JPS60162631A - Manufacture of resin molded item - Google Patents

Abstract

PURPOSE:To mass-produce a resin molded item, by molding a plurality of production molds using a single master. CONSTITUTION:The pressure in a hollow chamber 3 of a master 1 is reduced by suction, and a thermoplastic synthetic resin molding film 8 that has been heated to be softened is placed on the top surface of the master 1. A frame 6 is placed on the master 1 on which the molding film 8 is firmly placed, the space formed by the frame 6 and the molding film 8 is filled with a particular material 10 and a screening film 9 is placed thereon. When the pressure in the space containing the particular material 10 is reduced, the particular material 10 is compacted by the atmospheric pressure thereby forming a production mold P. The production mold P is turned, then layers of a hardening agent-containing liquid resin 11 and a fiber reinforcement 12 are alternatively superposed on the upper surface thereof in position until a prescribed thickness is obtained, and they are pressed so that the layers of the fiber reinforcement 12 comes in firm contact with the production mold P. Then the molding film 8 is peeled off from the molded item, and burrs and the like are removed therefrom to give a resin molded item containing the fiber reinforcement 12.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a resin molded article.

Conventionally, there are the following methods for manufacturing resin molded products.

That is, on the surface of the master mold coated with a mold release agent, sheet-like or cloth-like reinforcing materials made of polyester resin added with a curing catalyst and fiber materials such as glass fiber, carbon fiber, hemp fiber, etc. are alternately applied. This is a method of stacking or applying a polyester resin containing the fiber materials and a curing catalyst, and after curing the resin, separating the stacked fiber materials or the resin containing the fiber materials from the master mold. By the way, in this conventional manufacturing method, it takes half a day for the resin to harden to a releasable state, which makes it difficult to manufacture a large number of molded products in a short period of time.

Is there a problem such as the need for a large number of master molds?
child .

The present invention has been made in view of the above circumstances, and its purpose is to provide a method for manufacturing resin molded products that can manufacture a large number of molded products within a short time using one master mold.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. (1) is a wooden or plaster master mold, and the upper surface has a mold part (2
) is formed and a hollow chamber (3) is provided in the lower part. The surface of the mold part (2) has suction holes (4) (4).
The hollow chamber (3) is connected to the hollow chamber (3) through the hollow chamber (3).
is connected to a vacuum pump (not shown) via a ventilation pipe (5). Reference numeral (6) denotes a frame body, and the frame body (6) is provided with an intake mechanism that is communicatively connected to a vacuum pump (not shown). The intake mechanism includes a hollow chamber (16) formed in the side wall of the frame (6) and connected to the vacuum pump via a ventilation pipe (15), and a hollow chamber (16) formed in the side wall of the frame (6) from inside the hollow chamber (16). A large number of through holes (17) are provided through the chamber (16) to communicate the hollow chamber (16) with the inner space of the frame (6).
(17) and is attached to the inner surface of the side wall of the frame (6) and penetrates.
It consists of a wire mesh (18) that allows only air to pass through the through hole (17) (17). (8) is a flexible but non-breathable molded film made of polyethylene, polypropylene, styrene, vinyl chloride, pyridene chloride, polyamide, polycarbonate, ionomer-, ethylene-
Those made from synthetic resins such as vinyl acetate copolymer,
Some are made of rubber such as ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, butyl rubber, and natural rubber.

Note that when the adhesiveness between the resin molded product and the molded film (8) is poor, treatment such as applying an adhesive to the molded film (8) in advance is required. (9) is a non-breathable shielding membrane, which is made of plastic, rubber, metal, or paper. (1
Particulate matter 0) includes inorganic particles such as metal powder, glass powder, sand, and other inorganic compounds, and organic particles such as wood powder and plastic powder. And this particulate matter (
The necessary properties for 10) are good filling properties, and in addition, if the molding resin (11) described below generates heat during curing or needs to be heated to a certain extent during molding, it must have sufficient resistance to these temperatures. It is to have heat resistance so as to obtain.

Further, the particle size of the particulate material (10) may be about 10 μm to 3 μm, but care must be taken because the smoothness of the surface of the molded product is affected by the particle size. If the particle size is small, the smoothness of the surface of the molded product and the transferability of fine uneven patterns will be improved, but particulate matter (1
0) becomes difficult to handle and generates dust, which worsens the environment. On the other hand, if the particles are coarse, the opposite phenomenon will occur, and the particle size is generally about 50 to 600 μm. (11)
is a molding resin, a polyester resin containing a hardening agent,
There are epoxy resins, etc. (12) is a fiber reinforcement material, which is made by binding fibers such as glass fiber, carbon fiber, hemp fiber, etc. into a cloth shape, or by cutting fibers into short lengths and forming them into a mat shape using a binder. ,
Some fibers are tied up and cut into short pieces.

Next, a method for manufacturing a resin molded product will be explained.

By driving a vacuum pump (not shown), the inside of the hollow chamber (3) of the master mold (1) is suctioned and depressurized to apply suction to the upper surface of the master mold (1) and the surface of the mold part (2), and then softened by heating. When the molded film (8) made of thermoplastic synthetic resin is placed on the top surface of the master mold (1), the molded film (8) is suctioned and stretched and covers the top surface of the master mold (1) and the mold part (2).
) Adsorb onto the surface. Next, the frame (6) is placed on the master mold (1) to which the molding film (8) has been adsorbed, and the master mold (1) is placed in the space constituted by the frame (6) and the molding film (8).
The particulate matter (10) is introduced and filled while vibrating the frame (6), and then the frame (6) and the particulate matter (10) are filled.
A shielding film (9) is placed on top to shield the upper end opening of the frame (6). Next, a vacuum pump (not shown) is driven to suck and depressurize the space formed by the frame (6), the molded film (8), and the shielding film (9) and containing the particulate matter (10) through the suction mechanism. Then, the particulate matter (10) is solidified by the action of atmospheric pressure. Next, by stopping the driving of the vacuum pump (not shown), the suction action on the upper surface of the master mold (1) and the surface of the mold part (2) is stopped, and the upper surface of the master mold (1) and the surface of the mold part (2) of the molding film (8) are removed. Then, the frame (6) that solidifies and holds the particulate matter (10) is separated from the master mold (1) and raised, thereby molding the resin into a molded product. A production mold (P) can be obtained. Next, the production mold (
The liquid polyester containing a curing agent is also inverted at a predetermined position on the upper surface of the production mold (P), that is, at the position where the molded product will be molded corresponding to the mold part (2) of the master mold (1). A molding resin (11) is applied, and then a fiber reinforcing material (12) made of glass fibers molded into a mat is stacked and adhered to the top surface. In this case, the fiber reinforcing material (12) can be easily brought into close contact with the production mold (P) by pressing with a roller, but the particulate matter (10) or the molded film (8) is black or dark blue. By using a dark colored material such as dark green, air bubbles in the molding resin (11) can be easily discovered and then squeezed out using a roller. In this way, the production mold (P
) The molding resin (11) and the fiber reinforcing material (12) are alternately stacked on top of the molding material (12) to a predetermined thickness (see Fig. 2).

After the molding resin (11) has reacted and hardened, the drive of the vacuum pump (not shown) is stopped to stop the suction action into the frame (6),
Next, when the shielding film (9) is removed (and the particulate matter (10) is discharged from the frame (6), the molding resin (
11) is cured, a molded film (8) is attached to the surface thereof, and a molded product having an unnecessary portion protruding from its outer periphery can be taken out. Molded film (8) from this molded product
By peeling off the fibers and cutting off unnecessary parts such as ribs, a resin molded product incorporating the fiber reinforcing material (12) can be obtained.

In addition, if a color or uneven pattern is required on the surface of the molded product, use a colored film or a film with an uneven pattern as the molding film (8), and remove the excess portion of the molding film (8). and leave it attached to the molded product. In the above embodiment, the molding resin (11) and the fiber reinforcing material (12) are alternately stacked on the top surface of the production mold (P) to produce a molded product. If this is not necessary, the molding resin (11) mixed with short cut fiber reinforcing material and a curing agent may be applied to a predetermined position on the upper surface of the production mold (P). In this case, since the molding resin (11) may hang down from the coating surface, it is necessary to add a substance that increases thixotropy, such as fine silica, to the molding resin (11) in advance.

As is clear from the above description, according to the present invention, by molding multiple production molds with one master mold, resin molded products can be manufactured on a mass production basis, and the productivity is extremely high. This has excellent effects such as making it easier for the reinforcing material to adhere to the production mold and for squeezing out air bubbles from the molding resin, while also making it possible to reliably manufacture resin molded products.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views illustrating the main steps of the present invention, and FIG. 3 is an enlarged view of section A in FIG. 2. (1): Master mold (2): Mold part (6): Frame (8): Molded film (9): Shielding film (10): Particulate matter (11):
Molding resin (12): Fiber reinforcing material (16): 1 hollow chamber etc. 3 completed 2 drawings

Claims (1)

[Claims] 1. After adsorbing a molding film to the upper surface of a master mold having a mold portion on the upper surface and the surface of the mold portion, the upper surface of the master mold is provided with an air intake mechanism on its side wall that acts on the inner hollow portion thereof. A space is defined by the molded film and the frame, and after filling the space with particulate matter, a shielding film is placed over the upper surface of the frame and the particulate matter, and the frame is closed. shielding the upper opening of the body;
The particulate matter is solidified by suctioning and reducing the pressure in the space constituted by the frame, the molding film, and the shielding film and containing the particulate matter through the suction mechanism, and After releasing the adsorption state to the mold surface, the frame was separated from the master mold to form a production mold, and liquid molding resin and fiber reinforcing material were alternately stacked at predetermined positions of the production mold. After that, the fiber reinforcement material is pressed with a roller to tightly adhere it to the predetermined position of the production mold, and air bubbles are squeezed out from within the liquid molding resin, and after the molding resin hardens,
The solidified state of the particulate matter is released, the resin molded article to which the molded film is attached is taken out, and unnecessary materials are cut and removed from the molded product, or the unnecessary materials are cut and removed and the molded film is peeled off. A method for manufacturing a resin molded product. 2. The method for manufacturing a resin molded article according to claim 1, wherein the molded film is dark-colored. 3. The method for manufacturing a resin molded article according to claim 1, wherein the particulate matter is dark-colored.