JPH0148863B2 - - Google Patents

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,
Since it takes half a day for the resin to harden to a releasable state, there are problems such as the need for a large number of master molds when producing a large number of molded products in a short period of time.

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. Reference numeral 1 denotes a wooden or plaster master mold, on the upper surface of which a mold part 2 having substantially the same shape as the outline of the resin molded product is formed, and a hollow chamber 3 is provided in the lower part. The surface of the mold part 2 is communicated with a hollow chamber 3 through suction holes 4, 4, and the hollow chamber 3 is connected through a ventilation pipe 5 to a vacuum pump (not shown). Reference numeral 6 denotes a frame body, and an air-permeable intake pipe 7 is installed in the space of the frame body 6, and the intake pipe 7 is inserted through a hollow chamber (not shown) provided in the frame body 6 (not shown). Connected to the vacuum pump. 8 is a flexible but non-breathable molded membrane made of synthetic resin such as polyethylene, polypropylene, styrene, vinyl chloride, byylidene chloride, polyamide, polycarbonate, ionomer, ethylene-vinyl acetate copolymer, etc. There are also those 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 may be made of plastic, rubber, metal, or paper. Reference numeral 10 denotes particulate matter, which includes inorganic particles such as metal powder, glass powder, sand, and other inorganic compounds, and organic particles such as wood powder and plastic powder. The necessary property of this particulate material 10 is that it has good filling properties.Furthermore, if the molding resin 11 described below generates heat during curing or needs to be heated to a certain extent during molding, these temperatures It must have sufficient heat resistance to withstand. The particle size of the particulate matter 10 may be about 10 μm to 3 mm, 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 are improved, but the particulate matter 10 becomes difficult to handle and generates dust, which worsens the environment. On the other hand, the opposite phenomenon will occur with coarse particles, and generally the particle size is 50~
Something around 600μ is good. 11 is a molding resin;
There are polyester resins, epoxy resins, etc. that contain hardening agents. 12 is a fiber reinforcing material, such as fibers such as glass fibers, carbon fibers, hemp fibers, etc., which are tied together and woven into a cloth shape, fibers that are tied and cut into short lengths and formed into a mat shape using a binder, and fibers. There is one that is tied and cut into short pieces.

Next, a method for manufacturing a resin molded product will be explained.
Master mold 1 is created by driving a vacuum pump (not shown).
The inside of the hollow chamber 3 is depressurized by suction to apply suction to the upper surface of the master mold 1 and the surface of the mold part 2, and then a molded film 8 made of thermoplastic synthetic resin softened by heating is applied.
When the molded film 8 is placed on the upper surface of the master mold 1, the molded film 8 is attracted to the upper surface of the master mold 1 and the surface of the mold part 2 while being stretched by suction. Next, the frame 6 is placed on the master mold 1 to which the molded film 8 has been adsorbed, and the particulate matter 10 is poured into the space formed by the frame 6 and the molded film 8 while vibrating the master mold 1 and the frame 6. Then, the frame 6 and the particulate matter 10 are covered with a shielding film 9 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 intake pipe 7, thereby removing the particulate matter 10. is solidified by the action of atmospheric pressure. Next, by stopping the drive 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 molded film 8 is removed.
The adsorption state on the upper surface of the master mold 1 and the surface of the mold part 2 is released, and then the frame body 6 that solidifies and holds the particulate matter 10 is separated from the master mold 1 and raised. A production mold P for molding into a molded article can be obtained. Then,
After inverting the production mold P, a liquid polyester molding resin 11 containing a curing agent is placed at a predetermined position on the upper surface of the production mold P, that is, at a position corresponding to the mold part 2 of the master mold 1 and at which a molded product will be molded. Next, a fiber reinforcing material 12 made of glass fibers formed into a mat shape is stacked and adhered to the top surface. In this case, the fiber reinforcement material 12 is pressed by a roller.
The molding resin 11 can be easily brought into close contact with the production mold P by using the particulate matter 10 or the molding film 8 that is colored in a dark color such as black, dark blue, or dark green. It is also possible to easily find the air bubbles inside and use a roller to squeeze out the air bubbles. In this way, the molding resin 11 and the fiber reinforcing material 12 are alternately stacked on the upper surface of the production mold P to a predetermined thickness (see FIG. 2). After the molding resin has reacted and hardened, the drive of the vacuum pump (not shown) is stopped to stop the suction action into the frame 6, and then the shielding film 9 is removed and the particulate matter 10 is discharged from the frame 6. and molding resin 11
The molded product is cured, the molded film 8 is attached to the surface thereof, and the molded product whose unnecessary portion protrudes from its outer periphery can be taken out. By peeling off the molded film 8 from this molded product and cutting off unnecessary parts such as burrs, a resin molded product containing the fiber reinforcing material 12 can be obtained.

If a color or uneven pattern is required on the surface of the molded product, use a colored film 8 or a film with a textured pattern, and remove the excess portion of the molded film 8 to form the molded product Leave it attached to. In the above embodiment, the molding resin 11 and the fiber reinforcing material 12 are stacked alternately on the top surface of the production mold P to produce a molded product, but if the molded product does not require much strength, it can be shortened. The molding resin 11 mixed with the cut fiber reinforcing material and added with a curing agent may be applied to a predetermined position on the upper surface of the production mold P for manufacturing. 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 explanation, 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 to adhere the reinforcing material to the production mold and squeezing out air bubbles from the molding resin, and 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 section, 7: Intake pipe, 6:
Frame, 8: Molding film, 9: Shielding film, 10: Particulate matter, 11: Molding resin, 12: Fiber reinforcement material.

Claims (1)

[Claims] 1. After a molded film is adsorbed onto the upper surface of a master mold having a mold portion on the upper surface and the surface of the mold portion, a frame body equipped with a suction tube is placed on the upper surface of the master mold, and the molded film is adsorbed onto the upper surface of the master mold. and a frame, defining a space, filling the space with particulate matter, and then covering the upper surface of the frame and the particulate matter with a shielding film to shield the upper end opening of the frame;
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 pipe, 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 reinforcement were alternately stacked at predetermined positions of the production mold. Thereafter, the fiber reinforcing material is pressed with a roller to tightly adhere to a predetermined position of the production mold, and air bubbles are squeezed out from within the liquid molding resin. After the molding resin has hardened, the solidified state of the particulate matter is released and the A method for manufacturing a resin molded product, which comprises taking out a resin molded product to which a molded film is attached, and cutting and removing unnecessary materials from the molded product, or cutting and removing unnecessary materials and peeling off the molded film. 2. The method for manufacturing a resin molded product 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.