JP2015048126A - Plastic bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic bottle which increases structural strength of a plastic bottle provided with a plurality of reduced pressure absorbing panels on a barrel part and materializes light weight of the bottle.SOLUTION: Panel surfaces 422 of reduced pressure absorbing panels 42 of a bottle 1 are composed of protruded curved surfaces 422a and upper and lower protruded restoration surfaces 422b and 422c. Upper parts of the upper protruded restoration surfaces 422b and right and left both side parts are connected with depressed parts 421 respectively via an upper curved surface 422b1 which stands up from an edge part of an upper side inclination surface of the depressed parts 421 and is inflated to bottle outer side and via right and left side curved surfaces 422b2 and 422b2 which stand up from respective edge parts of right and left inclination surfaces of the depressed parts 421 and is inflated to bottle outer side, and thereby, the strength with respect to reduced pressure of the panel surfaces 422 is increased.

Description

  The present invention relates to a plastic bottle (hereinafter, also referred to as “bottle”) formed by stretching and forming a polyethylene terephthalate resin, and relates to a structure having a plurality of reduced pressure absorption panels in the body of the bottle.

  As a plastic bottle used as a packaging container for liquid seasonings and the like, as shown in FIG. 7, a plurality of annular grooves 102 for buckling reinforcement and a plurality of reduced pressure absorptions for absorbing vacuum are formed in the body 101 of the bottle 100. Each panel 103 is provided, and by forming the annular groove 102 and the reduced pressure absorption panel 103 in a predetermined range with respect to the outer diameter size and the thickness of the bottle 100, etc. A structure is known in which both the absorption effect against a load and impact applied to the bottle 100 from the outside and the absorption effect of the reduced pressure generated inside the bottle are enhanced (for example, see Patent Documents 1 and 2).

JP 2007-186225 A JP 2008-7132 A

  In the case of the bottle 100 having a full capacity of about 1000 ml filled with the liquid seasoning, it is used to improve the handling convenience when carrying the bottle 100 by hand or pouring the liquid. From the viewpoint of reducing the environmental load by reducing the amount of resin, there is a practical demand for molding the bottle 100 in a light weight.

In the bottle 100 in which the content liquid is filled in a high temperature state such as a liquid seasoning, the structural strength, that is, the heated content liquid is bottled in the vacuum absorption panel that functions to absorb the change in the bottle internal pressure. 100 due to the positive pressure immediately after filling the cap and attaching the cap and sealing, the strength against bulging deformation of the panel part toward the outside of the bottle due to heat, and the volume reduction due to the cooling of the content liquid in the sealed bottle The intensity | strength with respect to this pressure reduction toward the inside is requested | required.
When the weight of the bottle 100 that is currently molded to a weight of about 40 g is reduced to 35 g, the amount of plastic raw materials used is reduced and the thickness of the bottle is reduced, so the molded bottle 100 is filled with a high-temperature content liquid. When the cap is sealed, any part enclosed by a broken line in FIG. 7 is folded inside the bottle due to the reduced pressure toward the inside of the bottle as the liquid content cools, and crushing occurs starting from the broken part. Thus, the bottle appearance is impaired.

  In order to reduce the weight of the bottle 100, it is necessary to take measures to increase the structural strength of the bottle 100 without reducing the absorption function with respect to changes in the bottle internal pressure even when the thickness of the entire bottle is reduced. is there.

  SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, an object of the present invention is to increase the structural strength of a plastic bottle provided with a plurality of reduced pressure absorption panels in the body portion, thereby realizing a weight reduction of the bottle. .

In solving the above-mentioned problems, the present invention is a plastic bottle formed by blow molding having a cylindrical body part, and is directed outward from the bottle in a recessed part that is inclined from the surface of the body part and is recessed toward the inside of the bottle. In a plastic bottle provided with a plurality of reduced pressure absorption panels provided on the peripheral surface of the body, provided with a panel surface bulging
The panel surface is a convex curved surface that bulges in an arc shape in plan view toward the outer side in the bottle radial direction, and an upper side that bulges in an arc shape in plan view toward the outer side in the bottle radial direction located above and below the convex curved surface, respectively. Consists of a convex restoration surface and a lower convex restoration surface,
The upper and lower convex restoring surfaces are inclined inward of the bottle from the upper part to the lower part of the upper convex restoring surface, and the lower convex restoring surface from the lower part to the upper part of the bottle. Continuing from the convex curved surface, a boundary line is formed along the circumferential direction at the boundary between the upper convex restoration surface and the convex curved surface,
At least the upper convex restoring surface of the upper and lower convex restoring surfaces is connected to the recessed portion via an upper curved surface whose upper portion rises from the edge of the upper inclined surface of the recessed portion and bulges outward from the bottle. And the left and right side portions are connected to the recessed portions via left and right curved surfaces that rise from the respective edge portions of the left and right inclined surfaces of the recessed portion and swell outward from the bottle. .

According to this, the upper convex restoration surface is connected to the concave portion through the upper curved surface and the left and right sides through the left and right curved surfaces, and the upper and left and right curved surfaces and concave portions are connected to each other. A groove-shaped rib projecting inward from the bottle is formed at the boundary portion of the bottle, that is, the upper convex restoration surface is surrounded by the groove-shaped rib and connected to the recessed portion, so that the high-temperature content The strength against the pressure (positive pressure) toward the outside of the bottle due to heat immediately after the liquid is filled in the bottle increases, and the panel surface is less likely to be broken or crushed.
In addition, combined with this, the upper convex restoration surface and the left and right sides are connected to the concave portion through the upper and left and right curved surfaces, so that the convex curved surface is changed from the upper convex restoration surface. The degree of protrusion to the outside of the bottle along the longitudinal direction of the bottle that reaches the lower convex restoration surface sandwiched between the upper convex restoration surface and the bottle extending from the upper part to the lower part of the upper convex restoration surface Since a large amount of inward inclination (inclination angle) is secured, the strength against pressure reduction applied to the inside of the bottle increases due to cooling of the liquid in the bottle, and it is difficult for the panel surface to be bent or crushed due to pressure reduction. It becomes a structure.
In order to increase the strength against the positive pressure toward the outside of the bottle and to make the panel surface foldable and crushed due to the reduced pressure inside the bottle, it is more difficult to come in. The lower part is connected to the recessed part via the lower curved surface that rises from the edge of the upper inclined surface of the recessed part and bulges outward from the bottle, and the left and right side parts are respectively the left and right inclined surfaces of the recessed part. It is preferable to have a configuration in which each is connected to a recessed portion via left and right curved surfaces that rise from the edge of the bottle and bulge outward from the bottle.

In the bottle having the above-described configuration, the upper convex restoration surface is provided so that the left and right widths gradually increase from the boundary line with the convex curved surface which is the lower portion thereof to the upper portion thereof, and the convex curved surface and the lower convex shape are provided. It is preferable that the restoration surface is provided so that the left and right widths gradually increase from the boundary line to the lower part of the lower convex restoration surface.
According to this, the panel surface consisting of the upper and lower convex restoration surfaces and the convex curved surface between them, the periphery when viewed from the front, the upper half of the panel surface is a substantially equal leg with the short side on the lower side A trapezoidal shape with a lower half on the upper side with a short side opposite to the upper half is provided with a substantially isosceles trapezoidal shape, and the width between both sides is the same across the upper and lower ends Compared with the panel surface with a width, that is, the periphery of which is bordered in a rectangular shape when viewed from the front, the buckling strength of the panel surface is increased, and it is high when a force along the vertical direction is applied to the panel surface While strength can be obtained, the inward displacement of the panel surface can be allowed and absorbed with respect to changes in the pressure inside the bottle.

In the bottle having the above-described configuration, the upper convex restoration surface and the left and right curved surfaces provided on the left and right sides of the lower convex restoration surface are not formed at the boundary with the convex curved surface, respectively, and the upper convex restoration The left and right curved surfaces of the surface are directed from the boundary to the upper part of the upper convex restoration surface, and the left and right curved surfaces of the lower convex restoration surface are directed from the boundary to the lower part of the lower convex restoration surface, It is preferable to provide each so as to increase the rising amount from the edge of the recessed portion.
According to this, when the rising amount of the left and right curved surfaces is large at the boundary with the convex curved surface, when the change in the bottle internal pressure is absorbed by the panel surface, the convex restoration surface is not affected by the movement of the convex curved surface. It does not follow smoothly and stress tends to concentrate on the boundary part where the rising amount is large, and it tends to bend and crush, but as described above, if it is provided so that the rising amount of the edge of the recessed part gradually increases, The convex restoration surface smoothly follows the movement of the convex curved surface, and the change in the bottle internal pressure can be reliably absorbed.

Furthermore, in the bottle having the above-described configuration, the boundary between the upper and lower convex restoration surfaces and the curved surface surrounding the periphery, and the ridge line that is the boundary between the curved surface and the edge of the recessed portion, each of the boundary portions is an arcuate curved surface. It is preferable that the ridgeline is formed by a smooth curved surface.
According to this, if the outline of the boundary with the curved surface and the boundary with the edge is an acute angle, the stress concentration is generated and the panel surface is likely to be broken or crushed. By preventing stress concentration, the panel surface can be operated smoothly so as to follow changes in the bottle internal pressure.

The curvature radius (R) of the curved surface that bulges outward from the edge of the recessed portion can be provided in the range of 1.5 mm to 10 mm.
In general, if the bottle thickness is uniform, the smaller the radius of curvature of the curved surface is, the larger the range of operation of the panel surface with respect to the change in the bottle internal pressure, which can be effectively absorbed. However, in plastic bottles formed by blow molding, where the radius of curvature of the curved surface is too small, it is generally difficult to follow the mold of the heated resin when the bottle thickness is thin, and the curvature is large. In addition to becoming a part, the part may be thicker than other parts. And the location where the wall thickness is extremely non-uniform may reduce the bottle strength.
Therefore, in the plastic bottle of the present invention formed by blow molding, the lower limit of the radius of curvature of the curved surface is set to 1.5 mm to improve the mold followability of the heating resin and reduce the wall thickness. A large operating range of the panel surface is ensured by keeping it uniform, and conversely, if the radius of curvature of the curved surface is too large, the panel surface will approach a shape with no rise from the edge. Since the operating range of the surface becomes small and the strength may be insufficient for the pressure reduction toward the inside of the bottle, the upper limit of the radius of curvature of the curved surface is set to 10 mm, and the pressure reduction toward the inside of the bottle It is preferable that a sufficient strength is secured.
In particular, for a bottle with a full capacity of about 1000 ml, the radius of curvature of the curved surface is preferably in the range of 3 mm to 6 mm.
By configuring in this way, the structural strength of the vacuum absorbing panel is increased, and even if the entire bottle is formed thin, the strength against vacuuming toward the inside of the bottle is increased, and the panel surface is unlikely to be broken or crushed. It can be a structure.

The bottle having the above-described configuration can be applied to a bottle having an appropriate volume exceeding 350 to 1000 ml.
When applied to a bottle that is filled with the content liquid in a high temperature state such as a liquid seasoning with a full injection volume of about 1000 ml, the bottle has its barrel surface constricted inward of the bottle at the approximate center of the barrel. A constricted portion is provided, and a plurality of annular grooves are provided on the peripheral surface of the body portion above the constricted portion, and a plurality of reduced pressure absorption panels are provided on the peripheral surface of the body portion below the constricted portion. It is preferable to have.
According to this, the vertical load and impact applied from above the bottle are effectively absorbed and relaxed by the annular groove, and the body is prevented from buckling and deformed. There is no problem that the rigidity is increased and the body portion is deformed into a flat shape. Further, the reduced pressure in the bottle is absorbed and relaxed by the plurality of reduced pressure absorption panels, and as described above, the content liquid is filled under severe filling conditions in combination with the structural increase in the strength of the panel surface. Even in this case, it is possible to effectively prevent the occurrence of deformation, breakage, and crushing of the vacuum absorbing panel corresponding to the change in the pressure inside the bottle, and to maintain the bottle in a good appearance shape. .

  In addition, as resin used for shaping | molding of a bottle, a polyethylene terephthalate type-resin, mainly PET resin can be used. Copolyesters containing ethylene terephthalate units as the main component and other polyester units can also be used. In order to improve heat resistance, a small amount of resin such as nylon resin or polyethylene naphthalate resin is used. May be.

It is a front view of the plastic bottle of one embodiment of the present invention. FIG. 2 is a cut end view taken along line II-II in FIG. 1. It is the figure which expanded and showed the panel surface provided in the bottle trunk | drum of FIG. FIG. 4 is a cut end view taken along line IV-IV in FIG. 1. (A)-(D) are the cutting | disconnection end elevations along the AA line of FIG. 4, BB line, CC line, and DD line. It is the figure which showed the relationship between the pressure reduction degree of a bottle and the suction amount in an Example and a comparative example. It is a front view of the conventional bottle.

Preferred embodiments of the present invention will be described with reference to the drawings.
A plastic bottle 1 shown in FIG. 1 is a so-called PET bottle in which a parison made of polyethylene terephthalate resin is biaxially stretched and blow-molded, and is composed of a plug part 2, a shoulder part 3, a trunk part 4, and a bottom part 5. .
The plastic bottle 1 according to the present embodiment has a total length of 225 to 260 mm and a full capacity of 1035 to 1055 ml, and is used as a packaging container for a large-capacity liquid seasoning.

  As shown in the figure, the bottle 1 of this embodiment is connected to a substantially conical shoulder portion 3 having a curved peripheral surface from a lower edge of the mouthpiece portion 2 to which the cap is attached. A cylindrical body 4 having an appropriate height is connected to each other, and a bottom part 5 is provided below the body 4.

  Specifically, a constricted portion 6 in which the peripheral surface of the body portion 4 is narrowed toward the center of the bottle is provided at the approximate center of the body portion 4. Are provided with a label portion 4A in which the annular groove 41 is disposed, and a pressure absorbing portion 4B in which a plurality of vacuum absorbing panels 42 described later are disposed in the lower portion. In the vicinity of the bottom of the body 4, a reinforcing bottom annular groove 7 is provided.

The label portion 4A serves as a grip portion of the hand and is a portion around which a label on which information on the content liquid is written is wound. By pouring the label portion 4A by hand and tilting the bottle 1, the content liquid is poured out. Is done.
The label portion 4A has a maximum outer diameter of 70 to 80 mm, and a plurality of annular concave grooves 41 for buckling reinforcement that are continuous in the circumferential direction are arranged in parallel at substantially equal intervals in the vertical direction. . Although the space | interval P of the upper and lower sides of the annular ditch | groove 41 can be suitably set according to the height of a bottle and the outer diameter of a trunk | drum, it is normally set in the range of 12-17 mm.

In FIG. 2, the annular groove 41 is formed in a cross-sectional shape having a groove depth of 1.0 to 1.5 mm, preferably 1.2 to 1.4 mm. The curvature radius is set to 0.5 to 1.0 mm. The upper and lower sides of the annular groove 41 are preferably connected to the cylindrical outer surface of the cylindrical body with smooth curved surfaces having a curvature radius of 2.0 to 4.0 mm.
The annular groove 41 satisfying such conditions preferably acts on a bottle formed with a thin label portion 4A, and the vertical load or impact applied to the spout portion 2 from above is caused by the annular groove 41. Absorption is effectively reduced, and the rigidity of the body 4 is increased by the rib effect due to the presence of the annular groove 41 in the body 4, and the body 4 is deformed into a flat shape even when the body 4 is gripped by hand. There will be no troubles.

The pressure absorbing portion 4B is configured by arranging six decompression absorbing panels 42 in parallel at equal intervals in the circumferential direction of the bottle 1.
Each decompression absorption panel 42 is provided with a panel surface 422 having an elastic restoring function, which bulges toward the outside of the bottle in a recessed portion 421 which is inclined from the surface of the body portion 4 and is recessed vertically inward of the bottle. It is provided in the arranged shape.

  The panel surface 422 bulges in a circular arc shape in plan view toward the outer side in the bottle radial direction located above and below the convex curved surface 422a and the convex curved surface 4223a, respectively. The upper convex restoration surface 422b and the lower convex restoration surface 422c.

  Specifically, as shown in FIGS. 3 and 4, the upper and lower convex restoration surfaces 422 b and 422 c are in the bottle vertical direction, and the upper convex restoration surface 422 b extends from the upper part to the lower part, and the lower convex shape. The restoring surface 422c is inclined inward from the lower part to the upper part, and is connected to the convex curved surface 422a. The boundary lines 422d and 422e are provided along the circumferential direction at the boundary with the convex curved surface 422a. Is formed.

  The upper convex restoring surface 422b is connected to the concave portion 421 through an upper curved surface 422b1 whose upper portion rises from the edge of the inclined surface on the upper side of the concave portion 421 and bulges outward from the bottle. Each of the left and right inclined surfaces of the recessed portion 421 is provided in a shape connected to the recessed portion 422 via left and right curved surfaces 422b2 and 422b2 that rise from the respective edge portions of the recessed portion 421 and swell outward. Further, the lower convex restoration surface 422c is connected to the concave portion 421 via a lower curved surface 422c1 whose lower portion rises from the edge of the lower inclined surface of the concave portion 421 and bulges outward from the bottle, In addition, the left and right side portions are provided in a shape connected to the recessed portion 422 through left and right curved surfaces 422c2 and 422c2 that rise from the respective edge portions of the left and right inclined surfaces of the recessed portion 421 and bulge outward from the bottle.

  In addition, as shown in FIG. 3, the upper convex restoration surface 422b is provided so that the left and right widths gradually increase from the boundary line 422d to the convex curved surface 422a, which is the lower part, to the upper part thereof. The convex curved surface 422a and the lower convex restoration surface 422c are provided so that the left and right widths gradually increase from the boundary line 422d to the lower portion of the lower convex restoration surface 422c.

The left and right curved surfaces 422b2 and 422b2 of the upper convex restoration surface 422b have different curvature radii (R) from the edges of the concave portions 421 over the entire left and right sides of the upper convex restoration surface 422b. (Ra, Rb, Rc, Rd in FIG. 5), the rising amount from the edge of the recessed portion 421 increases from the boundary portion 422d with the convex curved surface 422a toward the upper portion of the upper convex restoration surface 422b. Is provided. On the contrary, the left and right curved surfaces 422c2 and 422c2 of the lower convex restoration surface 422c are recessed from the boundary portion 422e with the convex curved surface 422a toward the lower portion of the lower convex restoration surface 422c. The amount of rising from the edge of 421 is increased.
The curved surfaces 422b2 and 422c2 on both sides of the upper and lower convex restoration surfaces 422b and 422c are not provided on both sides of the boundary lines 422d and 422e (see FIG. 5D).

The thickness of the pressure absorbing portion 4B can be made thin like the label portion 4A.
The curvature radius in the circumferential direction of the convex curved surface 422a and the upper and lower convex restoration surfaces 422b and 422c of the vacuum absorbing panel 42 can be arbitrarily set as long as it is equal to or less than the curvature radius of the bottle body surface. The dent (depth) of the panel surface 422 can be set to 1 mm or more.
The curvature radii (R1 in FIG. 4 and Ra, Rb, Rc, Rd in FIG. 5) of the curved surfaces 422b1, 422b2, 422c1, and 422c2 surrounding the upper and lower convex restoration surfaces 422b and 422c are: It can set to the range of 5 mm-10 mm, and it is more preferable to set to the range of 3 mm-6 mm.

When the bottle 1 of this embodiment configured as described above is filled with a high-temperature content liquid and sealed, the inside of the bottle becomes hot and positive pressure state, so that the panel surface 422 protrudes from the surface of the bottle body. .
That is, the panel surface 422 including the convex curved surface 422a and the upper and lower convex restoration surfaces 422b and 422c protrudes from the surface of the bottle body while elastically deforming with the recessed portion 421 as a fulcrum, and the positive pressure in the bottle is absorbed and relaxed. The At this time, boundary lines 422d and 422ec between the convex curved surface 422a and the upper and lower convex restoration surfaces 422b and 4222c become inflection points, and excessive protrusion of the panel surface 422 is suppressed.
And with respect to the density change due to the cooling of the content liquid, the convex restoring surfaces 422b and 422c are recessed inside the bottle by the restoring action of the convex restoring surfaces 422b and 422c positioned above and below the convex curved surface 422a. When the convex curved surface 422a is recessed inside the bottle, all the panel surfaces 422 are restored to the original state.
When the temperature of the content liquid further decreases to normal temperature, the inside of the bottle becomes negative pressure, but the entire panel surface 422 having a shape bulging in an arc shape with respect to the circumferential direction is drawn inside the bottle. By deforming into a flat or concave curved surface, the reduced pressure in the bottle is absorbed and relaxed.

  The upper and lower convex restoration surfaces 422b and 422c are surrounded by curved surfaces 422b1, 422b2, 422c1, and 422c2 that are connected to the concave portions 421, and the boundary between the curved surfaces and the concave portions 421 is inside the bottle. Since the groove-shaped rib projecting in the direction is formed, the strength against the pressure (positive pressure) toward the outside of the bottle is increased, and further, the upper and lower convex restoration surfaces 422b are surrounded by these curved surfaces. , 422c is secured to the inside of the bottle, so that the strength against pressure reduction applied to the inside of the bottle increases, and the effect of maintaining rigidity against the internal stress of the bottle 1 is enhanced. The structure is difficult to come.

  The number and size of the reduced pressure absorption panels 42 are arbitrary, and can be appropriately selected according to the capacity of the bottle 1 and the density change due to cooling of the high-temperature filled content liquid. . As shown in FIG. 2, the total surface area of the vacuum absorbing panel 42 is set to be about 1/3 of the entire surface area of the bottle, and the vertical lengths of the upper and lower convex restoration surfaces 422b and 422c are It is preferable to set it to be about 1/3 of the length of the convex curved surface 422a in the vertical direction.

  Next, a comparison result between the bottle 1 of the present embodiment and the bottle of the conventional form when a bottle that is usually formed into 40 g is formed into 35 g will be described.

(Example)
The bottle 1 shown in FIG. 1 was formed by biaxial stretch blow molding.
The weight of the molded bottle 1 was 35 g, and the average thickness of the body part 4 was 0.311 mm.
The curvature radius R1 of the upper curved surface 422b1 of the upper convex restoring surface 422b is 5.28 mm, and the curvature radii of the left and right curved surfaces 422b2 at the position in FIG. 5 are Ra of 5.28 mm and Rb of 4.84 mm, respectively. Rc was set to 4.25 mm, and Rd was set to 9.77 mm.

(Comparative example)
The bottle 100 shown in FIG. 7 was formed by biaxial stretch blow molding.
The molded bottle 100 was of the same capacity as the bottle 1, its weight was 35 g, and the average thickness of the body 4 was 0.319 mm.
In addition, when the bottle 100 shown in FIG. 7 is formed into a usual 40 g, the average thickness of the body 4 is about 0.344 mm.

The bottle 1 of the example and the bottle 100 of the comparative example were filled with 78 ° C. hot water as a content solution, a cap was attached, the inside was sealed, and the external shape of the bottle was visually confirmed.
Immediately after sealing, it was confirmed that the panel surface 421 of the reduced pressure absorption panel 42 swelled to the outside of the bottle and absorbed the positive pressure in both the bottle 1 and the bottle 100. However, in the state where the content liquid is cooled to room temperature, the appearance of the bottle 1 remains normal only by the panel surface 421 being recessed toward the inside of the bottle, but the bottle 100 is shown in FIG. The panel surface 421 was folded inward at the broken line portion, and partial crushing occurred.

Next, with respect to the bottle 1 of the example and the bottle 100 of the comparative example, in order to confirm the pressure resistance at the time of decompression, each of the bottles 1 is installed in the suction pump and the inside of the bottle is sucked from the plug part 2, The relationship was measured.
For the measurement, a suction pump is connected to the stopper part of the bottle filled with the cooled content liquid, and a gauge and a pressure gauge for measuring the suction volume are installed on the conduit between the stopper part and the suction pump. Then, the water level rise of the content liquid was read with a gauge, and this was taken as the suction volume. Then, while sucking at a rate of 5 liters / minute with a suction pump, the relationship between the suction amount indicated by the gauge and the degree of decompression indicated by the pressure gauge was recorded and measured until the measurement bottle was damaged. .

The measurement results are shown in FIG. In the bottle 1 of the example, crushing of the bottle occurred when the degree of decompression reached −168 mmHg. In the bottle 100 of the comparative example, crushing of the bottle occurred when the degree of vacuum reached -134 mmHg.
From the measurement results, it was confirmed that when the bottle was reduced in weight, the bottle 1 of this embodiment improved the pressure-resistant strength until the bottle was crushed by about 25% compared to the bottle 100 of the conventional embodiment. .

  In addition, the illustrated bottle shows an example of the embodiment of the present invention, and the present invention is not limited to the illustrated form, and can be configured in other appropriate forms.

DESCRIPTION OF SYMBOLS 1 Plastic bottle, 2 mouthpiece part, 3 shoulder part, 4 trunk | drum part, 4A label part, 4B pressure absorption part, 41 annular groove, 42 decompression absorption panel, 421 recessed part, 422 panel surface, 422a convex curved surface, 422b Upper convex restoration surface, 422c Lower convex restoration surface, 422d, 422e Boundary line, 5 bottom part, 6 constricted part, 7 bottom annular groove

Claims (5)

It is a plastic bottle formed by blow molding having a cylindrical body part, and is provided with a panel surface that bulges outward from the bottle in a recessed part that is inclined from the surface of the body part and recessed toward the inside of the bottle. In a plastic bottle equipped with a plurality of vacuum absorption panels on the peripheral surface of the trunk,
The panel surface is a convex curved surface that bulges in an arc shape in plan view toward the outer side in the bottle radial direction, and an upper side that bulges in an arc shape in plan view toward the outer side in the bottle radial direction located above and below the convex curved surface, respectively. Consists of a convex restoration surface and a lower convex restoration surface,
The upper and lower convex restoring surfaces are inclined inward of the bottle from the upper part to the lower part of the upper convex restoring surface, and the lower convex restoring surface from the lower part to the upper part of the bottle. Continuing from the convex curved surface, a boundary line is formed along the circumferential direction at the boundary between the upper convex restoration surface and the convex curved surface,
At least the upper convex restoring surface of the upper and lower convex restoring surfaces is connected to the recessed portion via an upper curved surface whose upper portion rises from the edge of the upper inclined surface of the recessed portion and bulges outward from the bottle. And the left and right side portions are connected to the recessed portions via left and right curved surfaces that rise from the respective edge portions of the left and right inclined surfaces of the recessed portion and swell outward from the bottle. Plastic bottle.   The upper convex restoration surface is provided so that the left and right widths gradually increase from the boundary line with the convex curved surface which is the lower part to the upper part, and the convex curved surface and the lower convex restoration surface form the boundary 2. The plastic bottle according to claim 1, wherein the plastic bottle has a configuration in which the left and right widths gradually increase from the line to the lower part of the lower convex restoration surface.   The left and right curved surfaces provided on the left and right sides of each of the upper and lower convex restoration surfaces are not formed at the boundary with the convex curved surface, and the left and right curved surfaces of the upper convex restoration surface are restored to the upper convex shape from the boundary. The left and right curved surfaces of the lower convex restoration surface toward the upper part of the surface increase from the boundary part to the lower part of the lower convex restoration surface so that the rising amount from the edge of the concave part increases. The plastic bottle of Claim 1 or 2 which has the structure provided.   The ridgeline that is the boundary between the upper and lower convex restoration surfaces and the curved surface that surrounds it, and the boundary between the curved surface and the edge of the concave part, connects each boundary part with an arc-shaped curved surface, and the ridgeline is smooth The plastic bottle according to claim 1, wherein the plastic bottle has a configuration formed by a curved surface.   A constricted part with the body peripheral surface constricted inward of the bottle is provided in the approximate center of the body part, and a plurality of annular concave grooves are provided on the peripheral surface of the body part above the constricted part, and below the constricted part. The plastic bottle in any one of Claims 1-4 which has the structure by which the several pressure reduction absorption panel was provided in the trunk | drum peripheral surface.

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