JPH03146326A - Manufacture of fiber-reinforced thermoplastic resin pipe - Google Patents

Abstract

PURPOSE:To improve the accuracy of an outside diameter, and to enable accurate joining with a joint without executing fabrication by a method wherein sections among filaments are impregnated with a thermoplastic resin, a continuous reinforced fiber bundle is formed in a tape-shaped fiber composite body having a uniform width and thickness, the fiber composite body is wound on the outer circumference of a thermoplastic resin pipe and a reinforced layer is shaped. CONSTITUTION:The thermoplastic resin pipe 16 of an internal layer as a core material is shaped by passage through a mold 2 of a thermoplastic resin extruded from an extruder 1. A continuous reinforced fiber bundle 30 in which sections among filaments are impregnated with the thermoplastic resin is heated and pressed by a roll 40 and a fiber composite body 50 having uniform width and thickness is formed, and the fiber composite body 50 is wound on the outer surface of the thermoplastic resin pipe 16, and fused and unified, thus shaping a reinforced layer 16a. It is desirable that continuous reinforced fibers are wound so as to be mutually crossed. The tubular body 16 is introduced to a coating mold 12, and the outer surface of the tubular body 16 is coated with a thermoplastic resin extruded from an extruder 11, thus forming an external layer. The tubular body 16 is cooled by a cooling system 14, and taken off by a take-off unit 15, thus acquiring a fiber-reinforced thermoplastic resin pipe 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a fiber-reinforced thermoplastic resin pipe in which reinforcing fibers are wound around the outer periphery of the thermoplastic resin pipe.

(Prior Art) Resin pipes are widely used because they have excellent properties such as being lightweight and rust-free compared to metal pipes. However, this resin tube is inferior to metal tubes in pressure resistance and impact resistance. Therefore, in order to impart pressure resistance and impact resistance to these resin tubes, a reinforcing layer made of fiber-reinforced thermoplastic resin is provided around the outer periphery of the core thermoplastic resin tube. A fiber-reinforced thermoplastic resin pipe coated with a thermoplastic resin layer has been proposed (see, for example, Japanese Patent Application Laid-Open No. 152786/1986). A method for manufacturing this fiber-reinforced thermoplastic resin pipe is to apply a thermoplastic resin between filaments. There is a method in which a strand-shaped reinforcing fiber impregnated with is heated and fused around the outer periphery of the thermoplastic resin tube as an inner layer, or a method in which the reinforcing fiber is wound around the outer periphery of the thermoplastic resin tube and fused by heating. After a reinforcing layer made of a fiber-reinforced thermoplastic resin is provided by a method or the like, the outer periphery of the reinforcing layer is coated with the thermoplastic resin by extrusion.

(Problem III to be Solved by the Invention) However, according to the above-mentioned conventional method for manufacturing a fiber-reinforced thermoplastic resin pipe, a strand-shaped reinforcing fiber bundle impregnated with a thermoplastic resin between the filaments is attached to the outer periphery of the thermoplastic resin pipe. The filaments are wound around each other, but there are gaps between the filaments.
Because the cross-sectional area is small, the distribution of filaments of the reinforcing fiber bundle in the reinforcing layer tends to be uneven, which causes unevenness on the surface of the reinforcing layer. However, it could not be completely resolved. Such fiber-reinforced thermoplastic resin pipes have poor outer diameter accuracy, and when joining the pipe and the joint, secondary processing such as cutting the outer surface of the pipe is required.

The present invention was made to solve the above problems, and provides a method for manufacturing a fiber-reinforced thermoplastic resin pipe that has excellent outer diameter accuracy and can be joined to a joint with high accuracy without special secondary processing. is intended to provide.

(Means for Solving the Problems) The method for manufacturing a fiber-reinforced thermoplastic resin pipe of the present invention includes (A)
A process of heating and pressurizing a continuous reinforcing fiber bundle in which a thermoplastic resin is impregnated between the filaments to form a tape-shaped fiber composite having a uniform width and thickness; (B) extruding the tape-shaped fiber composite; (C) forming a reinforcing layer by uniformly and densely winding and fusing the inner layer thermoplastic resin tube continuously extruded from a machine mold; (C) heating the outer periphery of the reinforcing layer; The method is characterized in that it includes a step of extrusion coating with a plastic resin.

In the present invention, thermoplastic resins used as raw materials for the inner layer thermoplastic resin pipe serving as the core material include polyvinyl chloride, chlorinated polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, and polyether. Examples include ether ketone, etc., and there is no particular restriction as long as it is a thermoplastic resin that can be molded into a tubular shape. These thermoplastic resins may be used alone or as a mixture of two or more. It may be a laminate formed by laminating multiple layers of resins selected from thermoplastic resins.
Further, additives such as heat stabilizers, plasticizers, lubricants, antioxidants, ultraviolet absorbers, pigments, inorganic fillers, reinforcing fibers, fillers, processing aids, modifiers, etc. may be added.

The continuous reinforcing fiber bundle is made of reinforcing fibers that are thermally stable at the molding temperature of thermoplastic resins such as glass fibers, carbon fibers, metal fibers, aramid fibers, vinylon, or various other synthetic fibers, and have a diameter of about 1 to 40μ. It is formed by impregnating a thermoplastic resin into a roving- or strand-like reinforcing fiber bundle composed of tens to thousands of continuous filaments.

The thermoplastic resin to be impregnated into the reinforcing fiber bundle is not particularly limited as long as it is a thermoplastic resin that can be fused to the thermoplastic resin tube of the inner layer. A thermoplastic resin that melts or softens at a temperature equal to or lower than that of the resin of the thermoplastic resin pipe is preferably used.

The tape-shaped fiber composite is made by impregnating thermoplastic resin between the filaments of a reinforcing fiber bundle and heating and pressurizing it to a thickness of 0.1 to 2.
- The width is about 5 to 50II11. The amount of fibers in this tape-shaped fiber composite is 5 to 80% by volume. If it is less than 5% by volume, a sufficient reinforcing effect cannot be obtained, and if it exceeds 80% by volume, the fusion property with the inner layer thermoplastic resin pipe will decrease, making it impossible to obtain a fiber-reinforced resin pipe with a sufficiently fused interface.
Methods for impregnating thermoplastic resin between filaments include (1) passing through a liquid bath in which powdered thermoplastic resin is dispersed and then drying; (11) passing molten thermoplastic resin through a bath; An example is a method of passing and then drying. In addition, in the case of methods (t) and (ii), the thermoplastic resin impregnated between the filaments may be used in powder form, or the thermoplastic resin may be heated and melted first. It may be.

The thermoplastic resin used to extrusion coat the outer surface of the fused reinforcing layer of the tape-shaped fiber composite is capable of being fused with the thermoplastic resin impregnated into the continuous reinforcing fiber bundle, and is less likely to be melt-molded. It is preferable to use a thermoplastic resin having a high temperature because the thermoplastic resin of the reinforcing layer is sufficiently melted by the heat of the covering thermoplastic resin, and high fusion strength can be obtained.

Furthermore, a method for manufacturing a fiber-reinforced thermoplastic resin pipe of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing an example of a manufacturing apparatus used in carrying out the method for manufacturing a fiber-reinforced thermoplastic resin pipe of the present invention, and in this figure, ▪ is an extruder for extruding a thermoplastic resin. A mold 2 for extruding and forming a thermoplastic resin into a hollow tube shape is attached to the tip of the extruder 1. A winding device 20 that rotates and winds the tape-shaped fiber composite 50 around the inner layer thermoplastic resin tube 16 that is extruded from the mold 2 and serves as a core material is installed in the mold 2 on the opposite side of the extruder 1. There are two consecutively installed at the front. Each winding device 20 is
The continuous reinforcing fiber bundle 30 impregnated with thermoplastic resin is heated and
It is equipped with a heating roll 40 that performs pressure treatment to form a tape-shaped fiber composite 50. A heating device 3 that heats the outer surface of the thermoplastic resin tube 16 around which the tape-shaped fiber composite 50 is wound is provided at the front end of each winding device 20,
A cylindrical body 16a in which a tape-shaped fiber composite 50 is sequentially wound around the outer surface of a thermoplastic resin pipe 16 from this point forward.
a coating resin extruder 11 for extruding a thermoplastic resin for further coating the outer surface with a thermoplastic resin, and this extruder 11
A covering mold 12 attached to the tip, a cooling device 14 such as a water tank, and a take-off 815 are provided.

As the extruder 1.11, various types of extruders can be used, such as an extruder commonly used for molding thermoplastic resin tubes.

Next, a method for manufacturing the fiber-reinforced thermoplastic resin pipe of the present invention using the above-mentioned apparatus will be explained.

First, the thermoplastic resin extruded from the extruder 1 passes through the mold 2 to form the inner layer thermoplastic resin tube 1 which becomes the core material.
6 is formed.

Subsequently, the continuous reinforcing fiber bundle 30 impregnated with a thermoplastic resin between the filaments is heated and pressurized with a roll 40 to form a fiber composite 50 with uniform radiance and thickness, and this fiber composite 50 is heated with the thermoplastic resin. The resin pipe 16 is wound so that no gaps or overlaps occur on the outer surface thereof, and the thermoplastic resin pipe 16 and the fiber composite 50 are fused and integrated.

As shown in FIG. 5, the continuous reinforcing fiber bundle 30 is produced by passing a reinforcing fiber bundle 4 in the form of a roving cane or strand through a fluidized bed 5 of powdered thermoplastic resin to impregnate the thermoplastic resin between the filaments. Manufactured by

The winding device 20 rotates around the thermoplastic resin tube 16 by a power device (not shown), and thereby each roll 60
A continuous reinforcing fiber bundle 30 with thermoplastic resin impregnated between the filaments is sequentially unwound from each of the filaments, and heated and pressurized as it passes through a heating roll 40 to form a tape-shaped fiber composite 50 with uniform width and thickness. is formed and is configured to be wound around the outer surface of the thermoplastic resin tube 16. As shown in FIG.
A reinforcing layer in which continuous reinforcing fibers are arranged so as to intersect with each other can be formed on the outer periphery of the pipe, which is preferable in that a fiber-reinforced thermoplastic resin pipe with excellent pressure resistance can be obtained.

The heating roll 40 is, for example, a pair of rolls as shown in FIG. 2, including an upper roll 40a and a lower roll 40b.
By appropriately selecting the clearance radius and thickness, a tape-shaped fiber composite 50 having a desired radius and thickness can be obtained. Here, the heating roll 40 is heated to a temperature higher than the softening temperature of the thermoplastic resin impregnated into the continuous reinforcing fiber bundle 30. The method for heating the rolls is as follows:
Methods such as heating with an electric heater and heating with heating medium circulation are used. Alternatively, the heating roll 40 may be a roll at room temperature, and the continuous reinforcing fiber bundle 30 may be heated to a temperature equal to or higher than its softening temperature using a heating means such as a far-infrared heater, an infrared heater, or hot air, and then supplied to the roll.

When the thermoplastic resin pipe 16 and the fiber composite 50 are fused together, they may be heated and fused together from the outer periphery of the wound fiber composite 50 by the heating device 3, if necessary. ,
In order to prevent the thermoplastic resin tube 16 from being deformed when the fiber composite 50 is wound and fused on the outer surface of the thermoplastic resin tube 16, an inner core protruding from the resin outlet of the mold 2 in the extrusion direction is inserted. Alternatively, the fiber composite 50 may be wound around the outer surface of the thermoplastic resin tube 16 at a position outside the inner core, or cooling air may be blown into the thermoplastic resin tube 16 from the tip of the mold 2 to form a thermoplastic resin. A method of winding the fiber composite 50 while cooling the inner surface of the tube 16 may be adopted.

Subsequently, the tubular body 16a around which the tape-shaped fiber composite 50 is wound as described above is guided to the covering mold 12, and the thermoplastic resin extruded from the extruder 11 is applied to the outer surface of the tubular body 16a. The outer layer 16b is formed by coating.

Subsequently, it is supplied to a cooling device 14 to be cooled, and then taken off by a take-off machine 15 to obtain a fiber-reinforced thermoplastic resin pipe 13.

Next, another example of the manufacturing apparatus used to carry out the method for manufacturing a fiber-reinforced thermoplastic resin pipe shown in FIG. 3 will be described. Portions corresponding to those shown in FIG. 1 above are designated by the same reference numerals, and description thereof will be omitted. As shown in Figure 1 above-
In this example, all the steps are performed simultaneously, but in other examples, the previous steps are performed separately.

That is, in the manufacturing method shown in FIG. 3, a continuous reinforcing fiber bundle 30 with thermoplastic resin impregnated between the filaments is prepared in advance as shown in FIG. The unwound continuous fiber reinforced bundle 30 is formed into a fiber composite 50 having a uniform width and thickness using a heating roll 40, and a roll 70 of this fiber composite 50 is created.
This roll 70 is placed in the winding device 20, and the other operations are the same as those described in FIG. 1 above.

In the above description, the step of forming a tape-like fiber composite from a continuous reinforcing fiber bundle with a thermoplastic resin impregnated between the filaments involves heating and pressurizing the continuous reinforcing fiber bundle to increase the width and width.
Although we have shown an example of forming a uniform thickness, it is also possible to form a tape-shaped fiber composite by heating and pressurizing a continuous reinforcing fiber bundle to form a reinforcing fiber material with a uniform thickness, and then cutting it to the desired width. Alternatively, one tape-shaped fiber composite may be formed from a plurality of continuous reinforcing fiber bundles.

Further, in the above description, an example was shown in which two winding devices were provided, but the number is not particularly limited and is appropriately determined depending on the thickness and desired physical properties of the reinforcing layer to be molded. For example, one winding device may be provided, or three or more winding devices may be provided, or a roll in which a continuous reinforcing fiber bundle impregnated with a thermoplastic resin between filaments is wound around one winding device. A plurality of heating rolls for forming a fiber composite from continuous reinforcing fiber bundles may be provided.

(Function) Thermoplastic resin is extruded to form the inner thermoplastic resin tube, and continuous reinforcing fiber bundles impregnated with thermoplastic resin between the filaments are heated and pressurized to form a tape with uniform width and thickness. A fiber composite is formed, and this tape-shaped fiber composite is uniformly and densely wound around the outer circumference of a thermoplastic resin pipe as an inner layer, and fused to form a reinforcing layer. Cover.

(Example) Embodiments of the present invention will be described based on the drawings.

1) I imitated the bottom of the base (Fig. 5); Acetic acid-vinyl chloride copolymer resin: 100 parts by weight Butyltin malephate stabilizer = 3 parts by weight Stearyl alcohol: 0.5 parts by weight A powdered thermoplastic resin assembly 6 is obtained by mixing the mixture consisting of 1.0 parts with a super mixer, and this assembly 6 forms a fluidized bed 5 as shown in FIG. A reinforcing fiber composed of a glass filament with a diameter of 17 μ-, in this example, a glass fiber roving (2200 g/lv) 4 is passed through the inside,
This glass fiber roving (2200g/km) 4
The powdered thermoplastic resin composition 6 was impregnated between the filaments to create a continuous reinforcing fiber bundle 30 in which the thermoplastic resin was impregnated between the filaments, and a roll 60 was prepared. The fiber/resin ratio was 40/60 by volume.

2) of
A fiber-reinforced thermoplastic resin pipe was manufactured using the manufacturing apparatus shown in FIG.

Polyvinyl chloride resin: 100 parts by weight Butyltin malephate stabilizer: 3 parts by weight Polyethylene wax: 0.5 parts by weight Stearyl alcohol
: A blend consisting of 1 part by weight was supplied to an extruder 1 and extruded from a mold 2 (temperature: approximately 200°C) to form a thermoplastic resin tube 1 with an outer diameter of 30+sm and an inner layer of wall thickness of 1.5m-.
6 was molded.

The roll 60 of the continuous reinforcing fiber bundle 30 with thermoplastic resin impregnated between the filaments obtained in step 1) above is set in the winding machine 20, and heated with the heating roll 40 (temperature: 190°C).
While applying pressure to form a tape-shaped fiber composite 50 with a width of 20 mm and a thickness of 0.4 mm, the thermoplastic resin tube 16 of the inner layer is
Wind it so that there are no gaps or overlaps around the outer circumference of the
The thermoplastic resin tube 16 and the fiber composite 50 were fused and integrated by heating with a far-infrared heater 3 to form a reinforcing layer. The thickness of the obtained reinforcing layer was approximately 0.8. Next, the tubular body 16a around which the tape-shaped fiber composite 50 was wound was introduced into the coating mold 12, and the chlorinated polyvinyl chloride resin = 100 parts by weight Butyltin maleate stabilizer: 3 parts by weight Polyethylene wax: 0.5 parts by weight Stearyl alcohol
= 1 part by weight UV absorber:
A blend consisting of 0.2 parts by weight was supplied to the extruder 11 and extruded from the coating mold 12 (temperature: about 200° C.) onto the outer surface of the tubular body 16a to form an outer layer with a thickness of 1.2 mm. Subsequently, it was cooled by a cooling device 14 and taken by a take-up machine 15 to obtain a fiber-reinforced thermoplastic resin pipe 13.

No unevenness due to uneven distribution of glass fibers was observed on the outer surface of the obtained fiber-reinforced thermoplastic resin tube, and the tube had excellent outer diameter accuracy.

(Effect of the invention) According to the method for manufacturing a fiber-reinforced thermoplastic resin pipe of the present invention,
Unlike conventional methods, continuous reinforcing fiber bundles with thermoplastic resin impregnated between filaments are made into a tape-shaped fiber composite with uniform width and thickness, and then wrapped around the outer circumference of a thermoplastic resin tube to form a reinforcing layer. Since the outer periphery of this reinforcing layer is coated with a thermoplastic resin, the distribution of reinforcing fibers in the reinforcing layer is uniform, and the unevenness generated on the outer surface of the obtained fiber-reinforced thermoplastic resin tube is extremely small and has good dimensional accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an example of a manufacturing apparatus used to carry out the method for manufacturing fiber-reinforced thermoplastic resin pipes of the present invention, FIG. 2 is a side view of the heating roll in FIG. 1, and FIG. A schematic explanatory diagram showing the other side of the manufacturing apparatus used for carrying out the invention, FIG. 4 is an explanatory diagram showing the process of forming the tape-like fibrous composite in FIG. 3, and FIG. It is an explanatory view showing a process of forming a reinforcing fiber bundle. 1.11; Extruder 2; Mold 12; Covering mold 13; Fiber-reinforced thermoplastic resin pipe 14; Cooling device 15; Taking machine
16; Thermoplastic resin pipe 20; Winding device 30; Continuous reinforcing fiber bundle 40i heating roll 50; Tape-shaped fiber composite FIG.

Claims (1)

[Claims] (1), (A) heating and pressurizing a continuous reinforcing fiber bundle with thermoplastic resin impregnated between the filaments to form a tape-shaped fiber composite with uniform width and thickness; (B) the above-mentioned tape-shaped fiber composite; a step of uniformly and densely winding and fusing the fiber composite around the outer periphery of an inner layer thermoplastic resin tube continuously extruded from a mold of an extruder to form a reinforcing layer; (C) the above reinforcing layer; A method for producing a fiber-reinforced thermoplastic resin pipe, comprising the steps of: extrusion coating the outer periphery of the pipe with a thermoplastic resin.