JP2000334825A - Method for producing molding and plug for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the thickness spots of an obtained molding to a degree not to deteriorate the appearance of the molding, and manufacture a molding excellent in mechanical strength. SOLUTION: When a synthetic resin sheet is spread along the inner surface of the cavity 8 of a mold 6 and molded by evacuating the cavity 8 from its inner surface, the molding of the sheet 14 is assisted by pushing the sheet 14 in the mold 6 direction by using a plug 16 having a press part 162 in which a recessed part extending substantially in the direction X to be inserted into the cavity 8 from the opposite cavity side surface of the sheet 14 is on a peripheral wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a molded article and a plug used for the method.

[0002]

2. Description of the Related Art Vacuum forming is used for shaping a synthetic resin sheet into a predetermined shape and manufacturing containers such as cups and trays. In vacuum forming, after applying heat to the sheet to make it flexible, it is placed on the mold cavity, and the sheet is evacuated through the evacuation holes formed on the inner surface of the cavity, and the sheet is placed on the inner surface of the cavity. The shaping is performed according to.

In performing such vacuum forming, the sheet is drawn along the cavity of the mold by vacuum evacuation, and the sheet is formed by an assist plug from the surface opposite to the cavity side of the sheet to assist in shaping the sheet. Pushing in the mold direction is also performed. When this assist plug is used, the molded body is molded with higher precision and in a shorter time than in the case where the molded body is molded only by vacuum evacuation, and the productivity is improved.

[0004] This type of assist plug usually has a pressing portion that comes into contact with a sheet. However, conventionally, in order to increase the productivity of a molded product, the shape of the pressing portion is generally made to correspond to the cavity shape of a mold. I was

[0005]

However, even when the shape of the pressing portion substantially corresponds to the shape of the cavity, there are cases where unevenness in thickness occurs in the obtained molded article. If the molded article has uneven thickness, the appearance of the molded article is impaired. In particular, when a thin portion exists over a wide range of the molded body, the mechanical strength of the molded body is reduced, and the molded body may not be usable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, to suppress unevenness in thickness of the obtained molded article as much as possible without impairing its appearance, and to produce a molded article having excellent mechanical strength. It is an object of the present invention to provide a method for manufacturing a molded article and a plug used for the same.

[0007]

In order to achieve the above object, a method of manufacturing a molded article according to the present invention is characterized in that a vacuum is drawn from an inner surface of a cavity of a mold and a synthetic resin sheet is drawn along the inner surface of the cavity. When spreading and shaping, from the surface opposite to the cavity side of the sheet, using a plug having a pressing portion formed on the peripheral wall, a concave portion extending substantially along the direction to be inserted into the cavity, It is characterized in that shaping of the sheet is assisted by pushing the sheet in the mold direction.

[0008] The plug according to the present invention assists the shaping of the synthetic resin sheet when the plug is evacuated from the inner surface of the cavity to spread and shape the synthetic resin sheet along the inner surface of the cavity. And a pressing portion formed in a peripheral wall of the plug and extending substantially along a direction in which the plug is inserted into the cavity.

The recess is preferably formed so as to be more parallel to the direction in which it is inserted into the cavity, but may be formed slightly inclined.

The recess may be formed so as to extend substantially along the direction of insertion into the cavity, but is preferably formed continuously.

It is preferable that a plurality of the recesses are formed at substantially equal intervals in the circumferential direction of the plug. However, if the recesses are formed at positions suitable for adjusting the thickness, one recess may be provided. And more preferably 1 to 10.

The cross-sectional shape, size and length of the plug are as follows:
It can be appropriately selected according to the shape and size of the molded body, and is not necessarily a cylindrical shape, and may be a rectangular shape having a small cross section.

The ratio ((D2 / D1) × 100) of the maximum depth D2 of the concave portion to the outer diameter D1 of the cross section of the plug (the maximum outer diameter in the case of a shape other than a circle) is not particularly limited, but is preferable. Is 2 to 45, more preferably 4 to 15.

The maximum outer diameter D1 can be appropriately selected according to the size of the cavity.

The material of the plug is not particularly limited, and may be made of any material such as wood, metal such as aluminum, synthetic resin such as polyacetal resin and fluorine resin, and ceramic.
Wood or aluminum is preferred from the viewpoint of handleability and production cost.

[0016]

In the method of manufacturing a molded article according to the present invention, first, a sheet is brought into close contact with a mold. Soften the sheet before and after. Thereafter, the sheet is pressed down to a predetermined depth in the direction of the mold using a plug from the surface on the side opposite to the cavity of the sheet, and vacuum evacuation is performed, and the sheet is shaped along the inner surface of the cavity to obtain a molded body.

Conventionally, it has been considered that the shape of the plug used for such vacuum forming should be a shape corresponding to the inner shape of the cavity of the mold. However, even when the shape of the plug is made to correspond to the shape of the inner surface of the cavity, there are many cases where unevenness in thickness occurs in the obtained molded body. DISCLOSURE OF THE INVENTION The present inventors have studied diligently on a method for producing a molded article of a sheet capable of producing a molded article having excellent mechanical strength, while suppressing unevenness in thickness of the obtained molded article to the extent that its appearance is not impaired. As a result, the concave portion extending substantially along the direction of insertion into the cavity is positively formed on the outer periphery of the pressing portion of the plug, and conversely, the unevenness in the thickness of the molded body is eliminated, and the mechanical It has been found that the target strength is improved, and the present invention has been completed.

In the method for producing a molded article according to the present invention,
The reason why the thickness unevenness of the molded article is reduced is not necessarily clear, but is considered to be due to the following reason. That is, by providing a recess on the outer periphery of the pressing portion of the plug at a position corresponding to a position particularly suitable for thickness adjustment (a place where the thickness of the molded body is likely to be thin), conversely, the thickness of the molded body corresponding to that position is reduced. This makes it possible to secure the thickness and eliminate uneven thickness as a whole. In addition, it is considered that by increasing the thickness of the molded body at a position corresponding to the concave portion, that portion actively forms a rib, which contributes to an improvement in mechanical strength of the molded body.

The molded article obtained by the method according to the present invention can be suitably used for containers such as cups and trays, transport containers such as luggage, inner boxes or inner doors of refrigerators, and other tools.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a molded article according to the present invention will be described in detail based on an embodiment shown in the drawings.
1 (A) to 1 (D) are schematic views showing a method for manufacturing a molded article according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view showing an example of a molded article obtained by the method according to the present invention. 3 (A)
3 is a perspective view of a plug used in the method according to the present invention, FIG.
3B is a plan view of the plug of FIG. 3A, FIG. 3C is a front view of the plug of FIG. 3A, and FIG. 4 is a plan view showing an example of a case where a sheet is arranged on a mold. It is.

First Embodiment First, the configurations of a mold apparatus and a plug used in the method according to the present invention will be described.

As shown in FIG. 1A, the mold apparatus 2
It has a mold body 6 attached to the mold mount 4.
The mold body 6 has a cavity 8 formed therein, and the cavity 8 has a vent hole 82 for vacuum evacuation. A vacuum pump (not shown) is connected to the ventilation hole 82 via a pipe 10 connected to the mold mount 4. The formation position and the number of the ventilation holes 82 are not particularly limited. Such a mold body 6 is made of, for example, wood, metal, synthetic resin, or the like. The temperature of the mold body 6 may be controlled by a jacket, a heater, or the like. The control temperature in that case is appropriately determined depending on the type of the synthetic resin constituting the sheet to be shaped, but is usually in the range of 0 to 80 ° C.

The plug 16 is made of, for example, wood having a substantially circular cross section, and as shown in FIGS. 3A to 3C, a pressing portion 162 which comes into contact with the sheet 14 when the plug 16 is pressed.
Having. The pressing portion 162 includes the lower end 162a and the peripheral wall 1
62b, and four recesses 164 continuously extending along the direction X (see FIG. 3A) inserted into the cavity 8 of the mold body 6 are formed on the peripheral wall 162b at substantially equal intervals in the circumferential direction. I have. In the case of the present embodiment, the longitudinal direction of the concave portion 164 matches the longitudinal direction of the plug 16.

The ratio of the maximum depth D2 of the recess 164 to the maximum outer diameter D1 of the cross section of the plug 16 ((D2 / D1)
× 100) is preferably from 2 to 45. If the ratio of D2 to D1 is too small, the depression 164
Is not obtained, and if it is too large, the difference between the thick part and the thin part of the obtained molded article becomes too large, and the appearance tends to be impaired. The cross section of the plug 16 gradually decreases along the lower end direction.
It is preferable that the maximum depth D2 of the concave portion 164 becomes shallower along the lower end direction of the plug 16, but may be substantially the same.

The width W of the concave portion 164 is not particularly limited and may be the same or different for each concave portion, but is substantially the same from the viewpoint of forming a uniform rib on the obtained molded body. It is preferably in the range of 10 to 200 mm.

It is preferable that the pressing portion 162 has a smooth shape by chamfering or curving a corner. Also, the pressing portion 162 of the plug 16
It is preferable that a release treatment is performed in order to improve the release property from the sheet 14. This is because the pressing portion 162 of the plug 16 is favorably peeled off from the sheet surface after molding. The release treatment is not particularly limited. For example,
Felt ground application, felt ground coating, fluororesin processing, and the like can be given. These release treatments are particularly convenient for forming a heated sheet because they have excellent heat retention during sheet formation. In addition, such a plug 16
May be solid or hollow.

Next, a method for producing a molded article will be described. In the present embodiment, as shown in FIG. 2, a method for manufacturing a measuring cup 20 used for mixing paints and the like will be described as an example.

In vacuum forming using the mold apparatus 2, FIG.
As shown in (A), first, the sheet 14 clamped by the clamp frame 12 is heated using, for example, a heater (not shown).

The sheet 14 is made of, for example, polypropylene, polyethylene, propylene-ethylene copolymer (ethylene content is 1 to 50% by weight), high-density polyethylene, vinyl chloride resin, acrylonitrile-butadiene-styrene copolymer, polystyrene And various synthetic resins such as A-PET (amorphous polyethylene terephthalate). In addition, the sheet 14 may contain additives such as an inorganic filler, an antistatic agent, an ultraviolet absorber, and a pigment. The content of these additives is 0.1% in total with respect to 100 parts by weight of the resin.
The amount is preferably from 30 to 30 parts by weight, more preferably from 0.2 to 20 parts by weight. The sheet 14 may be formed of a single layer or a composite layer of a synthetic resin sheet and a foamed resin, or another resin, rubber, or the like. Sheet 14
Is not particularly limited, but is preferably 0.1 to 2 mm. If the thickness of the sheet is less than 0.1 mm, the rigidity tends to be insufficient, and if it exceeds 2 mm, the shapeability at the time of molding tends to be poor. 0.8 mm is more preferred. The heating temperature of the sheet 14 is a temperature at which the synthetic resin constituting the sheet 14 is softened, and is appropriately determined according to the type of the synthetic resin to be used, but is usually in the range of 60 to 320 ° C.

Next, as shown in FIG. 1 (B), the mold apparatus 2 is raised and brought into close contact with the sheet 14. Alternatively, the sheet 14 is lowered toward the mold apparatus 2.

Next, in the present embodiment, as shown in FIGS. 1B and 1C, the sheet 14 is pushed into the cavity 8 using a plug 16 from the surface of the sheet 14 opposite to the cavity side. As shown in FIG. 1 (D), a vacuum pump (not shown) is provided through the ventilation hole 82 and the pipe 10.
Vacuum. As a result, the sheet 14 is shaped into a shape along the inner peripheral surface of the cavity 8, and a molded body 20 as shown in FIG. 2 is obtained.

The plug 16 when pushed into the cavity 8
The pressing portion 162, particularly the lower end 162a, may be temperature-controlled by a heater or the like. The control temperature in that case is
4 differs depending on the material constituting the sheet 14, for example, the sheet 14
Is usually 0 to 180 ° C for polypropylene, usually 0 to 170 ° C for polyethylene, usually 0 to 315 ° C for polycarbonate, and usually 0 to 150 ° C for hard vinyl chloride. In the case of ABS resin, it can be appropriately selected within the range of usually 0 to 150 ° C, and in the case of impact-resistant polystyrene, it can be selected in the range of generally 0 to 150 ° C.

The plug 16 when pushed into the cavity 8
Is preferably controlled. This is because the lowering speed of the plug 16 affects the thickness distribution of the compact. The lowering speed of the plug 16 is usually 5 to 100 cm.
/ Second within the range.

The plug 16 when pushed into the cavity 8
The contact position between the sheet and the sheet 14 is a position suitable for thickness adjustment in the sheet 14 (a place where the thickness of the molded body is likely to be thin).
It is preferable that the concave portion 164 of the plug 16 be provided so as to be in contact therewith.

The evacuation is performed at a degree of vacuum enough that the sheet 14 adheres well to the inner peripheral surface of the cavity 8.

In this embodiment, since the plug 16 is used as an assist plug to assist the shaping of the sheet 14 during vacuum forming, the shaping of the sheet 14 is performed with higher precision than when the shaping of the sheet 14 is performed only by vacuum evacuation. The shaping of the sheet 14 can be performed in a short time, and the productivity of the obtained molded body 20 is improved. In particular, in the present embodiment, the sheet 16 is used by using a plug 16 in which four concave portions 164 continuously extending along the direction X inserted into the cavity 8 are formed in the peripheral wall 162a of the pressing portion 162 at substantially equal intervals in the circumferential direction. It is to assist the shaping of 14. For this reason, it is possible to secure the thickness of the portion where the thickness of the molded body 20 corresponding to the position of the concave portion 164 is likely to be thin, and the thickness unevenness of the molded body 20 is eliminated as a whole. The molded body 2 at a position corresponding to the concave portion 164
Since the thickness of 0 is increased, the portion constitutes a rib, and the mechanical strength of the molded body 20 can be improved.

Second Embodiment In this embodiment, as shown in FIG.
A description will be given of a case of multi-chamfering in which a large number of molded bodies (four in the present embodiment) are obtained at one time.

In the case of the multi-face molding as in the present embodiment, plugs corresponding to the number of molded articles to be obtained are required. As shown in FIG. 4, in the present embodiment, the pressing position 84 of the plug 16 against one sheet 14 is a position where the center of the cross section of each plug 16 is located at four corners of a regular square indicated by dotted lines. In the present embodiment, the plug 16
The plug 16 is arranged so that the concave portion 164 formed in the plug 16 is located at a position suitable for adjusting the thickness of the sheet 14, that is, at a position 22 where there is little room to extend when the sheet is formed, and then the sheet 14 is pushed.

A position 24 where there is a lot of room for extension during sheet shaping
In the present embodiment, the unevenness of the thickness of the molded body 20 can be further reduced as compared with the case where the sheet 14 is formed by disposing the plug 16 so that the concave portion 164 faces only the concave portion 164.

Other Embodiments Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and may be implemented in various modes without departing from the gist of the present invention. Obviously you can get it.

For example, after the mold apparatus 2 and the sheet 14 are brought into close contact with each other, air or the like is supplied from the ventilation holes 82 to expand the sheet 14 to the outside and extend it to some extent. 14 into cavity 8
It may be pushed in.

Further, after the sheet 14 is pushed into the cavity 8 by using the plug 16 from the surface of the sheet 14 opposite to the cavity side, a vacuum may be drawn.

Further, the recess 16 formed in the plug 16
The number of 4 does not necessarily need to be four, and it is sufficient that at least one is formed.

Further, instead of pressing the sheet 14 with the plug 16 after the sheet 14 is brought into close contact with the mold apparatus 2, the sheet 14 may be brought into close contact with the mold apparatus 2 while being pushed with the plug 16.

Further, the mold device 2 is arranged above the sheet 14 with the cavity 8 facing downward, and the plug 16 pushes the sheet 14 upward from the lower side toward the mold device 2. Is also good.

Furthermore, the shape of the obtained molded body 20 is not particularly limited, and may be, for example, a cylindrical shape or a rectangular shape having a narrow cross section. If at least one is formed, the effect of the present invention can be obtained.

[0047]

EXAMPLES Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples.

Example 1 First, a plug 16 shown in FIGS. 3A to 3C was prepared. The plug 16 is made of wood having a circular cross section with a maximum outer diameter D1 of 96.5 mm, and has four recesses 1 extending continuously along the direction X inserted into the cavity.
64. The width W of the recess 164 is 24.98 mm, the maximum depth D2 is 5.27 mm, and ((D2 / D1) × 10
0) was 5.46, and the spacing between adjacent recesses was substantially equal in the circumferential direction.

Next, the sheet was vacuum formed as described below.

Using a heater, a translucent synthetic resin sheet made of polypropylene having a length of 500 mm, a width of 420 mm and an average thickness of 0.78 mm is held by a clamp frame.
Heated at 400 ° C. for 15 seconds to soften. Then, as shown in FIG. 4, the heat-softened sheet was brought into close contact with a mold device in which four cavities 8 corresponding to the shape of the molded body were formed.

Then, the previously prepared plug 16
As shown in FIG. 4, the recesses 164 are arranged so as to be opposed to the positions 22 where there is little room for extension during sheet forming, and the cavity 8 formed in the mold from above the sheet 14 described above. The evacuation was performed while pushing the sheet 14 inward. Thereafter, the sheet 14 shaped into a predetermined shape is taken out and cut for each molded body, thereby obtaining a circular shape having a diameter of 101.5 mm as shown in FIG.
And a cylindrical molded body 20 having a height of 101.5 mm
4 (measuring cups) were obtained.

The appearance of the obtained molded body 20 was evaluated by visual inspection and found to be good.

Further, the thickness of the obtained molded body 20 was measured. As shown in FIGS. 5 (A) and 5 (B), the thickness is set such that the center of the bottom surface 202 of the molded body 20 is 0 mm and the thickness at a position shifted by 20 mm from the center toward the opening 204 of the molded body 20 therefrom. The measurement was performed (this direction is defined as a 0 ° direction). In addition, measurement was similarly performed in the 45 ° direction (oblique direction) and the 90 ° direction (vertical direction). Fig. 6 shows the results.
Shown in As can be seen from FIG. 6, the molded body of the present embodiment is:
It was confirmed that there was no extremely thin portion of 0.1 mm or less. In addition, at a distance of 10 to 130 mm from the center of the bottom surface 202, variations in the thickness in the circumferential direction (the maximum thickness and the minimum thickness of the substantially formed film portion excluding the edges in the 0 ° direction, 45 ° direction, and 90 ° direction). About 0.18m
m, and it was confirmed that there was little unevenness in film thickness. Further, at a distance of 10 to 130 mm from the center of the bottom surface 202,
It was confirmed that the variation in the film thickness in the vertical direction (the variation in the film thickness in each of the 0 ° direction, the 45 ° direction, and the 90 ° direction) was small.

Further, the mechanical strength of the obtained molded body 20 was evaluated using a drop impact tester for cushioning material (static compression test). The mechanical strength was measured as follows.
First, the compact 20 is placed on a table with its opening 204 (see FIGS. 5A and 5B) facing upward, and a 2 kg weight is lowered from the compact 20 at a constant speed. At the position where the weight contacts the opening 204 of the molded body 20, the forced movement of the weight is stopped. Thereafter, a load of the weight is applied to the opening 204 of the molded body 20, and the position where the molded body 20 is crushed and the weight stops is read by the displacement meter. The value thus read is converted into a cup holding height (mm). Molded body 20 in this embodiment
Since the height is 101.5 mm, the closer the cup holding height is to this value, the less the molded body is crushed and the higher the mechanical strength. One of these operations
Repeated 0 times. FIG. 7 shows the results. As can be seen from FIG. 7, the molded article of this example had the first and second cup holding heights of about 101.5 mm, and the initial mechanical strength was good. Also, for the third time, the cup holding height was still about 98 mm, and it was confirmed that it was durable.

Embodiment 2 The plug 16 is located at a position 2 where there is a lot of room for extension during sheet forming.
4 (see FIG. 4), four molded bodies 20 were obtained in the same manner as in Example 1, except that the sheet 14 was pushed in, with the recessed portions 164 facing each other.

The appearance of the obtained molded body 20 was evaluated by visual inspection and found to be good.

Further, the thickness of the obtained molded body 20 was measured in the same manner as in Example 1. FIG. 8 shows the results. As can be seen from FIG. 8, the molded body of this embodiment is similar to the first embodiment,
It was confirmed that there was no extremely thin portion of 0.1 mm or less. In addition, at a distance of 10 to 130 mm from the center of the bottom surface 202, variations in the thickness in the circumferential direction (the maximum thickness and the minimum thickness of the substantially formed film portion excluding the edges in the 0 ° direction, 45 ° direction, and 90 ° direction). About 0.19m)
m, and it was confirmed that there was little unevenness in film thickness. Further, at a distance of 10 to 130 mm from the center of the bottom surface 202,
It was confirmed that the variation in the film thickness in the vertical direction (the variation in the film thickness in each of the 0 ° direction, the 45 ° direction, and the 90 ° direction) was small.

Further, as a result of evaluating the mechanical strength of the obtained molded body 20, the same evaluation as in Example 1 was obtained (see FIG. 7).

COMPARATIVE EXAMPLE 1 Four molded bodies 20 were obtained in the same manner as in Example 1 except that a plug having no concave portion on the peripheral wall of the pressing portion was used, unlike in Examples 1 and 2.

When the appearance of the obtained molded body 20 was visually evaluated, a portion having a small thickness was conspicuous.

The thickness of the obtained molded body 20 was measured in the same manner as in Example 1. FIG. 9 shows the results. As can be seen from FIG. 9, it was confirmed that the molded body of this comparative example had an extremely thin portion of 0.1 mm or less (about 120 mm from the center of the bottom surface 202), unlike Examples 1 and 2. Also,
At a distance of 10 to 130 mm from the center of the bottom surface 202, variations in the circumferential film thickness (the maximum and minimum film thicknesses of the substantially formed film portion excluding the edges in the 0 ° direction, 45 ° direction, and 90 ° direction) About 0.32mm)
It was confirmed that there was more unevenness in film thickness than in Examples 1 and 2. In addition, the distance from the center of the bottom surface 202 is 10 to 10.
At 130 mm, the variation in the film thickness in the vertical direction (the variation in the film thickness in each of the 0 ° direction, the 45 ° direction, and the 90 ° direction) was also confirmed to be larger than in Examples 1 and 2.

Further, the mechanical strength of the obtained molded body 20 was evaluated. FIG. 7 shows the results. As can be seen from FIG. 7, the molded body of this comparative example has a first cup holding height of about 89 mm, and it is confirmed that the initial mechanical strength is inferior to those of Examples 1 and 2. Was done. In addition, the second time, the cup holding height became about 51 mm, and it was confirmed that the durability was poor.

[0063]

As described above, according to the present invention, it is possible to produce a molded article having excellent mechanical strength by suppressing unevenness in thickness of the obtained molded article as much as possible without impairing its appearance. It is possible to provide a method for producing a molded article and a plug used therefor.

[Brief description of the drawings]

FIGS. 1A to 1D are schematic views illustrating a method for manufacturing a molded article according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an example of a molded article obtained by the method according to the present invention.

3 (A) is a perspective view of a plug used in the method according to the present invention, FIG. 3 (B) is a plan view of the plug of FIG. 3 (A), and FIG. 3 (C) is FIG. FIG.

FIG. 4 is a plan view showing an example of a case where a sheet is arranged on a mold.

FIGS. 5 (A) and 5 (B) are views showing positions of thickness measurement of molded articles obtained in Examples and Comparative Examples.

FIG. 6 is a graph showing the measurement results of the thickness of the molded article obtained in Example 1.

FIG. 7 is a graph showing the results of a static compression test of the molded articles obtained in Examples 1 and 2 and Comparative Example 1.

FIG. 8 is a graph showing the measurement results of the thickness of the molded article obtained in Example 2.

FIG. 9 is a graph showing the measurement results of the thickness of the molded body obtained in Comparative Example 1.

[Explanation of symbols]

 2 Mold device 4 Mold mounting base 6 Mold body 8 Cavity 82 Vent 10 Pipe 12 Clamp frame 14 Sheet 16 Plug 162 Pressing portion 162a Lower end 162b Peripheral wall 164 Concave 20 Measuring cup (molded product) 202 ... Bottom surface 204 ... Mouth

Continuation of the front page (72) Inventor Kazuyuki Onishi 1-2-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Zeon Corporation General Development Center (72) Inventor Minoru Tomizawa 2-4-1 Shiba Park, Minato-ku, Tokyo No. ZEON Kasei Co., Ltd. F-term (reference) 4F202 AG07 AG26 AH55 CA09 CB01 CB29 CK41 CK64 CP06 CQ01 4F208 AG07 AH55 MA01 MB01 MC01 MC04

Claims (2)

[Claims] 1. A vacuum is drawn from an inner surface of a cavity of a mold,
When the synthetic resin sheet is stretched and formed along the inner surface of the cavity, a concave portion is formed in the peripheral wall from the surface opposite to the cavity side of the sheet and extends substantially along the direction in which the sheet is inserted into the cavity. A method for manufacturing a molded body, characterized by assisting shaping of a sheet by pushing the sheet in the direction of a mold using a plug having a pressing portion. 2. A vacuum is drawn from the inner surface of the cavity of the mold,
A plug used to assist shaping of the sheet when the synthetic resin sheet is extended along the inner surface of the cavity and shaped, substantially in a direction inserted into the cavity. A plug having a pressing portion having a recess extending along the peripheral wall.