JP2001018287A - Production of molded object having hollow part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a molded object having a hollow part by using molds requiring no recessed part or projected part accurately corresponding to the shape of a hollow part and simple in structure as upper and lower molds and using only a single upper mold without using a plurality of upper molds. SOLUTION: An upper mold 6 is pressed to a first material 4 to be molded by a pressure jig while the pressure jig having a planar shape almost same to or smaller than that of a mold recessed part of a lower mold 3 is brought into contact with the position corresponding to the mold recessed part on the first material 4 placed on a lower mold 3 having the mold recessed part 2 formed thereto and heated to predetermined temp. to plastically deform the first material 4 to be molded to form a recessed part 7 and a second material to be molded is placed on the first material 4 to be molded to weld the first and second materials to be molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a molded article having a hollow portion, and more particularly, to a method for efficiently producing a molded article having a hollow portion of a predetermined shape using a sheet-like material to be molded. About.

[0002]

2. Description of the Related Art When a molded article having a hollow portion is produced using a sheet-like material to be molded, conventionally, the molded article is conventionally produced, for example, by the following procedure.

As shown in FIG. 11, a molded body 60 (FIG. 1)
5 (a) and 5 (b)), a lower mold 53 having a concave portion 52 having a shape corresponding to the outer surface shape of the hollow portion 51 (FIG. 15 (b)) is used. A material to be molded (for example, a soft polyvinyl chloride resin sheet) 54 is placed. Then, as shown in FIG.
The upper mold 56 having the convex portion 55 having a shape corresponding to the inner surface shape of the hollow portion 51 (FIG. 15B) of FIG. 15 is heated while being pressed against the first molding material 54 from above. Then, the first molding material 54 is plastically deformed to form the concave portion 57 having a predetermined shape. After that, the upper mold 56 is moved, and as shown in FIG.
A sheet-shaped thermoplastic second molding material (for example, a soft polyvinyl chloride resin sheet) 58 is placed. Then, as shown in FIG. 14, the upper mold 59 having a flat lower surface is pressed against the second molding material 58 from above, and
Then, the first molding material 54 and the second molding material 58 are heated to a temperature at which the first molding material 54 and the second molding material 58 can be welded to a temperature at which the first molding material 54 and the second molding material 58 can be welded to the periphery of the concave portion 58. As shown in (a) and (b), a molded product (product) 60 having a hollow portion 51 at a predetermined position is manufactured.

[0004]

However, in the above-mentioned conventional manufacturing method, the lower mold 53 in which the concave portion 52 having a shape corresponding to the outer surface shape of the hollow portion 51 of the molded body 60 is formed, and the hollow of the molded body 60 is formed. An upper mold 56 formed with a convex portion 55 having a shape corresponding to the inner surface shape of the portion 51, and an upper mold 59 having a flat lower surface.
Therefore, a total of three dies are required, not only is the production of each die costly, but also two upper dies 56 and 59 must be used, which complicates the manufacturing process and reduces the production efficiency. There is a problem.

In the lower mold 53, a concave portion 52 having a shape corresponding to the outer surface shape of the hollow portion 51 of the molded body 60 is formed.
Since it is necessary to form the convex portion 55 having a shape corresponding to the inner surface shape of the hollow portion 51 of the molded body 60 in the upper die 56, the processing cost of the die significantly increases the manufacturing cost of the product. There is a problem that becomes.

The present invention solves the above-mentioned problem, and does not require a concave portion or a projection accurately corresponding to the shape of a hollow portion as an upper mold and a lower mold, and has a simple structure. The present invention provides a method for manufacturing a molded body capable of efficiently producing a molded body having a hollow portion using a single upper mold without using a plurality of upper molds. Aim.

[0007]

In order to achieve the above object, a method for producing a molded article having a hollow portion according to the present invention has a planar shape corresponding to the planar shape of the hollow portion to be formed in the molded article. A sheet-shaped thermoplastic first molding material is placed on a molding lower mold in which a concave portion or a through hole (hereinafter, referred to as “mold concave portion”) is formed, and the first molding material is formed. While pressing the pressing jig having a plane shape substantially the same as or slightly smaller than the plane shape of the mold concave portion at a position corresponding to the mold concave portion, the upper mold for molding is removed. By pressing the first molding material to a predetermined temperature while pressing the first molding material from above the pressing jig, the first molding material is formed into the mold concave portion. After the corresponding area is plastically deformed to form a recess of a predetermined shape, the first The upper mold and the pressing jig are removed from the molding material, and a sheet-shaped thermoplastic second molding material is placed on the first molding material. The first and second molding materials are heated while being pressed from above the molding material, and the first and second molding materials are welded to the periphery of the concave portion to form a hollow portion. It is characterized by forming a molded body.

[0008] A press having a plane shape substantially the same as or slightly smaller than the plane shape of the mold recess at a position corresponding to the mold recess on the first molding material placed on the lower mold. While pressing the jig, the upper mold for molding is pressed from above on the pressing jig to the first molding material, and is heated to a predetermined temperature, so that the first molding material is heated. By plastically deforming, the concave portion can be easily and reliably formed in the region corresponding to the mold concave portion.

Then, after removing the pressing jig, a second molding material is placed on the first molding material in which the concave portion is formed, and the upper mold is moved from above the second molding material. While pressing, the first and second molding materials are heated, and the first and second molding materials are welded in the peripheral portion of the concave portion, thereby efficiently producing a molded body having a hollow portion. It becomes possible.

That is, according to the present invention, there is no need to use a plurality of upper dies as in the prior art, and the upper and lower dies accurately correspond to the inner surface shape and outer surface shape of the hollow portion. Since it is not necessary to use the one having the recessed portions and the projections, it is possible to efficiently manufacture a molded article having a hollow portion while suppressing the cost of mold production.

In the present invention, a recess having the same shape as or different from the recess formed in the first molding material is formed in the second molding material in advance. By welding the first and second molding materials in a state where they face each other, it is also possible to manufacture a molded body having hollow portions projecting from both upper and lower surfaces. Note that the same method as that for forming the concave portion in the first molding material can be applied to the case where the concave portion is formed in the second molding material.

Further, in the method of manufacturing a molded article having a hollow portion according to the present invention, the pressing jig includes (a) a foam such as sponge or sponge, (b) an elastic body such as rubber, and (c) wood. And at least one selected from the group consisting of rigid bodies such as metals and resins, and having a shape corresponding to the hollow portion to be formed in the molded body when forming the concave portion in the first molding material. As long as the concave portion can be formed, a variety of shapes that do not strictly correspond to the shape of the concave portion and that are easy to mold are used.

In the present invention, there is no particular limitation on the material of the pressing jig, and it is possible to use one made of various materials, but (a) a foam such as sponge or sponge;
By using at least one member selected from the group consisting of an elastic body such as rubber and (c) a rigid body such as wood, metal, and resin, it is possible to easily and economically form a pressing jig. . In forming the pressing jig, it is possible to take various shapes in consideration of ease of molding, and it is possible to further improve productivity.

[0014] The shape of the pressing jig should be such that a concave portion having a shape corresponding to the hollow portion to be formed in the product can be formed when the concave portion is formed in the first molding material. In consideration of the easiness of the recess, it is possible to adopt various shapes that do not always correspond exactly to the shape of the concave portion, and it is possible to further improve the productivity.

That is, for example, as shown in FIGS. 1 (a) and 1 (b), a molded article 10 having an oval planar shape (FIG. 1 (a)) and having a hollow portion 1 having a dome shape is provided. As shown in FIG. 3, for example, a plate-like foam (sponge) is cut at a position on the first molding material 4 corresponding to the mold concave portion 2 using scissors or the like. An upper mold having a high-frequency heating function is brought into contact with a flat pressing jig 11 having a planar shape substantially corresponding to the planar shape of the mold concave portion 2 and having a shape slightly smaller than the planar shape. The first molding material 4 is pressed by the mold 6 from above the pressing jig 11 through the bakelite plate 12 which is an insulator, and is heated to a predetermined temperature. In addition, as shown in FIG. 5, a concave shape having an oval planar shape and a dome shape is provided. It can be formed.

The pressing jig 11 is not limited to the shape shown in FIG. 4, but may be of various shapes such as a square bar, a round bar, a square tube or a cylinder. It is also possible, in that case also the first molding material 4
In addition, as shown in FIG. 1, it is possible to form a concave portion 7 having a shape corresponding to the dome-shaped hollow portion 1 having an oblong planar shape. Further, the shape of the concave portion (that is, the hollow portion) to be formed is not limited to the shape shown in FIG.
By adjusting the shape of the pressing jig 11, concave portions having various shapes such as a circular shape and a substantially polygonal shape (triangular, rectangular, square, trapezoidal, parallelogram, hexagonal, octagonal and other shapes) are formed. It is possible to

However, the shape of the hollow portion 1 to be formed and the shape of the pressing jig 11 depend on the thickness and flexibility of the first molding material.
Alternatively, it is desirable to determine in consideration of the type of the constituent material. It has been confirmed by experiments that the concave portion 7 having a desired shape can be formed even when the shape of the pressing jig 11 does not exactly match the shape of the hollow portion 1 to be formed.

According to a third aspect of the present invention, in the method of manufacturing a molded article having a hollow portion, the first material to be molded has a thickness of 0.1 mm.
It is characterized by using a sheet material of 1 to 4.0 mm.

The first material to be molded has a thickness of 0.1 to
When a 4.0 mm sheet-shaped material is used, it is necessary to use an upper mold or a lower mold having depressions and projections corresponding to the inner surface shape and the outer surface shape of the hollow portion, or a pressing jig. Without applying the method of the present invention, it is possible to reliably form a concave portion having a desired shape in the first molding material, and the present invention can be made more effective. In addition, a more preferable range of the thickness of the first molding material is 0.5 to 1.5 mm.

According to a fourth aspect of the present invention, in the method of manufacturing a molded article having a hollow portion, the first and second molding materials are at least one selected from the group consisting of polyvinyl chloride, polyurethane, and polyethylene. It is characterized by:

By using at least one selected from the group consisting of polyvinyl chloride, polyurethane, and polyethylene as the first and second molding materials, a concave portion having a desired shape is formed in the first molding material. It is possible to make the present invention more effective.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a molded article having a hollow portion, wherein a predetermined container is charged into a concave portion formed in the first molded material, and then the first molded material is added to the concave portion. The method is characterized in that the second molding material is welded to form a molded body in which a hollow body accommodates an object.

After a predetermined container is charged into the recess formed in the first molding material, the second molding material is welded to the first molding material, so that the container is accommodated in the hollow portion. The formed body can be easily formed, and the present invention can be made more effective.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a molded article having a hollow portion, wherein at least one of the upper mold and the lower mold has a high-frequency heating function.

By using a mold having a high frequency heating function, it is possible to quickly heat the first molding material to form it into a predetermined shape and to weld the first and second molding materials. And productivity can be improved.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described, and features thereof will be described in more detail.

[Embodiment 1] In this embodiment, FIG.
As shown in (a) and (b), a case will be described as an example in which a molded body 10 made of a soft polyvinyl chloride resin and having a hollow portion 1 having an oval planar shape and a dome shape is manufactured. .

First, a concave portion or a through hole (a through hole in this embodiment) having a planar shape corresponding to the planar shape (an oval) of the hollow portion 1 to be formed in the molded body 10 (hereinafter referred to as a “mold concave portion”). 2.) A lower mold 3 for molding (FIG. 2) on which 2 is formed is prepared, and a sheet-shaped thermoplastic first molding material 4 is placed on the lower mold 3. In the first embodiment, a soft polyvinyl chloride resin sheet having a thickness of 1.0 mm was used as the first material to be molded. Then, as shown in FIG. 3, at a position on the first molding material 4 corresponding to the mold concave portion 2, the planar shape substantially corresponds to the planar shape of the mold concave portion 2, and is one turn more than that. While pressing the pressing jig 11 having a small shape, the upper mold 6 for molding is moved from the pressing jig 11 onto the first molding material 4.
5 and heated to a predetermined temperature, whereby the first molding material 4 is plastically deformed as shown in FIG. 5 to form the recess 7 in a region corresponding to the mold recess 2. In this step, the first molding material 4 is
1, is pressed downward, bends and deforms, and is deformed into a shape corresponding to the hollow portion 1 of the molded body 10.
By heating to a predetermined temperature, the first molding material 4 is plastically deformed to form a concave portion 7 having a shape corresponding to the shape of the hollow portion 1 (FIG. 1). In the first embodiment, the pressing jig 11 is a plate-like foam (sponge).
Was formed by cutting using scissors or the like,
A pressing jig 11 (FIG. 4) having a flat planar shape substantially corresponding to the planar shape of the mold concave portion 2 and having a shape slightly smaller than the flat concave shape was used. In the first embodiment, since the upper die 6 having the high-frequency heating function is used as the upper die 6, the pressing jig 11 is attached to the lower surface of the bakelite plate 12 which is an insulator.
2, the pressing jig was pressed against the first molding material 4. Note that the bakelite plate 12 can be attached to the upper mold 6 or can be used as a separate body. Next, the upper mold 6 is moved, and as shown in FIG. 6, a sheet-shaped thermoplastic second molding material 8 is placed on the first molding material 4 in which the concave portions 7 are formed. I do. In this embodiment, the second molding material 8 has a thickness of 1.0 mm.
(The same as the first molding material 4) was used. Then, as shown in FIG. 7, the upper mold 6 is pressed from above through the bakelite plate 12 against the second molding material 8, and the first molding material 4 and the second molding material 8 are pressed. The first molding material 4 and the second molding material 8 are welded around the recess 7 by heating the material 8 to a temperature at which welding is possible, and the periphery is cut and trimmed as necessary. As a result, as shown in FIG. 1, a molded article (product) 10 having the hollow portion 1 can be obtained. The trimming can be performed at the same time as the welding, or may be performed after the welding.

In the first embodiment, the pressing jig having an oblong plane shape and having a flat surface in contact with the first molding material is used. However, the contact surface with the first molding material is used. It is also possible to use a pressing jig having a convex shape (dome shape) substantially corresponding to the inner surface shape of the hollow portion.

Further, as the pressing jig, various shapes such as a square bar, a round bar, a square tube and a cylinder can be used.

There are no particular restrictions on the material constituting the pressing jig, such as foams such as sponge and sponge, elastic materials such as rubber, rigid materials such as wood, metal, and resin.
Alternatively, it is possible to use various materials such as cardboard paper, composite materials such as paper and wood.

In the above embodiment, the first and second molding materials are polyvinyl chloride resins, but the molding materials are various thermoplastic materials such as polyvinyl chloride, polyurethane and polyethylene. Can be used.

In the above embodiment, a 1.0 mm thick polyvinyl chloride resin is used as the first and second molding materials. However, the thickness of the molding material is not limited to this.
Various thicknesses can also be used. However, in order to efficiently perform molding using a pressing jig that does not necessarily correspond to the shape of the hollow portion, the thickness of the first and second molding materials is preferably in the range of 0.1 to 4.0 mm, more preferably. It is desirable to use the one having a range of 0.5 to 1.5 mm.

[Embodiment 2] In Embodiment 2, FIG.
As shown in FIG. 1, a case will be described in which a molded body 10a having a hollow portion in which a material (here, cardboard on which information such as characters and figures are printed) 1a is stored. When manufacturing the molded body 10a having the hollow portion of the second embodiment, the process of the first embodiment (the process of forming the concave portion 7 in the first molding material 4) and the process (the concave portion 7)
During the step of placing the second molding material 8 on the first molding material 4 on which the first molding material 4 has been formed, as shown in FIG. By providing a step of charging the container (cardboard) 1a into the formed concave portion 7, the molded body 10a having the hollow portion in which the container 1a is stored in the hollow portion 1 can be easily and reliably provided as shown in FIG. Can be manufactured.

Steps before and after the above 'are the same as those in the first embodiment, and therefore, description thereof will be omitted to avoid duplication. In the second embodiment, the case where the cardboard in which information such as characters and figures are printed is accommodated in the hollow portion is described as an example, but in addition, a resin sheet, a metal plate,
It is possible to manufacture molded articles containing various things such as powders and granules and liquids.

In the first and second embodiments, the case where the molded body has a structure in which the hollow portion protrudes on one surface side of the molded body has been described as an example. However, the present invention is not limited to the case shown in FIG. In addition, the present invention can be applied to the case of manufacturing a molded body 10b having a structure in which the hollow portion 1 protrudes on both sides.
In this case, a recess having the same shape as or different from the recess formed in the first molding material is formed in the second molding material in advance, and the recesses are opposed to each other. By welding the first and second molding materials, it is possible to form a molded body having hollow portions projecting from both upper and lower surfaces. Note that the same method as that for forming the concave portion in the first molding material can be applied to the case where the concave portion is formed in the second molding material.

Further, in the above embodiment, the case where a mold having a high-frequency heating function is used has been described as an example. However, a mold employing another heating method can be used.

Further, in the above embodiment, the case where the mold concave portion is a through hole has been described as an example, but it is also possible to use a bottomed hole instead of a through hole. In that case,
It is not necessary to form the bottomed hole in a shape corresponding to the outer surface shape of the hollow part of the molded body.

In other respects, the present invention is not limited to the above embodiment, but includes the shape of the molded body including the shape of the hollow portion, the molding conditions of the first and second molding materials, With regard to the specific configuration of the upper mold and the lower mold, various applications and modifications can be made within the scope of the invention.

[0040]

As described above, the method of manufacturing a molded article having a hollow portion according to the first aspect of the present invention corresponds to the mold concave portion on the first molding material placed on the lower mold. While pressing the pressing jig having a planar shape substantially the same as or slightly smaller than the planar shape of the mold concave portion at the position where Since the first molding material is plastically deformed by pressing the molding material and heating it to a predetermined temperature, a recess is formed in a region corresponding to the mold recess. It is not necessary to use a plurality of upper molds as in the above, and moreover, it is possible to use, as the upper mold and the lower mold, one having a concave portion or a protrusion that accurately corresponds to the inner surface shape or outer surface shape of the hollow portion. This is unnecessary, and a molded article having a hollow portion can be efficiently manufactured.

Further, in the present invention, there is no particular limitation on the material of the pressing jig, and it is possible to use a material made of various materials, but (a) sponge, sponge, etc. By using at least one member selected from the group consisting of a foamed body, (b) an elastic body such as rubber, and (c) a rigid body such as wood, metal, and resin, the pressing jig can be easily and economically manufactured. It can be formed. In addition,
When the concave portion is formed in the first material to be molded, the shape of the pressing jig is considered in terms of ease of molding as long as a concave portion having a shape corresponding to the hollow portion to be formed in the product can be formed. Various shapes are possible.

In the case of using a sheet material having a thickness of 0.1 to 4.0 mm as the first material to be molded, as in the method for producing a molded article having a hollow portion according to claim 3, By applying the method of the present invention without using an upper mold or a lower mold having a concave portion or a protrusion that accurately corresponds to the inner surface shape or the outer surface shape of
It is possible to reliably form a concave portion having a desired shape in the material to be molded, and the present invention can be made more effective.

Further, as in the method for producing a molded article having a hollow portion according to claim 4, the first and second molding materials are:
By using at least one member selected from the group consisting of polyvinyl chloride, polyurethane, and polyethylene, a recess having a desired shape is reliably formed in the first molding material, and a molded body having a hollow portion is efficiently manufactured. It becomes possible.

Further, as in the method for manufacturing a molded article having a hollow portion according to the fifth aspect, after a predetermined container is charged into the concave portion formed in the first molded material, the first molded material is added to the concave portion. Second
In the case where the material to be molded is welded, it is possible to easily form a molded body in which the contents are accommodated in the hollow portion, so that the present invention can be made more effective.

Further, by using a mold having a high-frequency heating function as in the method of manufacturing a molded article having a hollow portion according to claim 6, the first molding material is quickly heated to a predetermined shape. , And the first and second molding materials can be welded, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a molded article having a hollow portion manufactured by a method according to an embodiment (Embodiment 1) of the present invention, wherein (a) is a plan view and (b) is a front sectional view. .

FIG. 2 is a view showing a state in which a first material to be molded is placed on a lower mold in one step of the method for manufacturing a molded body according to the first embodiment of the present invention.

FIG. 3 shows a state in which a pressing jig is brought into contact with a first molding material placed on a lower mold in one step of a method of manufacturing a molded body according to the first embodiment of the present invention. FIG.

FIG. 4 is a perspective view showing a pressing jig used in Embodiment 1 of the present invention.

FIG. 5 is a view showing a state in which a concave portion is formed in a first molding material in one step of the method of manufacturing a molded body according to the first embodiment of the present invention.

FIG. 6 is a view showing a state in which a second molding material is placed on the first molding material in which the concave portion is formed in one step of the method of manufacturing the molded body according to the first embodiment of the present invention. is there.

FIG. 7 is a view showing a state in which a first material to be molded and a second material to be molded are welded in one step of the method for producing a molded body having a hollow portion according to the first embodiment of the present invention. .

FIG. 8 is a cross-sectional view showing a molded article having a hollow portion manufactured by a method according to another embodiment (Embodiment 2) of the present invention.

FIG. 9 is a view showing a state in which a container is charged into a concave portion formed in a first molding material in one step of the method of manufacturing a molded body according to the second embodiment of the present invention.

FIG. 10 is a cross-sectional view showing another example of a molded article that can be produced by the method for producing a molded article having a hollow portion of the present invention.

FIG. 11 is a cross-sectional view showing a state in which a first molding material is placed on a lower mold in one step of a conventional method for manufacturing a molded article having a hollow portion.

FIG. 12 is a view showing a step of forming a concave portion in a first molding material in one step of a conventional method of manufacturing a molded article having a hollow portion.

FIG. 13 is a view showing a state in which a second molding material is placed on a first molding material in which a concave portion is formed in one step of a conventional method for manufacturing a molded article having a hollow portion.

FIG. 14 is a view showing a state in which a first material to be molded and a second material to be molded are welded in one step of a conventional method for producing a molded body having a hollow portion.

FIG. 15 is a diagram showing a molded body produced by a conventional method for producing a molded body having a hollow portion, where (a) is a plan view,
(b) is a front sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow part 1a The accommodation thing accommodated in the hollow part 2 The through-hole (mold recessed part) formed in the lower metal mold 3 The lower metal mold 4 The 1st molding material 6 The upper metal mold 7 As the 1st molding material Formed recess 8 Second material to be molded 10, 10a, 10b Molded body 11 Pressing jig 12 Bakelite plate (insulator)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AA04 AA15 AA31 AC03 AG01 AG07 AJ02 AJ03 AJ05 AJ10 AK03 AR12 CA17 CB01 CB27 CB29 CK11 CL02 4F208 AA04 AA15 AA31 AC03 AG01 AG07 AJ02 AJ03 AJ05 MB03 MB03 MK08 MW01 MW26

Claims (6)

[Claims] 1. A lower mold for molding in which a concave portion or a through hole (hereinafter referred to as “mold concave portion”) having a planar shape corresponding to the planar shape of a hollow portion to be formed in a molded body is formed. A sheet-shaped thermoplastic first molding material is placed on the first molding material, at a position corresponding to the mold recess, substantially the same as or higher than the planar shape of the mold recess. While pressing the pressing jig having a slightly smaller planar shape, the upper mold for molding is moved from the pressing jig to the first die.
By pressing the first molding material to a predetermined temperature while pressing against the molding material of the above, the region of the first molding material corresponding to the mold concave portion is plastically deformed to have a predetermined shape. After forming the concave portion, the upper mold and the pressing jig are removed from the first molding material, and a sheet-shaped thermoplastic second molding material is placed on the first molding material. Then, the upper mold is pressed from above the second molding material, and the first and second molding materials are heated, and the first and second molding materials are heated around the concave portion. A method for producing a molded article having a hollow portion, wherein a molded article having a hollow portion is formed by welding. 2. The pressing jig includes at least one selected from the group consisting of: (a) a foam such as sponge or sponge; (b) an elastic body such as rubber; and (c) a rigid body such as wood, metal, or resin. A seed, and when forming the concave portion in the first molding material, the shape of the concave portion is within a range in which a concave portion having a shape corresponding to the hollow portion to be formed in the molded body can be formed. 2. The method for producing a molded article having a hollow portion according to claim 1, wherein the molded article has various shapes that do not correspond strictly and that takes into account the ease of molding. 3. The method according to claim 1, wherein the first material to be molded has a thickness of 0.1 mm.
The method for producing a molded article having a hollow portion according to claim 1 or 2, wherein a sheet-like material having a thickness of 1 to 4.0 mm is used. 4. The method according to claim 1, wherein said first and second molding materials are at least one selected from the group consisting of polyvinyl chloride, polyurethane and polyethylene. A method for producing a molded article having a hollow portion. 5. A predetermined container is charged into a concave portion formed in the first molding material, and then the second molding material is welded to the first molding material to form a hollow portion. 5. A molded body in which the contents are housed.
The method for producing a molded article having a hollow part according to any one of the above. 6. The molded article having a hollow portion according to claim 1, wherein at least one of said upper mold and lower mold has a high-frequency heating function. Production method.