JP2001330181A - Metal reinforced polyethylene tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite tube lightweight, low in cost, easily jointed by heat fusion and allowing a polyethylene tube to be piped in soil contaminated with an organic solvent or being exposed to the outside. SOLUTION: This composite tube is formed by winding a metal sheet on the outside of the polyethylene tube and further applying fiber reinforcement on the outside, or the composite tube is formed by winding the metal sheet on the outside of the polyethylene tube and further applying polyethylene coating on the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyethylene pipe for buried and exposed water supply.

[0002]

2. Description of the Related Art Conventional polyethylene tubing is PE.
If 100 is used and the maximum allowable pressure is 1 MPa, S
A pipe having a DR (ratio of pipe outer diameter to wall thickness) of 11 has been put to practical use in Japan as a standard of the Japan Water Works Association. PE100 is the highest grade polyethylene that is currently in practical use, but polyethylene pipes have features such as earthquake resistance, flexibility, and corrosion resistance, and the usage ratio for buried water supply is increasing. The polyethylene pipe has an elongation of several hundred percent of the polyethylene material. By making full use of this elongation, the pipe has a seismic resistance. In other words, pipes are joined together by heat fusion joining using an electric fusion joint or a butt fusion machine, and as an integrated pipeline structure, ground displacement such as land subsidence or earthquake is absorbed to exhibit seismic resistance. In addition, since the pipe itself is easily bent due to the large elongation of the material, the straight pipe can be bent as it is without using a special bend pipe at the bent portion of the pipe. Furthermore, polyethylene is resistant to acids and alkalis, and there is no fear of electrical corrosion when buried. As described above, polyethylene pipes have excellent features, so instead of metal cast iron pipes and steel pipes,
It is being used.

[0003]

However, when a polyethylene pipe for a buried water supply is laid on soil contaminated with an organic solvent, the organic solvent penetrates the thickness of the polyethylene pipe,
It will contaminate the tap water. Therefore, in such contaminated soil, it is necessary to change to a pipe type such as cast iron pipe or steel pipe that does not penetrate the solvent, or to take measures such as reforming the contaminated soil itself. Absent.

[0004] In addition, regarding the exposed piping of the polyethylene pipe for water supply, if the polyethylene is exposed to sunlight outdoors, it is deteriorated by photo-oxidation, so that it is necessary to take measures such as winding the steel sheet for protection. In addition, since polyethylene itself has lower strength than metal, if it is designed to withstand water pressure and earth pressure, the thickness of the polyethylene pipe will be relatively thick, which will increase the weight and cost during transportation. ing.

[0005] Further, when joining polyethylene pipes by a method of joining by heat fusion, the joining strength can be made stronger than the strength of the pipe itself. In general, when a composite tube with another material is used, since only the polyethylene portion is fused, a troublesome pretreatment such as separation of excess other material is required. The present invention solves the above problems, contaminated soil with an organic solvent, enables polyethylene pipe piping in outdoor exposure, thinner and lighter,
Provide low cost piping. It is another object of the present invention to provide a composite pipe capable of easily performing heat fusion bonding to sufficiently draw out the material properties of polyethylene.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is a composite pipe in which a metal sheet is wound around the outside of a polyethylene pipe, and the outside is further reinforced with fibers. In addition, the composite pipe has a metal sheet wound around the outside of the polyethylene pipe, and the outside thereof is further coated with polyethylene.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which each layer of the composite pipe of the present invention is exposed. A metal sheet 2 is wound around an outer layer of a polyethylene tube 1 and a fiber reinforcement 3 is applied to an outermost layer. As the fiber reinforcement 3, for example, a knitted carbon fiber or glass fiber is used. Polyethylene pipe 1 of the present invention
As for the material, PE100 may be used. However,
The SDR has a fiber reinforced 3 on the outermost layer even if thinner products such as 17 and 33 are adopted.
The pressure of MPa is sufficient.

The metal sheet 2 as the intermediate layer may be made of an extremely thin metal such as aluminum foil. The main function of this metal sheet is in contaminated soil such as organic solvents.
The purpose is to prevent the penetration of the solvent into the polyethylene pipe 1. However, it is desirable that the polyethylene tube be extremely thin in order to maintain the flexibility of the polyethylene tube itself.

[0009] It is said that it is difficult to securely bond polyethylene because it is originally an inert and very stable resin. In the present invention, an adhesive such as an adhesive is used between the metal sheet 2 and the polyethylene pipe 1. Not through. Therefore, if this composite pipe is cut, the metal sheet 2
Can be easily peeled off from the polyethylene pipe 1, and when the polyethylene pipe 1 is heat-sealed, since nothing other than polyethylene is interposed, simple joining can be performed without extra pretreatment.

In general, polyethylene is deteriorated by photo-oxidation, so buried piping is also used as a standard when used as a water pipe. When this is used for outdoor exposed piping such as a bridge bridge, the outside is made of steel plate or the like. Must be protected. On the other hand, in the composite pipe of the present invention, since the metal sheet 2 and the fiber reinforcement 3 play the role of light shielding, they can be used for outdoor exposed pipes without special protection.

FIG. 2 shows another embodiment of the present invention. A metal sheet 2 is wound around an outer layer of a polyethylene tube 1, and a polyethylene coating 4 is applied to an outermost layer.

The embodiment of FIG. 2 differs from the embodiment of FIG. 1 in that the outermost layer is not fiber reinforced but a polyethylene coating 4. The polyethylene coating 4 is a polyethylene tube 1
Can be manufactured by winding the metal sheet 2 and then coating the outer layer with a similar extruder. Therefore, the production is simpler in that similar equipment can be used rather than using fiber reinforcement. However, it differs from the embodiment shown in FIG. 1 in that it has a solvent permeation prevention function and a heat fusion bonding property in terms of functions, but cannot cope with thinning and weight reduction or outdoor exposure.

[0013]

As described above, the composite pipe of the present invention enables the pipe of polyethylene pipe to be exposed to soil contaminated with an organic solvent and exposed outdoors, and can provide a thin, lightweight and light-weight pipe.
In addition, it is a composite tube that can be heat-fused to sufficiently draw out the material properties of polyethylene.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state where each layer of a composite pipe is exposed in an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which each layer of a composite pipe is exposed in another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Polyethylene pipe 2 Metal sheet 3 Fiber reinforcement 4 Polyethylene coating

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H111 BA15 BA26 BA28 BA35 CB03 CB04 CB24 CC04 CC13 CC18 CC19 DA08 DA12 DB03 DB17 DB27 EA17 4F100 AB01B AB10 AD11 AG00 AK04A BA03 BA07 BA10A BA10C DA11 DG01C EJ94 EJ02 GB07 GB90 J90

Claims (2)

[Claims] 1. A metal reinforced polyethylene pipe in which a metal sheet is wound around the outside of a polyethylene pipe, and fiber reinforcement is applied to the outside of the metal sheet. 2. A metal reinforced polyethylene pipe in which a metal sheet is wound around the outside of a polyethylene pipe, and the outside is further coated with polyethylene.