JPS5932292B2 - Composite pipe manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite pipe, and in particular, it involves spirally winding a thermosetting resin-impregnated fiber material for the inner and outer layers and a relatively thick resin mortar material for the middle layer. The present invention relates to a new manufacturing method for composite pipes, which is improved so as to increase the physical strength of the intermediate layer, that is, the resin mortar layer, and improve the watertightness of the composite pipe.

Composite pipes that have thermosetting resin-impregnated fiber materials in the inner and outer layers and resin mortar material in the middle layer have recently been developed as a composite pipe that combines the characteristics of hume pipes (mortar pipes) and fiber-reinforced plastic pipes. It is attracting attention.

Various studies have been conducted on methods for manufacturing such composite pipes, and many industrially superior methods have been proposed and put into practice. The inventors of the present invention have also been conducting research on this type of composite pipe for some time, and have made extensive studies with the aim of increasing the efficiency, simplifying, and further improving the performance of their manufacturing. When manufacturing composite pipes using a rotating core metal,
A method is adopted in which the resin mortar material (composed of a thermosetting resin contained in a powder such as silica sand) formed as the intermediate layer is wound spirally as a relatively thick band. For example, it has been found that this method is extremely convenient for making the manufacturing process continuous, and that a composite tube with excellent physical properties such as bursting strength can be obtained. 1 and 2 are explanatory diagrams illustrating a method of manufacturing such a composite pipe, in which FIG. 1 is a schematic plan view and FIG. 2 is a sectional view taken along section line 2--2 in FIG. 1 in the direction of the arrow. In Fig. 1, reference numeral 1 schematically shows a core metal drive forming mechanism, which holds the mandrel 2 almost parallel, rotates the mandrel in a fixed direction, and winds the mandrel around the outer peripheral surface of the mandrel 2 without any gaps. It has a pressing device that pushes the endless steel belt 3 toward the tip of the mandrel 2 by belt width. The steel belt 3 on the mandrel 2 forms the core of the formed tube (composite tube), and around its outer periphery, a tube forming material as described below is wound and laminated, and a heat treatment device is installed inside and outside the mandrel 2. 16, the growing profile is hardened. When the hardening of the grown shape is completed, the steel belt 3 constituting the core metal is unraveled, passes through the center of the mandrel 2, is guided to the core metal drive forming mechanism 1, and is again attached to the mandrel 2 by the drive forming mechanism 1. It is wound and rotates continuously. Reference numeral 4 denotes a release material, which may be of a coating type, but in this example, a method of winding a release tape such as cellophane tape is shown.

5 is a nonwoven fabric impregnated with a thermosetting resin such as an unsaturated polyester resin or an epoxy resin mixed with a curing agent, a curing accelerator, and the like.

A continuous glass fiber 6 is wound around the outer periphery of the resin-impregnated nonwoven fabric 5 while maintaining an appropriate tension, but during its guidance, it is impregnated and guided into a tank of resin material as described above.

Further, in order to improve the longitudinal strength of the tube, glass fibers 7 for longitudinal reinforcement are added and wound around the outer periphery of the nonwoven fabric 5 while the continuous fibers 6 are being guided or just before being wound. These wound layers of continuous fibers and longitudinal fibers are generally referred to as filament winding, and the basis for manufacturing reinforced plastic tubes originates from filament winding. 8 is a mortar kneading extrusion device, which kneads powder particles such as silica sand, a binder, and suitable additives, and discharges a resin mortar 10 formed into a relatively thick band shape by an appropriate means such as a screw extrusion device; The strip-shaped resin mortar material 10 passes through the discharge guide portion 9 and is tightly wound around the outer periphery of the filament winding layers 6 and 7 to form an intermediate layer.

Reference numeral 13 denotes a glass continuous fiber for the outer layer, which is supplied and wound in the same manner as the glass continuous fiber for the inner layer 6, and the vertical stripes 14 are also supplied in the same manner as 7, and filament winding for the outer layer is performed. It will be done.

15 is a surface covering material wrapped as necessary; 16
indicates a heat treatment device.

In the process of manufacturing the composite pipe as described above, the process of forming the intermediate layer is as shown in FIG.
0 is wound while being held by a holding material 12 (for example, non-woven fabric, etc.) guided through a guide roller 11 to prevent it from falling downward, but the quality of this winding process is determined by the composite tube obtained. has a significant impact on performance. For example, FIG. 3 is an enlarged cross-sectional view of a main part showing a state in which band-shaped resin mortar material 10 is wound. The resin mortar materials 10, which should be wound adjacent to each other without any gaps, are tightly wound as desired. If it is not rotated, a gap 17 may be created as shown in FIG. If such a gap 17 is created in the intermediate layer, air will be drawn in and the mortar will not be fully integrated, which will reduce the physical strength such as burst strength and bending strength of the composite pipe. This is extremely undesirable since water will leak out from the gap 17. Therefore, in order to prevent such a situation, during the process of winding the resin mortar material 10, a worker constantly observes the winding state, monitors and adjusts the winding so that no gaps 17 occur, and arranges appropriate guides. A means is provided for winding the resin mortar material 10 while pressing it in the joining direction (direction of arrow A in FIG. 3). However, the former method of relying on procurement is not desirable as it is less reliable and reduces labor productivity, and the latter guide pressing method involves winding the resin mortar material 10 in an uncured and soft state. Because of this, the resin mortar material 10 may be deformed by the pressing force, causing the resin mortar material 10 to become distorted or folded during the winding process, and is currently not in practical use. On the other hand, it is also known from experience that when a composite pipe as described above is damaged, it often occurs along the joining line when the mortar material is spirally wound. In view of this situation, in order to further improve the physical strength of the composite pipe and to reliably prevent leakage of the fluid flowing through the pipe, the resin mortar material 10 should be tightly wound without any gaps during the spiral winding process. It is desirable to devise a method that can be wound and firmly bonded at the joint. The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a composite pipe with further improved physical strength and water leakage prevention properties.More specifically, It is an object of the present invention to provide a method in which a band-shaped resin mortar material is wound without any gaps in the process of forming a resin mortar layer as an intermediate layer, and the wound joints are tightly adhered to achieve integration of the mortar material. It is something.

The method of the present invention that achieves this objective is to form a relatively thick band around the outer periphery of the tube inner layer obtained by spirally winding a thermosetting resin-impregnated fiber material around the outer periphery of a rotating core metal. After a resin mortar material is spirally wound to form an intermediate layer, a thermosetting resin-impregnated fiber material is again spirally wound around the outer periphery of the intermediate layer to form an outer tube layer, which is then heat treated. When manufacturing a composite pipe, the intermediate layer is made by winding a band-shaped resin mortar with one or both side edges slightly thicker than the center.
The gist is that the thick portion is shaped by being pressed from the outer periphery. In the present invention, the thermosetting resin-impregnated fiber material includes, for example, the nonwoven fabric 5 shown in FIG. 1, continuous fibers 6, 13, vertical stripes 7, 14, etc. Of course, it is also within the technical scope of the present invention to omit one or more of these and apply a single layer or two layers of resin-impregnated fiber material as the pipe inner layer and the pipe outer layer. The configuration and effects of the present invention will be explained below based on drawings serving as embodiments. However, the following are merely representative examples, and it is within the scope of the present invention to modify the design in various ways in accordance with the spirit of the above and later explanations. It is within the technical scope of the invention. 4 to 7 are explanatory diagrams illustrating the process of forming the intermediate layer (i.e., the resin mortar layer) characterized by the present invention, in which the process of forming the winding of the band-shaped resin mortar material is cut in the tube axis direction. FIG. In FIG. 4, a strip-shaped resin mortar material 10 is formed into a relatively thick wall by the mortar kneading and extruding device 8, and its both side edges are formed to be slightly thicker than the center (thick wall portions 10a,
10b). When this band-shaped resin mortar material 10 is wound spirally, the thick parts 10a and 10b come to be adjacent to each other, but after or at the same time as the winding, the thick parts 10a and 10b become adjacent to each other.
10b is pressed from the outer periphery by a pressing roller 18. Then, the mortar material of the thick portions 10a and 10b is deformed by this pressing force and pushed toward the joint surface. In particular, in the present invention, since the thick portions 10a and 10b are formed on the side edges of the strip-shaped resin mortar material 10, these portions are most susceptible to the pressing force of the pressing roller 19, and the pressed mortar material are adjacent strip-shaped resin mortar materials 10
The two parts are pushed in the direction of joining, and are integrated by biting into each other. In addition, since the band-shaped resin mortar material 10 in this step is in an unhardened or semi-hardened state, the mortar materials pushed in the joining direction are in a state where they fuse with each other at the joint surface, so the integration of the intermediate layer is also significant. promoted. Furthermore, even if a gap 17 as shown in FIG. 3 occurs during the winding process of the strip-shaped resin mortar material 10, the gap 17 is filled with the mortar material that comes out when the thick parts 10a and 10b are pressed together. Moreover, air drawn into the joint during the winding process is pushed out of the intermediate layer by the pressing force.
In this way, it is possible to reliably prevent air from entering the joint and the generation of gaps, and to improve the adhesion of the joint, thereby making it possible to integrally join the adjacent strips of resin mortar material 10. As is clear from the explanation of FIG. 4, in the present invention, thick portions 10a and 10b are formed on the side edges of the strip-shaped resin mortar material 10, and adjacent thick portions 10a and 10b are pressed from the outer periphery. This is intended to strengthen the bonding force (force).
The shapes of the thick portions 10a and 10b are not limited in any way as long as this purpose can be achieved. Therefore, it is possible to employ a band-shaped resin mortar material 10 having a cross-sectional shape as shown in FIGS. 5 and 6 or various other cross-sectional shapes. In addition, as shown in FIG.
Even if a method is adopted in which a thick portion 10a is pressed against the thick portion 10a, the same effects as in FIGS. 4 to 6 can be obtained. In the present invention, the means for pressing the thick parts 10a, 10b is not particularly limited, but the point is to compress the thick parts 10a, 10b from the outer periphery, push the mortar protruding toward the earthwork in the joining direction, and As long as it has the effect of smoothing the winding surface, it is possible to use methods such as those shown in FIGS. 8 to 10 below, or various other methods.

That is, FIGS. 8 to 10 illustrate the pressing method, and are explanatory views corresponding to the 2-2 line direction red perspective view in FIG.
FIG. 8 shows a method using the pressing roller 18 shown in FIGS. 4-7. FIG. 9 shows a method using a presser plate 19, in which the presser plate 19 is pressed against the outer periphery of the thick portions 10a, 10b, or a vibrator 20 or the like is used as necessary to strengthen the bonding force and shape the surface shape. be. FIG. 10 shows a method using an endless pressing belt 21, and a pulley 22
This shows a method of pressure contact using an endless belt 21 stretched by belts a and 22b. In FIG. 10, 23 is a pressure roller for tension adjustment. Although the pressing means shown in FIGS. 8 to 10 are advantageously employed when carrying out the present invention, the pressing means themselves do not limit the present invention, so the means shown in the illustrations may be used as appropriate. Even if the method is modified or a different pressing means is adopted, such as a guide cylinder to restrict the pressing from the outer periphery, these are all within the technical scope of the present invention. It is. The method for forming the intermediate layer, that is, the resin mortar layer characterized by the present invention has been described above, but the method for forming the tube inner layer and the tube outer layer can be applied as is by the conventional filament winding method, and special means are not required. It's not necessary.

Therefore, according to the conventional method, a single layer or two or more thermosetting resin-impregnated fiber material layers are formed as the pipe inner layer, and an intermediate layer is formed on the outer periphery of the resin mortar material. The tube outer layer may be formed in the same manner as above, and then a composite tube can be obtained by curing the thermosetting resin component using an appropriate heat treatment device. Here, the pipe inner layer and the pipe outer layer do not necessarily have to have the same structure; for example, it is possible to adopt the pipe inner layer as a multilayer and the pipe outer layer as a single layer, or vice versa. It goes without saying that variations in the degree of implementation are included within the technical scope of the present invention. The present invention is constructed as described above, and in particular, the side edges of the band-shaped resin mortar material constituting the intermediate layer are formed to be slightly thicker than the center part, and the thick part is pressed during the winding process. As a result, it has been possible to increase the adhesion between adjacent strips of resin mortar material, thereby making it possible to join them together as one piece, and it has also succeeded in reliably preventing the generation of gaps and the inflow of air into the joint.

In this way, it has become possible to provide a composite pipe that reliably prevents water leakage and has excellent physical properties.

[Brief explanation of drawings]

Figures 1 to 3 show an example of manufacturing a composite pipe, which is the basis of the present invention. Figure 1 is a schematic plan view, Figure 2 is a sectional view taken along the line 2-2 in Figure 1, and Figure 3 is a cross-sectional view taken along the line 2-2 in Figure 1. FIG. 2 is a sectional view of a main part showing an example of forming an intermediate layer. Figure 4 and below show examples of the present invention, Figures 4 to 7 are sectional views of essential parts illustrating the process of forming a resin mortar layer as an intermediate layer, and Figures 8 to 10 are advantageously applied in the present invention. FIG. 1... Core metal drive forming mechanism, 2... Mandrel, 3...
Steel belt, 4...Release material, 5...
・Nonwoven fabric, 6... Continuous fibers, 7... Vertical stripes, 8... Mortar kneading and extrusion device, 9...
... Discharge guide section, 10 ... Band-shaped resin mortar material, 11 ... Guide roller, 12 ... Holding material, 13 ... Glass fiber, 14 ...・・・・・・
Vertical stripes, 15...Surface covering material, 16...
Heat treatment device, 17... Gap, 18...
・Press roller, 19...Press plate, 20...
... Vibrator, 21 ... Endless belt, 22
a, 22b...Pulley 1.

Claims (1)

[Claims] 1. A middle layer is formed by spirally winding a relatively thick band-shaped resin mortar material around the outer periphery of the pipe inner layer obtained by spirally winding a thermosetting resin-impregnated fiber material around the outer periphery of a rotating core metal. After forming, the thermosetting resin-impregnated fiber material is again spirally wound around the outer periphery of the intermediate layer to form a tube outer layer, and when this is heat-treated to produce a composite tube, the intermediate layer is A method for manufacturing a composite pipe, characterized in that a band-shaped resin mortar with both side edges slightly thicker than the central part is wound, and then the thick parts are pressed from the outer periphery to shape the mortar.