JP3588547B2 - Molding method of reinforced plastic pipe - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for forming a reinforced plastic pipe suitable for forming a drain pipe, which is provided with a downward slope, a so-called “inclined pipe”.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, pipes used for water supply and drainage pipes are required to be smooth without inner surface irregularities. The reason is that if there is unevenness on the inner surface of the tube, resistance is generated in the fluid flowing through the tube, and the transport efficiency is reduced.
[0003]
However, in the case of inclined pipes, the drainage contains a large amount of various foreign substances in addition to moisture, so if the inner surface is smooth, the flow rate of the drainage will be large, and the foreign substances will be greatly worn and the life will be long. Is short, it is necessary to increase the thickness of the tube wall, which inevitably increases the cost.
In order to solve such a problem, for example, as described in Japanese Patent Publication No. Hei 6-39132, a reinforced plastic pipe having an inner surface provided with irregularities is known.
[0004]
In order to mold such a reinforced plastic pipe having irregularities on the inner surface, as described in the above-mentioned Japanese Patent Publication No. 6-39132, the back surface around the core mold has releasability. A method of winding a cross tape having irregularities on its surface, winding a thermosetting resin-impregnated glass fiber thereon to form a reinforced plastic tube, removing a core mold, and peeling off the cross tape is known. .
[0005]
[Problems to be solved by the invention]
However, as described above, in a method of winding a cross tape having a release property on the back surface around the core mold and having irregularities on the surface, and winding a thermosetting resin-impregnated glass fiber thereon. When the glass fiber impregnated with thermosetting resin is wound from above the cloth tape wound around the core mold, the liquid thermosetting resin enters from the gap between the cloth tapes and adheres to the surface of the core mold. In addition, since the core mold is contaminated, a complicated operation for cleaning the core mold is required, and burrs are formed on the inner surface of the reinforced plastic tube to be molded.
[0006]
The present invention has been made in view of the above-described problems in the conventional method of molding a reinforced plastic pipe having irregularities on its inner surface, and aims to solve the above problems. It is an object of the present invention to provide a method for forming a reinforced plastic pipe which does not require an operation of cleaning a core mold and does not cause burrs on the inner surface.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method for molding a reinforced plastic pipe according to the present invention according to claim 1 is a method for forming a strip having a mold releasing property on a back surface and having irregularities on a surface around a core mold. In a method of forming a reinforced plastic pipe having irregularities on the inner surface by winding a molding material made of reinforcing fibers impregnated with a thermosetting resin from above, forming a flat surface at one edge on the surface. Leave the strip with irregularities in a spiral around the core so that the back surface is in contact with the core and the edge of the adjacent strip is stacked on the flat surface at one end of the strip. It is characterized by being wound.
[0008]
Further, in the method for molding a reinforced plastic pipe of the present invention according to claim 2 , a belt-shaped body having mold release properties on a back surface and having irregularities on the surface is wound around a core mold such that the back surface is in contact with the core mold, A method of forming a reinforced plastic tube having irregularities on the inner surface by winding a molding material made of reinforcing fibers impregnated with a thermosetting resin from above, comprising a belt-like shape having irregularities on one edge of the back surface and irregularities on the surface. One end of the strip adjacent to the unevenness of the surface of the strip is laminated with the unevenness of the back of one end of the strip adjacent to the unevenness of the edge of the strip so that the back surface is in contact with the core mold. it is characterized in that the rear surface of the unevenness of edge wound spirally around the core type so that engaged.
[0010]
In the present invention, as the thermosetting resin of the molding material, unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin, polyimide resin and the like can be used. As the reinforcing fibers, besides glass fibers, organic fibers such as aramid fibers, carbon fibers, and the like can be used.
[0011]
Various additives such as a low-shrinkage agent, a filler, a curing agent, a curing accelerator, and a coloring agent can be added to the molding material, if necessary, in addition to the thermosetting resin and the reinforcing fibers. As the filler, besides calcium carbonate, aluminum hydroxide, talc, clay, barium sulfate and the like can be used. As the curing agent, for example, an organic peroxide can be used. In particular, when fast curing is required, a transition metal salt, a complex, or an amine-based curing accelerator can be used. As the colorant, a toner in which an organic or inorganic pigment is dispersed in a resin can be used.
[0012]
In the present invention, the material of the belt-shaped body is not particularly limited as long as it can form irregularities by being wound around a core, and is not particularly limited. For example, natural fibers, synthetic fibers Alternatively, a band formed by woven metal fibers in a band shape, a band formed of a soft metal such as lead, or corrugated paper, or the like can be used.
[0013]
[Action]
In the method for molding a reinforced plastic pipe according to the present invention, the belt-shaped body having irregularities while leaving a flat surface at one end edge on the front surface has a flat surface at one end edge of the belt shape so that the back surface is in contact with the core mold. Are wound spirally around the core so that the edges of adjacent strips are stacked on top of each other, so that the edges of the stacked strips are in close contact with each other , and the edges of the strip are There is no gap between them.
[0014]
Further, in the method for molding a reinforced plastic pipe according to the present invention, the strip having an uneven surface at one end of the back surface and the uneven surface at the surface is so formed that the back surface is in contact with the core mold and the edge of the strip is provided. The irregularities on the back surface of one edge of the adjacent band are laminated on the irregularities of the core, so that the irregularities on the surface of the band and the irregularities on the back of the one edge of the adjacent belt are engaged with each other around the core mold. since those winding spirally, and edges between the engagement of the strip to be laminated, a gap does not occur between the edges between the strip.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an embodiment of a method for molding a reinforced plastic pipe according to the present invention.
In FIG. 1, reference numeral 1 denotes a core mold having a diameter d of 600 mm, and the core mold 1 is moved in the axial direction as shown by arrow b while rotating as shown by arrow a.
In FIGS. 1 and 2, reference numeral 2 denotes a polyester tape having a release property on the back side and a release treatment on the back side as a belt-shaped body having irregularities on both sides. And spirally wound. The overlapping margin between the edges of the adjacent polyester tapes 2 is about 10 mm. The width of the tape 2 is 95 mm, the thickness is 25 microns, the depth of the concave and convex portions is 1 mm, and the height of the convex portions is 1 mm.
[0017]
Next, a molding material composed of a glass fiber 31 impregnated with a thermosetting resin is wound thereon to form an inner surface layer 3, a mortar layer 4 is formed thereon, and a thermosetting resin is further impregnated thereon. The outer layer 5 is formed by winding a molding material made of the glass fiber 51 thus formed.
[0018]
After the inner surface layer 3, the mortar layer 4, and the outer surface layer 5 have been cured, the core die 1 is pulled out and the polyester tape 2 is removed, thereby forming a reinforced plastic tube A having irregularities on the inner surface as shown in FIG. Molded.
[0019]
As described above, the tape 2 is spirally wound by supplying the tape 2 to the surface of the core mold 1, and the overlap between the edges of the adjacent tapes 2 is set to about 10 mm, so that the thermosetting properties can be obtained. Even when the molding material made of the glass fiber 31 impregnated with the resin is wound, the thermosetting resin does not enter from between the edges of the adjacent tapes 2, and the core 1 does not need to be cleaned. Also, no burrs are formed on the inner surface of the molded reinforced plastic tube A.
[0020]
FIG. 4 is an explanatory view showing another embodiment of the method for molding a reinforced plastic pipe of the present invention.
In the method for molding a reinforced plastic pipe of the present invention shown in FIG. 4, a strip 2a having irregularities is used while leaving a flat surface 21 at one end on the front and back surfaces, and such a strip 2a is used as a core. When spirally wound around the mold 1, a flat surface 21 at one end of the back surface of the adjacent band 2a is laminated on a flat surface 21 at one end of the surface of the band 2a.
[0021]
Therefore, in the method for molding a reinforced plastic pipe of the present invention shown in FIG. 4, the edges of the strips 2a, 2a are flat surfaces 21, so that the edges of the stacked strips 2a, 2a are in close contact with each other. There is no gap between the edges of the strips 2a, 2a.
Therefore, even when the molding material made of the glass fiber 31 impregnated with the thermosetting resin is wound thereon, the thermosetting resin does not enter from between the edges of the adjacent tapes 2a, 2a, and the core mold 1 There is no need to wash. Also, no burrs are formed on the inner surface of the molded reinforced plastic tube.
[0022]
FIG. 5 is a partially cutaway perspective view showing another example of the belt-like body. In the belt-like body 2b shown in FIG. 5, corrugated unevenness 22 is provided at both end edges, and a large number of convex parts 23 and concave parts 24 are provided at the center part. Is provided.
When such a band 2b is used, when the band 2b is spirally wound in a core shape, the corrugated irregularities 22 at the edges of the adjacent bands 2b, 2b are engaged with each other. It is to be laminated so that
[0023]
In this way, the corrugated irregularities 22 at the edges of the adjacent strips 2b, 2b are engaged with each other, thereby preventing the thermosetting resin from entering between the edges of the adjacent strips 2b, 2b. You.
[0024]
Although the embodiment of the present invention has been described with reference to the drawings, the specific configuration of the present invention is not limited to the illustrated embodiment, and design changes within the scope of the present invention may be made in the present invention. included.
[0025]
For example, the entire back surface of the band 2a shown in FIG. 4 may be a flat surface.
[0026]
【The invention's effect】
In the method for molding a reinforced plastic pipe according to the first aspect of the present invention , the edges of the strips to be laminated are in close contact with each other and no gap is formed between the edges of the strips. No intrusion from between the edges, and there is no risk of contaminating the core mold. Therefore, the operation of cleaning the core mold is not required, and there is no possibility that burrs will be formed on the inner surface of the molded reinforced plastic tube.
[0027]
Further, in the molding method of the present invention reinforced plastic tube according to claim 2, wherein, to edge with each other engagement of the strip to be laminated, since a gap is not generated between the edges between the strip, a thermosetting resin Does not penetrate between the edges of the strip, and there is no risk of contaminating the core. Therefore, the operation of cleaning the core mold is not required, and there is no possibility that burrs will be formed on the inner surface of the molded reinforced plastic tube.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an embodiment of a method for molding a reinforced plastic pipe of the present invention.
FIG. 2 is an enlarged explanatory view of a main part of the embodiment shown in FIG. 1;
FIG. 3 is a partially cutaway front view of a reinforced plastic pipe formed by the method of the present invention.
FIG. 4 is an explanatory view showing another embodiment of the method for molding a reinforced plastic pipe of the present invention.
FIG. 5 is a partially cutaway perspective view showing another example of the band used in the method of molding a reinforced plastic pipe of the present invention.
[Explanation of symbols]
A Reinforced plastic tube 1 Core type 2, 2 a, 2 b Strip 21 Flat surface 22 Corrugated unevenness 23 Convex portion 24 Concave portion 3 Inner surface layer 4 Mortar layer 5 Outer surface layer

Claims (2)

A molding material comprising a reinforcing fiber impregnated with a thermosetting resin by winding a belt-shaped body having a releasable property on the back surface and having irregularities on the surface around the core mold so that the back surface is in contact with the core mold. In the method of forming a reinforced plastic pipe having irregularities on the inner surface by winding the same, the band-like body having irregularities leaving a flat surface of one edge on the surface so that the back surface is in contact with the core mold, and one end edge of the band-like material. A method for forming a reinforced plastic tube, wherein the reinforced plastic tube is spirally wound around a core so that edges of adjacent strips are stacked on a flat surface . A molding material comprising a reinforcing fiber impregnated with a thermosetting resin by winding a belt-shaped body having a releasable property on the back surface and having irregularities on the surface around the core mold so that the back surface is in contact with the core mold. And forming a reinforced plastic tube having irregularities on the inner surface by winding the belt so that the belt has irregularities on one end of the back surface and irregularities on the surface so that the back surface is in contact with the core mold and the edge of the band is around irregularities backside of unevenness of one edge of the strip adjacent is stacked on the, and the unevenness of the back surface of one edge of the strip adjacent to the unevenness of the surface of the strip is the core type so that engaged A method for forming a reinforced plastic pipe, which is wound spirally.

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