JP6623520B2 - Plastic bottle - Google Patents

Description

  The present invention relates to a plastic bottle, and more particularly, to a structure of a lightweight plastic bottle.

  For example, a plastic bottle is used as a container filled with a beverage. The plastic bottle has been used as a container for storing liquid foods such as seasonings which were conventionally stored in a glass container.

  The production volume of such plastic bottles is increasing every year. On the other hand, plastic bottles are lightened by reducing the amount of raw materials used in terms of reducing energy consumption and carbon dioxide emissions by saving resources, reducing garbage, and reducing the environmental burden during transportation. Is being worked on. However, when the weight of the plastic bottle is reduced, the thickness of the container of the plastic bottle becomes thinner, 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 a cardboard or the like with a plurality of containers facing upward. Therefore, the lower plastic bottle tends to be easily deformed by the load applied in the vertical direction, and may cause poor appearance and collapse of the load.

  By the way, in a plastic bottle in which the contents are sealed, when the temperature changes between the time of filling and the time of storing the contents, the internal pressure changes in accordance with the temperature change. For example, in a plastic bottle filled with contents by hot filling (hot filling method) in which contents heated to sterilization are filled into plastic bottles and sealed, the temperature of the contents is reduced by storage at room temperature. If the pressure is lower than at the time of filling, a reduced pressure is generated internally. On the other hand, plastic bottles whose contents have been filled by a sterile filling method (room temperature filling method), in which the contents are filled at room temperature and sealed in a plastic bottle whose interior has been sterilized in advance with a drug, are heated at the time of sale, etc. If the temperature is higher than at the time of filling, a pressure increase occurs internally. In addition, such a pressure change inside the plastic bottle is caused by a volume change accompanying a temperature change of the contents sealed inside.

  Further, the plastic bottle has a slight oxygen permeability. If the plastic bottle is stored for a long period of time, depending on the contents, oxidation occurs, which also causes a reduced pressure inside the plastic bottle.

  The plastic bottle is different from the glass container in that the material is soft, so that the plastic bottle is easily deformed by a change in internal pressure, and the lightened plastic bottle is more easily deformed. Therefore, when reducing the weight of a plastic bottle, it is more important to take measures against the internal pressure change together with the strength.

  Patent Literature 1 discloses a plastic bottle in which a plurality of reduced-pressure absorbing panels are formed at a lower portion of a body portion, and the reduced-pressure absorbing panels are deformed to absorb a change in pressure inside the container.

JP-A-2002-193229

  Here, when the weight of a plastic bottle having a decompression absorption panel in the body as in Patent Document 1 is reduced, the decompression absorption panel is greatly deformed when absorbing the pressure change inside the plastic bottle, and the appearance is maintained well. It may not be possible. Further, when a vertical load is applied to the plastic bottle, an eccentric load is applied to the column between the adjacent decompression absorption panels, so that the buckling strength may be reduced.

  Therefore, an object of the present invention is to provide a lightweight plastic bottle capable of absorbing the reduced pressure inside the plastic bottle while maintaining buckling strength and maintaining a good appearance.

In order to solve the above problems, the plastic bottle of the present invention
In a plastic bottle having a mouth, a shoulder, a trunk, and a bottom,
The torso,
Cylindrical shape of the same diameter,
It is divided into an upper cylindrical portion connected to the shoulder portion and a lower cylindrical portion connected to the upper cylindrical portion,
The opening angle is an annular peripheral groove of 45 degrees or more and 90 degrees or less, each having a plurality of shallow grooves and deep grooves,
A 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 to the width w2 of the deep groove is 0.2 or more and 0.95 or less;
The upper cylindrical portion is configured by combining a plurality of unit cylindrical structures each having one shallow groove and one deep groove in the same direction,
The lower cylindrical portion has a configuration in which the upper cylindrical portion is turned upside down,
The unit cylindrical structure,
All have the same structure,
Said one end has a shallow groove, the have a deep groove between the shallow groove and the other end,
The width w5 of the cylindrical portion between the shallow groove and the deep groove is configured to be smaller than the width w6 of the cylindrical portion between the deep groove and the other end, and the shape is maintained by the wide cylindrical portion. Is what you do.

  Therefore, the lightweight 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 the good appearance.

FIG. 2 is a front view illustrating an example of the plastic bottle according to the embodiment. 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 side cylindrical part . FIG. 5 is a sectional view taken along line VV of FIG. 4.

  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. FIG. 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 the upper side.

  As shown in FIGS. 1 to 5, the plastic bottle 1 according to the present embodiment has a mouth portion 10, a shoulder portion 20, a trunk portion 30, and a bottom portion 40. The trunk 30 has a plurality of shallow grooves 50 and deep grooves 51, each of which is a cylindrical shape having the same diameter and an opening angle of 45 degrees or more and 90 degrees or less. 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 of the width w1 of the shallow groove 50 and the width w2 of the deep groove 51 is: It is not less than 0.2 and not more than 0.95. In the following, a preferred embodiment of the plastic bottle 1 according to the present embodiment is an example in which the body 30 has eight shallow grooves 50 (50A to 50H) and seven deep grooves 51 (51A to 51G). And will be described in detail.

  The mouth 10 serves as a filling port, a spout, or a drinking mouth for the contents, and the plastic bottle 1 is hermetically sealed by attaching a cap (not shown) to the mouth 10. In addition, the form which seals the mouth part 10 is not specifically limited, A cap of a screwing type, a cap of a stopper type, etc. can be used.

  The upper part of the shoulder 20 is connected to the mouth 10, while the lower part is connected to the trunk 30. The shoulder portion 20 has a substantially frustoconical cylindrical shape whose diameter increases from above to below. The shoulder 20 is formed from an outwardly curved surface of the plastic bottle 1 in a vertical cross section, but may be an inwardly curved surface, and the shape of the shoulder 20 is not particularly limited. .

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

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

In the upper cylindrical portion 31, three shallow grooves 50 and three deep grooves 51 are alternately arranged from top to bottom. On the other hand, in the lower cylindrical portion 32, three shallow grooves 50 and three deep grooves 51 are alternately arranged from below to above. The arrangement of the shallow grooves 50 (50D to 50F) and the deep grooves 51 (51D to 51F) in the lower cylindrical portion 32 corresponds to the arrangement of the shallow grooves 50 (50A to 50C) and the deep grooves 51 (51A to 51C) in the upper cylindrical portion 31. And upside down.

The connection cylindrical part 33 is located between the upper cylindrical part 31 and the lower cylindrical part 32, and connects each. The connecting cylindrical portion 33 has a deep groove 51G at substantially the center in the vertical direction, and has shallow grooves 50G and 50H at the upper and lower ends, respectively. Therefore, the connecting cylindrical portion 33 has a vertically symmetric shape with the deep groove 51 as the center. The connecting cylindrical portion 33 is not limited to the above-described configuration, and may be a circumferential groove in which the depth, width, opening angle, and the like of the shallow grooves 50G, 50H and the deep groove 51G are different from those described below. good. In addition, from the viewpoint of improving the strength of the entire plastic bottle 1, the connecting cylindrical portion 33 may have peripheral grooves at the center, upper end, and lower end in the vertical direction, and may be vertically symmetrical with respect to the central peripheral groove. preferable.

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

The upper part of the bottom part 40 continues below the trunk part 30 (the lower cylindrical part 32). A chamfered portion 41 is formed between the adjacent lower cylindrical portion 32 and the bottom portion 40. The bottom 40 extends in a direction perpendicular to the body 30, and has a substantially flat bottom wall 42 serving as a ground surface of the plastic bottle 1, and a dome 43 projecting from the bottom wall 42 to the inside of 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 40. In addition, the bottom part 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 may be large (for example, twelve).

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

  As described above, the body 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 is inclined inward of the plastic bottle 1 from above to below. The groove bottom surface 54 is a vertical peripheral surface. The lower peripheral surface 55 is a peripheral surface that is inclined outward from the plastic bottle 1 downward from above. The upper peripheral surface 53 is connected to the upper edge of the groove bottom surface 54, and the lower peripheral surface 55 is connected to 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 of the shallow groove 50 is constant in the circumferential direction. The upper peripheral surface 53 and the lower peripheral surface 55 are vertically symmetrical about 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 between 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 that is 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 is inclined outward from the plastic bottle 1 downward from above. 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 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 between 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 of the depth d1 of the shallow groove 50 and the depth d2 of the deep groove 51 is 0.2 or more and 0.95 or less. The ratio w1 / w2 of the width w1 of the shallow groove 50 and the width w2 of the deep groove 51 is 0.2 or more and 0.95 or less. 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.

  The shallow groove 50 improves strength against a load in the horizontal direction and prevents buckling due to a load in the vertical direction. Furthermore, the shallow groove 50 has a small shrinkage deformation in the vertical direction when decompression occurs inside the plastic bottle 1, and plays a role of preventing appearance defects due to bending of the body 30 based on the shallow groove 50. . On the other hand, the deep groove 51, which is a deep groove, improves strength in the horizontal direction and prevents buckling due to a load in the vertical direction. Furthermore, when a pressure reduction occurs inside the plastic bottle 1, the deep groove 51 has a large contraction deformation in the vertical direction, and plays a role of absorbing the pressure reduction inside the plastic bottle 1. When the inside of the plastic bottle 1 is decompressed, the amount of contraction of the deep groove 51 in the vertical direction is larger than the amount of contraction of the shallow groove 50 in the vertical direction.

  By forming a plurality of two types of shallow grooves 50 and deep grooves 51 having different effects in the body 30 respectively, the strength of the body 30 in the vertical direction and the horizontal direction is improved, and the inside of the plastic bottle 1 is improved. The reduced pressure can be effectively absorbed, and the appearance can be favorably maintained. Here, when decompression occurs inside the plastic bottle 1, the shallow groove 50 mainly serves to maintain the shape, and the deep groove 51 mainly serves to absorb reduced pressure.

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

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

  Further, it is preferable that the body 30 includes a plurality of cylindrical units each having one shallow groove 50 and one deep groove 51, and is configured by combining a plurality of units. 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). Further, the lower cylindrical portion 32 is configured by combining three unit cylindrical structures 60 (60D to 60F), like the upper cylindrical portion 31.

  These six unit cylindrical structures 60 (60A to 60F) have the same structure, and the structure will be described with reference to 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 smaller 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 groove 50A and the deep groove 51A and effectively absorbing the reduced pressure inside the plastic bottle 1. Further, the unit cylindrical structure 60A has an effect of improving the strength of the inside of the plastic bottle 1 against decompression and vertical and horizontal loads by the cylindrical portion 61A having a width smaller than the cylindrical portion 62A. In addition, the unit cylindrical structure 60A has a cylindrical portion 62A wider than the cylindrical portion 61A, thereby increasing the range of the cylindrical shape when absorbing the reduced pressure inside the plastic bottle 1, and maintaining the body portion 30 in the cylindrical shape. Has an effect.

The upper cylindrical section 31, since three units cylindrical structure having the same configuration 60 (60A-60C) are constituted by combination, the effect of the unit cylindrical structure 60 at any point in the vertical direction is evenly exerted You. Therefore, the strength and the reduced pressure absorbing 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.

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

  The upper cylindrical portion 31 and the lower cylindrical portion 32 are vertically symmetrical with respect to the connecting cylindrical portion 33. Therefore, since the body portion 30 has equal strength and reduced pressure absorbing effect in the entire plastic bottle 1 and is balanced in the vertical direction, the reduced pressure inside the plastic bottle 1 can be effectively absorbed, and the appearance is improved. 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 d1 / of the depth d1 of the shallow groove 50 and the depth d2 of the deep groove 51 is used. d2 is 0.2 or more and 0.95 or less, and the ratio w1 / w2 of 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 respectively 45 degrees or more and 90 degrees or less. When 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 likely to decrease, and the shape of the body 30 is maintained. It becomes difficult to do. When 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 30 are likely to be reduced, and the shape of the body 30 Is difficult to maintain. When the angle θ1 and the angle θ2 are each smaller than 45 degrees or larger than 90 degrees, the reduced pressure absorbing effect and the strength of the body 30 are likely to be reduced, and the shape of the body 30 Is difficult to maintain.

  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. If the depth d1 is larger than 3.0 mm, the effect of preventing the trunk 30 from being bent with the shallow groove 50 as a base is not easily exerted, and the shapeability is likely to be deteriorated. 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 becomes difficult to be exhibited. If the depth d2 is larger than 5.0 mm, buckling deformation is likely to occur, and shapeability tends to deteriorate. On the other hand, if the depth d2 is smaller than 3.0 mm, the effect of absorbing the internal reduced pressure is less likely to be exhibited.

  Also, the width w1 of the shallow groove 50 is preferably 3.0 mm or more and 8.0 mm or less, 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, more preferably 5.0 mm or more and 7.0 mm or less. When 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 less likely to be exerted. On the other hand, if the width w1 is smaller than 3.0 mm, the effect of preventing the body portion 30 from being bent with the shallow groove 50 as a base is less likely to be exhibited, and the shapeability is likely to be deteriorated. If 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 less likely to be exhibited.

  The ratio w3 / w4 of the width w3 of the groove bottom of the shallow groove 50 to the width w4 of the groove bottom of the deep groove 51 is preferably 0.2 or more and 5.0 or less. With such a configuration, when decompression occurs inside the plastic bottle 1, the shallow groove 50 is unlikely to contract and deform in the vertical direction, and the deep groove 51 contracts and deforms in the vertical direction to effectively reduce the internal pressure. Can be absorbed. Therefore, the effects of the shallow groove 50 and the deep groove 51 are balanced, the strength of the body 30 in the vertical and horizontal directions is improved, and 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. If the width w3 and the width w4 are each larger than 2.0 mm, the effect of absorbing the internal decompression and the effect of preventing buckling due to the load in the vertical direction are less likely to be exhibited. In addition, when the pressure is reduced inside, the shallow groove 50 or the deep groove 51 does not shrink and deform in the vertical direction, the bending easily starts from the groove bottom 54 or the groove bottom 57, and the trunk 30 tends to be curved. On the other hand, if the width w3 and the width w4 are smaller than 0.01 mm, the shapeability tends to deteriorate.

  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. With such a configuration, the shallow groove 50 and the deep groove 51 have similar shapes with different depths and widths, which facilitates the production of a mold for molding the plastic bottle 1. Further, the appearance of the torso 30 is unified, and the eye catching effect, which is an effect of eye-catching or robbing the purchaser, is improved.

  Further, 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. When the width w5 is larger than 20.0 mm, the strength of the cylindrical portion 61 tends to decrease, and when 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 reduced. Easy to get worse. When the width w6 is larger than 20.0 mm, the strength of the cylindrical portion 62 tends to decrease, and when the width w6 is smaller than 4.0 mm, it becomes difficult to maintain the body portion 30 in a cylindrical shape, and the handleability decreases. It's easy to do. Note that the cylindrical portion 61 is a place where the basic structure of the cylindrical body 30 is formed. If the width w6 is smaller than 4.0 mm, the distance between the shallow groove 50 and the deep groove 51 becomes narrow, and the body 30 has a shape like a bellows with a dense circumferential groove. 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 is easy to manufacture a mold when the plastic bottle 1 is molded. In addition, the appearance of the body 30 is unified, and the eye catching property is improved.

  In addition, the body 30 is not limited to the above-described configuration, and may have a configuration having a reinforcing groove different from the above-described shallow groove 50 and the deep groove 51. However, with such a configuration, it is difficult to balance the strength of the body 30 and the reduced pressure absorbing effect, and it is difficult to maintain the appearance. In addition, the mold used to mold the plastic bottle 1 becomes complicated, and the productivity tends to decrease. Therefore, it is preferable that the body 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 size, and can be applied to various sizes. However, the plastic bottle 1 is suitable for the plastic bottle 1 having an inner 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 30 is preferably 50 mm to 120 mm, so that the effects of the plastic bottle 1 according to the present embodiment can be suitably obtained.

  As the 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 Is particularly preferable, and particularly, ethylene terephthalate-based thermoplastic polyester such as polyethylene terephthalate can be suitably used. Further, acrylonitrile resin, polyethylene, polypropylene, propylene-ethylene copolymer and the like can also be used. Further, a biomass-based plastic derived from a plant, for example, polylactic acid (PLA) can be used. The resin described above contains various additives such as a colorant, an ultraviolet absorber, a release agent, a lubricant, a nucleating agent, an antioxidant, an antistatic agent, and the like, as long as the quality of the molded article is not impaired. can do.

  As the ethylene terephthalate-based thermoplastic resin constituting the plastic bottle 1, most of the ester repeating portion, generally 70 mol% or more, is occupied by ethylene terephthalate units, 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 suitable. Further, as an ethylene terephthalate-based thermoplastic polyester, polyethylene terephthalate is particularly excellent in terms of pressure resistance and the like. A copolymerized polyester containing a small amount of an ester unit consisting of

  Further, the plastic bottle 1 may be composed of two or more thermoplastic polyester layers. When the plastic bottle 1 is constituted by two or more thermoplastic polyester layers, a barrier layer and an intermediate layer such as 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 manufactured by molding a preform manufactured 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 30 has a cylindrical shape having the same diameter and an opening angle of 45 degrees or more and 90 degrees or less. It has a plurality of shallow grooves 50 and a plurality of deep grooves 51, and the ratio d1 / d2 of the depth d1 of the shallow groove 50 to the depth d2 of the deep groove 51 is 0.2 or more and 0.95 or less. The ratio w1 / w2 between the width w1 of the deep groove 51 and the width w2 of the deep groove 51 is 0.2 or more and 0.95 or less. According to the configuration of the present embodiment, it is possible to absorb the reduced pressure inside the plastic bottle 1 while maintaining the buckling strength of the lightened plastic bottle 1 and maintain a good appearance.

  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]
The plastic bottle 1 according to the present 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 shape having the same diameter and an annular peripheral groove having an opening angle of 45 degrees or more and 90 degrees or less, The ratio d1 / d2 of the depth d1 of the shallow groove 50 to the depth d2 of the deep groove 51 is 0.2 or more and 0.95 or less, and the ratio w1 of the width w1 of the shallow groove 50 to the width w2 of the deep groove 51 is set. / W2 has a feature that it is 0.2 or more and 0.95 or less. The plastic bottle 1 was made of polyethylene terephthalate, weighed 23.8 g, and had a capacity of 1050 ml. The plastic bottle 1 has a total 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 test at room temperature)
1000 g of water heated to 70 ° C. was filled into the plastic bottle 1 of Example 1 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 allowed to stand at room temperature (23 ° C.). At this time, the overall height of the plastic bottle 1 in the upright state and the maximum horizontal displacement of the upper end with respect to the lower end of the body 30, that is, the amount of inclination of the body 30 were measured. Table 1 shows the results. It should be noted that the plastic bottle 1 was not deformed such as a dent, and the appearance was well maintained.

(Vertical seat strength test)
1000 g of water heated to 70 ° C. was filled into the plastic bottle 1 of Example 1 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 allowed to stand at room temperature (23 ° C.). At this time, the vertical buckling strength of the plastic bottle 1 in an upright state was measured. The measurement of the vertical buckling strength was performed using TOP LOAD, a tester manufactured by AGR. Table 1 shows the results.

  The following points have been derived from the above-described embodiment. In the first embodiment, when the contents are filled by the hot filling method, the reduced pressure inside the plastic bottle 1 at normal temperature is absorbed mainly by the contraction deformation of the deep groove 51, and this contraction deformation is substantially vertical. In this direction, the trunk 30 did not tilt significantly, no deformation such as dents occurred, and the appearance could be maintained satisfactorily. Further, the buckling strength of the plastic bottle 1 was 393N.

  From the above-described example, the plastic bottle 1 according to the present embodiment reduces the pressure inside the plastic bottle when the plastic bottle 1 is stored at room temperature after being filled by the hot filling method due to its configuration. It was shown that the material can be absorbed and maintain the buckling strength even when the thickness is reduced, and the appearance can be maintained well.

  The present disclosure can be suitably used for plastic bottles that are 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, for example, seasonings such as soy sauce, sauce, and mirin, or various non-carbonated beverages such as green tea, oolong tea, black tea, coffee, fruit juice, and the like. It is.

DESCRIPTION OF SYMBOLS 1 Plastic bottle 10 Mouth 20 Shoulder 30 Body 31 Upper cylinder 32 Lower cylinder 33 Connecting cylinder 40 Bottom 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 (1)

In a plastic bottle having a mouth, a shoulder, a trunk, and a bottom,
The torso,
Cylindrical shape of the same diameter,
It is divided into an upper cylindrical portion connected to the shoulder portion and a lower cylindrical portion connected to the upper cylindrical portion,
The opening angle is an annular peripheral groove of 45 degrees or more and 90 degrees or less, each having a plurality of shallow grooves and deep grooves,
A 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 to the width w2 of the deep groove is 0.2 or more and 0.95 or less;
The upper cylindrical portion is configured by combining a plurality of unit cylindrical structures each having one shallow groove and one deep groove in the same direction,
The lower cylindrical portion has a configuration in which the upper cylindrical portion is turned upside down,
The unit cylindrical structure,
All have the same structure,
Said one end has a shallow groove, the have a deep groove between the shallow groove and the other end,
The width w5 of the cylindrical portion between the shallow groove and the deep groove is configured to be smaller than the width w6 of the cylindrical portion between the deep groove and the other end, and the shape is maintained by the wide cylindrical portion. Do, plastic bottle.

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