JP2016132501A - Plastic bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-weighed plastic bottle capable of absorbing pressure reduction inside the plastic bottle while maintaining a buckling strength and capable of keeping favorable appearance.SOLUTION: A plastic bottle 1 comprises a mouth part 10, a shoulder part 20, a trunk part 30 and a bottom part 40. The trunk part 30 has a cylindrical shape with the same diameters, and has the respectively plural shallow and deep grooves 51 and 52 which are the annular peripheral grooves having the angle of aperture of 45 to 90 degrees. The ratio d1/d2 of the depth d1 of the shallow groove 51 to that d2 of the deep groove 52 is 0.2 to 0.95, and the ratio w1/w2 of the width w1 of the shallow groove 51 to that w2 of the deep groove 52 is also 0.2 to 0.95.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a plastic bottle, and more particularly, to a structure of a plastic bottle that is reduced in weight.

  For example, a plastic bottle is used as a container filled with a beverage. And a plastic bottle is used also as a container which accommodates liquid foods, such as a seasoning, conventionally accommodated in the glass container.

  The production volume of such plastic bottles is increasing year by year. On the other hand, the plastic bottles are lightened by reducing the amount of raw materials used from the viewpoint of reducing energy consumption and carbon dioxide emissions by saving resources, reducing waste, and reducing the environmental impact during transportation. Is addressed. However, when the plastic bottle is reduced in weight, the thickness of the plastic bottle container is reduced, so that the strength of the plastic bottle tends to decrease.

  Plastic bottles are stored and transported as a single pallet by stacking a plurality of containers packed in cardboard or the like with the mouths of a plurality of containers facing upward. Therefore, the plastic bottle in the lower stage tends to be easily deformed by a load applied in the vertical direction, and there is a risk that poor appearance or collapse of the load may occur.

  By the way, in the plastic bottle in which the contents are sealed, when a temperature change occurs between filling and storage of the contents, the internal pressure changes according to the temperature change. For example, in a plastic bottle filled with a hot filling method (high temperature filling method) that fills a plastic bottle with high-temperature content for sterilization and seals it, the temperature of the content is kept at room temperature. When the pressure is lower than that at the time of filling, decompression occurs inside. On the other hand, in plastic bottles filled with the contents by a sterile filling method (room temperature filling method) in which the contents are filled and sealed at room temperature in a plastic bottle that has been sterilized with drugs in advance, the contents are heated by heating at the time of sale. When the temperature becomes higher than that at the time of filling, pressure increase occurs inside. Such a pressure change inside the plastic bottle is caused by a volume change accompanying a temperature change of the contents sealed inside.

  The plastic bottle has a slight oxygen permeability. When the plastic bottle is stored for a long period of time, oxidation occurs depending on the contents, and this also causes decompression inside the plastic bottle.

  And unlike a glass container, a plastic bottle is soft and easily deformed due to a change in internal pressure, and a plastic bottle reduced in weight is more easily deformed. Therefore, when reducing the weight of the plastic bottle, a measure against an internal pressure change is more important as well as strength.

  Patent Document 1 discloses a plastic bottle in which a plurality of reduced pressure absorption panels are formed in the lower portion of a body portion, and the pressure change inside the container is absorbed by deformation of the reduced pressure absorption panel.

JP 2002-193229 A

  Here, when a plastic bottle having a vacuum absorption panel in the body as in Patent Document 1 is reduced in weight, the vacuum absorption panel is greatly deformed to absorb the pressure change inside the plastic bottle and maintain a good appearance. There are cases where it is not possible. Moreover, when a load in the vertical direction is applied to the plastic bottle, an eccentric load is applied to the column portion between adjacent decompression absorption panels, so that the buckling strength may be reduced.

  Accordingly, an object of the present invention is to provide a plastic bottle that can maintain a good appearance by absorbing the reduced pressure inside the plastic bottle while maintaining the buckling strength in the plastic bottle reduced in weight.

In order to solve the above problems, the plastic bottle of the present invention is
In a plastic bottle having a mouth, a shoulder, a torso, and a bottom,
The trunk is a cylindrical shape having the same diameter,
Each having a plurality of shallow grooves and deep grooves, which are annular circumferential grooves having an opening angle of 45 degrees or more and 90 degrees or less,
The ratio d1 / d2 between the depth d1 of the shallow groove and the depth d2 of the deep groove is 0.2 or more and 0.95 or less,
A ratio w1 / w2 of the width w1 of the shallow groove and the width w2 of the deep groove is 0.2 or more and 0.95 or less.

Furthermore, the depth d1 of the shallow groove is 1.0 mm or more and 3.0 mm or less,
The depth d2 of the deep groove is 3.0 mm or more and 5.0 mm or less.

Furthermore, the width w1 of the shallow groove is 3.0 mm or more and 8.0 mm or less,
The width w2 of the deep groove is 4.0 mm or more and 10.0 mm or less.

  Therefore, the weight-reduced plastic bottle of the present invention has the effect of absorbing the reduced pressure inside the plastic bottle while maintaining the buckling strength and maintaining a good appearance.

It is the front view by which an example of the plastic bottle which concerns on this embodiment was shown. It is a top view of the plastic bottle of FIG. It is a bottom view of the plastic bottle of FIG. It is the elements on larger scale of an upper trunk part. It is the VV sectional view taken on the line of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an example of a plastic bottle 1 according to the present embodiment. 2 is a plan view of the plastic bottle 1 of FIG. 1, and FIG. 3 is a bottom view of the plastic bottle 1 of FIG. In the following, for convenience of explanation, in the state of FIG. 1 in which the plastic bottle 1 is erected, the mouth portion 10 of the plastic bottle 1 in which the contents are filled in the container is referred to as the upper side.

  As shown in FIGS. 1 to 5, the plastic bottle 1 according to this embodiment includes a mouth portion 10, a shoulder portion 20, a trunk portion 30, and a bottom portion 40. And the trunk | drum 30 is a cylindrical shape of the same diameter, and has each the shallow groove | channel 50 and the deep groove | channel 51 which are cyclic | annular surrounding grooves whose opening angle is 45 degree | times or more and 90 degrees or less, respectively. The ratio d1 / d2 between the depth d1 and the depth d2 of the deep groove 51 is not less than 0.2 and not more than 0.95, and the ratio w1 / w2 between the width w1 of the shallow groove 50 and the width w2 of the deep groove 51 is It is 0.2 or more and 0.95 or less. Below, as a suitable aspect of the plastic bottle 1 which concerns on this embodiment, the trunk | drum 30 illustrates the form which has the eight shallow grooves 50 (50A-50H) and the seven deep grooves 51 (51A-51G). This will be described in detail.

  The mouth portion 10 becomes a filling port for contents, a spout, or a drinking mouth, and a cap (not shown) is attached to the mouth portion 10 to seal the plastic bottle 1. In addition, the form which seals the opening | mouth part 10 is not specifically limited, A screw-type cap, a cap-type cap, etc. can be used.

  The upper portion of the shoulder portion 20 is continuous with the mouth portion 10, while the lower portion thereof is continuous with the trunk portion 30. The shoulder portion 20 has a substantially truncated conical cylindrical shape that expands from the top to the bottom. The shoulder portion 20 is formed from a surface curved outward from the plastic bottle 1 in the vertical cross section, but may be a surface curved inward, and the shape of the shoulder portion 20 is not particularly limited. .

  Next, the trunk | drum 30 is a cylindrical shape of the same diameter, and the diameter is D1. Further, the body portion 30 has eight shallow grooves 50 (50A to 50H) and seven deep grooves 51 (51A to 51G), which are annular circumferential grooves that are recessed inward of the plastic bottle 1 and extend in the horizontal direction. ) And are formed. The shallow groove 50 and the deep groove 51 have different shapes. The shallow groove 50 and the deep groove 51 improve the strength of the body portion 30 against the load in the horizontal direction. In addition, the shallow groove 50 and the deep groove 51 serve as a cushion against a load in the vertical direction, and prevent the body portion 30 from buckling. Further, the shallow groove 50 and the deep groove 51 have an effect of absorbing this reduced pressure by contracting and deforming in the vertical direction when a reduced pressure is generated inside the plastic bottle 1, and details will be described later.

  Here, the torso 30 is divided into an upper torso 31 that continues to the shoulder 20 and a lower torso 32 that continues to the upper torso 31. The upper body part 31 and the lower body part 32 are connected via a connecting cylindrical part 33.

  In the upper body portion 31, three shallow grooves 50 and three deep grooves 51 are alternately arranged from above to below. On the other hand, in the lower body portion 32, three shallow grooves 50 and three deep grooves 51 are alternately arranged from the bottom to the top. And the arrangement | positioning of the shallow groove | channel 50 (50D-50F) and the deep groove 51 (51D-51F) in the lower side trunk | drum 32 is the shallow groove 50 (50A-50C) in the upper side trunk | drum 31, and the deep groove 51 (51A-51C). The arrangement is upside down.

  The connection cylinder part 33 is located between the upper trunk | drum 31 and the lower trunk | drum 32, and connects each. The connecting cylindrical portion 33 has a deep groove 51G at the approximate center in the vertical direction, and has shallow grooves 50G and 50H at the upper end and the lower end, respectively. Accordingly, the connecting cylindrical portion 33 has a vertically symmetrical shape with the deep groove 51 as the center. The connecting cylindrical portion 33 is not limited to the above-described configuration, and the depth, width, opening angle, etc. of the shallow grooves 50G, 50H and the deep groove 51G may be different from the configurations described later. good. In addition, from the viewpoint of improving the strength of the entire plastic bottle 1, the connecting cylindrical portion 33 has circumferential grooves at the center, upper end, and lower end in the vertical direction, and has a vertically symmetrical shape with the central circumferential groove as a center. preferable.

  Here, the deep groove 51 </ b> G of the connecting cylindrical portion 33 is located at the approximate center of the trunk portion 30 in the vertical direction. The arrangement of the shallow groove 50 and the deep groove 51 in the upper body portion 31 is opposite to the arrangement of the shallow groove 50 and the deep groove 51 in the lower body portion 32 in the vertical direction. That is, the shallow groove 50 (50A to 50H) and the deep groove 51 (51A to 51F) are disposed substantially vertically symmetrically about the deep groove 51G in the trunk portion 30.

  The bottom 40 is continuous with the lower part of the trunk part 30 (lower trunk part 32). A chamfered portion 41 that is chamfered is formed between the adjacent lower body portion 32 and the bottom portion 40. The bottom portion 40 extends in a direction perpendicular to the body portion 30, and includes a substantially flat bottom wall 42 that serves as a ground contact surface of the plastic bottle 1, and a dome 43 that protrudes inward from the bottom wall 42 to the plastic bottle 1. The dome 43 includes eight radial ribs 44 extending radially in the radial direction of the plastic bottle 1 (see FIG. 3). The dome 43 and the radial rib 44 improve the strength of the bottom portion 40. Note that the bottom portion 40 is not limited to the above-described configuration. For example, the number of the radial ribs 44 may be small (for example, four) or large (for example, twelve).

  Next, details of the shallow groove 50 and the deep groove 51 included in the body portion 30 will be described. FIG. 4 is a partially enlarged view of the upper body portion 31, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. 5 is a vertical cross-sectional view of the shallow groove 50 and the deep groove 51, and the right side of FIG.

  As described above, the body portion 30 is formed with eight shallow grooves 50 (50A to 50H) and seven deep grooves 51 (51A to 51G). As shown in FIG. 5, the shallow groove 50 includes an upper peripheral surface 53, a groove bottom surface 54, and a lower peripheral surface 55. The upper peripheral surface 53 is a peripheral surface that inclines inward of the plastic bottle 1 from above to below. The groove bottom surface 54 is a vertical circumferential surface. The lower peripheral surface 55 is a peripheral surface that inclines outward from the plastic bottle 1 from above to below. The upper peripheral surface 53 is continuous with the upper edge of the groove bottom surface 54, and the lower peripheral surface 55 is continuous with the lower edge of the groove bottom surface 54.

  The depth d1 of the shallow groove 50 is constant in the circumferential direction. The groove width w1 of the shallow groove 50 is constant in the circumferential direction. The width of the groove bottom surface 54, that is, the width w3 of the groove bottom portion of the shallow groove 50 is constant in the circumferential direction. The upper peripheral surface 53 and the lower peripheral surface 55 are vertically symmetric with respect to the groove bottom surface 54, and the angle of inclination of the upper peripheral surface 53 with respect to the horizontal and the angle of inclination of the lower peripheral surface 55 with respect to the horizontal are the same. The angle formed by the upper peripheral surface 53 and the lower peripheral surface 55, that is, the opening angle of the shallow groove 50 is θ1.

  On the other hand, the deep groove 51 has the same configuration as the shallow groove 50, and includes an upper peripheral surface 56, a groove bottom surface 57, and a lower peripheral surface 58. The upper peripheral surface 56 is a peripheral surface inclined inward of the plastic bottle 1 from above to below. The groove bottom surface 57 is a vertical peripheral surface. The lower peripheral surface 58 is a peripheral surface that inclines outward from the plastic bottle 1 from above to below. The upper peripheral surface 56 is continuous with the upper edge of the groove bottom surface 57, and the lower peripheral surface 58 is continuous with the lower edge of the groove bottom surface 57.

  The depth d2 of the deep groove 51 is constant in the circumferential direction. The groove width w2 of the deep groove 51 is constant in the circumferential direction. The width of the groove bottom surface 57, that is, the width w4 of the groove bottom portion of the deep groove 51 is constant in the circumferential direction. The upper peripheral surface 56 and the lower peripheral surface 58 are vertically symmetrical about the groove bottom surface 57, and the angle of inclination of the upper peripheral surface 56 with respect to the horizontal and the angle of inclination of the lower peripheral surface 58 with respect to the horizontal are the same. The angle formed by the upper peripheral surface 56 and the lower peripheral surface 58, that is, the opening angle of the deep groove 51 is θ2.

  Here, the ratio d1 / d2 between the depth d1 of the shallow groove 50 and the depth d2 of the deep groove 51 is not less than 0.2 and not more than 0.95. The ratio w1 / w2 between the width w1 of the shallow groove 50 and the width w2 of the deep groove 51 is not less than 0.2 and not more than 0.95. Further, the opening angle θ1 of the shallow groove 50 and the opening angle θ2 of the deep groove 51 are 45 degrees or more and 90 degrees or less, respectively.

  And the shallow groove | channel 50 improves the intensity | strength with respect to the load of a horizontal direction, and prevents buckling by the load of a perpendicular direction. Further, the shallow groove 50 has a small shrinkage deformation in the vertical direction when decompression occurs in the plastic bottle 1, and plays a role of preventing an appearance defect due to the bending of the body portion 30 with the shallow groove 50 as a base point. . On the other hand, the deep groove 51, which is a deep groove, improves the strength in the horizontal direction and prevents buckling due to a load in the vertical direction. Furthermore, the deep groove 51 has a large shrinkage deformation in the vertical direction when a reduced pressure is generated inside the plastic bottle 1, and plays a role of absorbing the reduced pressure inside. When the decompression occurs inside the plastic bottle 1, the vertical shrinkage of the deep groove 51 is larger than the vertical shrinkage of the shallow groove 50.

  By forming a plurality of shallow grooves 50 and deep grooves 51 having different effects in the body 30, the vertical and horizontal strength of the body 30 can be improved and the inside of the plastic bottle 1 can be improved. The vacuum can be effectively absorbed and the appearance can be maintained well. Here, when decompression occurs inside the plastic bottle 1, the shallow groove 50 mainly plays a role of maintaining the shape, and the deep groove 51 mainly plays a role of absorbing reduced pressure.

  Although the arrangement of the shallow grooves 50 and the deep grooves 51 is not particularly limited, it is preferable that the shallow grooves 50 and the deep grooves 51 are arranged substantially symmetrically in the vertical direction. By adopting such a configuration, two types of shallow grooves 50 and deep grooves 51 having different effects are arranged vertically symmetrically in the body portion 30, so that the balance between the strength of the entire body portion 30 and the reduced pressure absorption effect is vertical. Therefore, the reduced pressure inside the plastic bottle 1 can be effectively absorbed while maintaining the buckling strength.

  Moreover, it is preferable that the shallow grooves 50 and the deep grooves 51 are alternately arranged in the vertical direction. With this configuration, the strength and the reduced pressure absorption effect in the entire body portion 30 are equalized in the vertical direction, and the reduced pressure inside the plastic bottle can be effectively absorbed while maintaining the buckling strength.

  Moreover, it is preferable that the trunk | drum 30 is equipped with several cylindrical units which have one each of the shallow groove | channel 50 and the deep groove | channel 51, and is comprised combining a some unit. Here, the upper cylindrical portion 31 includes three unit cylindrical structures 60 each having one shallow groove 50 and one deep groove 51, and is configured by combining three unit cylindrical structures 60 (60A to 60C). The lower cylindrical portion 32 is configured by combining three unit cylindrical structures 60 (60 </ b> D to 60 </ b> F) similarly to the upper cylindrical portion 31.

  These six unit cylindrical structures 60 (60A to 60F) are all the same structure, and the configuration will be described by taking up the unit cylindrical structure 60A shown in FIG. The unit cylindrical structure 60A has a cylindrical shape with the same diameter, has a shallow groove 50A at one end, and has a deep groove 51A between the shallow groove 50A and the other end. The width of the cylindrical portion 61A between the shallow groove 50A and the deep groove 51A is w5, and the width of the cylindrical portion 62A between the deep groove 51A and the other end is w6. The width w5 of the cylindrical portion 61A is narrower than the width w6 of the cylindrical portion 62A.

  The unit cylindrical structure 60A having such a configuration has the effect of improving the strength in the vertical direction and the horizontal direction by the shallow grooves 50A and the deep grooves 51A, and effectively absorbing the reduced pressure inside the plastic bottle 1. In addition, the unit cylindrical structure 60A has an effect of improving the strength against pressure reduction in the plastic bottle 1 and vertical and horizontal loads by the cylindrical portion 61A having a narrower width than the cylindrical portion 62A. Further, the unit cylindrical structure 60A has a cylindrical portion 62A that is wider than the cylindrical portion 61A, and widens the range of the cylindrical shape when absorbing the reduced pressure inside the plastic bottle 1, and maintains the barrel portion 30 in the cylindrical shape. Has an effect.

  And since the upper cylindrical part 31 is comprised combining three unit cylindrical structures 60 (60A-60C) of the same structure, the effect by the unit cylindrical structure 60 is exhibited uniformly in any location of a perpendicular direction. . Therefore, the strength and the reduced pressure absorption effect in the entire upper cylindrical portion 31 are equalized in the vertical direction, and the reduced pressure inside the plastic bottle can be effectively absorbed while maintaining the buckling strength.

  Similarly to the upper cylindrical portion 31, the lower cylindrical portion 32 is configured by combining three unit cylindrical structures 60 (60D to 60F) having the same configuration. The lower cylindrical portion 32 has a configuration that is inverted upside down from the upper cylindrical portion 31 and has the same effect as the upper cylindrical portion 31.

  The upper cylindrical portion 31 and the lower cylindrical portion 32 are vertically symmetric with respect to the connecting cylindrical portion 33. Accordingly, since the strength and the reduced pressure absorption effect in the entire plastic bottle 1 are equalized and the balance is achieved in the vertical direction, the body portion 30 can effectively absorb the reduced pressure inside the plastic bottle 1 and has a good appearance. Can be maintained.

  Here, as described above, from the viewpoint of absorbing the reduced pressure inside the plastic bottle 1 and maintaining the strength and shape of the body 30, the ratio d 1 / d of the depth d 1 of the shallow groove 50 and the depth d 2 of the deep groove 51. d2 is 0.2 or more and 0.95 or less, and the ratio w1 / w2 between the width w1 of the shallow groove 50 and the width w2 of the deep groove is 0.2 or more and 0.95 or less. The opening angle θ1 and the opening angle θ2 of the deep groove 51 are 45 degrees or more and 90 degrees or less, respectively. If the ratio d1 / d2 is smaller than 0.2 or larger than 0.95, the reduced pressure absorption effect and the strength of the body 30 are liable to occur, and the shape of the body 30 is maintained. It becomes difficult to do. Further, if the ratio w1 / w2 is smaller than 0.2 or larger than 0.95, the reduced pressure absorption effect and the strength of the body portion 30 are liable to occur, and the shape of the body portion 30 is increased. It becomes difficult to maintain. Also, if the angle θ1 and the angle θ2 are smaller than 45 degrees or larger than 90 degrees, respectively, the reduced pressure absorption effect and the strength of the body 30 are liable to occur, and the shape of the body 30 is reduced. It becomes difficult to maintain.

  In addition, the depth d1 of the shallow groove 50 is preferably 1.0 mm or more and 3.0 mm or less, and the depth d2 of the deep groove 51 is preferably 3.0 mm or more and 5.0 mm or less. When the depth d1 is larger than 3.0 mm, the effect of preventing the body portion 30 from being bent with the shallow groove 50 as a starting point is hardly exhibited, and the formability is liable to deteriorate. On the other hand, when the depth d1 is smaller than 1.0 mm, the effect of improving the strength in the horizontal direction and preventing buckling due to the load in the vertical direction is hardly exhibited. In addition, when the depth d2 is greater than 5.0 mm, buckling deformation is likely to occur, and shapeability tends to deteriorate. On the other hand, when the depth d2 is smaller than 3.0 mm, the effect of absorbing the internal reduced pressure is hardly exhibited.

  Further, the width w1 of the shallow groove 50 is preferably 3.0 mm or more and 8.0 mm or less, and more preferably 4.0 mm or more and 6.0 mm or less. The width w2 of the deep groove 51 is preferably 4.0 mm or more and 10.0 mm or less, and more preferably 5.0 mm or more and 7.0 mm or less. If the width w1 is larger than 8.0 mm, the effect of improving the strength in the horizontal direction and preventing buckling due to the load in the vertical direction is hardly exhibited. On the other hand, when the width w1 is smaller than 3.0 mm, the effect of preventing the bending of the body portion 30 with the shallow groove 50 as a base point is hardly exhibited, and the formability is liable to deteriorate. In addition, when the width w2 is larger than 10.0 mm, buckling deformation is likely to occur. On the other hand, if the width w2 is smaller than 4.0 mm, the effect of preventing buckling due to the load in the vertical direction and the effect of absorbing the internal reduced pressure are hardly exhibited.

  The ratio w3 / w4 between the width w3 of the groove bottom of the shallow groove 50 and the width w4 of the groove bottom of the deep groove 51 is preferably 0.2 or more and 5.0 or less. With this configuration, when decompression occurs inside the plastic bottle 1, the shallow groove 50 is less likely to shrink and deform in the vertical direction, and the deep groove 51 shrinks and deforms in the vertical direction, effectively reducing the internal decompression. Can be absorbed. Therefore, the effect of the shallow groove 50 and the deep groove 51 is balanced, the strength in the vertical direction and the horizontal direction of the body portion 30 is improved, the reduced pressure inside the plastic bottle 1 can be effectively absorbed, and the appearance is good. Can be maintained.

  The width w3 of the groove bottom of the shallow groove 50 and the width w4 of the groove bottom of the deep groove 51 are both preferably 0.01 mm or more and 2.0 mm or less. When the width w3 and the width w4 are each larger than 2.0 mm, the effect of absorbing the internal reduced pressure and the effect of preventing the buckling due to the load in the vertical direction are hardly exhibited. Further, when the pressure is reduced inside, the shallow groove 50 or the deep groove 51 is not contracted and deformed in the vertical direction, and is easily bent from the groove bottom part 54 or the groove bottom part 57, and the body part 30 is likely to be curved. On the other hand, if the width w3 and the width w4 are smaller than 0.01 mm, the formability tends to deteriorate.

  Further, the opening angle θ1 of the shallow groove 50 and the opening angle θ2 of the deep groove 51 are preferably the same, and more preferably 75 degrees. By adopting such a configuration, the shallow groove 50 and the deep groove 51 have similar shapes with different depths and widths, and it becomes easy to manufacture a mold when the plastic bottle 1 is molded. In addition, the appearance of the torso 30 is unified, and eye catching, which is an effect of attracting and taking away the purchaser's eyes, is improved.

  In the unit cylindrical structure 60, the width w5 of the cylindrical portion 61 is preferably 4.0 mm or more and 20.0 mm or less, and the width w6 of the cylindrical portion 62 is preferably 4.0 mm or more and 20.0 mm or less. If the width w5 is larger than 20.0 mm, the strength of the cylindrical portion 61 is likely to be reduced. If the width w5 is smaller than 4.0 mm, it becomes difficult to maintain the body portion 30 in a cylindrical shape and the shapeability is improved. It tends to get worse. If the width w6 is larger than 20.0 mm, the strength of the cylindrical portion 62 is likely to be reduced, and if it is smaller than 4.0 mm, it becomes difficult to maintain the barrel portion 30 in a cylindrical shape, resulting in reduced handling. It's easy to do. The cylindrical portion 61 is a place that is a basic structure of the cylindrical body portion 30. If the width w6 is smaller than 4.0 mm, the distance between the shallow groove 50 and the deep groove 51 becomes large, and the body portion 30 becomes a bellows-like shape with dense circumferential grooves. The width w5 of the cylindrical portion 61 and the width w6 of the cylindrical portion 62 may be the same. With such a configuration, it becomes easy to produce a mold when the plastic bottle 1 is molded. Moreover, the external appearance of the trunk | drum 30 is unified and eye catching property improves.

  In addition, the trunk | drum 30 is not limited to the above-mentioned structure, The structure which has the reinforcement groove | channel of a structure different from the above-mentioned shallow groove 50 and the deep groove 51 may be sufficient. However, such a configuration makes it difficult to balance the strength of the body portion 30 and the reduced pressure absorption effect, and makes it difficult to maintain the appearance. Moreover, the metal mold | die at the time of shape | molding the plastic bottle 1 becomes complicated, and productivity tends to fall. Therefore, it is preferable that the trunk portion 30 includes only the shallow groove 50 and the deep groove 51.

  The plastic bottle 1 according to the present embodiment is not limited by the size and can be applied to various sizes. However, the plastic bottle 1 is suitable for the plastic bottle 1 having an internal volume of 200 ml to 2000 ml. It is. In particular, the overall height H1 of the plastic bottle 1 is preferably 130 mm to 300 mm, and the diameter D1 of the body portion 30 is preferably 50 mm to 120 mm, and the effects exhibited by the plastic bottle 1 according to this embodiment can be suitably obtained.

  As a thermoplastic resin constituting the plastic bottle 1, for example, a thermoplastic polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, or a copolymer thereof, these resins, or other resins In particular, an ethylene terephthalate thermoplastic polyester such as polyethylene terephthalate can be preferably used. Furthermore, acrylonitrile resin, polyethylene, polypropylene, propylene-ethylene copolymer and the like can also be used. Furthermore, it is also possible to use plant-derived biomass plastics such as polylactic acid (PLA). Various additives such as colorants, UV absorbers, mold release agents, lubricants, nucleating agents, antioxidants, antistatic agents, etc. are blended with the above-mentioned resins within a range that does not impair the quality of the molded product. can do.

  As the ethylene terephthalate-based thermoplastic resin constituting the plastic bottle 1, the ethylene terephthalate unit occupies most of the ester repeating portion, generally 70 mol% or more, and has a glass transition point (Tg) of 50 to 90 ° C. Those having a melting point (Tm) in the range of 200 to 275 ° C. are preferred. In addition, as an ethylene terephthalate thermoplastic polyester, polyethylene terephthalate is particularly excellent in terms of pressure resistance, but in addition to ethylene terephthalate units, dibasic acids such as isophthalic acid and naphthalenedicarboxylic acid, and diols such as propylene glycol Copolyesters containing a small amount of ester units consisting of can also be used.

  Furthermore, the plastic bottle 1 can be composed of two or more thermoplastic polyester layers. When the plastic bottle 1 is constituted by two or more thermoplastic polyester layers, an intermediate layer such as a barrier layer or an oxygen absorbing layer can be provided between the layers. As the oxygen absorbing layer, a layer containing a combination of an oxidizable organic component and a transition metal catalyst, or a gas barrier resin that does not substantially oxidize can be used.

  The plastic bottle 1 can be produced by molding a preform produced by injection molding of the above-described material by blow molding.

  As described above, in the plastic bottle 1 according to the present embodiment, the body portion 30 is a cylindrical shape having the same diameter, and is an annular circumferential groove having an opening angle of 45 degrees or more and 90 degrees or less. A plurality of shallow grooves 50 and deep grooves 51 are provided, and a ratio d1 / d2 between the depth d1 of the shallow grooves 50 and the depth d2 of the deep grooves 51 is not less than 0.2 and not more than 0.95. The ratio w1 / w2 of the width w1 of the deep groove 51 and the width w2 of the deep groove 51 is not less than 0.2 and not more than 0.95. And according to the structure which concerns on this embodiment, the pressure reduction inside a plastic bottle 1 is absorbed with respect to the plastic bottle 1 reduced in weight, maintaining a buckling strength, and an external appearance can be maintained favorable.

  Hereinafter, the present invention will be described in more detail and specifically with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
A plastic bottle 1 according to this embodiment shown in FIG. 1 was used. That is, the plastic bottle 1 has a plurality of shallow grooves 50 and deep grooves 51, each of which has a cylindrical portion with an identical diameter and an annular circumferential groove with an opening angle of 45 degrees or more and 90 degrees or less, The ratio d1 / d2 between the depth d1 of the shallow groove 50 and the depth d2 of the deep groove 51 is not less than 0.2 and not more than 0.95, and the ratio w1 between the width w1 of the shallow groove 50 and the width w2 of the deep groove 51. / W2 has a characteristic of 0.2 or more and 0.95 or less. The plastic bottle 1 was made of polyethylene terephthalate and had a weight of 23.8 g and a capacity of 1050 ml. The plastic bottle 1 has an overall height H1 of 252.5 mm, a diameter D1 of the body 30 of 81 mm, a depth d1 of the shallow groove 50 of 2.0 mm, and a depth d2 of the deep groove 51 of 3.0 mm. The width w1 of the shallow groove 50 was 4.5 mm, the width w2 of the deep groove 51 was 5.7 mm, and the opening angle θ1 of the shallow groove 51 and the opening angle θ2 of the deep groove were 75 degrees. The plastic bottle 1 was produced by blow molding a preform.

(Appearance confirmation test at normal temperature)
The plastic bottle 1 of Example 1 was filled with 1000 g of water heated to 70 ° C. by a hot filling method, and the mouth 10 was sealed with a cap. The plastic bottle 1 filled with the contents by the hot filling method was left to stand at normal temperature (23 ° C.). At this time, the total height of the plastic bottle 1 in an upright state and the maximum horizontal displacement of the upper end with respect to the lower end of the barrel 30, that is, the amount of inclination of the barrel 30 were measured. Table 1 shows the results. The plastic bottle 1 was not deformed such as a dent, and the appearance was kept good.

(Vertical seat strength test)
The plastic bottle 1 of Example 1 was filled with 1000 g of water heated to 70 ° C. by a hot filling method, and the mouth 10 was sealed with a cap. The plastic bottle 1 filled with the contents by the hot filling method was left to stand at normal temperature (23 ° C.). At this time, the vertical buckling strength of the plastic bottle 1 in an upright state was measured. This vertical buckling strength was measured using a tester, TOP LOAD, manufactured by AGR. Table 1 shows the results.

  The following points were derived from the examples described above. In the first embodiment, when the contents are filled by the hot filling method, the decompression inside the plastic bottle 1 in the normal temperature state is absorbed mainly by contraction deformation of the deep groove 51, and the contraction deformation is substantially vertical. The body portion 30 was not greatly inclined and the deformation such as the depression did not occur, and the appearance could be maintained satisfactorily. Furthermore, the buckling strength of the plastic bottle 1 was 393N.

  From the above-described examples, the plastic bottle 1 according to the present embodiment can reduce the pressure inside the plastic bottle when stored at room temperature after being filled by the hot filling method in the plastic bottle reduced in weight. It was shown that it can absorb and retain its buckling strength even when it is thinned, while maintaining its good appearance.

  The present disclosure can be suitably used for a plastic bottle stored at room temperature after hot filling. However, the present disclosure is not limited to the above-described embodiments and examples. The plastic bottle of the present disclosure is useful for any container containing contents such as soy sauce, sauce, mirin, or other non-carbonated beverages such as green tea, oolong tea, tea, coffee, fruit juice, etc. It is.

DESCRIPTION OF SYMBOLS 1 Plastic bottle 10 Mouth part 20 Shoulder part 30 Body part 31 Upper body part 32 Lower side body part 33 Connection cylindrical part 40 Bottom part 50 Shallow groove 51 Deep groove 60 Unit cylindrical structure d1 Shallow groove depth d2 Deep groove depth w1 Shallow groove Width w2 Deep groove width w3 Shallow groove bottom width w4 Deep groove bottom width θ1 Shallow groove opening angle θ2 Deep groove opening angle

Claims (3)

In a plastic bottle having a mouth, a shoulder, a torso, and a bottom,
The trunk is a cylindrical shape having the same diameter,
Each having a plurality of shallow grooves and deep grooves, which are annular circumferential grooves having an opening angle of 45 degrees or more and 90 degrees or less,
The ratio d1 / d2 between the depth d1 of the shallow groove and the depth d2 of the deep groove is 0.2 or more and 0.95 or less,
The plastic bottle according to claim 1, wherein a ratio w1 / w2 of the shallow groove width w1 and the deep groove width w2 is 0.2 to 0.95. The depth d1 of the shallow groove is 1.0 mm or more and 3.0 mm or less,
The depth d2 of the deep groove is 3.0 mm or more and 5.0 mm or less,
The plastic bottle according to claim 1. The width w1 of the shallow groove is 3.0 mm or more and 8.0 mm or less,
The width w2 of the deep groove is 4.0 mm or more and 10.0 mm or less,
The plastic bottle according to claim 1 or 2.

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