JPH03187725A - Preparation of fiber-reinforced plastic pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing a fiber-reinforced plastic pipe, and more particularly to a method of manufacturing a flat fiber-reinforced plastic pipe with a smooth portion. be.

[Conventional technology]

Conventionally, in the method of manufacturing flat fiber-reinforced plastic pipes with smooth parts, it is extremely difficult to satisfy strict requirements for smooth parts such as parallelism and flatness. There was a problem.

That is, as a conventional method for manufacturing a flat fiber-reinforced plastic pipe with a flat surface, for example, a substantially flat mandrel 2 with a flat portion 1a as shown in FIG.
By passing glass fibers or the like through a resin bath, the fibers are impregnated with resin and wound around a mandrel 2 in an uncured state.

[Problem that the invention seeks to solve]

However, in order to wrap the uncured prepreg 4, which is fiber impregnated with resin, around the mandrel 2, the mandrel 2
Although both ends 3a and 3b in the longitudinal direction of the cross section can be wrapped with a predetermined tension, the flat part 1a bulges outward, and as shown in Fig. 2, the cross-sectional shape at the time of winding is different from that of the final product. In contrast, the amount of resin is extremely large in the flat portion 1a.

Therefore, the upper and lower parts of the outwardly bulging part are held between pusher plates and pressure is applied to make the entire smooth part parallel. However, as shown by the dotted lines in Figure 2, The width and Xz were not uniform.

Therefore, it is not possible to obtain the desired product shape with conventional autoclave molding using a pusher plate, and in the end, press molding with spacers on both sides is used to improve productivity. There was a problem that it was not possible.

[Purpose of the invention]

This invention was devised in view of the above-mentioned problems, and it is possible to stably manufacture products with high precision by using a flat fiber-reinforced plastic pipe with a smooth portion, and to improve productivity. It is an object of the present invention to provide a method for manufacturing a fiber-reinforced plastic pipe that can improve the performance of the fiber-reinforced plastic pipe.

[Means for Solving the Problems] In order to achieve the above object, the present invention impregnates the fibers with a thermosetting resin on a substantially flat mandrel having a flat part, and holds the semi-cured prepreg under a certain tension. The gist of this method is to form a flat pipe with a smooth portion by winding the pipe while heating and curing it by heating.

[Action of the invention]

The present invention is constructed as described above, and by winding the semi-cured prepreg around a mandrel while applying a constant tension, the curing process does not require press molding with a spacer in between, and can be used as a normal bushing. Only by autoclave curing using a plate, the parallelism of the smooth portion can be formed with high precision, and a product with good flatness on the surface of the smooth portion can be manufactured.

[Embodiments of the invention]

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

Note that the same components as those in the conventional example are given the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a cross-sectional view of a mandrel 2 in which a prepreg 4 is wound around a mandrel 2 according to the present invention.
In this example, a substantially flat shape having a flat portion 1a is used.

The method for manufacturing a fiber-reinforced plastic pipe according to the present invention includes a substantially flat mandrel 2 having a flat portion 1a;
When the fibers are impregnated with a thermosetting resin and the prepreg 4 in a semi-hardened state is wound, a cross-sectional shape as shown in FIG. 1 can be obtained by winding the prepreg 4 while applying a constant tension. Curing in this state does not require press molding with a spacer in the curing process, and only requires autoclave curing using a normal pusher plate. It is possible to form the product with high precision, and also to produce a product with good surface flatness in the smooth portion 5.

In the examples of this invention, when the volume fraction of pre-pre-gloving was 55% to 60%, the finished product had a volume fraction of 63% to 66%. In addition, when winding the semi-cured prepreg 4, it is wound with a constant tension, but the mandrel 2 is slightly bent when it is horizontal, vertical, or diagonal, and therefore the state of the mandrel 2 is generally The amount is 800g to 2000g.

Since the fiber-reinforced plastic pipe is manufactured by the method described above, it is possible to efficiently manufacture a product with a stable and highly accurate smooth portion 5.

〔Effect of the invention〕

This invention involves wrapping a semi-hardened prepreg made by impregnating fibers with a thermosetting resin around a substantially flat mandrel with a flat surface as described above while applying a constant tension, and then heating and curing the prepreg. As a result, since a flat pipe with a smooth portion is formed, a highly accurate product with stable smooth portions can be efficiently manufactured, and productivity can be improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a prepreg wrapped around a mandrel according to the present invention, and FIG. 2 is a cross-sectional view of a conventional mandrel wrapped with prepreg. 1a... Flat part, 2a... Mandrel, 4... Prepreg, 5... Smooth part.

Claims (1)

[Claims] In a method for manufacturing a flat fiber-reinforced plastic pipe with a flat part, a semi-hardened prepreg is applied to a substantially flat mandrel with a flat part by impregnating the fibers with a thermosetting resin and applying a certain tension to the semi-hardened prepreg. A method for manufacturing a fiber-reinforced plastic pipe, characterized by forming a flat pipe with a smooth portion by winding the pipe while heating and curing it.