JP2000071341A - Pipe joint and pipe made of fiber reinforced plastic and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce an FRP pipe joint and an FRP pipe generating no porosity and excellent in cut-off properties. SOLUTION: A pipe joint and a pipe are produced by winding roving 3 impregnated with a thermosetting resin around the outer peripheral molding surface of a mold 2. Subsequently, a glass tricot tape 4 formed into a strip like fabric or knitted fabric is wound around the outer peripheral surface of the roving layer through the thermosetting resin developed on the surface of the roving 3 and the thermosetting resin is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber reinforced plastic pipe joint (hereinafter referred to as a pipe joint) manufactured by curing a reinforcing fiber wound on a mold with a thermosetting resin impregnated in the reinforcing fiber. The present invention relates to an FRP pipe joint, a fiber reinforced plastic pipe (hereinafter, simply referred to as an FRP pipe), and a method for producing them.

[0002]

2. Description of the Related Art Generally, there are known FRP pipe joints and FRP pipes formed by hardening a reinforcing fiber wound around an outer peripheral forming surface of a mold with a thermosetting resin impregnated in the reinforcing fiber. As the reinforcing fibers, those made of a long fiber material such as roving and those made of a tape-shaped fiber material made into a belt-like woven or knitted fabric are known. Among them, the long fiber material only holds the thermosetting resin between the strands constituting the roving, while the tape-shaped fiber material holds a large amount of the thermosetting resin in the weave or stitch. . Therefore, the proportion of the thermosetting resin in the portion where the tape-shaped fiber material is wound is greater than that in the portion where the long fiber material is wound.

[0003] Therefore, conventional FRP pipe joints and FRP
The pipe uses a tape-like fiber material with a high proportion of thermosetting resin for the innermost reinforcing fiber that comes into contact with the fluid, and with this abundant resin layer obtained, aims to improve the water stoppage, A long fiber material such as roving is used for the reinforcing fibers on the outer surface side to improve the strength.

[0004]

However, it is difficult for the tape-like fiber material to sufficiently impregnate the thermosetting resin in all the weaves and stitches. Therefore, even if the tube is not damaged, the fluid may easily seep out from a place where the amount of resin impregnation is small, and a so-called sweating action may occur. Also, even if the impregnation is sufficient, if the thermosetting resin is impregnated in advance and then wound around the outer peripheral molding surface of the mold, the thermosetting resin impregnated halfway through the winding Bleeds, creating voids in the weaves and stitches. As a result, there is an inconvenience that a cavity is easily formed in the FRP pipe joint and the FRP pipe due to a void.

[0005] Therefore, a thermoplastic resin is applied to the outer peripheral molding surface of the mold in advance to perform gel coating, and a tape-like fiber material is wound over the thermoplastic resin layer obtained by the gel coating. Although the gaps formed in the weaves and stitches of the tape-like fiber material are closed, the operation becomes cumbersome in this case.

In order to improve the above, it is common to increase the thickness of the pipe by increasing the number of layers of the pipe or increasing the number of turns of the fiber.
The weight of the tubing is increased, and the FRP tubing feature of being lightweight is lost.

[0007] Alternatively, the innermost surface of the tube is made of a material having excellent water resistance for the rigid polyvinyl chloride tube to reduce the sweating action. Two steps of molding are required, increasing costs.

Further, the above-mentioned conventional FRP pipe joint and FRP
When a tape-like fiber material is used for the innermost reinforcing fiber that comes into contact with the fluid, such as a pipe, the tape-like fiber material is wound around the outer peripheral molding surface of the mold. However, the outer peripheral molding surface of the mold is usually uneven due to an enlarged diameter portion and a reduced diameter portion. Therefore,
Even if it is attempted to wind the tape-like fiber material around such uneven portions, the tape-like fiber material is in a belt shape, so that it does not conform to the uneven shape of the outer peripheral molding surface of the mold. Will occur.

Therefore, in this case, it is necessary to carefully wind the tape-like fiber material by the hand lay-up method and while properly conforming to the uneven shape of the outer peripheral molding surface of the mold, which makes the operation cumbersome.

[0010] The present invention has been made in view of the above circumstances, and is an FRP having excellent water stopping properties without forming a nest.
An object of the present invention is to provide a pipe joint and an FRP pipe, and a method for efficiently manufacturing the FRP pipe joint and the FRP pipe.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a fiber-reinforced plastic pipe joint and a pipe according to the present invention comprise a thermosetting resin impregnated in a wound reinforcing fiber. A pipe joint and a pipe made of fiber reinforced plastic cured by the method described above, wherein a reinforcing fiber made of a long fiber material such as roving is wound on the innermost side of the pipe joint and the pipe, and the outside of the long fiber material Further, a reinforcing fiber made of a tape-like fiber material formed into a belt-like woven or knitted material is formed in a wound state. Further, a reinforcing fiber made of a long fiber material such as roving is wound on the outer side of the tape-like fiber material.

In order to solve the above-mentioned problems, a fiber-reinforced plastic pipe joint and a pipe according to the present invention are arranged such that a reinforcing fiber impregnated with a thermosetting resin is wound around an outer peripheral molding surface of a mold, and then thermoset. A method for manufacturing a fiber-reinforced plastic pipe joint and pipe formed by curing a thermosetting resin, the method comprising: forming a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin into a mold. Around the outer peripheral molding surface of the long fiber material, via a thermosetting resin exposed on the surface of the long fiber material, on the outer peripheral surface thereof, a reinforcing fiber composed of a tape-like fiber material made into a belt-like woven or knitted fabric is used. It is to be wound. Further, the tape-shaped fiber material is impregnated with a thermosetting resin in advance and wound. Further, a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is further wound around the outer peripheral surface of the tape-shaped fiber material.

Examples of the reinforcing fiber made of a long fiber material include glass roving and carbon fiber.

Examples of the reinforcing fiber made of a tape-like fiber material include a glass mat, a glass tape, a glass cloth, a tricot tape (glass fiber knit) and the like. The width of the tape-shaped fiber material is not particularly limited, but a width of about 50 to 250 mm is convenient because the tape is less likely to be twisted when the tape is wound by a machine.

As the thermosetting resin, a resin which is usually liquid and can be cured by the action of a curing agent, such as an unsaturated polyester resin or an epoxy resin, can be used. As a curing method, a method such as heat curing, room temperature curing, or light curing is adopted, and the type of the curing agent may be changed according to the curing method to be applied.

The long fiber material is impregnated with a thermosetting resin and then wound around the outer peripheral molding surface of a mold. At this time, the long fiber material is wound around the entire outer peripheral molding surface of the mold so as to replace the gel coat layer. In addition, the long fiber material is wound so as to fill at least the concave portions of the concave and convex portions of the outer peripheral molding surface of the outer peripheral molding surface of the mold, so that the tape-shaped fiber material can be wound on the outer peripheral molding surface in a smooth state. I do. The long fiber material is automatically delivered to the mold using a robot, etc., because the thermosetting resin is only held between the strands that make up the long fiber material and does not hold a large amount of the thermosetting resin. Even so, the impregnated thermosetting resin does not flow down during the delivery process. Therefore, when the long fiber material impregnated with the thermosetting resin is wound around the outer peripheral molding surface of the mold, the long fiber material is tightened, and the thermosetting resin impregnated in the long fiber material is exposed. As a result, the outer peripheral molding surface of the mold can be in a state as if gel coating was performed.

After the tape-shaped fiber material is impregnated with a thermosetting resin, the tape-shaped fiber material is wound around the outer surface of the long fiber material. Tape-like fiber materials can be impregnated with a large amount of thermosetting resin because of the weave and stitches,
When the impregnated thermosetting resin is automatically sent out to the mold using a robot or the like, the impregnated thermosetting resin flows down in the process of being sent out, and voids are formed in the weaves and stitches. However, since the thermosetting resin impregnated in the long fiber material is exposed from the long fiber material wound on the outer peripheral molding surface of the mold, the voids formed in the weaves and stitches of the tape-like fiber material are formed. Is
The thermosetting resin exposed from the long fiber material is impregnated. Therefore, the tape-shaped fiber material can be automatically sent out continuously to the long fiber material. Also,
When the tape-shaped fiber material is wound thinly, it is wound on the outer peripheral surface of the long fiber material without impregnating the thermosetting resin, and the thermosetting resin exposed from the long fiber material is directly tape-shaped. The voids formed in the weaves and stitches of the fiber material may be impregnated.

In the present invention, the smoothness of the inner surface is improved by winding a nonwoven fabric, glass paper, or the like having a low count in a mold or the like before winding a reinforcing fiber made of a long fiber material such as roving. Can be done. Further, a long fiber material impregnated with a thermosetting resin may be further wound around the outer peripheral surface of the wound tape-shaped fiber material in order to increase the strength of the tubular body. As the long fiber material used here, rovings, mats, cloths, sludges made of reinforcing fibers such as glass fibers or carbon fibers can be applied.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

[0020]

Example 1 100 parts by weight of unsaturated polyester resin
1 part by weight of a curing agent (1298-1 manufactured by Kayaku Akzo),
A thermosetting resin was prepared by mixing 20 parts by weight of a low-shrinking agent (Modiper manufactured by NOF Corporation).

Next, the reinforcing fiber impregnated with the above-mentioned thermosetting resin was wound around the outer peripheral surface of a mold, and a double-ended FRP pipe joint 1 having a diameter of 200 mm as shown in FIG. 1 was formed.
As shown in FIG. 2A, the mold 2 used was one in which a pair of silicone rubber rings 21 were fitted to each end in order to form a waterproof packing mounting portion (undercut portion). Further, the reinforcing fiber impregnated with the thermosetting resin is wound around the mold 1 by using an automatic winding device (not shown) in which a mold rotating device and a reinforcing fiber feeder are synchronized with each other. The fibers were made by self-winding the mold.

First, the automatic winding of the reinforcing fiber around the mold 2 is performed as follows.
As shown in FIG. 2 (b), the # 4450 roving 3 impregnated with the thermosetting resin was wound along the circumferential direction of the mold 1. However, the roving 3 is not wound around the outermost peripheral surface of each silicone rubber ring 21,
1 was wound so that the irregularities of the silicone rubber ring 21 were alleviated and the outer peripheral surface of the mold 2 was smoothly continued. The thickness of the roving layer 31 around which the roving 3 is wound is 1 m.
m.

Next, as shown in FIG. 2C, a glass tricot tape (glass fiber knit) 4 having a width of 120 mm impregnated with the above-mentioned thermosetting resin was placed on the above-mentioned roving layer 31.
And 20% of the entire width was wound while being overlapped on the surface. The thickness of the tape layer 41 around which the glass tricot tape 4 was wound was 1 mm.

Further, as shown in FIG. 2D, the roving 3 of # 4450 impregnated with the thermosetting resin was
It is wound around the surface of the tape layer 41 along the circumferential direction of the mold 2, and is further wound on the tape layer 41 with respect to the axial direction of the mold 2.
An oblique winding was performed at an angle of ° to form a reinforced layer 32 having the strength of the pipe joint. The thickness of the reinforcing layer 32 was 3 mm.

After winding the reinforcing fibers in this manner,
The thermosetting resin impregnated in these reinforcing fibers is cured and cured in an atmosphere at a temperature of 55 to 65 ° C. for several hours in a curing furnace, and the mold 2 and the silicone rubber ring 21 are removed from the pipe joint 1.
Was completed. Thereby, as shown in FIG. 2D, a three-layer structure of the roving layer 31, the tape layer 41, and the reinforcing layer 32 is formed in order from the inner peripheral surface side, and the pipe joint 1 in which these three layers are integrated is obtained. Can be

Thus, four pipe joints 1 were formed by the same forming method. As shown in FIG. 1, in each of the pipe joints 1, the shape (the shape of the silicone rubber ring) of the waterproof sealing mounting portion 11 inside the receptacle was completely formed. Further, for each pipe joint 1, the internal water pressure is set to 20.
The pressure was increased to kgf / cm2, but nothing leaked.

[0027]

Example 2 Isophthalic unsaturated polyester resin 1
1 part by weight of a curing agent (Kakuyaku Akzo 12
98-1) and 1 part by weight of a curing accelerator were mixed to prepare a liquid thermosetting resin.

Next, the reinforcing fiber impregnated with the liquid thermosetting resin was wound around the outer peripheral surface of a mold to form an FRP tube 5 having a diameter of 150 mm as shown in FIG. Also,
The reinforcing fiber is wound around the mold 6 shown in FIG. 4 (e) by using an automatic winding device (not shown) in which a mold rotating device and a reinforcing fiber sending device are synchronized with each other. The reinforcing fibers impregnated with the resin were automatically wound around a mold 6.

First, the automatic winding of the reinforcing fiber around the mold 6 is performed as follows.
As shown in FIG. 4F, the # 2200 roving 3 impregnated with the liquid thermosetting resin was wound along the circumferential direction of the mold 6. The thickness of the roving layer 31 around which the roving 3 was wound was 1.5 mm.

Next, as shown in FIG. 4 (g), a glass tricot tape (glass fiber knit) 4 having a width of 120 mm impregnated with the liquid thermosetting resin was applied to the surface of the roving layer 31 over the entire width thereof. Was wound while being overlapped. The thickness of the tape layer 41 around which the glass tricot tape 4 was wound was 2.0 mm.

Further, as shown in FIG. 4 (h), a glass roving drip 7 having a width of 120 mm impregnated with the liquid thermosetting resin is placed on the surface of the tape layer 41 in a mold 3.
, And from above, the oblique winding was performed at an angle of 60 ° with respect to the axial direction of the mold 3 to form a reinforcing layer 32 having the strength of the pipe joint. This reinforcement layer 3
2 had a thickness of 1.5 mm.

After winding the reinforcing fibers in this manner,
The thermosetting resin impregnated into these reinforcing fibers is cured by heating in a curing furnace in an atmosphere in the range of 55 to 65 ° C. for 30 minutes, and then left to cool outside the furnace, and the mold 3 is removed. To complete the forming of the tube 5. Thereby, as shown in FIG. 4H, a three-layer structure of the roving layer 31, the tape layer 41, and the reinforcing layer 32 is formed in order from the inner peripheral surface side, and the tube 5 in which these three layers are integrated is obtained. .

After the mold was released, jigs for water pressure test were attached to both ends of the tube, and the tube was filled with water and pressurized to perform a water pressure test. As a result, the internal water pressure was increased to 15 kgf / cm ² , but no sweating from the tube, damage to the tube, and water leakage were observed.

[0034]

Comparative Example 1 The roving layer 31 was formed by the roving 3 shown in FIG.
A pipe joint was formed in the same manner as in Example 1 except that the pipe joint was formed as described above.

Thus, four pipe joints were formed by the same forming method. As shown in FIG. 5, in each of the pipe joints 8, the shape (the shape made of the silicone rubber ring) of the waterproof sealing mounting portion 81 inside the receptacle was not completely formed. Further, for each pipe joint 5, the internal water pressure is set to 2
It was pressurized to 0 kgf / cm2, but three out of four leaked water.

[0036]

As described above, according to the present invention, a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is wound around an outer peripheral molding surface of a mold, and the length of the reinforcing fiber is reduced. Through the thermosetting resin exposed on the surface of the fibrous material, the reinforcing fiber composed of the tape-shaped fibrous material formed into a belt-like woven or knitted material is wound on the outer peripheral surface thereof. Even if the thermosetting resin is not impregnated, the thermosetting resin exposed on the surface of the long fiber material plays a role of a gel coat, and makes up for the shortage. Therefore, an FRP pipe joint and a FRP pipe without nests can be manufactured, and no sweating action occurs.

Further, after the long fiber material is wound around the outer peripheral molding surface of the mold, the tape-like fiber material is wound, so that the irregular shape of the outer peripheral molding surface of the mold is relaxed by the long fiber material. From which the tape-shaped fiber material can be wound.
Therefore, the tape-shaped fiber material does not need to be carefully wound in accordance with the irregular shape of the outer peripheral molding surface of the mold, and can be automatically wound on the outer peripheral molding surface of the mold by a robot or the like together with the long fiber material. it can. As a result, the FRP pipe joint and the FRP pipe can be efficiently manufactured by automatic winding of the long fiber material and the tape-shaped fiber material.

Further, the FRP pipe joint and the FRP pipe obtained in this manner are free from nests due to the tape-like fiber material on the innermost side which comes into contact with the fluid, and the pipe joint and the FRP pipe are FR with excellent water-blocking properties without the uneven shape of the inner peripheral surface of the tube receiving port causing molding failure
It becomes a P fitting and an FRP pipe.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fiber reinforced plastic pipe joint according to a first embodiment of the present invention.

FIGS. 2 (a) to 2 (d) are process diagrams showing a manufacturing process of a method for manufacturing a fiber reinforced plastic pipe joint according to the present invention.

FIG. 3 is a cross-sectional view of a fiber-reinforced plastic pipe according to a second embodiment of the present invention.

FIGS. 4 (e) to 4 (h) are process diagrams showing the production steps of the method for producing a fiber-reinforced plastic pipe according to the present invention.

5 is a sectional view of a fiber reinforced plastic pipe joint of Comparative Example 1. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 FRP pipe joint 2 Die 3 Roving (long fiber material) 4 Glass tricot tape (tape fiber material) 5 FRP pipe 6 Die 7 Glass roving drip

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 31:24

Claims (10)

[Claims] Claims: 1. A fiber-reinforced plastic pipe joint in which a wound reinforcing fiber is cured by a thermosetting resin impregnated in the reinforcing fiber, wherein the pipe joint and the pipe have the most inner surface. A reinforcing fiber made of a long fiber material such as roving is made into a wound state, and a reinforcing fiber made of a tape-shaped fiber material made into a belt-like woven or knitted material is formed outside the long fiber material in a wound state. A fiber reinforced plastic pipe joint characterized by being made. 2. The fiber-reinforced plastic pipe joint according to claim 1, wherein a reinforcing fiber made of a long-fiber material such as roving is wound further outside the tape-like fiber material. 3. A fiber-reinforced plastic pipe joint formed by winding a reinforcing fiber impregnated with a thermosetting resin around an outer peripheral molding surface of a mold and then curing the thermosetting resin. A method of manufacturing, wherein a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is wound around an outer peripheral molding surface of a mold, and a thermosetting material exposed on the surface of the long fiber material is formed. A method for producing a fiber-reinforced plastic pipe joint, comprising winding a reinforcing fiber made of a tape-like fiber material formed into a belt-like woven or knitted material on the outer peripheral surface of the pipe joint through a conductive resin. 4. The method according to claim 3, wherein the tape-like fiber material is impregnated with a thermosetting resin in advance and wound. 5. The fiber-reinforced plastic pipe joint according to claim 3, wherein a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is further wound around the outer peripheral surface of the tape-shaped fiber material. Manufacturing method. 6. A fiber reinforced plastic pipe obtained by curing a wound reinforcing fiber with a thermosetting resin impregnated in the reinforcing fiber, wherein a length of roving or the like is provided on the innermost side of the pipe. It is assumed that a reinforcing fiber made of a fiber material is made into a wound state, and a reinforcing fiber made of a tape-shaped fiber material made into a belt-like woven or knitted material is formed outside the long fiber material in a wound state. Characterized by fiber reinforced plastic tubes. 7. The fiber reinforced plastic tube according to claim 6, wherein a reinforcing fiber made of a long fiber material such as roving is wound outside the tape-like fiber material. 8. Production of a fiber-reinforced plastic tube formed by winding a reinforcing fiber impregnated with a thermosetting resin around an outer peripheral molding surface of a mold and then curing the thermosetting resin. A method in which a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is wound around an outer peripheral molding surface of a mold, and a thermosetting resin exposed on the surface of the long fiber material is formed. A method for producing a fiber-reinforced plastic tube, comprising winding a reinforcing fiber made of a tape-like fiber material formed into a belt-like woven or knitted material around the outer peripheral surface of the tube through a resin. 9. The method according to claim 8, wherein the tape-like fiber material is impregnated with a thermosetting resin in advance and wound. 10. The fiber reinforced plastic tube according to claim 8, wherein a reinforcing fiber made of a long fiber material such as a roving impregnated with a thermosetting resin is further wound around the outer peripheral surface of the tape-shaped fiber material. Production method.