JPH047127A - Molding process of frp - Google Patents

Abstract

PURPOSE:To enable the inner surface of a molded object to be smoothed, while the FRP molded object with complicated and precise shape is effectively produced by a method in which after the FRP materials have been laminated and cured on the mold made of wax, the mold made of wax is removed by melting it. CONSTITUTION:FRP materials are laminated on the mold made of wax, and then are molded and cured. In this case, such inconvenience that the wax begins to melt at 60 - 70 deg.C and the mold breaks, occurs. Accordingly the curing agent to be compounded with the matrix resin of FRP is switably decreased, and the resin is slowly cured at room temperature. After the FRP material has been cured, the mold 1 made of wax is removed by heating and melting, whereby a product is obtained. Then, as the melting method of the mold made of wax, the steam heating in an autoclave, the melting in a furnace and the dipping in boiled water, etc., are used. The mold made of wax is melted and a FRP product 2 may be taken out in the sport time of 2 - 3 minutes. The wax separated by fusion may be used again by separating it from the water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an FRP molding method using a wax mold capable of performing the lost wax method.

[Conventional technology]

Conventionally, fittings for FRP (fiber-reinforced plastic) vibes that use glass fiber as a reinforcing material have been mainly molded using the hand lay-up method, but the molds used for this are made of aluminum or steel, and the A split die is used when directional die cutting is difficult.

Figure 3 is a cross-sectional view of the FRP elbow during manufacture.
In the figure, 6.6a and 6b are metal split molds, 5 is an FRP elbow that is laminated by hand lay-up on a mold that combines the above split molds, and molded and hardened; after molding, the split molds 6.6a, 6b can be easily removed.

[Problem to be solved by the invention]

However, when using the above-mentioned split type described in the prior art, there are the following problems and it is not preferable. That is, (1) In order to improve productivity, a large number of divided molds are required, which increases mold costs and is uneconomical.

(2) Since the mold is repeatedly divided and reassembled for each molding process, the process takes time and manufacturing costs increase.

(3) Since the parting line of the mold is transferred to the molded product, the commercial value of pipe joints, etc., which require inner surface smoothness, decreases.

An object of the present invention is to provide an FRP molding method that does not have the above-mentioned drawbacks.

[Means to solve the problem]

In order to achieve the above object, in the FRP molding method of the present invention, an FRP material is laminated on a wax mold, and after molding and curing, the wax mold is melted and removed.

The above-mentioned molding and curing is preferably carried out at room temperature in order to prevent the melting mold from deteriorating in the wax mold.

〔Example〕

Hereinafter, the present invention will be described in detail based on the drawings.

Figure 1 is a cross-sectional view of the FRP elbow during manufacture.
1 is a wax mold made by molding a wax material with a melting point of about 83 to 87°C, which is a mixture of paraffin, natural wax, and rosin, using a molding machine with a low mold internal pressure of about 30 kgf/ciN; This is an FRP elbow in which FRP materials are laminated on a mold 1 using the hand-laying method and then molded and hardened.

In this case, the mold 1 is made of wax with good melting properties, so the surface is generally smooth and inert, so direct hand lay-up is possible without using a mold release agent as usual. be.

However, in this case, the wax mold is made of wax, so if care is not taken to avoid heat generation when the hand-layed up FRP material hardens, the wax will begin to melt at 60 to 70°C and the mold will collapse. Therefore,
Depending on the type of wax, hand laid up FR
The P material is cured slowly at room temperature. To achieve this, the curing agent blended into the matrix resin of FRP (if the matrix resin is vinyl ester resin or unsaturated polyester resin, the formulation shown in Table 1) should be adjusted to an appropriate range compared to that for normal room temperature curing ( (80% or less of the usual amount).

After curing, the FRP material in Table 1 is manufactured by heating and melting the wax mold to remove it.The methods for melting the wax mold at this time include steam heating in an autoclave, melting in a heating furnace, Although immersion in boiling water or the like is used, it is possible to melt the wax mold and take out the FRP product in a short time of about 2 to 3 minutes. Note that the melted and separated wax can be reused if it is separated from water.

Furthermore, according to the method of the present invention, even complex-shaped FRP molded products can be easily molded. To explain this example, the second
Figure (a) is a cross-sectional view of an FRP pipe having an undercut portion during manufacture, where 3 is a wax mold, 4 is an FRP pipe laminated on the wax mold 3,
By melting and separating the wax mold 3, an FRP having an undercut portion 4a as shown in the cross-sectional view of FIG. 2(b) is formed.
Pipe 4 can be obtained.

The wax mold of the present invention can be applied not only to the hand lay-up method according to the above embodiments, but also to the spray-up method and filament winding method.

〔Effect of the invention〕

According to the present invention, since a mold made of wax is used, the mold can be easily removed by heating after molding the F'RP material with the mold, so that FRP material with complex and precise shapes can be easily removed. It is possible to manufacture molded products efficiently and economically.

Furthermore, the inner surface of the FRP molded product becomes extremely smooth, increasing its commercial value.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an FRP elbow when manufactured by the FRP molding method of the present invention, FIG. Figure (b) is a cross-sectional view of an FRP pipe having an undercut portion manufactured according to Figure 2 (a), and Figure 3 is a cross-sectional view of an FRP elbow manufactured by a conventional molding method. Explanation of symbols 1-Wax mold 2-F RP elbow 3...-
Wax mold 4 - FRP vibe a Undercut part FRP elbow a 6b - Split mold Fig. 2 Fig. 3

Claims (1)

[Claims] 1. After laminating FRP material on a wax mold and curing the mold,
An FRP molding method characterized by melting and removing the wax mold. 2. The FRP molding method according to claim 1, wherein the molding and curing is room temperature curing.