JPH074877B2 - Method for manufacturing fiber-reinforced resin pipe - Google Patents

Description

The present invention relates to a method for manufacturing a fiber-reinforced resin pipe.

[Conventional technology]

Synthetic resin pipes have been used more widely than before because they have the excellent properties of being lighter in weight and less rusting than metal pipes. However, the synthetic resin pipe is inferior to the metal pipe in pressure resistance and impact resistance. Therefore, in order to solve this problem, there has been proposed a composite pipe in which a thermosetting resin reinforced layer in which continuous reinforcing fibers are arranged in the longitudinal direction of the pipe and the substantially circumferential direction of the pipe is formed on the outer surface of the thermoplastic resin pipe. (See Japanese Patent Publication No. 62-773 and Japanese Patent Publication No. 62-22038).

The above-mentioned composite pipe is not only excellent in pressure resistance and impact resistance, but since the continuous reinforcing fibers are arranged in the longitudinal direction of the pipe, the thermal expansion and contraction of the pipe is small, and the trouble due to the thermal expansion and contraction of the pipe in the piping line. Has the advantage that

Further, as another method for producing a composite pipe, a method has been proposed in which a thermoplastic resin is used for the continuous fiber reinforced layer and the thermoplastic resin layer is extruded and formed on both inner and outer surfaces thereof.

[Problems to be Solved by the Invention]

A composite pipe using a thermoplastic resin for the reinforcement layer has a weak adhesion to the thermoplastic resin layer of the inner layer, and when the composite pipe is used with hot water or at high temperature, the thermoplastic resin layer and the reinforcement layer have their linear expansion. There is a problem that peeling easily occurs at the interface between the thermoplastic resin layer and the reinforcing layer due to the difference in the ratio.

In addition, the composite pipe using the thermoplastic resin for the reinforcing layer includes the extrusion step twice because the thermoplastic resin layer is formed inside and outside the reinforcing layer in the manufacturing process, which complicates the manufacturing of the composite pipe. At the same time, the manufacturing equipment was complicated.

An object of the present invention is to provide a manufacturing method capable of easily and continuously obtaining a fiber-reinforced resin pipe which is excellent in pressure resistance and impact resistance and has no problem even when flowing hot water or used at high temperature. To do.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the method for producing a fiber-reinforced resin pipe according to the present invention comprises a fiber-reinforced composite layer for a first reinforcing layer in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction, and the same. From a sheet consisting of a thermoplastic resin layer formed on one surface, a thermoplastic resin layer is formed into a tubular shape with the thermoplastic resin layer inside, and the thermoplastic resin inner layer and reinforcing fibers on the outside are first reinforced Forming a two-layer tube having two layers, and
A second fiber-reinforced composite layer for reinforcing layers, in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction on the outer periphery of the layer tube while advancing as it is, and a thermoplastic resin layer formed on one side thereof. A tape made of is wound spirally with the outer layer of the thermoplastic resin on the outside, and the fiber composite is fused to the first reinforcing layer, and the reinforcing fibers are arranged on the outer surface of the first reinforcing layer in a substantially circumferential direction. And a step of forming a four-layer tube by forming a second reinforcing layer and a thermoplastic resin outer layer outside the second reinforcing layer.

As the reinforcing fibers used in the first and second reinforcing layers,
All of the continuous fibers that can be used for reinforcing thermoplastics are used. Specifically, glass fiber, carbon fiber,
Examples thereof include inorganic fibers such as silicon / titanium / carbon fibers, boron fibers and fine metal fibers, and organic fibers such as aramid fibers, vinylon fibers, econol fibers, polyester fibers and polyamide fibers.

As the continuous reinforcing fiber, a roving-like or strand-like one made of continuous filaments having a diameter of 1 to several tens of μm is used. The reinforcing fiber for the first reinforcing layer and the reinforcing fiber for the second reinforcing layer may be of the same type or different types.

Further, the continuous reinforcing fibers are arranged in the longitudinal direction in both the fiber composite layers, but in addition to this, in the case of the fiber composite layer for the first reinforcing layer, the continuous reinforcing fibers are orthogonal or intersect with the continuous reinforcing fibers arranged in the longitudinal direction. The continuous reinforcing fibers or the fibers having a finite length may be arranged, or a cloth-shaped fiber material or a net-shaped fiber material having a finite length may be arranged. In the case of the fiber composite layer for the second reinforcing layer, in addition to the continuous reinforcing fibers arranged in the longitudinal direction, fibers having a finite length similar to the above may be included.

The thermoplastic resin used for each layer is not particularly limited, and one suitable for the purpose of use of the pipe can be adopted,
Specifically, polyvinyl chloride, chlorinated polyvinyl chloride,
Examples thereof include polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, and polyether ether ketone. These thermoplastic resins may be used alone or as a mixture of a plurality of types depending on the purpose of use of the tube. The thermoplastic resin is mixed with a heat stabilizer, a plasticizer, a lubricant, an antioxidant, an ultraviolet absorber, a pigment, an additive such as a reinforcing fiber, an inorganic filler, a processing aid, and a modifier. May be.

The thermoplastic resin for the first and second reinforcing layers is not particularly required to be the same as the thermoplastic resin for the inner and outer layers, and may be any thermoplastic resin having a good fusion property.

The thickness of the first and second reinforcing layer fiber composite layers is 0.1 to 4 mm.
And particularly preferably 0.5 to 2 mm. If it is less than 0.1, the reinforcing effect is not sufficient, and if it exceeds 4 mm, it becomes difficult to mold the tube. The thickness of the thermoplastic resin layer formed on one side of each of the fiber composite layers is also 0.1 to 4 mm, of which 0.5
~ 2mm is desirable.

The amount of fibers in both fiber composite layers is 5 to 70% by volume. 5
If it is less than volume%, a sufficient reinforcing effect cannot be obtained, and if it exceeds 70 volume%, the cohesive force of the fiber itself is small, and a sufficiently strong reinforcing layer in which the resin is fused cannot be obtained.

[Action]

The method for producing a fiber-reinforced resin pipe according to the present invention comprises a sheet-shaped fiber composite layer for a first reinforcing layer in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction, and a heat formed on one surface thereof. A two-layer tube formed from a sheet comprising a thermoplastic resin layer into a tubular shape with the thermoplastic resin layer inside and a thermoplastic resin layer and a first reinforcing layer in which reinforcing fibers on the outside are arranged in the axial direction. The two-layer pipe was formed on one side of the fiber composite layer for the second reinforcing layer, in which the thermoplastic resin is held by the continuous reinforcing fibers arranged in the longitudinal direction, while advancing the two-layer pipe as it is. A tape composed of a thermoplastic resin layer is wound in a spiral shape with the thermoplastic resin layer on the outside, and the fiber composite is fused to the first reinforcing layer, and the reinforcing fiber is substantially surrounded on the outer surface of the first reinforcing layer. Direction reinforcing second reinforcement layer and its outer thermoplastic Since those formed with the 4 Sokan by forming the resin layer, a thermoplastic resin is fused integrally in the boundary between the first reinforcing layer and the second reinforcing layer.

〔Example〕

First, an apparatus used in an embodiment of the present invention will be described with reference to the drawings. In the following description, the term "front" means the rightward direction in FIG.

Example 1 A fiber-reinforced resin pipe manufacturing apparatus shown in FIGS. 1 to 3 has a first reinforcing layer fiber composite layer (A1) in which a thermoplastic resin is held by continuous reinforcing fibers arranged in a longitudinal direction. ) And a thermoplastic resin layer (B1) formed on one surface of the rewinding roll (1) around which a sheet (a) is wound, and a front end of the rewinding roll (1) is bent forward at a right angle. An inner die (2) that is bent and extends in the unwinding direction of the sheet (a), has a circular cross section, a heating means (3) arranged on one side of the rear portion of the inner die (2), and an inner die. A pair of drum-shaped shaping rolls (4) sandwiching the mold (2) from both sides, and a shaping roll (4)
Second reinforcing fiber composite layer (C1) in which a thermoplastic resin is held by continuous reinforcing fibers arranged in front of and in the longitudinal direction and a thermoplastic resin formed on one side thereof A winding machine (5) for winding a tape (C) comprising a layer (D1), a heating means (6) arranged on one side of the winding position, and a heating means (6) arranged in front of the heating means (6). And an outer mold (7) concentric with the inner mold (2), a cooling device (9) arranged in front of the outer mold (7), and arranged in front of the cooling device (9). It is equipped with a take-up machine (10).

Between the inner mold (2) and the pair of drum-shaped shaping rolls (4), there is a gap corresponding to the thickness of the tubular body (b) to be molded. The inner mold (2) extends slightly to the front of the outer mold (7), and the inner mold (2) and the outer mold (7) have the same thickness as the four-layer pipe (d) to be molded. The gap is provided.

Each of the fiber composites of the sheet (a) and the tape (c) is
It is 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 gas (G) such as air or nitrogen sent from the gas supply passage is introduced from below the perforated plate (12). It is ejected upward through a large number of holes. As a result, the powdery thermoplastic resin put in the tank of the fluidized bed apparatus (11) is fluidized by the jet gas (G) to form the fluidized bed (R). A guide roll (13) for guiding the bundled reinforcing fibers is provided in the tank of the fluidized bed apparatus (11) and at the upper ends of the front and rear walls thereof.

Using the above fluidized bed apparatus (11), a bundle reinforcing fiber (F1) 12 composed of a large number of continuous filaments from a rewinding roll (14) 12
The book is rewound by the take-up roll (15) while preventing twisting, and a fluidized bed (R) of powdery thermoplastic resin is obtained.
The powdery resin is attached to each filament of the bundle-like reinforcing fiber (F1) by passing through the inside. As the powdery thermoplastic resin, chlorinated polyvinyl chloride (polymerization degree about 530, chlorination degree about 6
7% polymerized, average particle size 250 μm), and roving glass fiber (4400 tex) composed of filaments 23 μm in diameter was used as the reinforcing fiber.

Powdered thermoplastic resin adhesion-reinforced fiber (F2) is passed through a pair of heating rolls (16) heated to 23 ° C to heat and pressurize to melt the thermoplastic resin and integrate it with the reinforcing fiber. A sheet-shaped fiber composite (F3) having a thickness of 1 mm is obtained, and a 0.7 mm-thick thermoplastic resin sheet (S) rewound from the rewinding roll (17) is guided by a guide roll (18). Then, the sheets are laminated and passed through a pair of heating rolls (19) heated to 230 ° C to heat and pressurize to melt the thermoplastic resin to obtain a sheet (X) in which the two are integrated, and the sheet is wound. It was wound into a roll (15). As the thermoplastic resin for the sheet (S), chlorinated polyvinyl chloride (average degree of polymerization: 700,
The chlorination degree was 68% by weight).

A sheet (a) having a width of 107 mm and a thickness of 1.7 mm in which continuous reinforcing fibers are arranged in the longitudinal direction is obtained by cutting the sheet (X), and a width of 28 mm and a thickness of 1.7 mm in which continuous reinforcing fibers are arranged in the longitudinal direction. The tapes (C) of The thickness of each fiber composite layer (A1) (C1) of the sheet (a) and the tape (c) was 1 mm, and the thickness of each thermoplastic resin layer (B1) (D1) was 0.7 mm.

The sheet (a) manufactured as described above is transferred to the rewinding roll (1) shown in FIG. 1, and while being rewound, hot air is blown and heated by a hot air generator which is a heating means (3),
Next, the thermoplastic resin layer (B1) is placed inside, but the edges of the sheet (a) are butted, and the tubular shape is continuously formed by the shaping roll (4) and the inner mold (2) heated to 190 ° C. To form a two-layer pipe (b) having an outer diameter of 35 mm and having a thermoplastic resin inner layer (B2) and a first reinforcing layer (A2) in which reinforcing fibers on the outer side are arranged in the axial direction.

While advancing the two-layer pipe (b) as it is, the tape (c) is wound around the outer periphery of the thermoplastic resin layer (D1) by the winding machine (5), and the spiral shape is formed at an angle of 75 ° to the axial direction. The two-layer tube (b) and the tape (c) are heated by the infrared heater which is the heating means (6) while the fiber composite layer (C1) of the latter is fused to the first reinforcing layer (A2). After wearing, it is allowed to pass through the gap between the outer mold (7) and the inner mold (2) heated to 220 ° C., and then the cooling device (9) is sized to give the first reinforcing layer ( By forming a second reinforcing layer (C2) in which reinforcing fibers are arranged in a substantially circumferential direction on the outer surface of A2) and a thermoplastic resin outer layer (D2) outside thereof, 4
Formed as a layer tube (d). The above series of steps was carried out while being taken by a take-up machine (10) to continuously produce a fiber reinforced resin pipe having an inner diameter of 31.6 mm and an outer diameter of 38.4 mm made of a four-layer pipe (d) as shown in FIG.

In addition, the inner mold (2) is a shaping roll (4) and a winder (5).
Since it extends to the outer mold (7), deformation of the pipe during molding can be prevented and sizing can be facilitated. A water tank is generally used as the cooling device (9), but the cooling device (9) is not limited to this.

Example 2 A fiber reinforced resin pipe having an inner diameter of 45 mm and an outer diameter of 55 mm was manufactured through the same steps as in Example 1 except for the following differences from Example 1.

An ethylene-vinyl-acetate copolymer was used as the powdery thermoplastic resin, and the temperature of the heating roll (16) was set to 150 ° C. The thickness of the thermoplastic resin sheet (S) is 1.2 mm.
The temperature of the heating roll (19) is 150
℃ was made.

The width of the sheet (a) is 150 mm, the thickness is 2.5 mm, and the width of the tape is
40 mm, thickness 2.5 mm, thickness of each fiber composite layer (A1) (C1) 1.5 mm, thickness of each thermoplastic resin layer (B1) (D1) 1.0
mm.

The temperature of the inner mold (2) is 140 ℃, the outer diameter of the two-layer pipe (b) is 50 m
The temperature of the outer mold (7) was 160 ° C.

〔The invention's effect〕

According to the present invention, it is possible to easily and continuously obtain a fiber-reinforced resin tube in which thermoplastic resins are fusion-bonded and integrated at each boundary between the first reinforcing layer and the second reinforcing layer.

And, in the first reinforced layer of the obtained fiber reinforced resin pipe, continuous reinforced fibers are arranged in the axial direction of the pipe, so that the linear expansion of the pipe is suppressed, and as a result, the amount of heat shrinkage is reduced and each layer is reduced. It becomes difficult for peeling to occur at the interface. Further, since the continuous reinforcing fibers are arranged in the second reinforcing layer in the substantially circumferential direction of the pipe,
The second reinforcing layer improves the pressure resistance and impact resistance of the tube.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a fiber reinforced resin pipe manufacturing apparatus used for carrying out the present invention, and FIGS. 2 and 3 are sectional views taken along lines II-II and III-III of FIG. 1, respectively. Figure, 4th
FIG. 5 is a vertical sectional view of a fluidized bed apparatus, and FIG. 5 is a partial perspective view of a fiber reinforced resin pipe obtained by the present invention, in which an outer layer, a second reinforced layer and a first reinforced layer are partially cut out in order. (A) ... sheet, (b) ... two-layer pipe, (c) ... tape,
(D) ... 4-layer tube, (A1) ... Fiber composite layer for first reinforcing layer,
(A2) ... first reinforcing layer, (B1) (D1) ... thermoplastic resin layer,
(B2) ... inner layer of thermoplastic resin, (C1) ... fiber composite layer for second reinforcing layer, (C2) ... second reinforcing layer, (D2) ... outer layer of thermoplastic resin.

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Claims (1)

[Claims] 1. A) A first fiber-reinforced composite layer for reinforcing layer (A1) in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction, and a thermoplastic resin layer (1) formed on one side thereof. B1)
A first reinforcing layer in which a thermoplastic resin inner layer (B2) and reinforcing fibers on the outer side thereof are axially arranged from a sheet (a) consisting of (A2)
And a step of forming a two-layer pipe (b) having b), while advancing the two-layer pipe (b) as it is, on the outer periphery thereof,
A tape comprising a second fiber-reinforced composite layer for reinforcing layer (C1) in which a thermoplastic resin is held by continuous reinforcing fibers arranged in the longitudinal direction, and a thermoplastic resin layer (D1) formed on one side thereof ( C) is spirally wound with the thermoplastic resin layer (D1) on the outside, and the fiber composite (C1) is fused to the first reinforcing layer (A2) to form an outer surface of the first reinforcing layer (A2). A fiber-reinforced resin pipe including a step of forming a second reinforcement layer (C2) in which reinforcement fibers are arranged substantially in the circumferential direction and a thermoplastic resin outer layer (D2) outside the second reinforcement layer (C2) to form a four-layer pipe (d). Manufacturing method.