JPS6020167B2 - Manufacturing method of glass fiber reinforced cement pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for manufacturing glass fiber reinforced cement pipes.

Recently, with the development of alkali-resistant glass fibers, in order to reduce the weight and cost of cement pipes, the above-mentioned type of key was used instead of the copper wire key that was conventionally used as a reinforcing member for cement pipes. It has been proposed to use long glass fibers as a reinforcing member, and a typical manufacturing method thereof is shown in FIG.

In FIG. 1, reference numeral 11 denotes a formwork that is supported at both ends by end plates 12 and rotates on a rotating mechanism 13. During the rotation of this formwork 11, a nozzle 14 is inserted into the inside of the formwork to reciprocate in the axial direction. make it move. Cement slurry and continuous glass fibers 2 are supplied to this nozzle 14 through a pipe 15,
These are sprayed from the nozzle 14 toward the inner periphery of the formwork 11, and as a result, a cement pipe 1 is formed in which the long glass fibers 2 are embedded in a spiral shape with a pitch commensurate with the moving speed of the nozzle 14. Obtained. Here, 16 is a joint tube for cement slurry, and two reinforcing layers made of long glass fibers 2 are formed on the inner and outer peripheral sides.
This figure shows the process of forming the reinforcing layer on the inner peripheral side. In cement pipes manufactured in this way, if the long glass fibers are straight, they can effectively withstand annular breaking stress, but the bending strength in the direction of the ball is not sufficient. Since a small amount of cement is required to compensate for the bending strength, it is not possible to manufacture small-sized ridges with this, so to improve this, it is recommended to make the long glass fibers wavy. It was proposed in Group No. 48. By the way, in such a product, if the waveform is small and there is no overlapping part (intrusion part), the continuous axial force in the direction of the ball cannot flow, so an overlapping part is formed. You must do so. Therefore, the inventor conducted experiments on a flat plate in which long glass fibers were arranged in a straight line in the opposite direction, and in a waveform arrangement with a rolling part, and found that in the latter case, the height of the overlapped part was If the height of the corrugation is not more than 1/2, it will not be possible to obtain the same axial strength as the former, and when creating such a corrugation, it is economically disadvantageous as it requires a large number of glass fibers. It has been found that there are drawbacks such as difficulty in adjusting the directional bending strength. The object of the present invention is to provide a method of manufacturing a cement pipe that can eliminate the drawbacks of the conventional cement pipe as described above.

This invention will be explained with reference to embodiments shown in FIG. 2 and subsequent figures. In this embodiment, the same parts as those in the conventional system are given the same reference numerals to simplify the explanation of the parts.

A reinforcing pith 5 having ropes formed by circumferential fibers 3 made of long glass fibers and koji fibers 4 in the formwork 11
(Details of this will be described later), concrete or cement mortar is poured while rotating the formwork 11, and after the reinforcing marrow 5 is embedded in the concrete or cement layer, the concrete or cement The injection of mortar is stopped, and cement slurry and continuous glass fibers 2 are sprayed from the nozzle 14 toward the inner periphery of the mortar, and in this way, the glass long fiber reinforcement structure 5 is formed on the outer periphery side.
A cement tube 1 is obtained in which the spiral long glass fibers 2 are included on the inner circumferential side. In this case, the reinforcing key 5 or the fibers 2 may be formed in multiple layers as required. The long glass fibers 2, 3, and 4 used in the above are made of 1150 tex, and the mesh of the reinforcing fiber 5 is large enough to allow the largest size of aggregate in the concrete or cement mortar to easily pass through. It's sato.

Such reinforcing pulp 5 may be formed by any method, and one example will be described with reference to FIG. 3.

A release paper 22 such as cellophane paper is attached to the outer periphery of the cylindrical core 21, and while the core 21 is rotated, the outer periphery is pre-impregnated with cement mortar or a thermosetting resin such as epoxy resin to form a continuous length of glass. The fibers are spirally wound at an appropriate pitch to form a circumferential fiber 3, and a plurality of axial fibers 4 are attached to the outer periphery of the fiber in a direction substantially parallel to the central axis of the core bar 21, and are attached to both ends of the core bar 21. The ring 23 is stretched using a projection 24 provided on the ring 23. In this case, the fibers 3 do not need to be spirally shaped. After completing the molding work in this way, the mortar or resin is cured by heating or steam curing, and the fibers 3 and 4 are cut at section A in FIG.
It is pulled out from the core metal 21, and the release paper 22 is taken out from inside.

This invention is as described above, and the inner periphery of a rotatable circular form is made of circumferential fibers made of long glass fibers impregnated with cement mortar or thermosetting resin and long glass fibers. Since the axial fibers are used to harden the mortar or resin and to form a network through which the largest aggregate in the concrete or cement mortar can pass, the reinforcing marrow is pre-configured. This eliminates the need to put the long glass fibers contained in the outer periphery into a rotating formwork, and the reinforcing core can be quickly embedded into the concrete or cement layer, reducing the manufacturing time of cement pipes. can be realized.

In addition, in the above case, since the circumferential fibers and the axial fibers of the reinforcing dragon are integrally bonded by cement mortar or hardening of thermosetting resin, the mesh is deformed by the rotation of the formwork, and the There is no irregular arrangement such as the fibers being lopsided, and since the mesh allows the largest size of aggregate to pass through, the aggregate can be evenly distributed in the concrete or cement layer inside and outside the mesh. . moreover,
According to this manufacturing method, the centrifugal manufacturing equipment can be used as is, which is economical, and the bending strength in the axial direction can be improved by using a small amount of filamentous fibers made of long glass fibers. In addition, it has an excellent effect in that the bending strength in the ball direction can be easily adjusted by adjusting the number or amount of fibers in the axial direction.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional front view for explaining a typical manufacturing method of a conventional glass fiber reinforced cement pipe, Fig. 2 is a vertical sectional front view for explaining the manufacturing method of the present invention, and Fig. FIG. 2 is a partially longitudinal front view for explaining an example of a method for manufacturing a reinforcing key for a cement pipe according to the invention. 1... Cement pipe, 2... Spiral glass long fiber, 3...
... Circumferential long glass fibers, 4... Circumferential glass long fibers, 5... Reinforcement key, 11... Rotating formwork, 14...
nozzle. Rare l figure rare 2 figure 3 figure

Claims (1)

[Claims] 1 Inside a rotatable cylindrical form, circumferential fibers made of long glass fibers impregnated with cement mortar or thermosetting resin and axial fibers made of long glass fibers are placed inside a rotatable cylindrical form, and the mortar or resin is cured. A reinforcing basket is installed in advance to form a network through which the largest size aggregate in the concrete or cement mortar can pass, and concrete or cement mortar is poured in while rotating the formwork to reinforce the reinforcement. After embedding the cage in the concrete or cement layer, continuous glass fibers are sprayed spirally on the inner periphery of the cage along with cement slurry to form a reinforcing cage on the outer periphery and spiral glass fibers on the inner periphery. A method for manufacturing a cement pipe, characterized in that a glass fiber-reinforced cement pipe with a desired thickness is obtained.