JPS6195911A - Static attraction type reinforced plastic molding method - Google Patents

Abstract

PURPOSE:To obtain a large molded article which is thin or in a complicated shape or possesses a deep riser, by a method wherein a static attraction layer is formed by making a thin piece of a fibrous reinforced material made of substance like a dielectric, which is attractable through static electricity, attract statically on the surface made of the dielectric and an impregnated static attraction layer is cured. CONSTITUTION:A releasant layer 5 is formed on the surface 2 of a grounded 4 mold 3. The inside of a hopper 6 is filled with pieces 7 of a fibrous reinforced material made of attractable substance through static electricity such as glass fiber and high voltage is applied to the hopper 6. High voltage is applied to the fine piece 7 falling through a fine hole 8 when the same passes through the fine hole 8. The fine piece 7 to which the high voltage has been applied is attracted to the surface 2 of the mold 3 which is in ground potential by the static electricity and a static attraction layer 9 is formed. The layer 9 is made to impregnate with particulate 10 setting resin in an atomized or droplet state by spraying the same, then when the layer 9 is made of thermosetting resin, the static attraction layer 9 is made to cure through heat and when the layer 9 is made of thermosoftening resin, it is made to cure through cooling after heating, through which a molded article is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for molding a reinforced plastic molded article containing fiber reinforcement.

Conventional technology Conventional reinforced plastic molded bodies are produced by injection molding a mixture of a fiber reinforcing material such as glass fiber and a curable resin into the cavity of a mold, and then curing the resin to form a molded body, or by molding the mixture into a piece. After pressure molding, the resin was cured to form a molded product.

Problems to be solved by the invention Conventional reinforced plastic molded products cannot be made thin;
Further, there are problems in that it is not possible to obtain large molded bodies with complex shapes or deep rises, requires skilled workers, and makes mass production difficult.

Means for Solving the Problems The present invention provides a method of applying high voltage by bringing strips of fibrous reinforcing material, such as glass fibers, made of a material such as a dielectric material that can be attracted by static electricity into contact with a high voltage electrode. A voltage is applied, and then the strips are electrostatically adsorbed to the surface of a conductor having an arbitrary shape to form an electrostatic adsorption layer, and the electrostatic adsorption layer is further coated with a mist, droplet, etc. The above-mentioned problems could be solved by an electrostatic adsorption reinforced plastic molding method in which a molded product is obtained by spraying and impregnating the resin with fine particles of curable resin and then curing the impregnated electrostatic adsorption layer. It is something.

Function: The reinforced plastic molding method of the present invention produces thin and complex shapes that could not be obtained using conventional methods.

This makes it possible to mold large, reinforced plastic molded products with deep rises.

Example Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a mold 3 having a surface 2 having the same basic shape as the molded article 1 shown in FIG. 5 is prepared. Since the surface 2 of the pattern 3 is normally at ground potential, it may be formed of metal or other conductor such as a mold, or may be made of a poor electrical conductor such as a wooden resin mold depending on the purpose.
A thin conductive layer may be formed by coating or the like.

The mold 3 is grounded 4 as shown in FIGS. 2 and 3. It is preferable to form a release agent layer 5 on the surface 2 of the mold 3.

A second hono-ri 6, which also serves as a high-voltage electrode, is placed directly above the mold 3.
Install as shown in the figure.

The hopper 6 is filled with pieces γ of a fibrous reinforcing material made of a substance such as glass fiber that can be attracted by static electricity.

A high voltage is applied to the hopper 6.

The hopper 6 of the embodiment shown in FIG.
However, when passing through the pore 8, a high voltage is applied.

When high frequency vibration is applied to the hopper 6, the strips 7 are more likely to fall through the pores 8 in a more even distribution.
is adsorbed to the surface 2 by static electricity, forming an electrostatic adsorption layer 9.

By stopping the supply of the strips 7 and, if necessary, temporarily stopping the application of high voltage, the electrostatic adsorption layer 9 formed on the surface 2 of the mold 3 is coated with a mist or droplet as shown in FIG. A curable resin in the form of fine particles of 10 is sprayed to impregnate it.

As the curable resin, a thermosetting resin such as an unsaturated polyester resin can be used, but depending on the purpose, a thermoplastic resin that hardens at room temperature can also be used.

Next, the electrostatic adsorption layer 9 impregnated with a curable resin is cured by heating in the case of a thermosetting resin, and is cured by heating and cooling in the case of a thermoplastic resin to obtain a molded article. If necessary, as another example, as shown in FIG. 4 and FIG. After pressing and adjusting, the electrostatic adsorption layer T is cured, and the upper mold 1 is
When the mold 1 and the mold 3 are separated, it is possible to obtain a molded product 1 whose both surfaces are smoothly finished by the upper mold 11 and the mold 3. In this case, it is easier to separate if a release agent layer is also provided on the inner surface of the upper mold 11.

The fiber reinforcing material is not limited to glass fibers, but whisker-like fiber reinforcing materials, such as carbon fibers whose surface has been treated with a poor conductor, metal fibers, ceramic fibers, and the like can also be used.

In addition, various methods are used to make the curable resin into fine particles, such as atomization that takes advantage of centrifugal force, atomization that uses static electricity, and spraying that uses high voltage between the gun and the mold. Means are used.

Effects of the Invention According to the present invention, it is possible to make a reinforced plastic molded product thinner and lighter, it is possible to mold reinforced plastic in a complicated shape, and it is also possible to add a hardening accelerator to the impregnated electrostatic adsorption layer in the form of fine particles. By shortening the curing time by adding , heating, etc., it becomes possible to continuously produce reinforced plastic molded bodies through mechanization without the need for skilled workers, and it is possible to produce large quantities of reinforced plastic molded bodies with stable quality. At the same time, by adopting an electrostatic adsorption method, it is possible to prevent the scattering of small pieces of fiber reinforced material, and it is also possible to improve the working environment.If necessary, by using an upper mold, both sides of the molded product can be Finishing is possible, and not only metal molds, but also wooden molds and plastic molds can be used, making it easy to process into molds.Molds with complex shapes can also be easily obtained, making molding inexpensive. In addition, it is possible to reduce the production cost and cost of reinforced plastic molded products as a whole.
It has unique effects not found in reinforced glass molding methods.

[Brief explanation of the drawing]

Fig. 1 is a side view of an embodiment of a mold used in the present invention, Fig. 2 is a side view of an embodiment of an apparatus used in the present invention, and Fig. 3 shows the curable resin impregnation step of the present invention. Side view, Figure 4,
FIG. 5 is a side view showing the molding process of another embodiment of the present invention. 2: surface, 3: mold, 1: strip, 9: electrostatic adsorption layer, 10
: Fine particles.

Claims (1)

[Claims] After electrostatically adsorbing small pieces of fiber reinforced material that can be electrostatically adsorbed onto the surface of an arbitrary mold to form an electrostatic adsorption layer, and then impregnating the electrostatic adsorption layer with fine particles of curable resin, An electrostatic adsorption reinforced plastic molding method that is characterized by hardening and molding.