JPH04185313A - Manufacture of molded body for which thermoplastic resin coated reinforced fiber complex is used - Google Patents

Abstract

PURPOSE:To make a molding process sanitary and contrive a reduction of a manufacturing cost of a molded body and impregnated body, by a method wherein a composite reinforced fiber roving or its aggregate obtained by coating yarn comprised of a plurality of reinforcing fiber single fibers with thermoplastic resin is heated at a temperature melting the thermoplastic resin or higher and pressurized. CONSTITUTION:Carbon fibers 1, 2, 3 which are oxidation-treated after firing are split into yarn of single fibers by 200 pieces, the yarn is passed through dies 5, 5' meantime the yarn is coated with molten thermoplastic resin 7. The coated yarn is cooled by a cooling roll 9 mounted on the lower part, composite units are obtained, which are wound up while bundling 15 pieces and a composite carbon fiber roving 8 is obtained. Then composite reinforced fiber roving or its aggregate (textiles, knitting, plating) is heated up to a temperature where coated thermoplastic resin is melted, fluid and pressurized, through which the same is molded as a composite. With this construction, an impregnated molded material or a molded body is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a composite impregnated molded material or molded body having a thermoplastic resin as a matrix.

(Prior Art) Prepregs in which reinforcing fibers are impregnated with thermoplastic resin are commercially available, but these are rigid and difficult to make into fabrics, braids, or sheet-like objects, and are inferior in formability. Furthermore, it is difficult to perform so-called tape-laying on curved surfaces. On the other hand, flexible materials have been developed in which thermoplastic resin is made into fibers or powder and mixed with reinforcing fibers, but mixing tends to result in non-uniformity. In order to reliably obtain a molded product with a high temperature, it requires pressure and time exceeding a certain level in the impregnation molding process, which has the disadvantage that the process cost increases accordingly.

(Problems to be Solved by the Invention) The present invention is a thermoplastic material that has sufficient flexibility for textile processing such as tape-laying and weaving, has excellent formability, and can be impregnated during molding very easily and quickly. The objective is to obtain an impregnated body or an adult body at low cost using a composite material.

(Means for Solving the Problems) The present invention provides a composite reinforcing fiber roving or an aggregate thereof, which is composed of a plurality of composite units obtained by coating a thread composed of a plurality of single reinforcing fibers with a thermoplastic resin. This is a method for producing an impregnated molded material or a molded body, characterized in that the thermoplastic resin is heated to a temperature higher than the temperature at which the thermoplastic resin melts and pressurized.

In order to maintain flexibility, the composite reinforcing fiber roving used in the present invention is composed of a plurality of composite units, and each composite unit contains a limited number of reinforcing fiber units to facilitate impregnation during molding. It has a structure in which threads made of fibers are substantially coated with thermoplastic resin. The composite reinforcing fiber roving is heated to a temperature at which the thermoplastic resin melts and flows, and then pressurized to obtain an impregnated molded material or molded body.

The reinforcing fibers in the composite reinforcing fiber roving of the present invention include fibers such as glass fibers, carbon fibers, and aramid fibers, but are not particularly limited to these.

Examples of the thermoplastic resin include nylon 6, nylon 66, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polypropylene, polyetherimide, polyphenylene sulfide, polyether ether ketone, etc., but are not particularly limited thereto.

The content of reinforcing fibers in the roving of the present invention is 10 to 80
vo1% is preferable. If it is less than 10%, the reinforcing effect of the reinforcing fibers cannot be effectively exerted when it is used as a combo shift. If it is 80% or more, it is difficult to impregnate it when forming a component knot, and void defects are likely to occur.

Here, the method for obtaining the composite reinforcing fiber roving of the present invention will be explained using a specific example.

The carbon fibers that have been subjected to oxidation treatment after firing are divided in-line into threads each containing 200 single fibers, and the threads are passed through a die schematically shown in Figs. Coating is performed. The coated yarn is cooled by a cooling roll installed at the bottom to obtain a composite unit, and 15 pieces are bundled and wound to obtain a composite carbon fiber roving.

The number of reinforcing fibers contained in a composite unit is 5 to 10.
00 preferably should be in the range 20-600.

When the number of single fibers becomes too large, the impregnation speed of the composite roving decreases, flexibility decreases, and textile processability, etc., decreases. If it is too small, the cost of composite roving will increase abnormally.

The thus obtained composite reinforcing fiber roving or its aggregate (woven fabric, knitted fabric, braided fabric, etc.) can be heated to a temperature at which the coated thermoplastic resin melts and flows, and then pressurized to form a composite. The effective molding method will be specifically explained below. A rod or tape as shown in FIG. 4 can be made continuously by passing heated composite glass fiber roving between pressure rolls or pressure belts as shown in FIG. In addition, by cutting rondo or tape of appropriate thickness into, for example, 10-inch pieces, pellets for injection molding or compression molding can be made. By shaking off the roving as it is or cutting it into a predetermined length to form a sheet, and heating and pressing the roving, a so-called flat solid stampable sheet can be produced.

Further, a flat solid sheet can be made by heating and compressing a cloth-like material such as a woven fabric, knitted fabric, or braided fabric obtained from the present roving.

By continuously heating the present roving or a tape obtained from the present roving while winding it around a mandrel and applying pressure, so-called filament winding molding can be performed.

In addition, so-called pultrusion molding can be performed by drawing out a large number of heated rovings while die-cutting them into a predetermined shape.

By cutting the thus obtained glass fiber-axially oriented rod-shaped composite into a length of 5 to 50 m+, a pellet-shaped molded material useful for injection molding and the like can be obtained. Furthermore, another promising molding method is to place the roving or its cut pieces directly on a mold, or to place a cloth-like material obtained from the roving on a mold and compression mold it using an open mold. can be mentioned. As a modification of this molding method, molding can also be performed using the principle of so-called internal pressure molding. For example, hollow (tubular) as shown in Figure 6.
A heating mold is used, and the mold is heated with a heater. This roving cloth material is placed in a mold as shown in the figure, and a heat-resistant elastomer tube (balloon) inserted into the center is inflated and pressurized. By applying the principle of internal pressure forming, it is possible to form not only a cylindrical body but also a T-shaped stiffener having a curvature in the longitudinal direction as shown in FIG. 7, for example.

(Function) In the molding method of the present invention, the molding process is hygienic because (1) there is almost no scattering of glass fibers, and (2) no solvent or reinforcing liquid is used.

In addition, since impregnation is easy and proceeds at low pressure, the manufacturing cost of molded bodies and impregnated bodies is reduced. In addition, woven fabrics, knitted fabrics, and braided fabrics can be molded according to molds, making it possible to obtain molded objects with complex shapes.6 Furthermore, since a thermoplastic matrix is used compared to heat-strengthened FRP, it is stronger. Composite molded bodies can be made.

(Example) Example 1 Composite glass fiber roving with a glass fiber composition ratio of 55 vol. 1%, consisting of 32 composite fiber units obtained by coating 50 E glass fibers each having a diameter of 13 μm with NY6 resin. An impregnated rod obtained by aligning four rovings using a roving and heating them to 250°C and passing them between a pair of pressure rolls in a slot mold at a speed of 10 m/min. By cutting the embryo to the length, we were able to obtain a pellet-shaped molding material called long fiber engineering plastic.

Example 2 Using one of the rovings of Example 1, a grooved roller having a cross-sectional shape as shown in FIGS. 5-b was passed through while applying tension as shown in FIG. A monofilament with a circular cross section was obtained. The diameter of this monofilament was 1.2 m.

Example 3 Using the roving of Example 1, the warp density was 20/cm
After weft density 1 piled and heated to 240°C, 2
It was compressed and cooled at a pressure of kg/cm. Thus 50
A flat plate of crrr square and 2 coats thick was obtained. This flat plate can be subjected to so-called deep drawing.

Example 4 Using the roving of Example 1, the roving was cut to a length of 15 mm and distributed uniformly on the surface to obtain a sheet of 1800 g/i. After heating the sheet to 240'C, it was placed in a press machine. The mixture was compressed at a pressure of 2 kg/CIj and cooled. Thus 5
Obtained a slab of thickness/cabinet of 01 square. This flat plate can be usefully applied to so-called flow scraping molding.

Example 5 The roving of Example 1 was warb-winded using a filament winding device schematically shown in FIG. 8 and wound up at a speed of 5 m/min. The temperature of the heated air was 310'C, and the temperature of the surface material of part A was 240C. Note that the mandrel was heated to 160°C.

In this way, it was possible to obtain a straight pipe with an outer diameter of 20 cm, a thickness of 3 a11, and a length of 10 cta17), which was well impregnated with a matrix having a flat surface.

Example 6 Heating dies installed in a series schematically shown in FIG.
100 rovings of (1) heated to 260°C were passed through the cooling die at a speed of 5 m/min.

The temperature of the heating die block is set to 110°C, and the cooling die block temperature is set to 20°C. Thus 10m
It was possible to obtain an impregnated rod with a rectangular cross section of mX3.

Example 7 By inserting the roving (1) into the open groove schematically shown in Figure 10, heating the roving to a temperature of 240°C, and cooling it by applying a pressure of 3 kg/cm. A square plate-shaped molded product with a grid having a thickness of 5s111 and a side length of 100 mm was obtained. In No. 10-a and bo, 2 is a groove portion, and the groove width is 5 m and the groove depth is 20 m. Figure 10-b is a sectional view of one groove of the mold 1. 3 is an aluminum plate, 4 is a heat insulating layer of glass wool, and 5 is a hollow portion that serves as a flow path for heated air as a heating source and room temperature air as a cooling source. 6 is a pore for reducing pressure, 7 is a molded material, 8 is a piston for pressurizing, and this piston is driven by air pressure to apply pressure.

[Brief explanation of drawings]

FIG. 1 shows a cutaway cross section of an apparatus for producing composite carbon fiber rovings coated with a thermoplastic resin according to the present invention. 1 and 2.3 in Fig. 1: Yarn (multiple carbon fibers) 4 Ni guide roll 5.5' Double opening/closing guide 6: Inert gas 7, molten thermoplastic resin 8: Covered carbon fiber roving 9: Cooling roller 10: chamber wall for storing molten thermoplastic resin FIG. 2 shows the surface (grooved rim) of the opening/closing die 5.5' in FIG. FIG. FIG. 4 shows a composite monofilament, and the figure shows a single reinforcing fiber. Figures 5-a and 5-b show a heating roll for heating and melting the matrix fiber portion of the core-sheath composite fiber of the present invention, and Figure 5-a is an overall view of the heating roll, 5-
Figure b is a cross-sectional view of the roll taken along the line A-A. In the figure, ■ indicates a composite fiber multifilament.■ indicates a roll groove when viewed from the A-A plane of the heating roll. FIG. 6 shows a method of forming a cloth-like article using a tubular heating mold. In the figure, ■: roving fabric ■: type ■: heater ■: elastomer (closed tube shape) ■: air. FIG. 7 shows a T-shaped feature having curvature along its length. In the figure, ■: Reinforcing fiber-containing resin molded portion ■: Hollow portion. FIG. 8 shows a filament winding device, in which ■: pressure roller ■: heated air ■ = roving ■: mandrel. FIG. 9-a shows a molding apparatus in which a heating die and a cooling die are installed in a mold, and FIG. 7-b is a sectional view thereof. In the figure, ■: heating goo; ■: cooling gou. FIG. 10 shows an example of an open type, in which a is a plan view and b is a side view. In the figure, ■ Two rovings ■: Groove ■ Ni-aluminum plate ■ Niglass wool insulation layer ■: Hollow section ■: Pore for pressure reduction ■: Molded material ■; Pressure piston is shown. Patent Applicant Keyaki Toyobo Co., Ltd. Figure #2111 弗3Figure Haya41!1 ノ■ #5-CIE! 1, ρ world 5-b diagram ■ $6 Figure world 7 diagram ■ Early 8! ! ! Early 9Il! 1-0 A ■ ■ ■ ＃-]○-Q! ! 1 ■ ■ Early 1O-bl! 1 7 ■ 2 ■ Anu Procedural Amendment (Method) % Formula % 1. Indication of the case 1990 Patent Application No. 312387 2 Title of the invention Method for manufacturing a molded article using a thermoplastic resin-coated reinforced fiber composite 3 , Relationship with the case of the person making the amendment Patent applicant 2-2-8-5 Dojimahama, Kita-ku, Osaka City, "Brief explanation of drawings" column 6 of the specification to be amended, Contents of the amendment (1) Description "Figure 7-b" on page 13, line 13 is corrected to "Figure 9-b." ,

Claims (1)

[Claims] (1) A composite reinforcing fiber roving or an aggregate thereof consisting of a plurality of composite units obtained by coating a yarn consisting of a plurality of single reinforcing fibers with a thermoplastic resin is melted by the thermoplastic resin. A method for producing an impregnated molded material or molded body, which comprises heating to a temperature higher than that at which the material is heated and pressurizing it.