JPH0531810A - Manufacture of fiber-reinforced thermoplastic resin pipe - Google Patents

Abstract

PURPOSE:To improve the productivity by a method wherein though a core metal is used in a manufacture of a fiber-reinforced synthetic resin pipe by a filament winding method, a process extracting to core metal is not required and continuous production of long-sized one also can be carried out. CONSTITUTION:A sheetlike fiber complex A1 to be set to a rewind roll 1 is a sheet comprised by being held thermoplastic resin by a continuous reinforced fiber arranged in a longitudinal direction, the same is molded into a tubular body A2 by a mandrel 2 while transferring, around the outside circumference of which a tapelike fiber complexes B, C, which are in the same constitution, are wound spirally, laminated by heating and bonding and received continuously by a receiving machine 10. Then, in the sheetlike fiber complex A1 and tapelike fiber complexes B, C parts of those where the respective ones are bonded, which are provided beforhand with a bonded resin layer comprised of the thermoplastic resin of the same family are used for them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber-reinforced thermoplastic resin tube comprising a thermoplastic resin and reinforcing fibers.

[0002]

2. Description of the Related Art Fiber-reinforced synthetic resin pipes are lighter than metal pipes, do not rust, and are more resistant to impacts and have higher strength than general synthetic resin pipes, so that they are not only used as piping members. It is also used as a structural member.

This fiber-reinforced synthetic resin tube uses glass fibers, carbon fibers, organic fibers, etc. as reinforcing fibers, and liquid thermosetting resin is adhered or impregnated into the reinforcing fibers as a matrix resin, and the core metal ( It was manufactured by a so-called filament winding method in which the mandrel) is continuously wound, and then the mandrel is placed in a heating furnace together with a core bar and heated, and when the thermosetting resin is cured, the core bar is removed.

However, the filament winding method using this thermosetting resin has a drawback that it takes a long time to be heated and cured, resulting in poor productivity, so that recently, for example, JP-A-62-244622 has been disclosed. As described in (1), a method using a thermoplastic resin as a matrix resin has been proposed. In this method, the thermoplastic resin is supplied in a molten state to the reinforcing fibers and impregnated therein. Then, the reinforcing fiber impregnated with the resin is wound around the cored bar, and then heated to a softening temperature of the resin or higher, and then placed in a mold and cooled under pressure to remove the cored bar.

According to this method, the drawbacks found in the above-mentioned thermosetting resins of the related art are eliminated, and the productivity is certainly improved.

[0006]

However, when a tubular body is formed by using reinforcing fibers impregnated with a thermoplastic resin, only the reinforcing fibers are surfaced at the stage of heating above the softening temperature of the resin. However, if the surface portions where only the reinforcing fibers were raised were pressed to form a tubular body, the fusion between the fibers was insufficient and there was a problem in the quality of the obtained tubular body.

Further, the step of extracting the cored bar is still necessary, and the productivity cannot be said to be sufficiently improved. Further, there is a problem that it is not possible to continuously manufacture a bar longer than the cored bar. there were.

Although the present invention is a method using a core bar, it provides a method for efficiently and continuously producing a long fiber-reinforced thermoplastic resin tube which does not require a step of extracting the core bar, and It is an object of the present invention to provide a manufacturing method in which reinforcing fibers do not float on the surface and fusion between fibers is not insufficient.

[0009]

DISCLOSURE OF THE INVENTION According to the present invention, a sheet in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction from the supporting end side of a mandrel having a substantially circular cross section whose one end is supported. Feeding the fiber-shaped composite and making it into a tubular body by closely enclosing the mandrel while advancing on the mandrel, and while advancing the tubular body along the mandrel as it is, on the outer periphery thereof, it is arranged in the longitudinal direction. A tape-shaped or string-shaped fiber composite, in which a thermoplastic resin is held by continuous reinforcing fibers, is spirally wound, laminated on a tubular body, and fused, and the above sheet-shaped fiber composite and tape-shaped Alternatively, the string-like fiber composite is a fiber-reinforced thermoplastic resin pipe characterized in that a fusion-bonding resin layer made of a thermoplastic resin is provided in advance in a portion where each is laminated and fused. It is to a manufacturing method and its gist.

In the present invention, as the reinforcing fibers used for the sheet-shaped, tape-shaped or string-shaped fiber composite, all conventionally known reinforcing fibers used for reinforcing a thermoplastic resin can be used.

Specifically, inorganic fibers such as glass fiber, carbon fiber, silicon / titanium / carbon fiber, boron fiber and fine metal fiber, aramid fiber, vinylon fiber, liquid crystal polymer fiber, polyester fiber, polyamid fiber, etc. Organic fibers are mentioned.

From the continuous reinforcing fiber, a sheet shape,
To obtain a tape-shaped or string-shaped fiber composite, the diameter is 1
A case where a composite is formed by continuously transferring a large number of roving-like or strand-like fibers composed of continuous fibers of several tens of μm in a state of being arranged in one direction, and a roving-woven roving cloth, In some cases, a strand is cut into a predetermined length, dispersed in random directions and laminated in a uniform thickness, and processed into a cross shape or a net shape such as a chopped strand mat to be used as a composite.

When forming the above-mentioned sheet-shaped, tape-shaped, or string-shaped fiber composite, further shorter reinforcing fibers may be mixed therein. The reinforcing fibers used in this composite may be of the same type or of different types.

The state of the thermoplastic resin held by the reinforcing fibers in the sheet-shaped, tape-shaped or string-shaped fiber composite is such that the resin is sufficiently impregnated and held between the filaments of the continuous fiber. In order to improve the watertightness of the tubular body and the adhesiveness between the fiber and the resin, it is necessary to have such a holding state. It is preferable to perform a surface treatment in which a thermoplastic resin is already adhered or impregnated between the filaments in advance before the method for producing the filamentous fiber composite.

In the present invention, the thermoplastic resin retained by the reinforcing fibers is not particularly limited, and a suitable resin is selectively used depending on the purpose of use of the tubular body. Examples of the resin include polyvinyl chloride, chlorinated polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, and polyether / etherketone.

Further, as the thermoplastic resin used for the resin layer for fusing provided in advance in the portion where the sheet-shaped fiber composite and the tape-shaped or string-shaped fiber composite are laminated and fused, The thermoplastic resin retained by the reinforcing fibers may be the same type of resin, or may be another type of resin, but the resin used as the resin layer for fusing is naturally a resin It is preferable that the resin has excellent fusion-bonding property, and further resins of the same system are preferable.

Specific examples of the thermoplastic resin used include, in addition to the above, polyvinyl acetate and a copolymer of vinyl acetate and dibutyl phthalate or ethylene, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. And the like, and a polymer obtained by copolymerizing these with methacrylate, styrene, acrylonitrile, vinyl acetate and the like, if necessary, and polyesters, polyurethanes and the like.

The thermoplastic resin retained by the reinforcing fibers and the thermoplastic resin forming the resin layer for fusing can be used alone or in combination of plural kinds.

Further, the above thermoplastic resin may contain additives such as a heat stabilizer, a plasticizer, a lubricant, an antioxidant, an ultraviolet absorber and a pigment, or an inorganic filler, a processing aid and a modifier depending on the case. Agents, reinforcing fibers, etc. are added. Furthermore, it is optional to perform modification for improving the adhesion with other reinforcing fibers.

As a method for holding the thermoplastic resin in the continuous reinforcing fiber, all known methods can be adopted. For example, (1) the continuous reinforcing fiber is placed in a fluidized bed of powdered thermoplastic resin. A method of passing the powdery thermoplastic resin onto the fiber filament and then heating it to integrate the resin with the fiber, (2) passing continuous reinforcing fiber through the emulsion of the thermoplastic resin, and then heating Then, the fibers and the resin are integrated, or the fibers are passed through the emulsion and then dried, and then heated to a temperature higher than the melting temperature to integrate them. (3) In the case of a resin having a low melt viscosity A method of immersing the continuous reinforcing fibers in a bath filled with the molten resin, (4) a method of laminating a film-like thermoplastic resin on the continuous reinforcing fibers, and heating and pressing the same are adopted.

The amount of fibers in the composite is 5 to 70% by volume. If the amount is less than 5% by volume, a sufficient reinforcing effect cannot be obtained, and if it exceeds 70% by volume, fusion bonding is difficult. .. or,
In the present invention, as described above, in the sheet-shaped fiber composite, and in the tape-shaped or string-shaped fiber composite, it is necessary to previously provide a resin layer for fusing to a portion where each is laminated, As a method, (1) a method of laminating a film made of a thermoplastic resin having a predetermined thickness at a predetermined position of these composites, (2) a powdery thermoplastic resin at a predetermined position of the composite being transferred. And the like, followed by heating and fusion bonding, and (3) a method of applying a thermoplastic resin emulsion or an organic solvent solution in advance to a predetermined portion of these composites, and then drying.

The thickness of the resin layer for fusing is preferably not less than the diameter of one filament of the reinforcing fiber in the composite, and specifically, the thickness is about 3 to 5 times the diameter. Is preferred.

The width of the sheet-shaped fiber composite is preferably substantially the same as or longer than the outer peripheral length of the mandrel used. In the former case, both ends of one sheet-shaped fiber composite body are abutted against each other, and in the latter case, both edges are overlapped and shaped into a tubular body. Alternatively, a plurality of sheet-shaped fiber composites having a width less than the outer peripheral length of the mandrel may be used, and the mandrel may be densely surrounded and shaped into a tubular body.

The mandrel has a circular cross section in most cases, but may have a square shape with large R at four corners. In this case, the tubular body obtained from the sheet-shaped fiber composite is a so-called square pipe. It is called.

The thickness of the sheet-shaped fiber composite is generally 0.
It is 1 to 10 mm, and particularly preferably 0.5 to 5 mm.
If it is less than 0.1 mm, the strength is insufficient to shape it into a tubular body while advancing on the mandrel.
When it exceeds, it becomes difficult to shape it into a tubular body.

In the case of a tape-shaped fiber composite, the width is usually 1
0 to 100 mm and a thickness of 0.1 to 10 mm, and in the case of a string-like fiber composite, the diameter is 0.1 to 10 mm.
Used. If the thickness and the diameter are less than 0.1 mm, the reinforcing effect is not sufficient, and if the thickness and the diameter are more than 10 mm, the winding becomes difficult.

The tape-shaped or string-shaped fiber composite to be wound may be one or plural. In the case of a plurality of windings, they may all be wound in the same direction, may be wound at different winding angles, or may be wound in different directions.

In order to fuse the tape-shaped or string-shaped fiber composite to the outer periphery of the tubular body, one or a plurality of the fiber-shaped composites may be wound while being heated, or after being wound, this may be heated together with the tubular body so that both of The thermoplastics are fused together.

[0029]

The present invention supplies a sheet-shaped fiber composite in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction from the supporting end side of a mandrel having one end supported and having a substantially circular cross section. Then, a tubular body is formed by closely enclosing the mandrel while advancing on the mandrel, and while advancing this tubular body along the mandrel as it is, on its outer periphery, continuous reinforcing fibers arranged in the longitudinal direction are made of thermoplastic resin. Since at least one of the tape-shaped or string-shaped fiber composites in which the fibers are held is spirally wound and laminated on the tubular body to be fused, the tubular body is formed without being restricted by the length of the mandrel. And there is no need to remove the mandrel after molding.

The present invention also provides the above-mentioned sheet-shaped fiber composite,
When laminating a tape-shaped or string-shaped fiber composite,
Each of the parts to be laminated and fused is provided with a resin layer for fusion which is made of a thermoplastic resin in advance, so that heat fusion is performed. Therefore, at the time of lamination, a force such as a winding tension in a heated state is applied. Even if the work occurs, the reinforcing fiber does not rise to the surface of the composite.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. First, an apparatus used for carrying out the present invention will be described. In the following description, the term "front" means the right direction in each drawing. Example 1 A manufacturing apparatus for a fiber-reinforced thermoplastic resin tube shown in FIGS. 1 to 3 is a rewinding roll 1 around which a sheet-shaped fiber composite A1 is wound, and a rewinding roll 1 disposed in front of the rewinding roll 1 and having a front end facing forward. A mandrel 2 having a circular cross section (outer diameter of 48 mm) that is bent at a right angle and extends in the unwinding direction of the sheet-shaped fiber composite A1, a heating means 3 disposed on one side of the rear part of the mandrel 2, and the front thereof. And a pair of drum-shaped shaping rolls 4 sandwiching the mandrel 2 from both sides, and a first winding machine 5 for winding two tape-shaped fiber composites B and C, which are arranged in front of and behind them, respectively. A second winding machine 6;
The first heating means 7 and the second heating means 8 are arranged on one side of both winding positions, and the take-up machine 10 is arranged in front of the second winding machine 6.

Between the mandrel 2 and the pair of drum-shaped shaping rolls 4, a gap corresponding to the thickness of the tubular body A2 to be molded is provided. The end of the mandrel 2 on the side of the rewinding roll 1 is supported and fixed by a support (not shown), and the other end extends slightly to the front of the second winding machine 6.

The above three fiber composites A1, B and C are manufactured using the fluidized bed apparatus 11 shown in FIG. The bottom of the fluidized bed apparatus 11 is formed by a perforated plate 12, and a gas G such as air or nitrogen sent from a gas supply path is passed from below the perforated plate 12 through a large number of these holes to the upper side. Is made to squirt. As a result, the powdery thermoplastic resin put in the tank of the fluidized bed apparatus 11 is brought into a fluidized state by the jetted gas, and the fluidized bed R is formed. A guide roll 13 for guiding the continuous reinforcing fibers is provided inside the tank of the fluidized bed apparatus 11 and at the upper ends of the front and rear walls thereof.

Using the fluidized bed apparatus 11, twelve bundles of continuous reinforcing fibers F1 composed of a large number of continuous filaments are unwound from a rewinding roll 14 and rewound by a winding roll 15 while preventing twisting, and powdered. The powdery thermoplastic resin is attached to each filament of the bundle-like reinforcing fiber F1 by passing through the fluidized bed R of the thermoplastic resin. As the powdery thermoplastic resin, a chlorinated vinyl chloride resin (average degree of polymerization = 700, degree of chlorination = 64% by weight, average particle size = 200
μm) was used. As the reinforcing fiber, a roving glass fiber (4400
tex) was used.

Further, a stretched film of chlorinated vinyl chloride resin from the rewinding roll 19 (average degree of polymerization = 700, degree of chlorination = 64% by weight, film thickness) above the powdery thermoplastic resin adhesion-reinforced fiber F2. = 75 μm), and guide the powdery thermoplastic resin adhesion-reinforced fiber F2 from above to overlap it, and a pair of heating rolls 16 heated to 230 ° C. and a pinch roll 17 arranged next to the heating rolls 16.
And the powdered thermoplastic resin to soften or melt the stretched film of the chlorinated vinyl chloride resin so that it is laminated and integrated with the reinforcing fiber F2, and thus fused. A resin layer was formed, and a sheet-like fiber composite body F3 having a thickness of 1 mm was manufactured. The fiber content of this F3 was 45% by volume.

Next, the sheet-like fiber composite body F3 is cut to obtain a sheet-like fiber composite body A having a width of 151 mm and a thickness of 1 mm.
1 to obtain a tape-shaped fiber composite C having a width of 30 mm and a thickness of 1 mm. These sheet-shaped and tape-shaped fiber composites A
Each of Nos. 1 and C was obtained by laminating on one surface a resin layer for fusing made of a stretched film of chlorinated vinyl chloride resin. For the tape-shaped fiber composite B, a similar manufacturing method is used, that is, rewinding rolls 19 are provided on the upper and lower sides in FIG. A stretched film of a chlorinated vinyl chloride resin was fed out and laminated to obtain a laminate in which a resin layer for fusion bonding made of a stretched film of a chlorinated vinyl chloride resin was laminated on both sides.

The sheet-like fiber composite A1 in which the thermoplastic resin is held by the continuous reinforcing fibers produced as described above and arranged in the longitudinal direction is rewound to the unwinding roll 1 shown in FIG.
While feeding it back to the mandrel 2 while avoiding the supporting part from the supporting end side while heating it by the far-infrared heater which is the heating means 3 while rewinding it, both edges of the mandrel 2 are moved forward. The mandrel 2 is tightly surrounded by the shaping roll 4 in an abutted state, and the outer diameter is 50 m.
A tubular body A2 of m is formed.

At this time, as a matter of course, it is necessary to take care so that the resin layer for fusing is located outside. Next, while advancing the tubular body A2 as it is, the tape-shaped fiber composite body B is spirally wound around the outer periphery of the tubular body A2 by the first winding machine 5 at an angle of about 79 ° with respect to the axial direction. Two-layer pipe A3 having an outer diameter of 52 mm is produced by blowing hot air from a hot air generator 7 which is a heating means to heat and fuse the surfaces of the tubular body A2 and the tape-shaped fiber composite B on which they are laminated.
Got

Further, while advancing the two-layer pipe A3 as it is, the tape-shaped fiber composite C is applied to the outer periphery of the two-layer pipe A3 by the second winding machine 6.
Is also spirally wound with the resin layer for fusing positioned inside at an angle of about 80 ° in the direction opposite to the tape-shaped fiber composite B with respect to the axial direction, and the second heating means Hot air is blown from the hot air generator No. 8 to heat the two-layer tube A3 and the tape-shaped fiber composite C on the surface side where they are laminated to fuse them together to form a three-layer tube A4 having an outer diameter of 54 mm. Got

Subsequently, while advancing the three-layer pipe A4, the three-layer pipe A4 is cooled in a water tank 9 which is a cooling means, and then is taken up by a take-up machine 10 to form three continuous fiber-reinforced layers a, b and b as shown in FIG. A fiber-reinforced thermoplastic resin tube D having an inner diameter of 48 mm and an outer diameter of 54 mm made of c was continuously manufactured. The mandrel 2 used in this embodiment may be capable of heating and controlling the temperature of the entire mandrel in order to facilitate the take-up of the composite pipe. Example 2 Only the following points are different from Example 1, and the other steps are the same as those in Example 1, and the two continuous fiber reinforced layers d as shown in FIG. A fiber-reinforced thermoplastic resin pipe E having a diameter of 56 mm was manufactured. ． As a powdery thermoplastic resin, a powdery product obtained by freeze-grinding a pelletized polypropylene resin (average particle size 250 μ
m) was used. ． As the reinforcing fibers F1, 26 pieces of the same roving glass fibers as in Example 1 were used. ． The sheet-shaped fiber composite F3 was manufactured by the apparatus shown in FIG. That is, in this apparatus, a powdery thermoplastic resin supply device 21 is provided at the place of exiting the fluidized bed device 11, and the powdery thermoplastic resin adhesion strengthening obtained at the stage of exiting the fluidized bed device 11 is enhanced. After the powdery polypropylene is applied to the upper surface of the fiber F2 by the powdery thermoplastic resin supply device 21, the heating roll 16 and the pinch roll 1 are applied.
7 to heat and pressurize the polypropylene to melt it and integrate it with the reinforcing fiber to form a sheet-like fiber composite F3 having a thickness of 2 mm and a fiber content of 50% by volume. ． The sheet-shaped fiber composite F3 is cut to have a width of 151 m.
m, a sheet-like fiber composite A1 having a thickness of 2 mm and a width of 40 m
A tape-shaped fiber composite C having a thickness of m and a thickness of 2 mm was prepared. ． The outer diameter of the tubular body A2 was 52 mm. At this time, the powdery polypropylene was placed so that the resin layer for fusing formed by laminating and laminating was on the outside. ． The resin layer for fusing of the tape-shaped fiber composite C was wound while being heated by the heating means 7 so as to come into contact with the tubular body A2, and melted and integrated to obtain a two-layer tube A3. At this time, the winding angle was 76 °, and the outer diameter of the two-layer pipe was 56 mm. ． Without using the second winding machine 6 and the second heating means 8, 2
It was cooled by the cooling means 9 while advancing the layer tube.

[0041]

INDUSTRIAL APPLICABILITY The present invention is a sheet-shaped fiber composite in which a thermoplastic resin is held by continuous reinforcing fibers arranged in a longitudinal direction from the supporting end side of a mandrel having one end supported and having a substantially circular cross section. To form a tubular body by closely enclosing the mandrel while advancing on the mandrel, and while advancing this tubular body along the mandrel as it is, heat is applied to the continuous reinforcing fibers arranged in the longitudinal direction on its outer periphery. Since a tape-shaped or string-shaped fiber composite, in which a plastic resin is held, is wound in a spiral shape and laminated on a tubular body and then fused, it is possible to form the tubular body without being restricted by the length of the mandrel. And there is no need to remove the mandrel after molding.

The present invention also provides the above-mentioned sheet-shaped fiber composite,
As the tape-shaped or string-shaped fiber composite, the one in which a fusion-bonding resin layer made of a thermoplastic resin is provided in advance in the respective laminated portions is used, so that it is in a heated state during lamination. Even if the force such as the tension of the winding works,
Reinforcing fibers do not stand out on the surface of the composite.

Therefore, according to the present invention, the manufacturing process is simplified, the workability is improved, and the product having excellent quality can be efficiently manufactured. Moreover, since a long product can be formed, the range of applications is expanded.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an apparatus for producing a fiber-reinforced thermoplastic resin tube used for carrying out the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG. 1 and viewed in the direction of the arrow.

FIG. 3 is a sectional view taken along line III-III in FIG. 1 and viewed in the direction of the arrow.

FIG. 4 is a vertical cross-sectional view showing an example of an apparatus for producing a sheet-shaped fiber composite body F3 including a fluidized bed apparatus.

FIG. 5 is a partially cutaway perspective view of a fiber reinforced thermoplastic resin tube obtained according to Example 1 of the present invention.

FIG. 6 is a partially cutaway perspective view of a fiber reinforced thermoplastic resin tube obtained according to Example 2 of the present invention.

FIG. 7 is a vertical cross-sectional view showing another example of an apparatus for producing a sheet-shaped fiber composite F3 including a fluidized bed apparatus.

[Explanation of symbols]

 A1 Sheet-shaped fiber composite A2 Tubular body A3 Two-layer pipe A4 Three-layer pipe B Tape-shaped fiber composite C Tape-shaped fiber composite D Fiber-reinforced thermoplastic resin pipe E Fiber-reinforced thermoplastic resin pipe F1 Reinforced fiber F2 Powder Thermoplastic resin adhesion reinforced fiber F3 sheet fiber composite R fluidized bed 2 mandrel

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Claims (1)

Claim: What is claimed is: 1. A sheet-shaped fiber comprising a mandrel having a substantially circular cross-section, one end of which is supported, and a thermoplastic resin being held by continuous reinforcing fibers arranged in the longitudinal direction from the supporting end side. Supplying the complex and moving it on the mandrel to form a tubular body by closely enclosing the mandrel, and continuously strengthening the tubular body along the mandrel while continuously advancing along the mandrel and longitudinal reinforcement. A step of winding a tape-shaped or string-shaped fiber composite in which a thermoplastic resin is held on the fiber in a spiral shape, laminating the tape-shaped fiber composite to a tubular body, and fusing the sheet-shaped fiber composite and the tape-shaped or string The fiber-shaped composite is made of a fiber-reinforced thermoplastic resin pipe characterized in that a fusion-bonding resin layer made of a thermoplastic resin is provided in advance at the portions where they are laminated and fused. Method.