Manufacturing method of self-standing tubular container and self-standing tubular container

Abstract

To provide a manufacturing method of a self-standing tube container, formed of an extrusion-molded tube, which enables a stable self-standing posture, and the self-standing tube container.SOLUTION: A manufacturing method of a self-standing tube container comprises: an erecting step of erecting a rod-like mandrel Q1 inside an extrusion-molded tube P in an inverted state; a bottom plate supporting step of supporting a bottom plate 4 on the upper end of the rod-like mandrel Q1; a mold clamping step of arranging a cavity die R on the upper surface side of the bottom plate 4 from the outside of a barrel 2; and a molding step of molding a bottom part 3 by injecting a bottom material 5 on the upper surface side of the bottom plate 4.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a self-standing tube container in which a flat bottom is formed on an extruded tube container, and to a self-standing tube container. [Background technology]

[0002] The bottom of an extruded tube container is a linear bottom formed by bonding the inner surfaces of the body together, so to make this type of tube container stand on its own, it must be placed with the cap side facing downwards, or a separate stand must be provided.

[0003] Therefore, various tube containers have been proposed in which the bottom of the tube container is formed in a shape that allows it to stand on its own.

[0004] The tube container described in Patent Document 1 has a sandwiched seal portion 3 that is bonded in a radial (cross-shaped) shape rather than in a straight line when the inner surfaces of the body are bonded together. The tube container described in Patent Document 2 has a radial seal portion 11 formed at the bottom of the body that extends in three directions from the axis toward the peripheral wall.

[0005] On the other hand, the tube container described in Patent Document 3 has a configuration in which a circular bottom made of a hard resin is sealed to the end of a body made of a tubular flexible resin film.Then, like a conventional bottom, a linear mouth is formed at the mouth of the tube container by bonding the inner surfaces of the body together. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-28619 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-220826 [Patent Document 3] Utility Model Registration No. 3241791 Summary of the Invention [Problem to be solved by the invention]

[0007] The tube containers described in Patent Documents 1 and 2 are both configured to be self-standing by making the bottom of the extruded tube radial. As a result, the area of ​​the bottom must be smaller than the circumference of the body, and even if the tube can stand on its own, there is an issue of lack of stability.

[0008] On the other hand, the tube container described in Patent Document 3 has a circular bottom sealed to the body, allowing it to stand on its own with stability. However, the neck of this tube container is formed in the same manner as the bottom formed on a conventional extruded tube, and therefore this neck has a linear sealed shape.

[0009] That is, the method of joining the bottom 2 and the body 3 involves setting a tubular resin film that will become the body 3 in a mold, and then injection molding the resin that will form the bottom 2 in place of the conventional neck. Therefore, since this mold cannot be used to injection-mold a conventional neck, a neck that is sealed in a straight line is formed. As a result, the sealed neck cannot be closed once opened, which has the disadvantage of limiting its use as a tube container.

[0010] Other joining methods described include joining the bottom 2 and body 3 by heat welding or adhesive. In this case, the joining strength of the bottom 2 is disadvantageously affected by the thickness of the body 3. Therefore, the tubular resin film that becomes the body 3 needs to be sufficiently thick, which also limits the uses of the tube container.

[0011] Generally, it is possible to form a flat bottom and a capped neck with a blown bottle without using an extruded tube. However, blown bottles cannot be used to form tube containers using multi-layer extruded tubes, and different sizes of molds are required depending on the content volume, which is inconvenient as it requires a very large investment in molds.

[0012] Therefore, the present invention was created to solve the above-mentioned problems, and aims to provide a method for manufacturing a self-standing tube container and a self-standing tube container that can provide various types of tube containers that can stand stably and independently at low cost using extruded tubes. [Means for solving the problem]

[0013] The first means of the present invention is a method for producing a self-standing tubular container in which a flat bottom 3 is formed on an extruded tube P having a neck 1, the method comprising: an erection step 100 in which the extruded tube P is placed on a mandrel Q with the neck 1 facing downward and a rod-shaped mandrel Q1 is erected from the neck 1 into the interior; a bottom plate support step 200 in which the periphery of a bottom plate 4 is fitted inside the lower end of a body 2 and the bottom plate 4 is supported horizontally on the upper end of the rod-shaped mandrel Q1; a mold clamping step 300 in which a cavity mold R for forming the bottom 3 is positioned on the mounting surface side of the bottom plate 4 from the outside of the body 2; and a molding step 400 in which a thermoplastic resin bottom member 5 is injected onto the mounting surface side of the bottom plate 4 to form the bottom 3.

[0014] In the bottom plate supporting step 200 of the second means, a fitting portion 4A is formed in the center of the inside of the bottom plate 4, and the upper end of the rod-shaped mandrel Q1 is fitted into the fitting portion 4A.

[0015] The third means is a self-supporting tube container in which a flat bottom 3 is formed on an extruded tube P having a mouth 1, and the bottom 3 is provided with a bottom plate 4 formed of a thermoplastic resin that is harder than the body 2, and the periphery of the bottom plate 4 is fitted into the inside of the lower end of the body 2, and the placing surface side of the bottom plate 4 is covered from the inside of the lower end of the body 2 with a bottom member 5 made of thermoplastic resin to form the bottom 3.

[0016] The fourth means is that the body portion 2 is formed of a multi-layer extruded tube, and the material of the inner peripheral surface of the body portion 2 is the same material as the bottom plate 4 and the bottom member 5. [Effects of the Invention]

[0017] As in the present invention, by molding the bottom 3 by injecting a thermoplastic resin bottom member 5 onto the supporting surface side of the bottom plate 4 fitted to the inside of the lower end of the body 2, it has become possible to form a flat bottom 3 on a tube container using an extruded tube.

[0018] As a result, the flat bottom 3 like a bottle can be used as a placing surface to stand the container, eliminating the need to form a cap that can stand on its own, and it becomes possible to combine a cap with a round top surface or a cap equipped with a pump.

[0019] Moreover, by changing the shape of the bottom plate 4, the shape of the bottom 3 can also be changed as desired, making it possible to use the tube container for a wider range of applications than ever before.

[0020] Furthermore, since the flat bottom formed in a blown bottle can also be formed in an extruded tube, it is possible to provide the product at low cost without requiring molds of various sizes as is required in blown bottles.

[0021] As described above, according to the present invention, it is possible to provide various types of tubular containers using collapsible tubes that are stable and self-standing at low cost. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view showing an embodiment of a tube container of the present invention. [Figure 2] FIG. 1 is a perspective view showing an inverted state of a tube container according to the present invention. [Figure 3] 1A is a schematic diagram showing an erection step and FIG. 1B is a schematic diagram showing a bottom plate supporting step in the manufacturing process of the present invention. [Figure 4] 1A and 1B are schematic diagrams showing the manufacturing process of the present invention, in which (a) is a diagram showing the state before the mold clamping step and (b) is a diagram showing the state after the mold clamping step. [Figure 5] 1A is a schematic diagram showing a molding step in the manufacturing process of the present invention, and FIG. 1B is a schematic diagram showing a state in which the molded tube container is removed from the rod-shaped mandrel. [Figure 6]1 is a block diagram showing a manufacturing process of the tube container of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The tubular container of the present invention is a self-supporting tubular container in which a flat bottom 3 is formed on an extruded tube P having a neck 1. The extruded tube P shown in the figure is formed by extrusion molding a pipe-shaped body 2, and the neck 1, which is integrated with a neck and a shoulder, is injection molded at one end of the body 2 (see Figure 1). The self-supporting tubular container is then constructed by forming the flat bottom 3 on this extruded tube P (see Figure 2).

[0024] Since the body 2 is formed by extrusion molding, it is also possible to use a multi-layer extruded tube. Therefore, the material of the body 2 can be, for example, a multi-layer extruded tube having layers of PE / Admer / EVOH / Admer / PE, or layers of PP / Admer / EVOH / Admer / PP.

[0025] The bottom 3 is provided with a bottom plate 4 made of the same material as the body 2 but a harder thermoplastic resin (see Figure 5 (b)). That is, if the body 2 is molded from polyethylene, the bottom plate 4 is made from the harder polyethylene. Also, if a multi-layer extruded tube is used for the body 2, the material of the surface that comes into contact with the bottom plate 4 is made from the same material as the bottom plate 4. Note that if the body 2 is made from polypropylene, the bottom plate 4 can also be made from polypropylene; for example, these materials can be changed as desired.

[0026] Then, this bottom plate 4 is fitted to the inside of the lower end of the body 2 (see FIG. 3(b)). The bottom plate 4 shown in the figure is formed in a circular shape to match the circular shape of the bottom 3 (see FIG. 2). Also, by changing the shape of this bottom plate 4, it is possible to change the shape of the lower end of the bottom 3.

[0027] Furthermore, a fitting portion 4A is formed on the inside of the bottom plate 4 shown in the figure (see FIG. 3(b)). This fitting portion 4A is a portion used when fixing the bottom plate 4 to the rod-shaped mandrel Q1 in the manufacturing process described below. In other words, by fitting the upper end of the rod-shaped mandrel Q1 into this fitting portion 4A, it becomes possible to support the bottom plate 4 horizontally. Note that any configuration that can support the bottom plate 4 on the upper end of the rod-shaped mandrel Q1 can be used instead of the fitting portion 4A.

[0028] Furthermore, the bottom 3 is formed by covering the inside of the lower end of the body 2 on the side of the placement surface of the bottom plate 4 with a bottom member 5 made of thermoplastic resin (see Figure 5(b)). This bottom member 5 is made of the same material as the body 2, and if the body 2 is molded from polyethylene, the bottom member 5 is also made of polyethylene. Furthermore, if a multi-layer extruded tube is used for the body 2, the surface in contact with the bottom plate 4 and bottom member 5, i.e., the inner peripheral surface of the body 2, is made of the same material as the bottom member 5.

[0029] Next, the manufacturing method of the present invention will be described with reference to Figures 3 to 6. The manufacturing method of the present invention includes an erecting step 100, a bottom plate supporting step 200, a mold clamping step 300, and a molding step 400 (see Figure 6).

[0030] The erection process 100 is a process in which the extruded tube P is placed on the mandrel Q with the neck 1 facing downwards, and a rod-shaped mandrel Q1 is erected from the tip of the neck 1 into the interior (see FIG. 3(A)). In this process, the extruded tube P is held by the rod-shaped mandrel Q1 inserted into the tip of the neck 1. The illustrated rod-shaped mandrel Q1 is erected vertically from the center of the plate-shaped mandrel Q and has a diameter that fits into the opening at the tip of the neck 1.

[0031] The bottom plate supporting process 200 is a process of fitting the periphery of the bottom plate 4 inside the lower end side (upper side in the figure) of the body portion 2, and supporting and fixing the bottom plate 4 horizontally to the upper end of the rod-shaped mandrel Q1 (see FIG. 3(b)). In the illustrated example, the upper end of the rod-shaped mandrel Q1 is fitted into a fitting portion 4A formed in the bottom plate 4, thereby supporting and fixing the bottom plate 4 in a stable state.

[0032] Furthermore, instead of the fitting portion 4A, it is also possible to form an enlarged mounting surface (not shown) at the upper end of the rod-shaped mandrel Q1 as a means for supporting and fixing the bottom plate 4 to the rod-shaped mandrel Q1. In this case, the mounting surface is limited to a size that can be inserted into the neck portion 1, but the means for supporting and fixing the bottom plate 4 can be changed as desired depending on the shape and size of the neck portion 1 and the body portion 2, the shape of the bottom plate 4, etc.

[0033] The mold clamping process 300 is a process of placing a cavity mold R on the mounting surface side of the bottom plate 4 from the outside of the body portion 2 (see FIG. 4). The illustrated cavity molds R are placed on the upper end side of the upside-down extruded tube P, i.e., a pair of cavity molds R are placed on the upper left and right sides of the bottom side of the extruded tube P (see FIG. 4(A)).

[0034] These cavity dies R are then moved above the extruded tube P to form a space for molding the bottom portion 3 (see Figure 4(b)). The illustrated cavity dies R press the bottom end of the body portion 2 inward to form a rounded periphery of the bottom portion 3. In this way, the thickness and shape of the bottom portion 3 can be freely changed by changing the shape and position of the cavity dies R.

[0035] The molding process 400 is a process for molding the bottom part 3 by injecting a bottom member 5 made of thermoplastic resin onto the upper surface side of the bottom plate 4 (see FIG. 5(A)). In this process, the bottom member 5 is injected from the cavity mold R toward the bottom plate 4 inside the body part 2, so that the bottom member 5 is filled from the inside of the body part 2 to cover the placing surface side of the bottom plate 4.

[0036] Then, when the bottom member 5 on the bottom plate 4 hardens, the bottom plate 4, the body 2, and the bottom member 5 are integrated to form the bottom 3 (see FIG. 5(b)). Therefore, by using the same material for the bottom member 5 and the body 2, it becomes possible to integrate the body 2 and the bottom 3 in particular.

[0037] Then, the extruded tube P with the bottom portion 3 formed thereon is removed from the rod-shaped mandrel Q1, completing a self-standing tube container (see FIG. 1).

[0038] The shape, size, material, etc. of each part of the present invention are not limited to those in the examples, and can be freely changed within the scope that does not change the gist of the present invention. [Explanation of symbols]

[0039] P Extruded Tube Q Mandrel Q1 Rod-shaped mandrel R Cavity Type 1 Mouth area 2. Torso 3 bottom 4 Bottom plate 4A Mating part 5 Bottom member 100 Erecting process 200 Bottom plate support process 300 Mold clamping process 400 Molding process

Claims

1. A method for producing a self-standing tube container having a flat bottom formed on an extruded tube having a mouth, comprising: an erecting step of placing the extruded tube on a plate-shaped mandrel with the mouth portion facing downward and erecting a rod-shaped mandrel from the mouth portion into the interior; a bottom plate supporting step of fitting the periphery of the bottom plate onto the inside of the lower end of the barrel portion and horizontally supporting the bottom plate on the upper end of the rod-shaped mandrel; a mold clamping step of placing a cavity mold for forming a bottom portion on the mounting surface side of the bottom plate from the outside of the body portion; a molding step of injecting a thermoplastic resin bottom member onto the mounting surface side of the bottom plate to form a bottom portion.

2. 2. The method for manufacturing a self-supporting tube container according to claim 1, wherein in the bottom plate supporting step, a fitting portion is formed at the center of the inside of the bottom plate, and an upper end portion of the rod-shaped mandrel is fitted into the fitting portion.

3. A self-supporting tube container having a flat bottom formed on an extruded tube having a mouth, wherein the bottom comprises a bottom plate formed of a thermoplastic resin harder than the body, the periphery of the bottom plate being fitted to the inside of the lower end of the body, and the bottom is formed by a bottom member made of thermoplastic resin covering the inside of the lower end of the body and the side of the bottom plate that faces the base.

4. 4. The self-standing tube container according to claim 3, wherein the body portion is formed of a multi-layer extruded tube, and the material of the inner peripheral surface of the body portion is the same as that of the bottom plate and the bottom member.

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