JPS5874321A - Molding method of frp product - Google Patents

Abstract

PURPOSE:To obtain the titled product such as a deeply drawn molded product by using a fibrous composite material whose reinforcing fibers are hardly cut and which has a high degree of fluidity by a method wherein the plate-like or a rod-like composite material of specific dimensions and containing the reinforcing fibers of specific length is hot pressure molded. CONSTITUTION:The reinforcing fibers such as glass fibers, carbon fibers or the like having the average fiber length of 10-50mm. are blended in a matrix of resin such as epoxy resin, unsaturated polyester resin, polyamide resin or the like so that the volumetric rate of content of the reinforcing fibers becomes 30-70%, so as to obtain a plate-like or a rod-like prepreg of a width of 1-20mm. and a length of 10-50mm.. Then the prepreg is inserted into a mold and hot pressure molded to thereby obtain the molded FRP product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding an FRP molded product,
In particular, the present invention relates to a method for efficiently molding a molding material containing reinforcing fibers having an average length in m of /θ to 50 cm.

The molding methods for FRP moldings include uD prepreg, which is made by impregnating matrix resin into unidirectionally aligned reinforcing fibers, and impregnating matrix into reinforcing fiber fabric or non-woven fabric.
A method of forming sprepreg using a mandrel has been developed and is used for forming fishing rods, tilt club shafts, and other straight outer shapes.
D prepreg and cross prepreg are extremely useful as forming materials for the above-mentioned barrel-shaped bodies and plate-shaped bodies, but they are relatively rough in shape and large in size, such as spinning reels, vehicle wheels, gears, It is extremely difficult to mold sprockets, bicycle caliber brakes, etc. using these molding materials. Therefore, there is a conventional method in which a mixture of reinforcing fibers cut into short fibers of several U or less and matrix resin is injection molded using an injection molding machine in order to make FRP molded products with such complicated shapes. However, although this method is an effective method for making small-sized FRP molded products, it does not reduce the amount of shear applied to the reinforcing fibers during the molding process.
Because reinforcing fibers become short due to force, there are many difficulties in using them as a molding method for large-sized FRP moldings that require full use of the strength of reinforcing fibers. In view of the above-mentioned situation, we investigated to obtain a molding material that does not cause 10 (10) cuts even when molding a large FRP molded product and has a high strength utilization rate of reinforcing fibers, and developed a special mtk ( j 4'-/ / ?θS9& We have proposed a new sheet-like prepreg in which a large number of short pieces of rectangular prepreg containing reinforcing fibers are two-dimensionally oriented and integrated on a matrix resin film, and the above purpose has been achieved. This sheet-like prepreg is used for a wide range of purposes as a vine prepreg.However, this sheet-like prepreg has a rough shape of the FRP molding snout and is not suitable for molding something with deep grooves. Due to insufficient mobility during molding, the strip-shaped prepreg could not be made to flow to every corner of the FRP molded product.
The appearance of the molded product was long awaited.

Therefore, the inventors of the present invention completed the present invention as a result of studying a method for molding an FRP molded product that obtains the above-mentioned T-view of 11@7jL.

The gist of the present invention is that the average rut length is 110-3
A plate-shaped or rod-shaped prepreg with a reinforcing fiber content of 30 to 70%, a length of 10 to 10 mm, and a wrinkle length of 10 to 10 mm is applied to the mold ψ, and the UIHE is A method for molding an FRP molded product, which is characterized by heat molding.

As specific examples of the reinforcing fibers used in carrying out the invention, authorized fibers such as 1 glass &% MW, silicon carbide fibers, alumina fibers, and aromatic polyamide rutted fibers can be used. In order to smoothly carry out the molding process of the prepreg used in the present invention and to easily carry out the process of forming the prepreg to every corner of the mold, the average fiber length must be 10Nsθ (7) Range 1etl It is preferable that the fiber length is 10 mm, and if the fiber length is 10 mm, the fluidity is good but it is not possible to obtain an FRP molded product with excellent strength. ;If the Owa length is increased by 1, there is a tendency that the fluidity in the molding process decreases and the strength utilization rate decreases. The shape of this reinforcing fiber is not limited to poly, but
It is preferable that the flexible legs be arranged in the length direction of the plate-shaped or rod-shaped fringe leg as much as possible in order to improve the strength utilization rate.

Matrix X * a used when carrying out non-invention
As for h, epoxy + l1iltf, fuben phase hysteryl ester at ah, vinyl ester *nh, fue/-
Heat-reformable resins such as resins, polyimide resins, etc.
Thermoplastic resins such as 11 resins, polyester W resins, polyamides, polycarbonate resins, polysulfone resins, AB8 resins, polyetherketone resins, polyethersulfone resins, etc. can be used.

The content of reinforcing fibers contained in the plate-shaped or rod-shaped prepreg produced when carrying out the present invention is 30 to 70%.
This volume content must be within a range of 30
It is possible to make FRP molded products with excellent mechanical properties from materials less than %.
If the flower is larger than 70%, the prepreg has insufficient fluidity during molding, and it becomes difficult to flow the prepreg to every corner of the mold during the molding process.

In addition, the length of the rod-shaped or plate-shaped prepreg needs to be in the range of 70 to SO.1If this length is less than IO-, it is difficult to make an FRP molded product with good strength; If the length exceeds the SO length, the ability to fill the mold and the uniform fluidity during the molding process will decrease.
This prepreg begins to have creases and cracks, and the mechanical properties of the resulting FRP molded product tend to deteriorate. Also, the width of this prepreg is l-10 mm, preferably 1 col.
It is preferable that the width is about 01, and if the width is less than 7 m, there is a remote island in *a, while if it is wider than -ko O, the molding workability is poor. '- The plate-shaped or rod-shaped prepreg mentioned above is NI! It is made by cutting a fiber tow impregnated with matrix resin into appropriate lengths, or by cutting unidirectionally aligned pongee strong rutted prepreg sheets or cross prepreg sheets into predetermined shapes. be able to.

Furthermore, in order to facilitate the handling of the prepreg used in the present invention, it is preferable to remove as much non-faii material as possible when transporting the prepreg into the castle.

To fill a mold with a plate-like or rod-like prepreg having the above-mentioned characteristics, there is a method of filling a predetermined amount of the prepreg in its original shape, or a method of filling a 1,000-meter mold, heat treatment, or microwave treatment. A method is adopted in which a pre-molded product is inserted into a mold and the layers are heated and pressed.

As shown in Fig. 1, the molding method is to fill a plate-shaped or rod-shaped prepreg (1) into a gold crab in a predetermined amount, close the mold, and mold under heat and pressure.This molding is performed by pressure molding. Other than this, when forming using the Q) molding method, the sleeves in the tri prepreg may cause cutting of the strong fibers or unnecessary flow of the prepreg, and the desired properties may not be achieved. And it is not possible to obtain an FRP molded article with the same shape.

According to the method of the present invention, it is possible to easily produce FRP molded products with relatively large, complex shapes, or hollow shapes, which were conventionally considered to be unreliable, and the strength utilization rate of reinforcing fibers has been sufficiently reduced. It can be made in any condition.

The present invention will be explained in more detail with reference to Examples below.Example: Carbon fiber lOθ00 filament tow was impregnated with epoxy resin so that the carbon fiber content was 60%.
The size and toe of the light suit are made of long fibers! rm, and make a molding comparand material with a width of about 3 mm as shown in <i> of /1ffl (a). Shape σ) With the entire wall, charge near the center of a molding die preheated to l5oc, apply pressure from above, close the die as shown in cross section in Figure 1 (0), and heat. The rod-shaped prepreg was allowed to flow in an axially symmetrical direction so that the surfaces of each of the seven langes were parallel to each other and layered to form five in-plane co-dimensional underlayers.

Pressure tsOkai/d, curing conditions/! When molded for 30 minutes, the molded product D was extremely smooth and conformed to the dimensions of the mold. When I made a cross-section of this material, as shown in Fig. 2, the prepreg was flowing well. After demolding, the resin 70- caused a shell 7j @
gb Ranmeto (I removed the shun as molding waste and produced 7 lunge parts.The same type of 7 lunge parts made of aluminum alloy weighs 0g, whereas the weight of the reinforced plastic one of the present invention is / The figure is a schematic process diagram of the FRP molding method of the present invention.
Figure 1 is a #[tf1 diagram] of an FRP molded product made according to the present invention.

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Claims (1)

[Claims] The average fiber length of the reinforcing fibers is 10 to SOW and the volume content is 30 to 70%.Width/~-〇ms Length/
F characterized by inserting a plate-shaped or rod-shaped composite material molding material called ONj Om into the entire area and heating and EE molding.
Molding method of ilP molded product 0