom Structure]

[0057] like Figure 5 , 8 As shown in Figures 9 and 1, a grounding portion 41 is formed at the bottom 4, which is grounded relative to a mounting surface such as a table, and a grounding portion 41 extends radially inward toward the inner side of the plastic bottle 100. Figure 5The dome 42 protrudes from the top of the plastic bottle 100. A dome center portion 421 with a flat shape is provided in the center of the dome 42, and a plurality of bottom recesses 422 (example of recesses) are provided from the outside of the dome center portion 421 to the inside of the ground portion 41. The bottom recesses 422 protrude further into the inside of the plastic bottle 100 from the dome 42.

[0058] like Figure 9 As shown, the bottom recess 422 has the following shape: a concave hexagonal shape (i.e., bow-shaped) with four convex vertices 422a and two concave vertices 422b with an interior angle of 70° when viewed from above. Here, the two vertices adjacent to the convex vertices 422a are the convex vertex 422a and the concave vertex 422b, and the two vertices adjacent to the concave vertex 422b are the two convex vertices 422a. Furthermore, each side of this concave hexagon is 3mm, and the length of the longest diagonal is 6mm. Additionally, the depth of the bottom recess 422 is 1.2mm.

[0059] like Figure 8 , 9 As shown, the bottom recess 422 is formed by multiple bottom recesses 422 arranged in a row, forming a row 423 (an example of a row of recesses). In the row 423 of bottom recesses, multiple bottom recesses 422 are arranged along a center line C that connects the center points of the two sides sandwiched by the two protruding vertices 422a. L The extended central axis C A With central axis C A The consistent configuration is to ensure that the elements are adjacent to each other.

[0060] like Figure 8 , 9 As shown, multiple bottom recesses 423 are configured with their respective central axes C. A They are arranged in parallel to each other. Furthermore, two adjacent bottom recessed rows 423a and 423b (examples of the first and second recessed rows) are arranged along the central axis C. A They are configured with mutual offsets, the width of which is equivalent to the centerline C. L Half the length (5.2mm), i.e., 2.6mm. Furthermore, the term "offset" here refers to a configuration where multiple bottom recess columns 423 are arranged such that the straight line connecting the two concave vertices 422b of the bottom recess 422 belonging to one side of the bottom recess column 423a is not the same as the straight line connecting the two concave vertices 422b of the bottom recess 422 belonging to the adjacent bottom recess column 423b of the other side. The term "offset width" refers to the distance between these straight lines.

[0061] Furthermore, the three adjacent bottom recesses 422 are configured such that two convex vertices 422a and one concave vertices 422b are close together. In other words, the adjacent convex vertices 422a of two adjacent bottom recesses 422 belonging to the bottom recess row 423a are configured such that, in top view, they are embedded on the outer side of the concave vertices 422b of the bottom recesses 422 belonging to the bottom recess row 423b. Figure 9 (Part A). The embedded structure is formed at all adjacent parts of the three bottom recesses 422.

[0062] In this embodiment, the plastic bottle 100 has an interlocking structure in the bottom recess 422 as described above, thereby restricting the movement of the bottom recess 422 in the direction of the bottom surface. As a result, deformation of the bottom 4 is hindered. Thus, the plastic bottle 100 gains resistance to loads that can cause deformation, resulting in an overall effect of the plastic bottle 100 being difficult to deform.

[0063] [Other Implementation Methods]

[0064] Finally, other embodiments of the plastic bottle of the present invention will be described. Furthermore, the structures disclosed in the following embodiments can be combined with the structures disclosed in other embodiments, provided that no contradictions arise.

[0065] In the above embodiment, a structure with one main peripheral rib 31 was described as an example. However, the structure is not limited to this, and the plastic bottle of the present invention may also have multiple peripheral ribs. However, from the viewpoint of effectively mitigating the load in the vertical direction, it is preferable to have one main peripheral rib as in the above embodiment, and it is even more preferable to have at least one secondary peripheral rib in addition to the main peripheral rib, and more preferably to have at least five secondary peripheral ribs in addition to the main peripheral rib.

[0066] In the above embodiment, an example was given where the main circumferential rib 31 has seven points of maximum depth 31a and seven points of minimum depth 31b. However, the structure is not limited to this; the number of points of maximum and minimum depth of the main circumferential rib can be arbitrary as long as they are the same and multiple. However, to better illustrate the effect of avoiding the concentration of horizontal loads, it is preferable that the main circumferential rib has 6 to 9 points of maximum and minimum depth.

[0067] In the above embodiment, an example was described using a structure where the maximum depth of the main peripheral rib 31 is 4.5 mm and the minimum depth is 3.5 mm. However, the structure is not limited to this; the maximum depth of the peripheral rib can be 4.0 to 5.5 mm, and the minimum depth can be 0.5 to 1.5 mm less than the maximum depth. Furthermore, the maximum depth of the peripheral rib is preferably 4.1 to 5.2 mm, more preferably 4.2 to 5.0 mm. Additionally, the minimum depth of the peripheral rib is preferably 0.6 to 1.4 mm less than the maximum depth, more preferably 0.7 to 1.3 mm less.

[0068] In the above embodiment, an example was described where the width of the main peripheral rib 31 in the vertical direction is 8.0 mm at point 31a where the depth is at its maximum and 7.2 mm at point 31b where the depth is at its minimum. However, the structure is not limited to this; the width of the peripheral rib in the vertical direction can be 6 to 9 mm. Furthermore, the width of the peripheral rib in the vertical direction is preferably 6.2 to 8.8 mm, and more preferably 6.5 to 8.5 mm.

[0069] In the above embodiment, a structure in which a peak-shaped portion 34a is formed at the point where the reference surfaces 34 of the two main body portions, extending from the first recess 33a of the two plates, meet is described as an example. However, the structure is not limited to this; for example, a planar connecting portion may be provided in the area where the reference surfaces of the two main body portions meet.

[0070] In the above embodiment, the structure of the first recess 33a of the plate having a planar shape was described as an example. However, it is not limited to such a structure; for example, the first recess of the plate may also have ribs for pressure reduction and absorption.

[0071] In the above embodiment, a structure with an interior angle of 70° for the convex vertex 422a and an interior angle of 220° for the concave vertex 422b was described as an example. However, the structure is not limited to this; the interior angle of the convex vertex may be greater than 60° and less than 80°. Furthermore, 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.

[0072] In the above embodiment, an example was described using a structure where the longest diagonal of the concave hexagon is 6 mm. However, the structure is not limited to this; the length of the diagonal can be 3 to 8 mm. Furthermore, the length of the diagonal is preferably 4 to 7 mm, and more preferably 5 to 7 mm.

[0073] In the above embodiment, a structure with a bottom recess 422 depth of 1.2 mm was described as an example. However, the structure is not limited to this; the depth of the bottom recess can be 0.6 to 2.4 mm. Furthermore, the depth of the bottom recess is preferably 0.5 to 2.5 mm, and more preferably 0.7 to 2.3 mm.

[0074] In the above embodiment, the offset width of two adjacent bottom recesses 423a and 423b is 2.6 mm, and it is the center line C. L The example described uses a structure with half the length (5.2 mm). However, the structure is not limited to this; the offset width can be 40-60% of the length of the center line. Furthermore, the offset width is preferably 45-55% of the length of the center line, more preferably 48-52% of the length of the center line, and particularly preferably 50% of the length of the center line.

[0075] Regarding other structures, all the points of the embodiments disclosed in this specification are illustrative, and the scope of the invention is not limited thereto. Those skilled in the art can make appropriate modifications without departing from the spirit of the invention. Therefore, other embodiments with modifications that do not depart from the spirit of the invention are naturally also included within the scope of the invention.

[0076] Industrial utilization potential

[0077] This invention can be used, for example, in containers for refreshing beverages.

[0078] Symbol Explanation

[0079] 100: Plastic bottles

[0080] 1: Mouth

[0081] 2: Shoulders

[0082] 3: Main body

[0083] 3a: Upper region of the main body

[0084] 3b: Central region of the main body

[0085] 3c: Lower part of the main body

[0086] 31: The main rib

[0087] 32: Sub-Zhou Rib

[0088] 33: Board

[0089] 33a: The first concave part of the plate

[0090] 33b: Second recess of the plate

[0091] 33c: Plate protrusion

[0092] 34: Main body reference plane

[0093] 34a: Peak-shaped portion

[0094] 4: Bottom

[0095] 41: Grounding part

[0096] 42: Rounded top

[0097] 421: Central part of the dome

[0098] 422: bottom concave part

[0099] 422a: Convex vertex of bottom concave portion

[0100] 422b: The concave apex of the bottom concave portion

[0101] 423 (423a, 423b): Bottom concave row

[0102] C A Central axis

[0103] C L Center line

[0104] A: Interlocking parts of the bottom recess

Claims

1. A plastic bottle having a recess at the bottom, characterized in that, The recess protrudes from the bottom toward the inside of the plastic bottle. The concave portion has a planar shape of a concave hexagon, which has four convex vertices with acute interior angles and two concave vertices with interior angles greater than 180° and less than 360°. The two vertices adjacent to the convex vertex are one convex vertex and one concave vertex, and the two vertices adjacent to the concave vertex are two convex vertices. At the bottom, the plurality of recesses are arranged in a row. In the column of recesses, which is a series of recesses, multiple recesses are arranged adjacent to each other along a central axis and aligned with the central axis, which is the extension of the center line connecting the center points of the two sides sandwiched by the two convex vertices of the concave hexagon. At least two of the said rows of recesses are arranged parallel to each other along the central axis. At least two columns of said recesses contain a first column of recesses and a second column of recesses that are adjacent to each other. The first row of recesses and the second row of recesses are offset from each other in a direction along the central axis, the width of the offset being equivalent to 40-60% of the length of the central line. The adjacent convex vertices of two adjacent recesses belonging to the first recess column are configured, in top view, to be embedded on the outside of the concave vertices of the recesses belonging to the second recess column in top view.

2. The plastic bottle according to claim 1, characterized in that, The interior angles of the four convex vertices are all equal, and the interior angles of the two concave vertices are equal to each other.

3. The plastic bottle according to claim 1 or 2, characterized in that, The interior angle of the convex vertex is greater than 60° and less than 80°.

4. The plastic bottle according to claim 1 or 2, characterized in that, The recess protrudes 0.5 to 2.5 mm from the bottom toward the inside of the plastic bottle.

5. The plastic bottle according to claim 1 or 2, characterized in that, The longest diagonal of the concave hexagon has a length of 3 to 8 mm.

6. The plastic bottle according to claim 1 or 2, characterized in that, The bottom has a rounded top that protrudes into the inside of the plastic bottle from the ground portion toward the radially inward side of the plastic bottle, and the recess is configured to protrude further into the inside of the plastic bottle from the rounded top.

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