JPH0559630A - Unidirectional reinforcing substrate - Google Patents

Abstract

PURPOSE:To prevent disturbance in orientation of fiber and change in width caused in producing a formed product of a modified cross section and obtain a readily formable unidirectional reinforcing base material having drapeability. CONSTITUTION:Yarn groups in which both end yarns 2 of unidirectional reinforcing fiber 1 are covered with low-melting polymer yarn and yarn groups in which auxiliary yarn fiber 3 is covered with thermoplastic low-melting polymer yarn are heated to construct the subject base material of a woven fabric form in which the unidirectional reinforcing fiber 1 is bound to the auxiliary yarn fiber 3 and the above-mentioned both end yarns 2 are bound to the auxiliary yarn fiber 3 in respective interlaced parts.

Description

Detailed Description of the Invention

[0001]

The present invention is used as a fiber reinforced reinforcing material, and more specifically, a fiber reinforced resin, a fiber reinforced metal, a fiber reinforced composite material such as a fiber reinforced composite material,
In particular, the present invention relates to a unidirectional reinforcing base material suitable as a reinforcing intermediate base material for fiber reinforced resin.

[0002]

2. Description of the Related Art Conventionally, when forming a fiber-reinforced composite material as described above, a unidirectional arrangement in which reinforcing fibers are arranged in parallel in one direction and in a sheet form and impregnated with a B-stage thermosetting resin. In this method, a large number of reinforcing fibers are unidirectionally formed prior to resin impregnation.
It is necessary to align them in parallel and sheet-like,
Unlike woven fabrics, there is no one that restrains the reinforcing fibers that are aligned in one direction, so the arrangement of reinforcing fibers is disturbed during resin impregnation, and cracks occur between reinforcing fibers especially when molding molded products of irregular cross section. However, there is a problem that it is difficult to obtain a uniform 000 prepreg due to the occurrence of a crack or a change in the width of the sheet.

Therefore, conventionally, various measures have been taken with a reinforcing base material or a woven fabric using a fused yarn. That is, as in JP-A-62-6932 relating to a method for manufacturing a reinforcing fiber woven fabric, a thermoplastic low melting point polymer yarn is fused to a reinforcing fiber to form a woven fabric composed of warps and wefts. The invention has been made in which the melting point polymer yarn is melted to bind the reinforcing fibers of the warp yarn and the weft yarn together.

However, in the above-mentioned invention, since all the warp yarns and the weft yarns are wound and fused with the thermoplastic low melting point polymer yarn, there is a problem that the cost is increased. Further, as in Japanese Utility Model Laid-Open No. 61-150891 concerning a reinforcing base fabric, there has been devised a non-woven fabric made of thermoplastic fibers arranged either between the weft yarn and the warp yarn or outside the weft yarn or the warp yarn. In this case, there is a problem that the reinforcing base cloth becomes thick and hard, and lacks drapeability.

Further, in Japanese Unexamined Patent Publication No. 61-296035 relating to a two-layer prepreg and a method for manufacturing the two-layer prepreg, two reinforcements are formed by arranging reinforcing fibers arranged so as to intersect each other in one direction in parallel and in a sheet shape. B for fiber group
-The thermosetting resin of the stage is impregnated, and the thermosetting resin contains a thermoplastic low-melting-point polymer. In this case, the invention relates to two-layer prepregs orthogonal to each other. Its use is different from that of the unidirectional reinforcing base material of the invention.

On the other hand, Japanese Patent Application No. Sho 58-2 relating to a reinforcing base cloth.
In Japanese Patent Application Laid-Open No. 63-66362, which is a divisional patent of 27585, both warp and weft are wound up with a fusion yarn at regular intervals to form a reinforcing base fabric which is arranged in the weft, the warp direction and the weft direction by heat fusion. It is designed to prevent blinding and disorder of orientation. However, in the present invention, the warp and the weft are arranged side by side to prevent the base fabric from being disturbed only by the binding of the fusion yarn, so that the binding between the warp and the weft is insufficient unless the heat fusion is secured. However, if the heat-sealing is done firmly, the base cloth becomes hard and the drape property is poor.
It is difficult to form a modified cross section, and in particular, since the warp fusible yarn is wound up, the cross section of the reinforcing fiber becomes round, and when the resin impregnation property into the reinforcing fiber becomes poor, the reinforcing strength is lowered.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and in particular, the disorder of the orientation of fibers and the change of the width which occur during the production of a molded product having an irregular cross section. It is an object of the present invention to provide a unidirectional reinforcing base material that prevents the above-mentioned phenomenon and has a drape property that can be easily molded.

[0008]

As a means for solving the above problems, in the unidirectional reinforcing base material of the present invention, both ends of the unidirectional reinforcing fiber group are covered with a thermoplastic low melting point polymer yarn. A unidirectional reinforcing fiber group and an auxiliary thread are formed by heating a woven fabric formed by using a thread group as a warp and an auxiliary thread fiber as a weft with a thread group covering a thermoplastic low-melting polymer thread as a weft. The fiber group and the both-end yarn group and the auxiliary yarn fiber group are formed by binding the respective entangled portions, and the unidirectional reinforcing fiber group, the both-end yarn group, and the auxiliary yarn fiber group include carbon fiber and glass fiber. , One or more fibers selected from silicon fiber, polyester fiber, polyamide fiber, aramid fiber, polyolefin fiber, polyvinyl chloride fiber, etc. It is preferably configured that.

Further, the auxiliary fiber is preferably a fiber having strength and elastic modulus equal to or lower than that of the unidirectional reinforcing fiber, and further, the density of the auxiliary fiber is
It is desirable that the density of the unidirectional reinforcing fibers is smaller than that of the unidirectional reinforcing fibers, and the fibers are alternately arranged at intervals of 10 to 30 mm, and the cross-sectional area of the auxiliary yarn fibers is 1/2 to 1/20 of that of the unidirectional reinforcing fibers. Furthermore, it is also preferable that the cross-sectional area of the yarns of the yarn groups at both ends of the unidirectional reinforcing fiber group is 1/1 to 1/10 of the yarn of the unidirectional reinforcing fiber group.

[0010]

EXAMPLES Examples of the unidirectional reinforcing base material of the present invention will be described below with reference to the drawings. First, FIG. 1 (A) and FIG.
In (B), a yarn group in which thermoplastic low-melting polymer yarns are covered with the fibers of the two-end yarn groups at both ends which are selvage yarns of the unidirectional reinforcing fiber group shown in 1 and auxiliary yarn fiber groups shown in 3 And a group of yarns in which thermoplastic low-melting polymer yarns are covered.

That is, the selvage yarns of the both-end yarns shown as 2 and the auxiliary yarn fibers of the auxiliary yarn fiber shown as 3 used for the core yarn are selected from one kind or two or more kinds from carbon fiber, aramid fiber, glass fiber and the like. A fiber is prepared, and a thermoplastic low-melting polymer yarn is wound around the core yarn of the selvage yarn and the auxiliary yarn to cover the yarn. At this time, basically, as shown in FIGS. 1 (A) and 1 (B),
It is not necessary that the yarn group and the third yarn group of the auxiliary yarns indicated by 3 are bonded, provided that the two end yarns of the unidirectional reinforcing fiber indicated by 2, that is, the second yarn group of selvage and the above-mentioned third yarn group are the bases. Since the material width 4 does not change, it is necessary to bond the intersections with the fusion yarns. Further, the covering directions of the fusible yarns may be basically twisted in the same direction, but this is not the case if the adhesion at each intersection is a problem.

The first yarn group as the unidirectional reinforcing fiber denoted by 1 may be arbitrarily selected according to its intended use. Here, in order to obtain a high strength and high elasticity composite molded body,
It is suitable to select one or more of carbon fibers, glass fibers, silicon fibers, polyester fibers, polyamide fibers, aramid fibers and the like. In the conventional case, the unidirectional reinforcing fibers 1 as the first yarn group are sprinkled with the fusible yarns to weave the base material in the form of a woven fabric to form the woven fabric in a bent or crimped state. However, in the present invention, the low melting point polymer yarn is not wound around the unidirectional reinforcing fiber 1, and the cross-sectional area is about 1/1 to 1/10 of the yarn of the first yarn group. The second yarn group shown by 2 which covers the yarn which is the selvage yarn of the thermoplastic low melting point polymer yarn, and the cross-sectional area is 1/2 to 1/2 of that of the first yarn group.
A third yarn group formed by covering thermoplastic low-melting point polymer yarns on the auxiliary yarn fibers indicated by 0 in 3 is formed in a woven form. In particular, the third yarn group of the auxiliary yarn fibers indicated by 3 is the first
Since the strength, the elastic modulus, the cross-sectional area, or the thickness of the yarn group is smaller than that of the yarn group, only the second yarn group and the third yarn group are bent to maintain the shape as shown in FIG. 1 (A). The unidirectional reinforcing base material in the form of a woven fabric can be formed without causing the decrease in strength as the purpose of the unidirectional prepreg.

After that, by heating the base material formed in this woven form, the thermoplastic low melting point polymer yarn is melted and bound with each fiber, preventing cracks between reinforcing fibers,
It is possible to obtain a uniform unidirectional prepreg base material having a sheet-like width 4 which does not change. Here, a heating roll, hot air, or the like can be considered as a heating means for the base material formed in the woven form, but it is preferable to melt the low melting point polymer yarn with hot air without using a heating roll.

The reason for this is that in the heating roll, the formed base material comes into contact with the roll surface, and the melted low-melting point polymer and reinforcing fibers adhere to the roller surface, resulting in poor heating efficiency. The reason is that since the roller surface becomes uneven, fluffing of the reinforcing fiber is likely to occur and the quality of the base material is deteriorated. Therefore, the base material and the heat generator are spaced from each other, the base material is heated by hot air without melting the base material, the low melting point polymer is melted, and the fibers are bound to each other. A good unidirectional reinforcing base material for a unidirectional prepreg can be provided.

1A and 1B, a unidirectional reinforcing fiber indicated by 1 is, for example, carbon fiber, and is unidirectionally aligned. The both-end yarns of the unidirectional reinforcing fiber, which is used as a warp form of the woven fabric and is denoted by 2, have a cross-sectional area of the unidirectional reinforcing fiber 1 or 1/5 of the thickness, for example, glass fiber, thermoplastic low melting point polymer. Of 50 to 200 t / m from 50 t / m, and the auxiliary yarn fiber shown in 3 is 1/10 of the cross-sectional area or thickness of the unidirectional reinforcing fiber 1.
, Such as glass fiber, with a thermoplastic low-melting polymer covering 20t / m to 80t / m, is used as a weft of a woven fabric to form a woven form to form a unidirectional reinforcing base material. There is.

Next, using a heat generator in which the above-mentioned base material is mounted on a loom, hot air at about 150 ° C to 250 ° C is applied to the base material to heat the base material to melt the low melting point polymer, Each entangled portion of the unidirectional reinforcing fiber of the first yarn group shown in FIG. 3 and the auxiliary yarn fiber of the third yarn group shown in 3, and both end yarns of the second yarn group shown in 2 and the auxiliary yarn fiber of the third yarn group shown in 3 Bind it with
Then, the unidirectional reinforcing base material of the present invention is formed by cooling.

2 and 3 show unidirectional reinforcing fibers which are different from each other, and have substantially the same structure and function as in Example 1 of FIG. 1 (A),
FIG. 2 shows a modification of the woven fabric structure in Example 2 and FIG. 3 in Example 3, and the same parts as those in FIG. 1 (A) are shown by the same reference numerals.

[0018]

According to the one-way reinforcing base material of the present invention described above, it can be handled in the same manner as a woven fabric, a knitted fabric, etc. even though it is a one-way reinforcing base material, and it is excellent in drapeability. There is an effect that it is possible to provide a high-quality unidirectional reinforcing base material that does not change the arrangement of reinforcing fibers or the width of the base material.

Further, according to the present invention, cracking of unidirectional reinforcing fibers and width change of unidirectional reinforcing base material, which are particularly caused when molding a molded product having an irregular cross section, are eliminated, and a unidirectional prepreg is manufactured. At this time, since it is formed in the form of a woven fabric, it is not necessary to set the unidirectional reinforcing fibers on the creel stand one by one, and further, the tension is not adjusted for each fiber, and the fibers are set immediately before the resin impregnation machine. When performing resin impregnation, a unidirectional prepreg molded product of good quality can be obtained without disturbing the fiber arrangement or changing the width of the base material.

[Brief description of drawings]

FIG. 1A is a partial plan view of Example 1 of a unidirectional reinforcing base material of the present invention. 1B is a cross-sectional view taken along the line AA of FIG.

FIG. 2 is a partial plan view of Example 1 of the unidirectional reinforcing base material of the present invention.

FIG. 3 is a partial plan view of Example 1 of the unidirectional reinforcing base material of the present invention.

[Explanation of symbols]

1 Unidirectional reinforcing fiber 2 Both-end yarn of unidirectional reinforcing fiber 3 Auxiliary yarn fiber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location D03D 15/00 G 7199-3B D04H 3/04 7199-3B 3/14 Z 7199-3B D06C 7 / 00 Z 7199-3B // B29K 105: 10 4F

Claims (5)

[Claims] 1. A warp is a yarn group in which both ends of a unidirectional reinforcing fiber group are covered with thermoplastic low melting point polymer yarns,
And, the woven fabric form in which the weft yarn is formed by covering the auxiliary yarn fibers with the thermoplastic low-melting polymer yarn, the low-melting polymer yarn is melted, and the unidirectional reinforcing fiber group, the auxiliary yarn fiber group, and the above-mentioned A unidirectional reinforcing base material in which a yarn group on both ends and a fiber group on an auxiliary yarn are bound at each entangled portion. 2. The unidirectional reinforcing fiber group, the both-end thread group, and the auxiliary thread fiber group are carbon fibers, glass fibers, silicon fibers, polyester fibers, polyamide fibers, aramid fibers, polyolefin fibers, and polyvinyl chloride. The unidirectional reinforcing base material according to claim 1, which is composed of one kind or two or more kinds selected from a series of fibers. 3. The unidirectional reinforcing base according to claim 1, wherein the auxiliary yarn fibers covering the thermoplastic low melting point polymer yarn have strength and elastic modulus equal to or lower than that of the unidirectional reinforcing fibers. Material. 4. The density of the auxiliary yarn fibers is lower than that of the unidirectional reinforcing fibers, and the auxiliary yarn fibers are alternately arranged at intervals of 10 to 30 mm, and the cross sectional area of the auxiliary yarn fibers is 1 / one of that of the unidirectional reinforcing fibers. The unidirectional reinforcing base material according to claim 1, which is 2 to 1/20. 5. The unidirectional reinforcing base of claim 1, 2, 3 or 4, wherein the cross-sectional area of the yarns of the yarn groups at both ends of the unidirectional reinforcing fiber group is 1/1 to 1/10 of the yarn of the unidirectional reinforcing fiber group. Material.