JPH0340834A - Production of gauze fabric of carbon fiber - Google Patents

Abstract

PURPOSE:To obtain a fabric for the reinforcement of plastics, etc., utilizing the excellent characteristics of carbon fiber such as high tenacity and elastic modulus to the utmost limit by using a carbon fiber and a low-rigidity yarn at a let-off rate higher than that of the carbon fiber and weaving a fabric using the above fibers as warps. CONSTITUTION:For example, carbon fiber warps 1,3 (e.g. pitch-based fiber) and a low-rigidity warp yarn 2 having lower rigidity than the carbon fiber (e.g. aramid fiber) are separately used to form a double beam. A fabric is woven by adjusting the let-off rate of the low-rigidity warp yarn 2 to be higher than that of the carbon fiber warps 1, 3 to obtain the objective reinforcing fabric having especially excellent linearity of the carbon fiber warp, free from slippage of mesh and having excellent handleability.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing leno textiles using carbon fibers with high strength and high modulus of elasticity, and more particularly relates to fiber reinforced plastics (FRP), Fiber reinforced concrete (FR
The present invention relates to a method for producing a carbon fiber tangled fabric having excellent properties as a reinforcing fabric such as C).

(Prior Art) Carbon fiber has physical properties such as high strength and high modulus of elasticity, and is useful as a reinforcing material for FRP, FRC, etc., and is usually used in fabrics such as plain weave, satin weave, and twill weave. is used as. In particular, the Kara-mi fabric can form an oven mesh, and the matrix material penetrates and integrates in the openings of the oven mesh, so FRP, FR
It is useful as a binding material for C and as a base fabric for various types of enamel.

However, in ordinary leno weave 111 weaving, when two warp threads become entwined, the warp threads bend, making it impossible to fully utilize the excellent properties of carbon fiber, such as high strength and high elastic modulus. there were.

(Problem M to be solved by the invention) As a result of intensive research in view of the above-mentioned problems of existing carbon fiber fabrics, the present inventors have found that carbon fiber yarns and specific yarns are used as the warp of leno textiles. The present invention was completed by discovering a method for weaving carbon fiber under specific operating conditions.The purpose of this invention is to maximize the excellent characteristics of carbon fiber, such as high strength and high elastic modulus. An object of the present invention is to provide a method for weaving a leno textile that has a special reinforcing effect that is fully utilized. Other objects and advantages of the present invention will become apparent from the following description.

(Means for Solving the Problems) The above object is to construct a warp with carbon fibers and threads with lower stiffness than the carbon fibers when weaving a leno fabric using carbon fibers, and to reduce the stiffness that intertwines with the carbon fibers. Make the amount of rigid fiber yarns sent out larger than the amount of carbon fibers. One way to increase the amount of yarns sent out is to prepare a warp beam of carbon fiber and a warp beam of low stiffness yarn separately to create a double beam. In contrast, the carbon fiber beam is actively fed to the amount determined by the weft density (number of wefts), while the low-rigidity yarn beam is passively fed with low tension to feed the carbon fiber. Alternatively, when using a direct creel to feed the warp directly from a bobbin of carbon fiber and low-stiffness yarn to the loom, only the carbon fiber is passed through actively driven rolls and the amount of feed is matched to the weft density. In contrast, for low-stiffness yarns, there is a method of increasing the amount of yarn being sent out by sending it out to the fibers with free tensile silane, and
In order to maintain the straightness of the warp carbon fibers, each yarn is fed out in an amount larger than the carbon fibers by the amount necessary for the low-rigidity yarns to grip the wefts and rotate around the paired carbon fibers. This can be done by a method such as active feeding.

It is necessary to increase the amount of low-rigid yarn fed out in proportion to the cross-sectional area of each yarn of the warp and weft used and the density of the weft, but increasing it more than necessary will reduce the gripping force at the intersection of the warp and weft. This results in a decrease in the fabric's handling properties, making it more likely that stitches will be misaligned. Therefore, it is necessary to adjust the amount of low-rigidity yarn to be fed out depending on the handling property and the degree of linearity required for the carbon fiber.

The carbon fibers referred to in the present invention are preferably pinch type or PAN type long fibers with high strength and high modulus suitable for use in fiber-reinforced composite materials.

In addition, the low-rigidity fiber threads have the effect of gripping the warp yarns with the weft yarns, and the carbon fibers contribute almost the majority of the reinforcing effect as a fiber reinforced composite material.

Therefore, the low-rigidity yarn may be any yarn with lower rigidity than the carbon fiber used for the warp, and it can be used depending on the price and purpose. Specific examples include aramid fiber, glass fiber, polyester fiber, nylon fiber, vinylon fiber, acrylic fiber, and cotton thread. Alternatively, it may be made of carbon fiber with a low fineness, or it may be a leno weave with two low-rigidity threads.

To explain the leno fabric of the present invention, first, in the weave structure of the conventional leno fabric, as shown in Fig. 2(a), -
The warp threads 1.1' of m are intertwined and bent. In addition, the weft 2 is connected to the warp 1, 1' as shown in FIG. 2(b).
is subjected to a force in the longitudinal direction by, and is therefore also bent.

On the other hand, the leno woven fabric of the present invention is shown in FIG. 1(a) and FIG.
In the leno fabric with reduced bending according to the present invention, the warp threads 1.2 of the set are separated from the carbon fiber thread 1 and the low-rigidity thread -2, and straightness is maintained by avoiding bending of the carbon fibers. Therefore, the carbon fibers 1 are substantially unrolled, and the low-rigidity yarns 2 are entwined with each other. Therefore, the carbon fiber yarn 1 is almost straight and exists on substantially one side of the Mi weave. On the other hand, weft 3
As shown in FIG. 1(b), the warp yarns 1 and 2 receive almost no force exerted by the warp yarns db in the longitudinal direction, so that the warp yarns are also substantially obedient.

In the leno fabric woven by the weaving method of the present invention, the threads of the warp, which have a lower rigidity than the carbon fibers, are fed out in a larger amount than the carbon fibers, so as shown in FIG. The carbon fibers are entwined in a clinging manner, and have a greater degree of curvature than the warp of a normal leno weave, but the carbon fibers have a correspondingly lower degree of curvature and stronger straightness. Furthermore, since the weft yarns are intertwined with the warp yarns in the manner described above, the degree of curvature is smaller and the straightness is stronger than that of a normal entwined fabric, as shown in Figure 1(b). Since the purpose is to improve the warp and warp, if the weft is also made of carbon fiber,
The present invention also improves the line drawing direction. Of course, even if the weft is not carbon fiber, at least the straightness of the warp carbon fiber can be obtained.

(Effect of the invention) According to the weaving method of the present invention, the linearity of the carbon fiber portion of the warp (or the high-rigidity side carbon fiber portion) and the weft can be improved compared to conventional woven fabrics using carbon fibers, and the When used as a material, the high strength and high modulus of carbon fiber can be used more effectively.

The present invention will be specifically explained below with reference to Examples.

Example-1 Trading card T-300-12000 thread (manufactured by Toshisha) (hereinafter C
F12) and Kepler 29400d thread (Dupo
(manufactured by NT Co., Ltd.) as warp threads and a density of 3.3 wood per 25 mm, respectively, and beams were prepared separately. When making a pair of CF12 and Kevlar threads and intertwining them, adjust the amount of feed of each beam so that the amount of feed of Kepler 29400d yarn is 1.07 times that of CF12,
CF12K was used as the weft yarn at a density of 3.3 threads/25 mm, and the warp yarn CF12K was woven in a leno weave so that the intersection with the weft yarn was always on the same side of the fabric.

Example-2 Trading card T-300-6000 thread (manufactured by Toshisha) (hereinafter referred to as CF)
6K) and Kevlar 49 195d yarns are used as warp threads and are passed directly to the creel, respectively, and the CF6 thread is passed through a positively driven rubber roll to regulate the amount of feed and sent to the loom, whereas the Kevlar thread is passed directly through the loom and The Kevlar thread bobbin was fed out without applying a brake.

The warp is CF per 25mm, Kepler is 3.3, and the weft is CF6K with 3.3 per 25mm, and the warp is C.
The leno fabric was woven so that the intersection of F with the weft thread CF was always on the same side of the ¥8 product. The amount of Kevlar yarn fed out at this time was 1.043 times that of the CF6 yarn.

In the leno woven fabrics obtained in Examples-1 and -2, the straightness of the carbon fibers in the warp yarns was extremely good, and the straightness of the weft yarns was also good. In addition, there was no misalignment of the stitches, and the fabric had good handling properties.

Comparative Example-1 A leno fabric was woven in the same manner as in Example-1, except that the CF yarn and the Kevlar yarn were fed and stirred in the same manner.

The warp CF yarn had a very large bend, similar to the conventional leno fabric.

[Brief explanation of drawings]

FIG. 1(a) and FIG. 1(b) are a plan view and a sectional view of an example of a leno fabric according to the present invention. l...Carbon fiber M warp, 2...Low rigidity warp, 3
...Carbon fiber weft, Figure 2(a) and ? 2(b) is a plan view and a sectional view of a conventional leno textile. 1.1'... Highly rigid warp thread, 3... Weft thread. Figure 1(a) Figure 2(a) Figure 2(b)

Claims (1)

[Claims] (1) When weaving a leno fabric using carbon fibers, the warp is composed of carbon fibers and yarns with lower rigidity than the carbon fibers, and the amount of the low-rigidity fiber yarns intertwined with the carbon fibers is determined by the amount of the carbon fibers. A method for producing a carbon fiber tangled fabric characterized by increasing the amount of carbon fiber.