JP6389359B2 - Bottle manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a bottle.

Conventionally, for example, a bottle formed in a bottomed cylindrical shape as shown in Patent Document 1 below is known. The bottom wall portion of the bottle is provided with a grounding portion located at the outer peripheral edge portion, and a multi-stage topped cylindrical deformation cylinder portion standing on the grounding portion and closing the inside of the grounding portion.
In this bottle, for example, when a high-temperature content is filled in the bottle and then cooled, etc., the first cylindrical shape located inside the bottle axial direction among the cylindrical portions constituting the deformable cylindrical portion. The deformed tube portion is deformed such that the portion is relatively displaced toward the inner side in the bottle axial direction with respect to the second tubular portion located on the outer side, so that the reduced pressure absorption performance is exhibited.

International Publication No. 2010/061758

By the way, in this kind of bottle, when the hot contents are filled in the bottle as described above, the first cylindrical part is affected by the heat of the contents, and the first cylindrical part is compared with the second cylindrical part. In some cases, the deformable cylinder portion is deformed so as to be relatively displaced toward the outside in the bottle axial direction. In such a bottle with the deformed tube portion deformed, the reduced pressure absorption performance may not be sufficiently exhibited.
In order to solve this problem, when the bottle is formed by blow molding using a mold, the bottom wall portion is formed by increasing the temperature of the bottom mold forming the bottom wall portion of the bottle. It is conceivable to improve the heat resistance of the deformed cylinder portion by heat setting.

However, in the manufacturing method, each cylindrical part of the deformed cylindrical part in the bottle molded in the cavity of the mold is fitted to the bottom mold separately, so that the bottom mold is released from the bottom wall part. Moreover, as described above, the bottom mold is heated to a high temperature, so that the bottom mold and the bottom wall of the bottle are easily adhered to each other due to the heat from the bottom mold. When the bottom mold is released from the bottle, there is a possibility that the deformed cylindrical portion of the bottle sticks to the bottom mold and, for example, reversely deforms in the bottle axial direction.
It is also possible to suppress the sticking of the bottle to the bottom mold by applying a surface treatment to the cavity surface of the bottom mold, but in this case, the surface treatment effect is effective in the process of producing a large number of bottles with the mold. It will weaken.

  This invention is made | formed in view of the situation mentioned above, Comprising: It aims at providing the manufacturing method of the bottle which can form a bottle with high precision.

In order to solve the above problems, the present invention proposes the following means.
The bottle manufacturing method according to the present invention is formed in a bottomed cylindrical shape, and has a grounding portion located on the outer peripheral edge portion on the bottom wall portion, and a multi-stage existence that stands upright on the grounding portion and closes the inside of the grounding portion. A deformed tubular portion having a top tube shape, and the deformed tubular portion is connected to the grounding portion from the inner side in the bottle radial direction and extends upward, which is the inner side in the bottle axial direction, and the rising portion An annular movable wall portion that protrudes inward in the bottle radial direction from the upper end portion of the peripheral wall portion, and the movable wall portion is movable upwardly around a connecting portion with the rising peripheral wall portion A bottle manufacturing method for forming an arranged bottle by blow molding using a mold, wherein the bottom wall portion of the mold is formed from the bottle molded in a cavity of the mold. In the mold release step of releasing the bottom mold to be formed, A boundary portion between the outer surface of the cylindrical portion and the cavity surface of the bottom mold is connected to the outside of the mold through a connection hole provided in the bottom mold, and the bottle is formed in the cavity. In the blow molding step of molding the cavity, the inside of the cavity is opened to the outside of the mold through the connection hole , and in the mold release step, the bottle portion is more radial than the rising peripheral wall portion in the boundary portion. A portion that is located on the inner side of the mold and that has the movable wall portion is connected to the outside of the mold through the connection hole .

According to the present invention, since the boundary portion is connected to the outside of the mold through the connection hole during the mold release process, when the bottom mold is released from the bottle, the boundary portion is passed through the connection hole from the outside of the mold. Air can be supplied to the boundary. Thereby, it becomes possible to release the outer surface of the deformable cylinder part from the cavity surface of the bottom mold and to prevent the deformed cylinder part from sticking to the bottom mold, and the bottle can be formed with high accuracy.
Also , during the blow molding process to mold the bottle in the cavity, the inside of the cavity is opened to the outside of the mold through the connection hole, so it is possible to improve the shapeability of the bottle and make the bottle more accurate Can be formed.
Further, in the mold release process, the portion located on the inner side in the bottle radial direction from the rising peripheral wall portion of the boundary portion is connected to the outside of the mold through the connection hole, so that the bottom die is moved from the bottle to the bottle axial direction. The movable wall part sticks to the bottom mold when it is pulled away to the lower side, which is the outside of the wall, and this movable wall part is restrained from moving downward about the connecting part with the rising peripheral wall part Thus, the bottle can be reliably formed with high accuracy.

  In the mold release step, a plurality of locations spaced in the circumferential direction of the bottle may be connected to the outside of the mold through the connection holes.

  In this case, at the time of the mold release process, a plurality of locations that are spaced apart in the bottle circumferential direction among the boundary portions are connected to the outside of the mold through the connection holes. Can be supplied. Thereby, it becomes possible to suppress that a part of the bottom wall portion of the bottle along the circumferential direction of the bottle sticks locally to the bottom mold, and the bottle can be formed with higher accuracy.

  In addition, during the mold release step, a plurality of locations that are spaced apart in the bottle radial direction may be connected to the outside of the mold through the connection holes.

  In this case, at the time of the mold release process, a plurality of locations spaced in the bottle radial direction among the boundary portions are connected to the outside of the mold through the connection holes. Can be supplied. Thereby, it becomes possible to suppress that the part along the bottle radial direction in the bottom wall part of a bottle sticks locally to a bottom mold | type, and a bottle can be formed with higher precision.

Further, the deformable cylinder portion includes a depressed peripheral wall portion extending upward from an inner end portion in the bottle radial direction of the movable wall portion, and the movable wall portion and At least one of the portions where the depressed peripheral wall portion is located may be connected to the outside of the mold through the connection hole .

  In this case, at the time of the mold release step, at least one part of each part where the movable wall part and the depressed peripheral wall part are located is connected to the outside of the mold through the connection hole. It becomes possible to suppress sticking to the bottom mold for both of the depressed peripheral wall portions, and the bottle can be more reliably formed with high accuracy.

  According to the bottle manufacturing method of the present invention, the bottle can be formed with high accuracy.

It is a side view of the bottle shown as one embodiment concerning the present invention. It is a bottom view of the bottle shown in FIG. FIG. 3 is a cross-sectional view of the bottle shown in FIG. It is a longitudinal cross-sectional view which shows the manufacturing method of the bottle shown in FIGS.

Hereinafter, a bottle according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the bottle 10 according to the present embodiment includes a mouth part 11, a shoulder part 12, a body part 13, and a bottom part 14, and these bottles are positioned in a state where their respective central axes are located on a common axis. It is set as the schematic structure connected in order.
Hereinafter, the common axis is referred to as a bottle axis O, and the mouth 11 side is referred to as the upper side and the bottom 14 side is referred to as the lower side along the bottle axis O direction. A direction perpendicular to the bottle axis O is referred to as a bottle radial direction, and a direction around the bottle axis O is referred to as a bottle circumferential direction.

The bottle 10 is integrally formed of a synthetic resin material such as polyethylene terephthalate. The bottle 10 is formed by, for example, biaxial stretch blow molding. Furthermore, this bottle 10 may be used as a so-called heat-resistant bottle filled with the content of 80 to 100 ° C. (preferably 83 to 93 ° C., for example, about 87 ° C.), or about 60 to 78 ° C. It may be used to fill the contents.
The mouth portion 11 is formed in a cylindrical shape, and a cap (not shown) is attached to the mouth portion 11. Further, each of the mouth part 11, the shoulder part 12, the body part 13, and the bottom part 14 has a circular cross-sectional view perpendicular to the bottle axis O.

The shoulder 12 is connected to the lower end of the mouth 11 and gradually increases in diameter as it goes downward.
The trunk portion 13 is formed in a cylindrical shape and extends downward from the lower end of the shoulder portion 12. Of the body portion 13, an intermediate portion 13 c between both end portions 13 a and 13 b in the bottle axis O direction has a smaller diameter than these both end portions 13 a and 13 b. An upper end groove 27 and a lower end groove 28 extending continuously over the entire circumference are formed in both end portions 13a and 13b of the body portion 13, respectively.

  In the intermediate portion 13c of the body portion 13, a plurality of circumferential grooves 16 extending continuously over the entire circumference are formed at intervals in the bottle axis O direction. In the illustrated example, the circumferential groove 16 is larger in both the groove width and depth than the upper end groove 27 and the lower end groove 28. The plurality of circumferential grooves 16 are arranged at intervals in the bottle axis O direction over the entire region in the bottle axis O direction of the intermediate portion 13 c of the body portion 13.

  The bottom portion 14 is connected to the lower end of the body portion 13 and is formed in a cup shape that closes the lower end opening of the body portion 13. Specifically, the bottom portion 14 has a heel portion 17 whose upper end opening is connected to the lower end opening portion of the body portion 13, a lower end opening portion of the heel portion 17 is closed, and an outer peripheral edge portion is a grounding portion 18. And a bottom wall portion 19.

  On the outer peripheral surface of the heel portion 17 and the outer peripheral surface of the lower end portion 13b of the body portion 13, a concavo-convex portion 17a having a low protruding height is formed by, for example, embossing. Thereby, in the filling process, when a large number of bottles 10 are transported, the outer peripheral surfaces of the heel portions 17 of the adjacent bottles 10 and the outer peripheral surfaces of the lower end portion 13b of the barrel portion 13 are in close contact with each other. Therefore, it is possible to suppress the slippage and to prevent the occurrence of so-called blocking. In the example shown in the figure, uneven portions 17 a are also formed on each surface of the lower end groove 28.

As shown in FIG. 2, the grounding portion 18 of the bottom wall portion 19 is formed in an annular shape that is arranged coaxially with the bottle axis O, and continuously extends over the entire circumference in the bottle circumferential direction. The grounding portion 18 is provided with a multi-tiered cylindrical deformable tubular portion 20 that closes the inside of the grounding portion 18.
The deformed cylinder portion 20 is a tubular shape in which the tubular portion located on the upper side (inner side in the bottle axial direction) is located on the lower side (outer side in the bottle axial direction). Deformation so as to be relatively displaced toward the upper side with respect to the part exhibits a reduced pressure absorption performance.

As shown in FIG. 3, the deformable cylinder portion 20 is connected to the ground contact portion 18 from the inside in the bottle radial direction and extends upward, and from the upper end portion of the rising peripheral wall portion 21 toward the inside in the bottle radial direction. And an annular movable wall portion 22 that protrudes upward, and a depressed peripheral wall portion 23 that extends upward from the inner end portion of the movable wall portion 22 in the bottle radial direction.
On the rising peripheral wall portion 21, an uneven portion 21 a is formed over the entire circumference. The concavo-convex portion 21a has a configuration in which a plurality of protruding portions formed in a curved shape protruding toward the inner side in the bottle radial direction are arranged at intervals in the bottle circumferential direction.

The movable wall portion 22 is formed in a curved shape protruding downward, and gradually extends downward from the outside in the bottle radial direction toward the inside. The movable wall portion 22 and the rising peripheral wall portion 21 are connected via a curved surface portion (a connecting portion with the rising peripheral wall portion) 25 that protrudes upward. The movable wall portion 22 is rotatable about the curved surface portion 25 so as to move the depressed peripheral wall portion 23 upward.
As shown in FIGS. 2 and 3, a plurality of ribs 29 are radially arranged around the bottle axis O in the movable wall portion 22. The rib 29 has a configuration in which a plurality of concave portions 29a that are recessed in a curved shape upward are intermittently disposed along the bottle radial direction.

The depressed peripheral wall portion 23 is disposed coaxially with the bottle shaft O, and a top wall 24 disposed coaxially with the bottle shaft O is connected to the upper end portion of the depressed peripheral wall portion 23, and these depressed peripheral walls The portion 23 and the top wall 24 are formed in a tubular shape with a top.
As shown in FIG. 3, the depressed peripheral wall portion 23 is formed in a multistage cylindrical shape whose diameter is gradually increased from the upper side toward the lower side. The depressed peripheral wall portion 23 is gradually expanded in diameter from the inner end portion of the movable wall portion 22 in the bottle radial direction toward the upper side and gradually reduced in diameter from the outer peripheral edge portion of the top wall 24 toward the lower side. The upper cylinder part 23b whose diameter is smaller than the lower cylinder part 23a and the annular step part 23c which connects both these cylinder parts 23a and 23b are provided.

A bottom view shape of the lower cylinder portion 23a is circular. The lower cylinder part 23a is connected to the inner end part of the movable wall part 22 in the bottle radial direction via a curved surface part 26 protruding downward. The curved surface portion 26 protrudes obliquely downward toward the inside in the bottle radial direction.
The annular step 23c is formed in an annular plate shape with the front and back surfaces facing the bottle axis O direction. The annular step portion 23 c is located above the upper end portion of the rising peripheral wall portion 21 or at an equivalent height.

  As shown in FIG. 2, the upper tube portion 23b is formed with a plurality of protruding portions 23d extending inward in the bottle radial direction so as to be connected in the bottle circumferential direction, so that the bottom view shape becomes the bottle circumferential direction. A rectangular tube portion 23f having a polygonal shape with a portion 23e between the adjacent protruding portions 23d as a corner portion and a protruding portion 23d as a side portion is formed.

The overhanging portion 23d is formed in a curved shape protruding toward the outside in the bottle radial direction in a bottom view, and a plurality of the overhanging portions 23d are arranged on the upper cylindrical portion 23b of the depressed peripheral wall portion 23 with an interval in the bottle circumferential direction. In the illustrated example, three projecting portions 23d are formed, and the shape of the rectangular tube portion 23f viewed from the bottom is an equilateral triangle.
Further, the portion 23e between the overhang portions 23d is formed in a curved shape protruding toward the outside in the bottle radial direction in the bottom view, and the end portion of the overhang portion 23d adjacent in the bottle circumferential direction along the bottle circumferential direction. They are linked together.

  In the bottle 10 as shown in FIG. 3, the movable wall portion 22 is disposed so as to be rotatable around the curved surface portion 25 so as to move the depressed peripheral wall portion 23 in the bottle axis O direction. When the inner pressure fluctuates, the movable wall portion 22 is rotated to absorb the fluctuation of the inner pressure, so that deformation of the shoulder portion 12 and the trunk portion 13 in the bottle radial direction can be suppressed.

Next, an example of a method for manufacturing the bottle 10 will be described.
In this manufacturing method, the bottle 10 is formed by blow molding using a mold 30 as shown in FIG. In addition, although the metal mold | die 30 shown in FIG. 4 is demonstrated below, the metal mold | die 30 is not restricted to this structure.

  The mold 30 includes a body mold 32 provided with a space for a cavity that opens downward, and a bottom mold 33 that closes the space from below to form a cavity 31. The cavity 31 is formed by combining the body mold 32 and the bottom mold 33. The shape of the cavity 31 is formed corresponding to the outer shape of the bottle 10, and the bottle axis O of the bottle 10 molded in the cavity 31 is located on the central axis of the cavity 31. In the illustrated example, the body mold 32 forms the body section 13 of the bottle 10, and the bottom mold 33 forms the bottom section 14 of the bottle 10.

  The body mold 32 is constituted by a pair of split molds formed by, for example, dividing a cylindrical body extending in the bottle axis O direction into two in the bottle radial direction. The body mold 32 is formed so as to be releasable from the bottle 10 formed in the cavity 31 in the bottle radial direction. The bottom mold 33 is formed so as to be separable from the bottle 10 formed in the cavity 31 to the lower side (outside in the bottle axial direction).

  The cavity surface 34 of the bottom mold 33 includes a first forming surface 35, a second forming surface 36, a third forming surface 37, a fourth forming surface 38, and a fifth forming surface 39. The first formation surface 35 forms the rising peripheral wall portion 21, and the second formation surface 36 forms the movable wall portion 22. The third forming surface 37 forms a lower cylindrical portion 23a of the depressed peripheral wall portion 23, the fourth forming surface 38 forms an annular step portion 23c of the depressed peripheral wall portion 23, and the fifth forming surface 39 is a depressed peripheral wall portion. The upper cylinder part 23b of 23 is formed.

  Among the cavity surfaces 34, the first forming surface 35, the third forming surface 37, and the fifth forming surface 39 face outward in the bottle radial direction, and the second forming surface 36 and the fourth forming surface 38 are on the upper side ( It faces the inside of the bottle axis direction). The second forming surface 36 is provided with a rib forming portion 36 a for forming the rib 29. The rib forming part 36a extends along the bottle radial direction, and a plurality of rib forming parts 36a are provided at intervals in the bottle circumferential direction.

  The bottom mold 33 is provided with connection holes 40a and 40b. The connection holes 40 a and 40 b extend from the cavity surface 34 of the bottom mold 33 toward the outside of the mold 30, and communicate the inside of the cavity 31 and the outside of the mold 30. The connection holes 40a and 40b extend downward from the cavity surface 34 (outside in the bottle axis direction) and open toward the upper side (inside in the bottle axis direction). As shown in FIG. 4, the connection holes 40 a and 40 b may extend downward from the cavity surface 34 and then continue to extend downward. For example, the connection holes 40 a and 40 b may extend downward from the cavity surface 34. After extending in the direction, it may be bent in the bottle radial direction.

  A plurality of connection holes 40a and 40b are provided at intervals in the bottle radial direction. The connection holes 40a and 40b are provided with an outer connection hole 40a located on the outer side in the bottle radial direction and an inner connection hole 40b located on the inner side in the bottle radial direction.

  Outer connection hole 40 a is provided in second formation surface 36 of cavity surface 34. The outer connection hole 40a is disposed at a position on the second forming surface 36 that avoids the rib forming portion 36a. In the illustrated example, the outer connecting hole 40a is disposed between the rib forming portions 36a adjacent to each other in the bottle circumferential direction. Yes. A plurality of outer connection holes 40a are provided at intervals in the bottle circumferential direction, and in the illustrated example, a plurality of outer connection holes 40a are arranged on the same circumference around the bottle axis O with equal intervals in the bottle circumferential direction. Has been.

  The inner connection hole 40 b is provided in the fourth formation surface 38 of the cavity surface 34. A plurality of inner connection holes 40b are provided at intervals in the bottle circumferential direction, and in the illustrated example, a plurality of inner connection holes 40b are arranged on the same circumference around the bottle axis O with equal intervals in the bottle circumferential direction. Has been. The inner connection hole 40b is provided in correspondence with the outer connection hole 40a, and the inner connection hole 40b and the outer connection hole 40b correspond to the outer connection hole 40b in a plan view when the bottom mold 33 is viewed from the bottle axis O direction. The connection hole 40a is arranged on the same straight line passing through the bottle axis O.

  The bottle manufacturing method according to the present embodiment using the mold 30 includes a blow molding process and a mold release process.

  In the blow molding process, for example, a bottomed cylindrical preform (not shown) is biaxially stretch blow molded. At this time, the mold 30 is combined to define a cavity 31 connected to the outside of the mold 30 through the connection holes 40a and 40b, and a neck provided at the mouth of the preform of the preform. In a state where the portion located above the portion (opening edge side of the mouth portion of the preform) is disposed outside the mold 30 and the other portion is disposed in the cavity 31 of the mold 30 Blow molding. If the temperature of the bottom mold 33 is raised to, for example, about 130 ° C., the bottom wall portion 19 of the bottle 10 is heat set and the heat resistance of the deformed cylinder portion 20 is improved, but the temperature of the bottom mold 33 is 130. It is not limited to around ℃.

In the release process, the mold 30 is released from the bottle 10 formed in the cavity 31.
In the present embodiment, when the bottom mold 33 is released from the bottle 10 in this mold releasing step, the boundary 41 between the outer surface of the deformable cylinder portion 20 and the cavity surface 34 of the bottom mold 33 is formed. Then, it is connected to the outside of the mold 30 through the connection holes 40a and 40b. The outside of the mold 30 is at atmospheric pressure, for example.

  At this time, a portion of the boundary portion 41 that is located on the inner side in the bottle radial direction from the rising peripheral wall portion 21 is connected to the outside of the mold 30 through the connection holes 40a and 40b. In the present embodiment, all the connection holes 40 a and 40 b connect a portion of the boundary portion 41 that is located on the inner side in the bottle radial direction from the rising peripheral wall portion 21 to the outside of the mold 30. These connection holes 40 a and 40 b connect the boundary portion 41 to the outside of the mold 30 from the boundary portion 41 downward.

  At this time, at least one part of each part where the movable wall part 22 and the recessed peripheral wall part 23 are located in the boundary part 41 is connected to the outside of the mold 30 through the connection holes 40a and 40b. In the present embodiment, the outer connection hole 40 a connects a plurality of portions of the boundary portion 41 where the movable wall portion 22 is located to the outside, and the inner connection hole 40 b includes the depressed peripheral wall portion 23 of the boundary portion 41. A plurality of locations where the is located are connected to the outside. The outer connection hole 40a and the inner connection hole 40b connect a plurality of locations in the boundary portion 41 with a space in the bottle radial direction to the outside. In addition, the outer connection hole 40a and the inner connection hole 40b respectively connect a plurality of locations at intervals in the bottle circumferential direction in the boundary portion 41 to the outside.

Through the mold release process as described above, a bottle 10 as shown in FIGS. 1 to 3 is formed. The density of the bottom wall portion 19 in the bottle 10 is equivalent to the density of the body portion 13 and is, for example, 1.37 to 1.39 g / cm ³ .
As shown in FIG. 2, hole marks 42 a and 42 b are formed in portions corresponding to the connection holes 40 a and 40 b in the bottom wall portion 19. The hole marks 42a and 42b are formed with an outer hole mark 42a located on the outer side in the bottle radial direction and an inner hole mark 42b located on the inner side in the bottle radial direction. The outer hole mark 42 a is formed in a portion corresponding to the outer connection hole 40 a in the bottom wall portion 19, and the inner hole mark 42 b is formed in a portion corresponding to the inner connection hole 40 b in the bottom wall portion 19.

  As described above, according to the bottle manufacturing method according to the present embodiment, the boundary portion 41 is connected to the outside of the mold 30 through the connection holes 40a and 40b in the mold release step. When releasing the bottom mold 33 from 10, air can be supplied to the boundary portion 41 from the outside of the mold 30 through the connection holes 40 a and 40 b. As a result, it becomes possible to release the outer surface of the deformable cylinder part 20 from the cavity surface 34 of the bottom mold 33 and prevent the deformable cylinder part 20 from sticking to the bottom mold 33, and form the bottle 10 with high accuracy. Can do.

As in the present embodiment, when the inside of the cavity 31 is opened to the outside of the mold 30 through the connection holes 40a and 40b during the blow molding process, the shapeability of the bottle 10 can be improved. Thus, the bottle 10 can be formed with higher accuracy.
Further, as in the present embodiment, in the mold release process, the boundary portion 41 is connected to the outside of the mold 30 through the connection holes 40a and 40b from the boundary portion 41 to the lower side. When pulling the bottle 10 downward from the bottle 10 (outside in the bottle axis O direction), it becomes possible to reliably supply air upward from the connection holes 40a, 40b to the boundary portion 41. It can be formed with high accuracy.

  Further, during the mold release step, a plurality of locations in the boundary portion 41 spaced apart in the bottle circumferential direction are connected to the outside of the mold 30 through the connection holes 40a and 40b. The air can be supplied with little bias. Thereby, it becomes possible to suppress a part of the bottom wall portion 19 of the bottle 10 along the circumferential direction of the bottle from sticking locally to the bottom mold 33, and the bottle 10 can be formed with higher accuracy.

  In the mold release process, a plurality of locations in the boundary portion 41 spaced apart in the bottle radial direction are connected to the outside of the mold 30 through the connection holes 40a and 40b. The air can be supplied with little bias. Thereby, it becomes possible to suppress that the part along the bottle radial direction in the bottom wall part 19 of the bottle 10 sticks locally to the bottom mold | type 33, and the bottle 10 can be formed with higher precision.

  In the mold release process, a portion of the boundary portion 41 that is located on the inner side in the bottle radial direction with respect to the rising peripheral wall portion 21 is connected to the outside of the mold 30 through the connection holes 40a and 40b. It is possible to prevent the movable wall portion 22 from sticking to the bottom mold 33 and moving the movable wall portion 22 downward about the curved surface portion 25 when the bottle 10 is pulled downward from the bottle 10. Thus, the bottle 10 can be reliably formed with high accuracy.

  Further, at the time of the mold release process, at least one part of each of the boundary portions 41 where the movable wall portion 22 and the recessed peripheral wall portion 23 are located is connected to the outside of the mold 30 through the connection holes 40a and 40b. In addition, it is possible to prevent both the movable wall portion 22 and the depressed peripheral wall portion 23 from sticking to the bottom mold 33, and the bottle 10 can be formed more reliably and with high accuracy.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the mold release process, the aspect of connecting the boundary portion 41 and the outside of the mold 30 is not limited to that shown in the above-described embodiment, and in the present invention, the shape, number, position, and the like of the connection holes are appropriately changed. be able to. For example, in the present invention, it is not necessary to connect at least one of the portions where the movable wall portion and the depressed peripheral wall portion are located to the outside through the connection hole. Moreover, in this invention, it is not necessary to connect the several location spaced apart in the bottle radial direction and the bottle circumferential direction among the said boundary parts through a connection hole. Furthermore, for example, only one connection hole may be provided in the bottom mold. Further, the boundary portion may be connected to the outside of the mold from the boundary portion in the bottle radial direction through the connection hole.

In the embodiment described above, the rectangular tube portion 23f is formed in the depressed peripheral wall portion 23, but the square tube portion 23f may not be formed.
Further, the uneven portion 17 a may not be formed on the outer peripheral surface of the heel portion 17 and the outer peripheral surface of the lower end portion 13 b of the trunk portion 13.
The rising peripheral wall 21 may be appropriately changed, for example, extending in parallel along the bottle axis O direction, or extending so as to be inclined with respect to the bottle axis O.
The movable wall portion 22 may be appropriately changed, for example, by protruding in parallel along the bottle radial direction.
The deformable cylinder portion 20 is not limited to the above-described form, and can be appropriately changed to another form having a multi-stage crested cylindrical shape standing on the grounding portion and closing the inside of the grounding portion.

The synthetic resin material forming the bottle 10 is not limited to polyethylene terephthalate, and may be appropriately changed, for example, polyethylene naphthalate, amorphous polyester, or a blend material thereof.
The bottle 10 is not limited to a single layer structure, and may be a laminated structure having an intermediate layer. Examples of the intermediate layer include a layer made of a resin material having a gas barrier property, a layer made of a recycled material, or a layer made of a resin material having an oxygen absorbing property.
In the embodiment described above, the cross-sectional view shape orthogonal to the bottle axis O of each of the shoulder portion 12, the trunk portion 13, and the bottom portion 14 is a circular shape. Also good.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

  Next, a verification test for the above-described effects will be described.

  In this verification test, first, unlike the mold shown in FIG. 4 described in the above embodiment, a conventional mold having no connection hole was newly created. After surface treatment was performed on the cavity surface of the mold, bottles were continuously produced by blow molding using the mold. As a result, at the beginning of the production of the bottle, the bottle did not stick to the bottom mold, but after producing 43,000 bottles, the sticking started to occur.

Therefore, after the connection hole as shown in FIG. 4 was additionally processed in the mold, the production of the bottle was resumed. After that, even when 37000 bottles were produced, the bottle was not stuck to the bottom mold. .
As described above, as in the bottle manufacturing method according to the embodiment, in the mold release process, the boundary between the outer surface of the deformed cylinder portion and the cavity surface of the bottom mold is connected to the mold through the connection hole. It was confirmed that sticking to the bottom mold of the deformed cylindrical portion can be suppressed by connecting to the outside.

DESCRIPTION OF SYMBOLS 10 Bottle 18 Grounding part 19 Bottom wall part 20 Deformation cylinder part 21 Standing peripheral wall part 22 Movable wall part 23 Depressed peripheral wall part 30 Mold 31 Cavity 33 Bottom mold 34 Cavity surface 40a, 40b Connection hole 41 Boundary part O Bottle axis

Claims (4)

A bottomed cylindrical portion is formed on the bottom wall portion, and a grounding portion located at the outer peripheral edge portion, and a multistage topped cylindrical deformable cylindrical portion standing on the grounding portion and closing the inside of the grounding portion, Provided ,
The deformed cylinder portion is connected to the grounding portion from the inner side in the bottle radial direction, and extends toward the upper side, which is the inner side in the bottle axial direction, and from the upper end portion of the rising peripheral wall portion toward the inner side in the bottle radial direction. And an annular movable wall portion projecting
A bottle manufacturing method in which the movable wall portion is formed by blow molding using a mold, with a bottle disposed movably upwardly around a connection portion with the rising peripheral wall portion ,
In the mold release step of releasing the bottom mold forming the bottom wall portion of the mold from the bottle molded in the cavity of the mold, the outer surface of the deformed cylinder portion and the bottom The boundary between the cavity surface of the mold is connected to the outside of the mold through a connection hole provided in the bottom mold,
During the blow molding process of molding the bottle in the cavity, the inside of the cavity is opened to the outside of the mold through the connection hole ,
During the mold release step, a portion of the boundary portion that is located on the inner side in the bottle radial direction from the rising peripheral wall portion and in which the movable wall portion is located is connected to the outside of the mold through the connection hole. A method for producing a bottle, characterized in that the bottle is connected . It is a manufacturing method of the bottle of Claim 1, Comprising:
In the mold release step, a bottle manufacturing method characterized in that a plurality of locations spaced in the bottle circumferential direction are connected to the outside of the mold through the connection holes. It is a manufacturing method of the bottle according to claim 1 or 2,
In the mold release step, a bottle manufacturing method characterized in that a plurality of locations spaced in the bottle radial direction are connected to the outside of the mold through the connection holes. It is the manufacturing method of the bottle of any one of Claim 1 to 3,
The deformable cylinder portion includes a depressed peripheral wall portion extending upward from an inner end portion in the bottle radial direction of the movable wall portion ,
At the time of the mold release step, at least one part of each part where the movable wall part and the depressed peripheral wall part are located in the boundary part is connected to the outside of the mold through the connection hole. Bottle manufacturing method.

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