JPS608980Y2 - heat shrinkable articles - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvements in heat-shrinkable articles.

Heat-shrinkable articles are used for covering steel pipe connections, cable connections, and the like.

Therefore, in order to cover the joints of steel pipes using conventional heat-shrinkable tubes, in order to prevent air from remaining between the coating layer and the outer circumferential surface of the steel pipes due to heat shrinkage of the tubes, it is necessary to After the tube is inserted into the top, the center part of the tube is first heat-shrinked, and then the heat-shrinking work is carried out toward both ends of the tube, or the heat-shrinking work is carried out from one end of the tube to the other. desirable.

However, when this conventional product is heated, it heat-shrinks almost simultaneously, so it is difficult to proceed with the heat-shrinking process according to the above procedure, and air remains between the coating layer and the outer circumferential surface of the steel pipe. often occur.

If air remains between the heat-shrinkable tube coating layer and the outer circumferential surface of the steel pipe, rainwater will penetrate and accumulate, leading to corrosion of the steel pipe.

Furthermore, since the outer circumferential surface of the steel pipe and the coating layer are not adhered to each other in the air remaining portion, the coating layer is not only easily damaged by external force, but also may cause peeling of the coating layer starting from this portion.

The present invention relates to a heat-shrinkable article that solves the problems of the conventional products described above, and is made by connecting heat-shrinkable members having different heat-shrinking temperatures.

The heat-shrinkable members used in the present invention include thermoplastics such as polyethylene, polypropylene, polyvinyl chloride, ethylene-vinyl acetate copolymer, and fluororesin, natural rubber, silicone rubber, butyl rubber, and ethylene-vinyl acetate copolymer.
It is made by blending appropriate amounts of additives such as anti-aging agents, fillers, colorants, etc. with rubber such as propylene copolymer or a mixture thereof, as desired.For example, these components are mixed uniformly and made into a sheet, It can be obtained by forming a bottom shape into a tube shape or the like, crosslinking as necessary, and then hot stretching in a predetermined direction to impart heat shrinkability to the molded product.

The heat-shrinkable article of the present invention is made by connecting heat-shrinkable members having different heat-shrinking temperatures, and the difference in heat-shrinking temperature between adjacent members is usually about 5 to 150°C, preferably about 10 to 50°C.
Set to ℃.

Hereinafter, examples of the present invention will be explained with reference to the drawings.

The tubular heat-shrinkable article shown in FIG. 1 is made of heat-shrinkable members 1 and 2 having different heat-shrinkage temperatures.

3 is a pressure-sensitive adhesive provided on the inner peripheral surface of the heat-shrinkable article;
This is an adhesive layer made of hot melt adhesive, mastic agent, etc.

This heat-shrinkable article is produced by first hot-stretching the left-hand portion of the tube in the radial direction, and then hot-stretching the right-hand half portion in the radial direction at a temperature different from that of the left-hand half portion, or each portion being hot-stretched in the radial direction at different temperatures. It can be obtained by, for example, a method of heat-sealing the ends of two tubes together.

In the heat-shrinkable article shown in FIG. 1 above, the heat-shrinkable members 1 and 2 have different heat-shrinkage temperatures, so when this is inserted into a steel pipe joint and heated with a burner, etc., the part with a lower heat-shrinkage temperature is first heat-shrinked, and then the portion having a high heat-shrinking temperature is heat-shrinked, so that no air remains between the heat-shrinkable article covering layer and the outer peripheral surface of the steel pipe, and a satisfactory covering layer can be formed.

FIG. 2 shows another example in which the central part is separated from the heat-shrinkable member 4 with a low heat-shrinking temperature, and the heat-shrinkable member 4 on both sides has a heat-shrinkable temperature higher than that of the heat-shrinkable member 4, and both heat-shrinkable temperatures are Approximately equal heat-shrinkable members 5 and 6 are connected.

When covering a steel pipe joint with this heat-shrinkable article, it is fitted into the steel pipe joint and heated with a burner or the like. Since the heat-shrinkable members 5 and 6 heat-shrink almost simultaneously, there is no residual air.

In the example shown in FIG. 2, the heat shrinkage temperatures of the heat shrinkable members 5 and 6 constituting both ends of the heat shrinkable article are approximately equal; You can keep it.

Furthermore, the heat shrinkage temperature can be set to increase successively from one end toward the other end.

The present invention is configured as described above, in which heat-shrinkable members having different heat-shrinking temperatures are connected and heat-shrinkable in order from the heat-shrinkable member with the lowest heat-shrinking temperature, so that the coating layer and the article to be coated are Air can be prevented from remaining between surfaces.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are both perspective views showing examples of heat-shrinkable articles according to the present invention. 1.2, 4, 5, 6... Heat shrinkable member 3...
...adhesive layer.

Claims (1)

[Scope of utility model registration request] A heat-shrinkable article made by connecting heat-shrinkable members having different heat-shrinkage temperatures.