JPH03182320A - Manufacture of fiber reinforced synthetic resin tube having recess on outer peripheral surface thereof - Google Patents

Abstract

PURPOSE:To form sharp recesses effective for preventing slip by biting the projections of a belt into the outer surface of a tubular body by a method wherein a pushing jig for winding the belt, having projections on the inside surface thereof with a substantially equal pitch same as a spiral running belt, is provided in the molding and curing zone of a mandrel constituted of the spiral running belt while the outer surface of the tubular body is formed by the pushing jig. CONSTITUTION:In the initial stage of molding, a tubular body is not cured yet, projections 54 on the belt 52 of a pushing jig 5 bite the surface of the tubular body, the curing reaction of FRP material is advanced while the tubular body runs integrally with the belt 52 of the pushing jig 5 and the tubular body becomes semi-cured or cured condition whereby both of them are meshed like as sprockets. Accordingly, slip will never be generated between the tubular body and the pushing jig 5 and the belt 52 of the pushing jig 5 is run into a spiral direction by the tubular body, whose belt 12 is advanced while rotating integrally with the mandrel 1 running into a spiral direction, whereby recesses are formed successively on the surface of the tubular body.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a fiber-reinforced synthetic resin pipe having a concave portion on its outer peripheral surface.

<Prior art> As shown in FIG. 3, as a continuous manufacturing method for fiber-reinforced synthetic resin pipes (hereinafter referred to as FRP pipes), a mandrel 1 for forming FRP pipes is used which is illuminated with a spiral running belt 12'.
'The methods used are known. In FIG. 3, 11' is a cylindrical frame with a number of rollers (not shown) attached to its outer surface, and 12' is a belt that is spirally wound around the frame and supported by the rollers so that it can run freely. , into an endless loop through the cylindrical frame 11'. Reference numeral 13' denotes a drive roll, which causes the belt 12' to travel in a spiral direction. The method of manufacturing an FRP pipe using this mandrel 1' differs depending on the fiber structure of the FRP pipe or whether it has a single-layer structure or a multi-layer structure, but in general, the belt 12' of the mandrel 1' is spirally Run the mandrel in the direction
A release agent is applied on the starting end side of the belt 12' (the side where the belt 12' enters), then uncured FRP material is supplied, and a presser tape is wrapped around it at a predetermined tension to form the uncured FRP material into a tubular shape. The process involves molding, curing it by heating, and continuously taking out the cured FRP pipe from the terminal end of the mandrel 1'. There are cases in which the tape is peeled off, and cases in which a surface mat is used as a holding tape and the tape is left fixed to the cured FRP pipe.

<Problems to be Solved> By the way, in FRP materials, it is often required to provide irregularities on the surface. FRP pipes may also be required to have irregularities in order to prevent them from slipping, that is, to prevent them from slipping down during transportation, especially during stacking and transportation, and when installing on slopes. In addition, when using FRP pipes as lining members for humid pipes, it is required to provide unevenness on the surface of the FRP pipes in order to increase the adhesion strength at the interface with the concrete layer.Usually, synthetic resin When a tube is to be textured, the tube is passed through a textured roll while the surface of the tube is still plastic. In the case of FRP pipes, the plasticity stage is a stage in which the curable resin is uncured. However, in the method for manufacturing FRP pipes that uses a mandrel configured with the spiral running belt described above, when the resin is not cured, there is a pressing tape on the surface, and the unevenness of this pressing tape hinders the biting of the roll. Therefore, it is difficult to provide sharp irregularities that are effective for preventing slippage.An object of the present invention is to provide sharp irregularities to the outer surface of an FRP pipe in the production of FRP pipe using a mandrel configured with the above-mentioned spiral running belt. The goal is to provide a method that allows you to do so.

Another object of the present invention is to provide a method for forming the outer surface of an FRP pipe using a spiral running belt in the same way as forming the inner surface, with an excellent finish and no slipping of the belt. be.

<Means for Solving the Problems> The method for manufacturing a fiber-reinforced synthetic resin pipe having a concave portion on the outer circumferential surface according to the present invention includes a method for manufacturing a fiber-reinforced synthetic resin pipe having a concave portion on the outer circumferential surface, in which a molding hardening zone of a mandrel for molding a fiber-reinforced synthetic resin pipe constituted by a spiral running belt is provided. A belt-type holding jig is provided in which a belt having convex portions on its side is wound at a pitch approximately equal to that of the spiral running belt, and reinforcing fibers and curable resin are supplied to the mandrel, and by contact with these materials, This configuration is characterized in that the belt of the belt-type presser jig is caused to run following the spiral belt of the mandrel, and the curable resin is semi-cured or hardened during contact with the belt.

<Explanation of Examples> Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing a manufacturing apparatus used in the present invention, and FIG. 2 is a sectional view taken along line nn in FIG. 1 and 2, reference numeral 1 is a mandrel for forming an FRP tube, in which a belt 12 is spirally wound around a cylindrical frame 11, passed through the cylindrical frame 11, and made into a blendless state, and a driving roll 13 is formed. The belt 12 is configured to run in a spiral direction, and the belt 12 has a roll, a rotatable ball, etc. 1 mounted on a cylindrical frame 11.
4, it is slidably supported. 2 is mandrel 1
This is a release agent applicator placed on the starting end side of the mold. 3 is uncured F
This is the RP material supply zone, and the FRP material is supplied by winding long fibers drawn from a bobbin in the belt spiral direction, scattering short fibers in the axial direction of a mandrel, dripping resin, or extruding from an extruder. The winding of the resin mortar in the belt spiral direction is carried out by a method such as the following. 4 is FR
This is the molding and hardening zone of P material. Reference numeral 5 denotes a belt-type holding jig provided in the molding hardening zone 4, which winds a belt 52 on the mandrel 1 at a pitch almost equal to that of the spiral running belt 12, and winds both ends of the belt with several direction-changing rolls. After 53..., it becomes an endless loop.

54... are protrusions provided on the inner surface of the belt 52.

According to the present invention, in order to manufacture an FRP pipe having four parts on the outer peripheral surface, the belt 12 of the mandrel 1 is moved to the drive roll 13.
The release material is applied to the outer surface of the belt by the release material applicator 2, and the uncured FRP material is supplied onto the mandrel 1 in the FRP material supply zone 3. A removable spacer 6 is attached to the inner surface of the belt of the belt-type presser jig 5 as shown by the dotted line in FIG.
The belt 52 on the mandrel 1 is kept under tension.

Therefore, the belt 52 of the belt-type presser jig 5 is pulled and pulled by the friction between the belt 12 of the mandrel 1 and the spacer 6.
It will be run. It is desirable to coat the inner surface of the belt 52 of this holding jig 5 with a release agent as well, as the belt 12 of the mandrel 1 runs.
When the P material is transported by the running belt 12 and reaches the starting end of the Pel 1 to type holding jig 5, the belt 1 of the mandrel 1
2, while being held down by the belt 52 of the holding jig 5, which is running in a spiral direction.
The spacers 6 described above have already been removed from the belt 52 entering the starting end of the holding jig 5, and the spacers 6 are successively removed from the belt 52 exiting from the terminal end.

Therefore, the FRP material is formed into a tubular shape with dimensions regulated by the inner diameter of the presser jig 5 and the outer diameter of the mandrel 1. At this initial stage of forming, the tubular body is uncured and the presser is not fixed. The convex portion 54 of the belt 52 of the tool 5 bites into the surface of the tubular body, and while the tubular body and the belt 52 of the holding jig 5 run together, the hardening reaction of the FRP material progresses and the tubular body is cut in half. The two mesh together like sprockets to reach a hardened or hardened state. Therefore, no slip occurs between the tubular body and the presser jig, and the belt 12 rotates and moves forward together with the mandrel 1 running in the spiral direction. The belt 52 of the tool 5 runs in a spiral direction, and recesses are formed one after another on the surface of the tubular body, and from the end of the holding jig, a semi-hardened or hardened tubular body with recesses on the surface is formed. At this time, the belt 52 of the presser jig 5 is peeled off from the hardened tubular body, and a tensile force is applied to the belt 52 of the presser jig 5 in accordance with the force required for the peeling.

The tensile force of the belt 52 of the holding jig 5 acts on the tubular body as molding pressure, and if the tensile force is too large, the wall thickness of the tubular body becomes thin. The tensile force of the belt 52 is adjusted to a predetermined value. In this way, it is possible to form a tubular body with a predetermined thickness.

In the above, a heating zone (for example, electric heating type, infrared type) can be provided in the middle of the holding jig 5 to promote the above-mentioned curing.

The above FRP material can be supplied in various ways9
For example, ■ Wrapping of continuous long fibers, ■ Spreading of short fibers (the direction of the short fibers is approximately in the direction of the mandrel axis), ■ Wrapping of strip-shaped resin mortar or premix from an extrusion type, ■ Spreading of short fibers, ■ Continuous The winding of long fibers, etc. can be performed sequentially. It is also possible to wrap the continuous long fibers 1 of (1) or (2) while impregnating them with a resin, and in this case, (2) may be omitted. It is also possible to omit the step 2 or 3 by scattering short fibers on the continuous long fibers 2 or 3 before winding them. Epoxy resin, polyester resin, phenol resin, etc. can be used as the curable resin of the resin mortar and Brimix.

The above-mentioned continuous long fibers can be a bundle of untwisted continuous fibers (roving) or a bundle of continuous fibers (yarn) that has been burnt to some extent. Fibers, polyamides, polyesters. Organic fibers made from synthetic resins such as polyolefins can be used. The short fibers can be those obtained by cutting the above-mentioned long fibers with a roving cutter.

<Effects of the Invention> As described above, in the method for manufacturing a fiber-reinforced synthetic resin pipe having a concave portion on the outer peripheral surface according to the present invention, the molding hardening zone of the mandrel configured with a spiral running belt has a convex portion on the inner surface. A holding jig is provided in which the belt is wound at approximately the same pitch as the spiral running belt, and although the outer surface of the tubular body is formed using this holding jig, there is no need to wrap a holding tape to form the outer surface. The belt convex portions can be easily bitten into the outer surface of the tubular body to form four sharp portions that are effective for preventing slipping. In addition, as the tubular body hardens, the tubular body and the jig's belt with convex portions mesh like sprockets, making it possible to avoid slipping of the holding jig's belt, allowing the surface of the tubular body to be finished neatly, and recessed areas. deformation can be prevented. Furthermore, since the spiral belt of the presser jig is driven by the propulsion force transmitted from the spiral belt of the mandrel, there is no need for a separate drive source to drive the presser jig, and there is no need for synchronization. The manufacturing equipment is also easy to operate.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a manufacturing apparatus used in the present invention, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG. 3 is an explanatory diagram showing a conventional FRP pipe manufacturing apparatus. 1... Mandrel

Claims (1)

[Claims] A belt-type presser jig is provided in the molding hardening zone of a mandrel for molding fiber-reinforced synthetic resin pipes composed of a spiral running belt, in which a belt having convex portions on the inner surface is wound at approximately the same pitch as the spiral running belt. , the mandrel is supplied with reinforcing fibers and a curable resin, and by contact with these materials, the belt of the belt-type presser jig is caused to run following the spiral belt of the mandrel, and during contact with the belt, the A method for producing a fiber-reinforced synthetic resin pipe having a concave portion on its outer circumferential surface, the method comprising semi-curing or hardening a curable resin.