JPS5836444A - Intermediate for composite material and its manufacture - 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] When forming and processing a composite material, the present invention involves forming a filamentary sheet made of high-strength, high-elasticity fibers as a reinforcing material, and laminating a plurality of sheets to form the composite material. The invention relates to a novel intermediate for

Conventionally, fiber threads exhibiting high strength and high elasticity have been used as reinforcing materials [by arranging the threads in parallel or making them into a fabric or a solid material to form sheets or various other shapes, and forming the surroundings of such an intermediate material. By incorporating resin or metal (hereinafter referred to as matrix) into composite materials (hereinafter referred to as composites), we have provided high-performance materials that take advantage of the physical properties of intermediates and matrixes. In addition, in this case, the provided intermediate is usually in the form of a sheet as mentioned above (these are the products in which the filament threads are one-dimensional or two-dimensional, whether the threads are aligned or the woven fabric is braided). They are arranged in the same direction, crossed, or intertwined.For this reason, the thickness of the sheet as an intermediate is very thin, and when the intermediate is used as a reinforcing material for a molded product, such an intermediate sheet is used as a reinforcing material for a molded product. It is customary to increase the thickness by stacking multiple layers according to the thickness.On the other hand, in recent years, weaving methods have been developed and three-dimensional fabrics that can achieve the required thickness have appeared, but the purpose is It is extremely difficult to knead while maintaining the desired shape, and the weaving equipment is extremely complicated, so it has not become widespread. (In the actual molding process involving resin, a thin sheet-like material or a 9-braided woven material is impregnated with a matrix resin as described above, and then a plurality of such sheet-like products are stacked together. However, according to this method, the restraint between the stacked sheets is simply due to adhesion to IIw, which is used as a matrix, and the reinforcing material There is no possibility of bonding through intermediate materials.Of course, it is obvious that the strength of the resin itself is superior to that of the reinforcing material, and for this reason, the strength of the resin itself is superior to that of the reinforcing material, and for this reason, can exert the strength of the reinforcing material, but in general, the strength in the stacked direction is lower than in the two-dimensional direction, although it depends on the resin itself and the adhesive strength between the resins. Furthermore, the molded workpiece obtained by such a method is subject to distortion due to the repeated action of stress, resulting in a peeling phenomenon of the sheet-like object.

Focusing on the above viewpoint, the present inventors have developed a method of stacking sheet-like intermediate bodies serving as reinforcing materials to impart a spider reinforcing effect in the stacked direction, that is, in a three-dimensional direction, instead of the conventional two-dimensional reinforcing effect. Obtained.

The main sections and methods are as follows.

The strength of a composite material is when the strength of the reinforcing material (fibrous) is fully demonstrated, and in order to fully demonstrate its strength, the strength of the reinforcing materials must be bonded to each other and the matrix. Ideally, each filament yarn or short fiber serving as a reinforcing material is firmly adhered to the matrix.

The gist of the present invention is to combine a thin sheet-like material made of fiber threads or fiber bundles arranged in one or two dimensions, and a sheet-like material obtained by kneading 9 knittings and 1 knitting. After layering, a needle with a hook is passed through these sheet laminates, and some of the fibers of the nine bundles of fiber yarn arranged two-dimensionally are rearranged from the two-dimensional arrangement to the three-dimensional direction. A sheet-like thing! When these laminated sheet-like materials are fixed and impregnated with matrix resin and molded, a counter force in three-dimensional directions can be obtained.

To explain the present invention in detail with reference to the drawings, FIG. 1 shows a cross section of a fabric in which fiber threads serving as a reinforcing material are woven into a plain weave.

In the figure, warp (1) and weft (2) are intertwined alternately. FIG. 2 shows a footer needle useful for needle punching the fabric shown in FIG. 1 in layers. That is, the throat plate (3
) Thinner (elongated and pointed at the tip) The needle stem (4) has hooks (5) that run in the direction of the flow from the tip of the needle and seven hooks (6) that run in the opposite direction. When the surface is pierced and the hook is pulled out, the fibers of the threads that make up the woven fabric fall out of the thread or are partially cut, causing fluff to form on the surface of the woven fabric.

In addition, when a plurality of fabrics are stacked by the vertical movement of the needle, the fuzz that is generated is deeply dug into the interior of the adjacent fabric, and each time the operation is repeated, fuzz is generated.

The biting increases, the bonding between the woven fabrics increases, and the three-dimensional fiber alignment progresses. Figure 3 shows this situation, and shows a group of fibers that have become fluffy from the warp (1) and weft (2).
It can be clearly seen that 7) protrudes from the surface of the fabric in a direction almost perpendicular to it, and further bites into and adheres to other adjacent fabrics.

The thus obtained sheet-like reinforcing intermediate having a thickness that eliminates the three-dimensional arrangement is impregnated with a resin or metal that will serve as a matrix, and then pressed and solidified to obtain a molded product. It is also possible to carry out after the matrix is impregnated and before molding.

Example Carbon fibers were woven into a filament-like plain weave consisting of so o o carbon fibers, with a covering yarn density of 15 pieces/inch, a weft yarn density of 15 pieces/inch, and a basis weight of 257 P/n1. Seven layers of woven fabric with a thickness of 0.30 ws were stacked to form a needle as shown in Figure 2 (needle length 751 EIL, needle stem diameter 1.0 mm, hook protrusion length 0.2 ms, hook angle [35°).

12 hooks) are lined up and the surface of the fabric is 1cm+”m25
The reciprocating penetrating vertical movement was carried out in a uniform manner to generate fuzz and bond the adjacent fabric surfaces.

Through this operation, the total thickness of the multilayer compact was 8.30 m.
(Including fluff on the front and back sides).

Thereafter, the laminated fabric was impregnated with an epoxy resin, placed in a mold, pressurized, and heat-treated at 130° C. for 60 minutes to solidify. A flat plate with a thickness of 5 m and a longitudinal fiber content of 45 cm was thus obtained. Although the strength of such a flat plate in the thickness direction is approximately 30% lower than that of a flat plate obtained by simply stacking seven fabrics, the shear peeling strength against repeated bending is dramatically improved.12.
It has tripled.

[Brief explanation of the drawing]

Figure 1 shows a cross-section of a fabric woven using fiber threads that can be used as a reinforcing material, Figure 2 shows the outline of a needle that penetrates the fabric surface and moves up and down to generate fluff. 2A and 2B show cross-sections of reinforcing intermediate bodies in which the needles shown in FIG. 2 are moved up and down through a plurality of stacked woven fabrics to form a fuzzy shape to join adjacent woven fabric surfaces.

Claims (2)

[Claims] (1) A sheet-like material obtained by arranging yarns in one or two dimensions, or intersecting or entangling them in a single weaving composition, is stacked in multiple layers, and the fiber group constituting the sheet-like material is A portion protrudes from Table 1 and enters into other adjacent sheet-like materials. An intermediate for a three-dimensional composite material made by joining. (2) Depending on whether the yarns are arranged one-dimensionally or two-dimensionally, or depending on the composition of the knitted yarn, [sheet-like materials obtained by crossing or intertwining are stacked in multiple layers, and a hook needle is used to penetrate and move the sheets up and down. By repeating this process, some of the fibers that make up the sheet material protrude from the surface. It is characterized in that by entering into another adjacent sheet-like object, a part of the fiber group constituting the sheet-like object protrudes from the surface, and enters into the other adjacent sheet-like object and joins each other. A method for producing an intermediate for a three-dimensional composite material.