JPH07178825A - Manufacture of composite resin pipe - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a composite resin pipe in which sufficient adhesive strength is secured in the time for joining even if sanding is not performed. CONSTITUTION:An unhardened FRP layer 3' is laminated on the external circumferential face of a core 2 constituted of a synthetic resin joint. A water-soluble resin layer 4 mixed with granular material such as fine sand or powdery material is laminated on the surface of the FRP layer 3'. Then the surface of the water-soluble resin layer 4 is covered with a film 5 and the FRP layer 3' is hardened in a tightened state. Thereafter the film 5 is peeled off and the water- soluble resin existing on the surface side of the FRP layer 3 after hardening is washed away by water. Thereby a composite resin pipe 1 is obtained in which many fine unevennesses are formed on the surface of the FRP layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for a resin composite pipe used for transporting various chemicals, fluids for chemical industry, hot water, hot spring water and the like.

[0002]

2. Description of the Related Art A resin composite pipe is disclosed, for example, in Japanese Patent Publication No. 5-439.
As disclosed in Japanese Patent Publication No. 17, the outer peripheral surface of a thermoplastic resin tube made of a hard vinyl chloride resin or the like is coated with an FRP layer (fiber reinforced resin layer containing a reinforcing material such as glass fiber) for reinforcement. Since it is superior in thermal properties and mechanical properties to a mere synthetic resin pipe, it is used for transportation of various chemical solutions and fluids for chemical industry.

As a method of manufacturing such a resin composite pipe,
Conventionally, for example, a filament winding method (FW method) and a hand layup method are known. The former is formed by impregnating a roving of glass fiber with a curable resin and then winding the roving around the outer peripheral surface of the synthetic resin pipe, and the latter is formed by impregnating the glass fiber with a curable resin. It is formed by stacking on the outer peripheral surface.

[0004]

By the way, in the resin composite pipe manufactured by the conventional method as described above, the surface of the FRP layer constituting the outer layer thereof is smooth. for that reason,
When joining other pipes or joints to reinforce the joints, it is necessary to secure adhesive strength, so a sanding process that preliminarily roughens the outer surface of the joints to be connected to the pipes etc. Although it is necessary to perform it, since the sanding step is to scrape the FRP layer, there is a problem in view of environmental hygiene that a large amount of glass powder is generated accordingly.

The present invention solves such a problem, and an object of the present invention is to provide a method for producing a resin composite pipe which can secure a sufficient adhesive strength at the time of joining without sanding.

[0006]

In order to achieve the above object, a first invention (an invention according to claim 1) and a second invention (an invention according to claim 2) of the present application are a core made of a synthetic resin joint. The method for producing a joint for resin composite pipe in which the FRP layer is provided on the outer periphery of the material is characterized by being configured as follows.

That is, in the first invention of the present application, first, the uncured F is formed on the outer peripheral surface of the core made of a synthetic resin tube.
After laminating the RP layer, a water-soluble resin layer mixed with fine particles such as sand or powder is laminated on the surface side of the FRP layer. Next, the FRP layer in the uncured state is cured in a state where the surface of the water-soluble resin layer is covered with a film and tightened or pressed with a mold, and then the film or the mold is removed to remove the FRP layer surface. Rinse the water-soluble resin with water.

In the first aspect of the invention, the uncured FR
When a water-soluble resin layer is laminated on the surface side of the P layer, the FR
From the viewpoint of preventing the glass fibers (glass strands) from rising to the surface due to the shrinkage of the FRP layer constituent resin during curing of the P layer, a nonwoven fabric is laminated on the surface of the FRP layer before laminating the water-soluble resin. You may keep it.

Examples of the water-soluble resin include polyvinyl alcohol (PVA) and the like. Examples of granular or powdery substances to be mixed with such a water-soluble resin include fine sand, glass powder, metal powder, and PV.
Examples thereof include beads coated with a water-soluble resin such as A.

Further, examples of the resin forming the FRP layer include thermosetting resins such as polyester resin, phenol resin and epoxy resin, and hard vinyl chloride is used as the resin forming the synthetic resin joint as the core material. Examples include resins and thermoplastic resins such as polyethylene.

Further, examples of the method for forming the FRP layer include the hand layup method and the FW method. On the other hand, in the second invention of the present application, an endless rotation type tube outer peripheral surface pressing die having a large number of irregularities on the die surface is arranged at a predetermined position, and first, the outer peripheral surface of the core material made of a synthetic resin tube is uncured. Or, a semi-cured FRP layer is laminated to produce an intermediate product. Then, while feeding this intermediate product forward along the pressing die at a predetermined speed, the FR of the intermediate product
While pressing the pressing die against the surface of the P layer, while moving the pressing die together with the intermediate product by a certain distance in that state, FR
The P layer is cured or almost cured, and then the pressing die is released from the surface of the FRP layer to return to the initial pressing position.

The irregularities on the mold surface of the tube outer peripheral surface pressing mold may be provided continuously or discontinuously.

[0013]

According to the above-described method of the first invention of the present application, when the uncured FRP layer laminated on the outer peripheral surface of the core material is cured, an aqueous solution containing fine particles such as sand or powdery matter is mixed. Since the water-soluble resin layer is pressed against the surface side of the FRP layer by tightening the film or pressing the mold from the outside, the granular or powdery substance in the water-soluble resin layer adheres to the surface side of the FRP layer or You will cut into it. Therefore,
After the FRP layer is cured, the film or mold is removed and the water-soluble resin on the surface of the FRP layer is washed away with water, and the surface of the FRP layer is free of particulate matter such as sand or powdery matter or traces thereof. Many fine irregularities remain. As a result, the surface of the FRP layer is roughened to a predetermined state without sanding, and a resin composite pipe capable of ensuring sufficient adhesive strength when connecting to other pipes or joints is obtained.

Further, according to the method of the second aspect of the present invention, the intermediate product formed by laminating the uncured or semi-cured FRP layer on the outer peripheral surface of the core material is fed at a predetermined speed while the intermediate product is being fed. When the FRP layer is cured while pressing the tube outer peripheral surface pressing die against the surface of the, the surface of the FRP layer is provided with irregularities due to the irregularities on the die surface side of the pressing die. It will remain on the surface of the subsequent FRP layer. Then, after the FRP layer is cured,
When the pressing die is separated from the surface and returns to the initial pressing position, the surface of the subsequent uncured or semi-cured FRP layer is similarly provided with unevenness. Therefore, according to the method of the second aspect of the invention, the resin composite pipe capable of roughening the surface of the FRP layer to a predetermined state without sanding and ensuring sufficient adhesive strength can be obtained. Such a resin composite pipe can be continuously manufactured.

[0015]

EXAMPLES Examples of the present invention will be described below. [First Embodiment] This embodiment relates to the case of manufacturing the resin composite pipe 1 as shown in FIGS. 1A and 1B. First, the resin composite pipe 1 will be briefly described.

As shown in FIG. 1, in the resin composite pipe 1, a core material 2 as an inner layer is made of a vinyl chloride resin pipe, and an FRP layer 3 as an outer layer is formed on the outer periphery thereof. In this embodiment, the FRP layer 3 is made of polyester resin reinforced with glass fiber (reinforcing material), and many fine irregularities are formed on the outer surface thereof.

Next, the method of this embodiment for producing such a resin composite pipe 1 will be described with reference to FIG.
First, as shown in (A) of the figure, an uncured FRP layer 3 ′ is laminated on the outer peripheral surface of the core material (vinyl chloride resin tube) 2 to be the inner layer. Such a laminating operation can be performed by a known method such as the hand layup method or the FW method.
The FRP layer 3'in this case is glass fiber impregnated with molten polyester resin.

Next, as shown in (B) of the same figure, a water-soluble resin layer 4 in which fine sand is carefully mixed is laminated on the uncured FRP layer 3 '. Then, as shown in (C) of the figure, the surface of the water-soluble resin layer 4 is covered with a film 5 and tightened, and in that state, the FRP layer 3 ′ is cured.

Thus, the FRP layer 3'which is initially uncured is replaced with the FRP layer 3 in the cured state as shown in FIG.
Then, after peeling the film 5 from the surface of the water-soluble resin layer 4, the water-soluble resin existing on the surface of the FRP layer 3 is dissolved with water as shown in FIG. .

According to such a method, the water-soluble resin layer 4 in which fine sand is mixed is laminated on the surface of the uncured FRP layer 3 ', and the surface side is covered with the film 5 and tightened. As a result ((C) of FIG. 2), the sand particles in the water-soluble resin layer 4 are attached or cut into the surface side of the FRP layer 3 ′. Then, since the FRP layer 3 ′ is cured in this state, the film 5 is peeled off after the curing and the constituent resin of the water-soluble resin layer 4 existing on the surface of the cured FRP layer 3 is washed away with water, The FRP layer 3
As shown in FIG. 2 (E), the above-mentioned sand grains or traces thereof remain on the surface of as a large number of fine irregularities. As a result, the surface of the FRP layer 3 is roughened to a predetermined state without sanding, and sufficient adhesive strength can be secured when connecting to other pipes or joints as shown in FIG. The resin composite pipe 1 is obtained. [Second Embodiment] The resin composite pipe manufactured in this embodiment is
Since it is basically the same as that shown in FIG. 1, its explanation is omitted.

First, the pressing device used in this embodiment will be described. As shown in FIG.
Reference numeral 0 denotes a pair of rotating members 21 and 21 arranged so as to sandwich the resin composite pipe 11 to be manufactured or an intermediate product 11 ′ (a molding material thereof) (which will be described later) along a molding path a. , Endless holding belts 22 and 22 'hung between these rotating members 21 and 21,
A plurality of pipe outer peripheral surface pressing dies (hereinafter referred to as pressing dies) 23 attached to the holding members 22 and 22 ', respectively.
23 and heaters 24, 24 for keeping the pressing molds 23 ... 23 at a predetermined temperature.

As shown in FIG. 4, each of the pressing dies 23 is divided into halves, and the die surface is recessed into a cylindrical surface. The recessed die surface is, for example, as shown in FIG. 5 (A). A large number of irregularities are provided. When the rotary members 21 ... 21 are rotationally driven by separately provided driving means, one of the holding belts 22 and the pressing dies 23.
3 in the direction of arrow b in FIG. 3 and the other holding belt 22 '.
23 and 23 are rotated in the direction of the arrow c in the figure and are brought into alignment with each other on the side of the molding path, so that the outer peripheral surface of the intermediate product 11 'is moved to the mold surface 23a, as shown in FIG. It is designed to be pressed by 23a.

Next, the method of this embodiment, which is carried out by using such a pressing device 20, will be described. As shown in FIG. 3, after arranging the pressing die device 20 at a predetermined position along the molding path a, an uncured or semi-cured FRP layer 13 ′ is formed on the outer peripheral surface of the core material 12 made of a synthetic resin tube. The above-mentioned intermediate product 11 'is made by stacking.

.. 23 on both sides of the pressing die device 20 are rotated in the directions of arrows b and c, respectively, and are kept at a predetermined temperature by the heaters 24, 24, while the pressing die 23. The intermediate product 11 ′ is sent forward along the molding path a at a predetermined speed (direction of arrow c ′ in FIG. 3) to pass between the pressing dies 23 ... 23 on both sides.

In this way, the pressing dies 23 on both sides are
.. As shown in FIG. 4, when the intermediate product 11 'passes between 23, the outer peripheral surfaces of the intermediate product 11' have mold surfaces 23a, 2 on both sides.
The surface of the uncured or semi-cured FRP layer 13 'which is pressed by 3a and is located on the outer peripheral surface side of the mold surface 2
Unevenness is provided by 3a and 23a.

Therefore, while feeding the intermediate product 11 'in the a'direction of FIG. 4, the pressing dies 23 ...
Until the intermediate product 11 'leaves the intermediate product 11'
The uncured FRP layer 13 ′ is cured by heat from each pressing die 23 side to form the FRP layer 13 in a cured state.

Since each pressing die 23 rotates in the directions of arrows b and c in FIG. 4, the pressing die 23 is moved by a certain distance while pressing the outer peripheral surface of the intermediate product 11 'as described above. After that, the operation of returning from the FRP layer 13 to the initial pressing position located on the left side of the figure and pressing the outer peripheral surface of the intermediate product 11 ′ having the uncured FRP layer 13 again at that position is repeated.

According to such a method, the intermediate product 11 ', which is obtained by laminating the uncured or semi-cured FRP layer 13' on the outer peripheral surface of the core material 12, has a predetermined speed in the arrow a'direction of FIG. 13 are pressed against the surface of the FRP layer 13 ′ while being fed, and unevenness is imparted by each mold surface 23 a, and heat from each pressing mold 13 side in that state. Thus, the FRP layer 13 'is cured. Therefore, the intermediate product 11 ′ is the pressing device 20.
When the resin composite pipe 11 having the FRP layer 13 in a cured state is discharged in the a'direction of FIG. 4 through the passage, the surface of the FRP layer 13 has many irregularities. become. And such a process is continuously performed by rotation of the pressing die 13. As a result, the surface of the FRP layer can be roughened to a predetermined state without sanding, and the resin composite pipe 11 that can secure sufficient adhesive strength can be continuously manufactured.

In this embodiment, as shown in FIG. 5A, the pressing die 23 having a large number of irregularities formed on the die surface 23a is used. As shown, a pressing die 33 having continuous wave-like irregularities on the die surface 33a
May be used.

[0030]

As described above, according to the first invention of the present application, when the uncured FRP layer is laminated on the outer periphery of the core material made of the synthetic resin tube and cured, it is laminated on the surface of the FRP layer. Since the surface of the FRP layer after curing is roughened to a predetermined state by giving fine irregularities due to the granular or powdery substance such as sand in the water-soluble resin layer, the conventional method for securing the adhesive strength is used. There is no need for the sanding process that was used. As a result, a method of manufacturing a resin composite pipe that is hygienic and that can secure sufficient adhesive strength at the joint is realized.

According to the second invention of the present application, the uncured or semi-cured FR is formed on the outer peripheral surface of the core made of a synthetic resin pipe.
While the P layers are stacked and sent in a predetermined direction to be cured, the surface of the FRP layer is pressed by a pipe outer peripheral surface pressing die and the same FR is used.
Since the unevenness is imparted to the surface of the P layer, a resin composite pipe in which the surface of the FRP layer is roughened to a predetermined state can be continuously obtained without sanding. This is hygienic and
Thus, the resin composite pipe capable of ensuring sufficient adhesive strength at the joint can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 shows an example of a resin composite pipe obtained by the method of the first embodiment of the present invention, (A) is an external view showing a part of the pipe in cross section, and (B) is orthogonal to the pipe axis. It is sectional drawing cut | disconnected by the direction.

FIG. 2 shows each step of the method of the embodiment, (A)
Is a partially cutaway external view showing a state in which an uncured FRP layer is laminated on the outer periphery of the core material, and (B) is a partially cutaway external view showing a state in which a sand-containing water-soluble resin layer is laminated on the surface of the FRP layer. Figure,
(C) is a partially cutaway external view showing a state in which the surface of the water-soluble resin layer is covered with a film, and (D) shows a state in which the film is peeled from the surface of the water-soluble resin layer after the FRP layer is cured. Partial cutaway external view, (E) is a partial cutout external view of the state after the water-soluble resin present on the surface side of the FRP layer after being cured is washed off with water.

FIG. 3 shows a method of a second embodiment of the present invention, in which an intermediate product is fed in a predetermined direction, and the surface of the FRP layer on the outer peripheral side thereof is hardened while imparting unevenness by a pressing die. It is a front view showing the state where the resin compound pipe is manufactured continuously.

FIG. 4 is an enlarged cross-sectional view taken along line IV-IV of FIG.

FIG. 5 shows a pressing die used in the method of the second embodiment as viewed from the die surface side. FIG. 5A shows a large number of irregularities provided discontinuously on the die surface. FIG. 4B is a plan view showing a pressing die, and FIG. 6B is a plan view showing another type of pressing die in which a large number of wavy irregularities extending in the generatrix direction are provided on the die surface.

[Explanation of symbols]

 1, 11 ... Resin composite pipe 2, 12 ... Core material (synthetic resin pipe) 3, 13 ... FRP layer after curing 3 ', 13' ... FRP layer in uncured or semi-cured state 4 ... Water-soluble resin layer 5 ... Film 11 '... Intermediate product 23, 33 ... Pressing mold 23a, 33a ... Mold surface

Claims (2)

[Claims] 1. A FR is provided on the outer periphery of a core material made of a synthetic resin pipe.
A method of manufacturing a resin composite pipe provided with a P layer, comprising:
First, after stacking an uncured FRP layer on the outer peripheral surface of a core material made of a synthetic resin tube, on the surface side of the FRP layer,
Laminate a water-soluble resin layer mixed with fine particles such as sand or powder, and then cover the surface of the water-soluble resin layer with a film and tighten or press it with a mold A method for producing a resin composite pipe, which comprises curing the FRP layer in a state, then removing the film or mold, and washing away the water-soluble resin on the surface of the FRP layer with water. 2. FR on the outer periphery of a core material made of a synthetic resin pipe.
A method of manufacturing a resin composite pipe provided with a P layer, comprising:
An endless rotating type tube outer peripheral surface pressing die having a large number of irregularities on the mold surface is arranged at a predetermined position, and first, an uncured or semi-cured F is formed on the outer peripheral surface of the core made of a synthetic resin tube.
An intermediate product made by stacking RP layers is made, and while pushing the pressing mold forward along the pressing mold at a predetermined speed, the pressing mold is pressed against the surface of the FRP layer in the intermediate product, and in that state, the pressing mold is pressed together with the intermediate product. A method for producing a resin composite pipe, characterized in that the FRP layer is cured or almost cured while being moved by a certain distance, and then the pressing die is released from the surface of the FRP layer and returned to the initial pressing position.