JPH06155590A - Continuous fiber reinforced thermoplastic resin molding sleeve - Google Patents

Abstract

(57) [Summary] [Objective] A molding material for a fiber-reinforced hollow body, in which the matrix is a thermoplastic resin and the reinforcing fibers are continuous fibers, and which has few unimpregnated parts into the reinforcing fibers and has high strength and high toughness. An object of the present invention is to provide a sleeve for molding a fiber reinforced thermoplastic resin capable of molding a hollow body. [Structure] A sleeve 1 in which a thread 3 made of reinforcing continuous fibers and a thread 2 made of thermoplastic resin fibers are braided in a tubular shape, and arranged in only one direction so that the continuous reinforcing fibers do not cross each other. Continuous fiber reinforced thermoplastic molding sleeve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding material suitable for molding a hollow cylindrical molded article (hereinafter referred to as a hollow body) of a fiber reinforced thermoplastic resin, and more specifically, a thermoplastic resin fiber. The present invention relates to a continuous fiber-reinforced thermoplastic resin molding sleeve which is formed into a tubular shape by means of and a continuous fiber for reinforcement.

[0002]

2. Description of the Related Art Heretofore, hollow bodies such as pipes having a thermoplastic resin as a matrix and reinforced with continuous fibers have been widely used. The following methods are known as molding methods.

A thin sheet material formed by previously impregnating continuous reinforcing fibers with a resin is used as a molding material, the molding material is wound on a core rod, and a polyimide tape is wound on the core material.
By heating, pressure is applied by the shrinking force of the polyimide tape to form it.

A mixed woven fabric in which reinforcing continuous fibers and thermoplastic resin fibers are woven together is used as a molding material, and the molding material is wound around a core rod, put in a mold, and heated and pressed to mold.

Reinforcing continuous fibers and thermoplastic resin fibers are twisted together in the state of fibers, commingle,
Also, a molding material is made by using a powder prepreg in which thermoplastic resin powder is impregnated between filaments of reinforcing continuous fibers, and the molding material is wound on a core rod heated so that the thermoplastic resin melts. Molding is performed by filament winding while defoaming with a heated roller or the like.

Reinforcing continuous fibers and thermoplastic resin fibers are twisted together in a fiber state, commingled,
Further, a powder prepreg in which thermoplastic resin powder is impregnated between filaments of reinforcing fibers is used, and the prepreg is braided to form a tubular braid (round braid), that is, braided into a sleeve. Or braid by alternately arranging continuous reinforcing fiber yarns and thermoplastic resin fiber yarns and braiding them, and using the braided sleeve as a molding material, such as a silicone tube inside. Are set, and internal pressure molding is performed in a mold (see, for example, PCT International Publication No. WO92 / 12847).

However, all of these conventional methods have problems and are not satisfactory. That is,
In this method, the sheet material impregnated with the resin is hard and it is difficult to wind it around the core rod. According to the method of (1), when the mixed woven fabric is wound around the core rod, the bending is likely to occur, and the winding is also difficult. In addition, since the reinforcing continuous fibers of the woven woven fabric intersect with each other and have intersections, in a thermoplastic resin matrix having a high resin viscosity, unimpregnated parts may remain at the intersections of the reinforcing continuous fibers. It was With this method, it is difficult to twist the reinforcing continuous fibers and the thermoplastic resin fibers together, to perform a commingle, and to make a powder prepreg, and since the molding is filament winding, it is a straight product. I could only do it. However, even with the method described above, it is difficult to twist the reinforcing continuous fibers and the thermoplastic resin fibers together, to perform commingling, and to make a powder prepreg. In addition, since there are intersections between the reinforcing continuous fibers in the sleeve, unimpregnated portions may remain at the intersections.

[0008]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems of various molding materials, and is most suitable among the materials for molding a fiber-reinforced hollow body, considering the final molded article. The present invention aims to provide a continuous fiber reinforced thermoplastic resin molding sleeve that is a molding material that employs a sleeve that seems to be a different material, prevents the generation of unimpregnated parts, which is its drawback, and is inexpensive to manufacture. .

[0009]

The present invention is a sleeve formed by braiding a yarn made of continuous reinforcing fibers and a yarn made of thermoplastic resin fibers into a tubular shape, wherein the continuous continuous fibers are reinforced. A continuous fiber reinforced thermoplastic resin molding sleeve is characterized in that the continuous fibers are arranged in only one direction so as not to intersect each other.

The yarn of the thermoplastic resin fiber used in the present invention is usually in the form of a multifilament yarn having a filament diameter of about 5 to 100 microns obtained by melt spinning a thermoplastic resin by a usual method. used. Needless to say, it may be in the form of a slit yarn obtained by slitting a monofilament or a film, and so-called thread-shaped one can be used as long as it is related to a braiding machine (brading device).

As the reinforcing continuous fiber thread, carbon fiber, glass fiber, aramid fiber,
Alumina fiber or the like having a filament diameter of about 3 to 50 microns and usually in the form of multifilament yarn is used.

The reinforcing continuous fiber and the thermoplastic resin fiber are used in a proportion of 30 to 70% by volume of the reinforcing continuous fiber.
It is preferable to adjust the degree.

The yarns constituting the sleeve made by braiding include those arranged in the S twist direction and those arranged in the Z twist direction intersecting with the S twist direction. In the present invention, a continuous reinforcing fiber is used. They are arranged in only one of them. Therefore, the reinforcing continuous fibers are arranged parallel to each other in only one direction within the sleeve, and the reinforcing continuous fibers do not intersect each other. All of the thermoplastic resin fibers may be arranged in a direction intersecting with the reinforcing continuous fibers, or a part of them may be arranged in the same direction as the reinforcing continuous fibers.

There is no particular limitation on the structure of the threads constituting the sleeve, but one example thereof will be described with reference to FIG. FIG. 1 shows an arrangement of threads constituting a sleeve 1 according to an embodiment of the present invention. The threads 2 arranged in an upward right direction are thermoplastic resin fibers, and the threads 3 arranged in an upward left direction are reinforced. It is composed of continuous fibers. One yarn 2a of thermoplastic resin fiber dives underneath two adjacent yarns 3a, 3b of reinforcing continuous fiber and then two adjacent yarns 3
Pass over c and 3d. Further, the yarn 2a of thermoplastic resin fiber
The yarn 2b adjacent to the bottom of the two continuous yarns 3b, 3c of the reinforcing continuous fiber, and then the two adjacent yarns 3
Pass over d and 3e. Threads of plural thermoplastic resin fibers 2
The cylindrical sleeve 1 is formed by braiding the reinforcing continuous fiber threads 3 with such a pattern.

A specific blading method is as follows. The thermoplastic resin fiber thread and the reinforcing continuous fiber thread, which have been wound around the braiding tube, are divided into groups in advance. A device such as a thread of thermoplastic resin fiber is attached to the tube insert. It suffices to determine which group is to be used for which tube, depending on the product to be manufactured, and is not particularly determined. The tubular sleeve 1 can be manufactured by braiding using those threads.

In the sleeve of the present invention, by heating or pressurizing it alone or by laminating it, only the thermoplastic resin fiber is melted to become a matrix impregnated with the reinforcing continuous fiber, which is reinforced with the reinforcing continuous fiber. A hollow thermoplastic resin body is formed. Here, the reinforcing continuous fiber in the sleeve of each layer has a shape in which the molded hollow body is reinforced in one direction without forming intersections. Therefore, when the reinforcing continuous fiber has a woven structure having an intersection point, the reinforcing continuous fiber is bent in the thickness direction between the intersection points. The continuous reinforcing fibers are arranged in a flat state without bending.
When the sleeves are laminated, by laminating the reinforcing continuous fibers so that the directions thereof cross each other, the molded body as a whole can be reinforced in two directions.

As a molding method using the sleeve of the present invention, a conventionally known molding method for a hollow body may be appropriately used. An example of a molding method using the sleeve of the present invention will be described below. As the sleeves to be used, two kinds of sleeves are prepared, for example, one in which the reinforcing continuous fibers are in the upward left direction as shown in FIG. 1 and one in which the continuous continuous fibers are in the direction intersecting the upward (rightward upward direction). First, a plurality of sleeves are laminated and covered on a core rod having a predetermined shape. At that time, two types of sleeves are alternately arranged so that the directions of the reinforcing continuous fibers intersect. The number of laminated sleeves is determined in consideration of the wall thickness required for the molded product, but it is usually preferable to set it to an even number.

After stacking a predetermined number of sleeves on the core rod,
Remove the core rod and set an internal pressure tube such as silicone. This set is put in a predetermined mold and pressurized with an internal pressure tube while heating. Pressurization, 2~5Kg / cm ²
It is suitable that the temperature and the temperature are higher by 30 to 50 ° C. than the melting point of the resin used. As a result, the thermoplastic resin fiber is melted and impregnated into the reinforcing continuous fiber. After that, the mold is cooled to solidify the resin, and then the molded product is taken out. Thus, a hollow body of thermoplastic resin reinforced with continuous fibers is formed.

[0019]

The continuous fiber reinforced thermoplastic resin molding sleeve of the present invention has a tubular shape formed by braiding fibers, and is flexible and easy to handle. It is extremely easy to attach it to the etc. Since each thread constituting the sleeve is composed of only the reinforcing continuous fibers or only the thermoplastic resin fibers, the reinforcing continuous fibers and the thermoplastic resin fibers are twisted together or braided before the braiding. Therefore, it is possible to manufacture at low cost.

When this sleeve is heated and pressed to be molded,
The thermoplastic resin is melted and impregnated into the reinforcing continuous fibers to obtain a hollow body reinforced with the continuous fibers. that time,
Since the reinforcing continuous fibers are unidirectional in one sleeve without the intersection of the reinforcing continuous fibers, unimpregnated portions that are likely to occur at the intersections are less likely to occur. Further, since the continuous reinforcing fibers are arranged in one direction and do not intersect with each other, and thus have no woven structure, no bending occurs in the continuous continuous fibers. For this reason, when a plurality of sleeves are laminated and molded, the reinforcing continuous fibers have a neatly layered shape, and large resin pools are less likely to occur between the reinforcing continuous fibers. Thus, a molded product having a large reinforcing effect by the continuous fibers and a good appearance can be obtained.

The hollow molded article formed by the sleeve of the present invention is suitable for applications requiring high strength, high toughness, moderate elasticity, and the like. For example, exercise equipment such as a tennis racket, a golf shaft, and a fishing rod. It is preferably used for

[0022]

Example 1 A unidirectional sleeve of 6K carbon fiber / nylon 6 was prepared under the following conditions. (1) Materials used Thermoplastic resin fiber Material Nylon 6 Number of filaments 36 Filament diameter 84 microns Thread count 230TEX (230g / 1000)
m) Reinforcing continuous fiber Material 6K carbon fiber Number of filaments 6000 Filament diameter 7 microns Thread count 392TEX (392g / 1000)
m) (2) Braiding Number of strokes: 64 Angle: 30 ° Sleeve diameter: 22 mm Braiding: Carbon fiber is placed in the right-handed tube insert and nylon fiber is placed in the left-handed tube insert.

Example 2 ECG37 1/0 glass fiber /
A nylon 6 unidirectional sleeve was made. (1) Material used Thermoplastic resin fiber Material Nylon 6 Number of filaments 24 Filament diameter 50 microns Thread count 54TEX Reinforcing continuous fiber material ECG37 1/0 glass fiber Number of filaments 800 filament size 9 micron Thread count 135TEX (2) Braiding Number of strokes: 96 Angle: 30 ° Sleeve diameter: 10 mm Braiding: A glass fiber is placed in the right-handed tube insert and a nylon fiber is placed in the left-handed tube insert.

Comparative Example 1 6K carbon fiber / nylon 6 under the following conditions
The continuous continuous fiber for reinforcement made the sleeve which has an intersection. (1) Material used Thermoplastic resin fiber Same as Example 1 (nylon 6) Reinforcing continuous fiber Same as Example 1 (6K carbon fiber) (2) Braiding The number of striking, the angle, and the sleeve diameter are the same as those in Example 1. the same. For braiding, both the left and right sides of the braid are laid with alternate braided pipes made of continuous reinforcing fibers and thermoplastic resin fibers.

Comparative Example 2 3K carbon fiber / nylon 6 under the following conditions
The continuous continuous fiber for reinforcement made the sleeve which has an intersection. (1) Material used Thermoplastic resin fiber Material Nylon 6 Number of filaments 36 filament diameter 60 micron Thread count 115TEX Continuous fiber for reinforcement Material 3K carbon fiber Number of filaments 3000 filament diameter 7 micron Thread count 198TEX (2) Braiding number: 96 angle: 30 ° sleeve diameter: 20 mm braiding: same as comparative example 1.

The sleeves produced as described above were subjected to a treatment suitable for glass fiber and carbon fiber, respectively, and molded as follows, and a comparative test was conducted.

The sleeve is cut open at one location along the 0 ° length direction (axial direction of the sleeve). In the case of Comparative Examples 1 and 2, a predetermined number of these sheets are aligned and laminated in the same direction, and molded at a temperature of 260 ° C. and a pressure of 5 Kg / cm ² . In addition, in the case of Examples 1 and 2, a predetermined number of the continuous reinforcing fibers are alternately laminated so that the reinforcing continuous fibers form an angle of 30 ° with respect to the 0 ° direction axis, and the last one is in the same direction as the first one. (To prevent warpage of the molded product) and mold. The molding conditions are the same as in the comparative example.

Table 1 shows the results of evaluation of the molded product (test piece) thus obtained. The method of measuring the void ratio is according to JIS K7053.

[0029]

[Table 1]

As can be seen from Table 1, the molded articles of the examples have a smaller void ratio and the unimpregnated parts are significantly reduced as compared with the comparative examples. Further, as is clear from the comparison between Example 1 and Comparative Example 1, the bending strength in Example 1 was increased even though the sleeve was made of the same thermoplastic resin fiber and continuous reinforcing fiber as the material and specifications. Is greatly improved.

Further, the cross sections (cross sections perpendicular to the reinforcing continuous fiber) of the test piece formed by using the sleeve of Example 1 and the test piece formed by using the sleeve of Comparative Example 1 were observed with a microscope. In the test piece of Example 1, as shown in FIG. 2, the reinforcing continuous fiber threads 5 were flat and orderly arranged, and only a small resin pool 6 was seen between them. On the other hand, Comparative Example 1
In the test piece of No. 3, as shown in FIG. 3, the reinforcing continuous fiber threads 5 were deformed irregularly, and a large resin pool 7 was present. This is probably because the continuous reinforcing fibers do not intersect in Example 1 and are regularly arranged in one direction, whereas the continuous continuous fibers in Comparative Example 1 intersect and bend in the thickness direction. . Moreover, it is considered that these sequences influence the strength.

[0032]

As described above, the sleeve of the present invention is a sleeve formed by braiding a yarn made of continuous reinforcing fibers and a yarn made of a thermoplastic resin fiber, and can be manufactured at low cost. Since it is a flexible tubular body, it is easy to handle when used to form a hollow body, and the continuous reinforcing fibers are arranged in one direction so that they do not intersect with each other. Therefore, there is an effect that it is possible to obtain a hollow molded article that has no intersecting portion that is difficult to impregnate, has good impregnating property, and has significantly improved performance.

[Brief description of drawings]

FIG. 1 is an enlarged schematic plan view showing a part of a sleeve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a test piece formed by using the sleeve of Example 1 is cut into reinforcing continuous fibers at a right angle, and the cross section is enlarged and viewed with a microscope.

FIG. 3 is a cross-sectional view showing a state in which a test piece molded using the sleeve of Comparative Example 1 is cut into reinforcing continuous fibers at a right angle and the cross section is enlarged and viewed with a microscope.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Sleeve 2, 2a, 2b Thermoplastic resin fiber thread 3, 3a, 3b, 3c, 3d, 3e Reinforcing continuous fiber thread 5 Reinforcing continuous fiber thread 6, 7 Resin pool

Claims (1)

[Claims] 1. A sleeve formed by braiding a thread made of continuous reinforcing fibers and a thread made of thermoplastic resin fibers in a tubular shape, wherein the continuous continuous fibers do not intersect with each other. A continuous fiber reinforced thermoplastic resin molding sleeve, which is arranged in only one direction.