JPS6114913A - Molding method of reinforced plastic product - Google Patents

Abstract

PURPOSE:To simplify the molding work and at the same time obtain the titled product with higher degree of freedom on product desin such as the designs of electronic appliances, fuselage of aircraft and the like by a method wherein reinforcing fibers such as glass fibers or the like are electrically flocked onto the tool surfaces of molding tools in advance and, after the tools are clamped, liquid resin such as polyester or the like is cast in the tools and cured. CONSTITUTION:Releasing agent such as silicone or the like is coated at first and secondly bonding agent such as liquid polyester or the like is coated in addition onto the tool surfaces 3 oa a male mold 1 and of a female mold 2. Thirdly, reinforcing fibers 3 such as glass fibers or the like are electrically flocked further onto the tool surfaces 3. Fourthly, the make mold 1 and the female mold 2 are clamped. Finally, liquid resin is cast through the resin bung hole 6 of the female mold 2 and cured in order to obtain a molded product. USE:For building material, medical appliance, communications equipments and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of molding a resin product reinforced with glass fiber or the like, so-called FRP.

FRP has many advantages such as high strength and light weight.
From aircraft bodies, car bodies, yachts, bathtubs,
It has come to be used in many different fields, including various building materials and skis.

The most common method for molding FRP is the no-no-dray-up method. With the nod lay-up method, molding can be performed using a simple mold that can be produced in a relatively short period of time and at low cost, and does not require any other auxiliary equipment.

Therefore, there is an advantage that it does not require a large amount of cost when starting product production, and can be applied relatively easily to products that are produced in small quantities. However, it is a molding method that requires a lot of manual labor, which tends to result in uneven product quality such as wall thickness, and requires skill.

In addition, the glass fibers used fly up into the work space,
It irritates the skin of workers, and the resin liquid has a strong odor.

There are also major constraints in product design.

Figure 1 shows a state in which reinforcing fibers impregnated with resin liquid are laminated on the molding surface of the mold amount using the hand lay-up method. A void (8) is formed, resulting in defective molding. This is because during lamination, even if the laminate surface is adjusted to the corner of the molding surface using a trowel or the like to prevent voids, the material springs up due to the elasticity of the reinforcing fiber cloth, etc.

Therefore, the product design must be such that the corners (7) are rounded as shown in Figure 2. The radius of this roundness is required to be 5 degrees or 1105 degrees, and from a product design perspective, it gives a sharp appearance and it is common knowledge that products with a sharp image cannot be molded with FRP. Further, although a smooth surface is obtained when molded in contact with the mold, there is also a drawback that the back surface is uneven or rough, making it impossible to obtain a uniform surface.

These drawbacks are the same for all FRP molding methods, with the exception of the highly mechanized 8MC molding method.
Despite the inherent physical advantages of molded products and the low burden on equipment, the scope of application remains within these constraints at present.

The present invention is a molding method that solves these drawbacks without requiring large-scale equipment while retaining the original advantages of FRP. This is a reinforced plastic molding method in which reinforcing fibers are densely electro-flocked in every detail, and after the mold is clamped, resin is injected and hardened to increase strength and produce a molded product with high precision on both the front and back surfaces.

Next, embodiments of the present invention will be explained with reference to the drawings.

The male mold (1) and female mold (2) in Figure 3 are made of epoxy, AB
This is a resin mold such as S, and the molding surface is made conductive by plating, electroforming, etc. Also, metals such as iron and aluminum may be used.

The molding procedure is to apply a mold release agent such as silicone to the molding surfaces (3) of the male mold (1) and female mold (2) in Fig. 3, and then apply an adhesive such as liquid polyester thereon. Then the fiber length is 0
．． 5m to 5u, fiber diameter 10#m to 10
Glass fibers (4) of 0 μm are electrically flocked by electrostatic force, and after the adhesive has hardened, the male mold and female mold (2) are combined and clamped as shown in FIG.

Next, resin such as polyester resin is injected from the resin injection port (6) of the female mold (2) in Fig. 4, left to harden, and the molds (1) and (2) are opened. Pour out the product (5) shown in the figure.

The thus obtained molded article (5) is a reinforced plastic molded article with a wall thickness of 2 to 5 N, high strength, and good formability on both the front and back surfaces faithful to the molding surface.

As a casting method, a method of casting a mixture of reinforcing fibers and liquid resin may be considered, but the viscosity increases with the amount of reinforcing fibers, making casting difficult.

For example, in the case of a mixture of two lengths of short glass fibers and a polyester resin, if the amount of glass fibers is only about 5% by volume, fluidity will not be lost and casting will not be possible.

In the present invention, since the reinforcing fibers are provided on the molding surface in advance, such problems are avoided (the amount of reinforcing fibers can be up to about 50% of the total in terms of volume ratio).

The resin used in the present invention may be epoxy, phenol, polyurethane resin, etc. in addition to unsaturated polyester, and the reinforcing fibers include glass fiber, vinylon,
Fibers such as polyester and aramid may also be used.

In this way, according to the present invention, by incorporating electric flocking, the process of cutting reinforcing fibers into the desired shape is not necessary, compared to the conventional FRP molding method, and it is also possible to mold products with sharp corners. This eliminates the trimming process after molding. In addition, it is now possible to mold products with holes, which was impossible with most conventional methods, increasing the degree of freedom in product design.
The work content is also extremely simplified, and the work environment is also improved.

In addition, high pressure is not required for resin injection (because it can be molded with inexpensive molds, it can be used for electronic equipment and computer-related equipment, which tend to be produced in high-mix, low-volume quantities).Using, medical equipment, physical and chemical equipment, and communication equipment. This is an extremely suitable molding method for manufacturing nozzles for equipment, measuring instruments, and other special commercial equipment.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views of a mold and a molded product molded by the hand lay-up method. FIG. 3 is a sectional view of a state in which reinforcing fibers are electro-flocked in the present invention. FIG. 4 is a sectional view of the completed molding state in the present invention. FIG. 5 is a sectional view of the demolded state in the present invention. In the figure (11...Male type (2)...Female type (3)
... Molding surface (4) ... Reinforcing fiber (5) ... Molded product (6) ... Resin injection port Figure 1 A drawing 2 compilation 4 Enmio 580

Claims (1)

[Claims] Reinforced plastic molded products made by electro-flocking reinforcing fibers such as glass fibers on the molding surfaces of the male and female molds in advance, and then injecting and curing liquid resin such as polyester after clamping the molds to integrate the reinforcing fibers. Molding method to obtain.