JPS608988Y2 - heat recovery tube - Google Patents

Description

[Detailed description of the invention] This invention is a heat-shrinkable tube that prevents dust, dirt, water, etc. from adhering to the inner and outer walls of the tube during storage or transportation, and keeps the inner and outer walls clean until use. Or it relates to a thermally expandable tube.

To prevent corrosion at the joints of steel pipes used for transporting gas, oil, water, etc., use heat-shrinkable tubes made of butyl rubber, or provide an adhesive layer on the inner wall of the heat-shrinkable tube. A type of heat-shrinkable tube with release paper temporarily attached in a spiral shape on top of the layer is used.

To cover the above-mentioned steel pipe connection portion with a heat-shrinkable tube, the tube is inserted into the steel pipe, adjacent steel pipes are welded together, and then the tube is set on the welded portion and heat-shrinked.

Furthermore, when installing steel pipes under a road, due to the length of time the road will be in use, the tubes may be buried with the tubes inserted after they have been welded together, and the next day the tubes may be dug up again and heat-shrinked.

Heat-shrinkable tubes for corrosion protection of steel pipes are heat-shrinked on the welded joints between steel pipes as mentioned above, but among conventional products, the former type is heat-shrinked inside the tube.

Since the wall surface is not protected in any way and remains exposed, it is easy for dust, dirt, water, etc. to adhere to it before it is heat-shrinked, and in the latter type, the release paper is only temporarily attached to the adhesive layer, so it is susceptible to vibrations during work. , the end peels off and floats due to impact, etc.
Similar to the former, dust, dirt, water, etc. are deposited on it.

On the other hand, heat-expandable tubes are often used for the inner lining of metal pipes, but there are no products that can keep the walls, especially the outer walls, clean until use. The lining work must be done after wiping the wall surface with a cloth, which is troublesome.

The present invention relates to a heat-recoverable tube having heat-shrinkable or heat-expandable properties devised in order to solve the problems of the conventional products mentioned above. The two ends of the two protective sheets are layered on the outside of both openings of the tube body, and the layered portions are integrated.

The heat-recoverable tube body in this invention is made of polyvinyl chloride, polyethylene, cross-linked polyethylene, polypropylene,
Single-layer type made of plastics such as fluorocarbon polymers, or rubber tubes such as natural rubber, silicone rubber, ethylene-propylene copolymer rubber, etc., processed to be heat-shrinkable or heat-expandable, or the inner wall of the single-layer type Alternatively, a multi-layer type in which an adhesive layer such as a pressure-sensitive adhesive, a self-fusing adhesive, or a heat-activated adhesive is provided on the outer wall can be used.

Further, as the protective sheet, a plastic sheet such as polyethylene, polyester, or polyvinyl chloride, nonwoven fabric, cloth, paper, or the like is used.

It is preferable to use a water-impermeable protective sheet because it can prevent not only dust and sand from adhering to the tube body, but also water from adhering to the tube body.

In addition, when using a plurality of types in which an adhesive layer that is constantly adhesive is provided on the inner or outer wall of the tube body, the protective sheet covering the adhesive layer may be a sheet that is non-adhesive to the adhesive layer, for example. It is preferable to use a polyethylene sheet or a sheet whose surface in contact with the adhesive layer has been subjected to a release treatment using a release treatment agent such as a silicone resin, since the peeling operation when removing the protective sheet can be carried out smoothly.

In the present invention, in order to cover the entire inner wall of the tube body using the above-mentioned protective sheet, (1) wrap the sheet once along the inner wall surface of the tube body and abut or overlap the ends of the sheet; A method of adhering a single-sided adhesive tape or a double-sided adhesive tape to the abutting or overlapping portions, (2) a method of wrapping the sheet multiple times along the inner wall surface of the tube body, and (3) a method of wrapping the sheet in advance by adjusting the inner diameter of the tube body. Make it a cylindrical body with the same outer diameter as,
This is carried out by, for example, inserting the cylindrical body into the tube body.

Further, the entire outer wall of the tube body may be covered with the protective sheet in accordance with the method for covering the entire inner wall described above.

The two protective sheets that cover the entire inner and wall surfaces of the tube body by the method described above are layered at both ends outside both openings of the tube body, and the layered portions are integrated.

This integration can be accomplished by (1) heat sealing, (2) adhesive fixing using an adhesive, single-sided adhesive tape, double-sided adhesive tape, etc., or (3) a method of attaching a protective sheet to both ends of each of the two protective sheets. This is done by using projections and depressions that fit together, or by fitting and fixing them using fasteners.

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

Figures 1 and 2 show an example of a heat-recoverable tube according to the present invention, and a tube body 2 with an adhesive layer 1 provided on the inner wall has an outer diameter of the same size as the inner diameter of the tube body 2. A protective sheet 3 formed into a cylindrical body having a diameter is inserted to cover the entire inner wall.

A protective sheet 4 covers the entire outer wall of the tube body 2, and is formed in advance into a cylindrical body having an inner diameter that is the same as the outer diameter of the tube body 2.

Both ends of the protective sheets 3 and 4 are layered on the outside of both openings of the tube body 2, and the layered portions are integrated by heat sealing.

5 is the heat seal portion.

Note that the surface of the protective sheet 3 that comes into contact with the adhesive layer 1 is subjected to a release treatment using silicone resin.

In the above, a cylindrical material with an outer diameter of the same size as the inner diameter of the tube body was used as a protective sheet to cover the entire inner wall, but in the present invention, a cylindrical material with an outer diameter of the same size as the inner diameter of the tube body was used. It is also possible to use a cylindrical object having an outer diameter of .

Similarly, a cylindrical object having an inner diameter slightly thicker than the outer diameter of the tube body may be used to cover the entire outer wall.

FIGS. 3 and 4 show another example, in which the entire inner and outer walls of the tube body 2 are covered with protective sheets 3 and 4, respectively.

As shown in FIG. 4, the protective sheets 3 and 4 are each wound once along the inner wall surface or outer wall surface of the tube body 1, and their ends are butted together, and a single-sided adhesive tape 6.7 is placed on the butted portion. It is glued.

The protective sheets 3 and 4 that cover the entire inner and outer walls of the tube body 1 in this manner are layered at both ends outside both openings of the tube body 1, and the layered portions are adhesively fixed with an adhesive 8. .

Next, the fifth example is a suitable example when there is no risk of water adhesion.
As shown in FIG.

Protective sheets 3 and 4 are placed on the inner and outer walls of the tube body 2.
are each wound in two layers (see Fig. 6).

Both ends of the protective sheets 3 and 4 are layered on the outside of both openings of the tube body, and the layered portions are heat-sealed and fixed.

In this case, it can also be fixed with staples.

In the examples shown in FIGS. 1 to 6 above, the protective sheet is in close contact with the inner wall surface or outer wall surface of the tube body, or the adhesive layer, but in the present invention, such close contact is not necessarily required, and both There may be a gap between them, but the point is that the inner wall surface, the outer wall surface, or the adhesive layer may be covered with a protective sheet to isolate them from the outside air.

Note that the protective sheet is removed immediately before the tube body is thermally shrunk or thermally expanded.

Since the present invention is constructed as described above, (1) it can effectively prevent foreign matter such as dust, sand, water, etc. from adhering to the tube, so that it can be tightly adhered or adhered to the adherend during use; (2) Since it has a relatively simple structure, it can be supplied to consumers at a low price.

[Brief explanation of the drawing]

Fig. 1.3.5 is a vertical cross-sectional view showing an example of the heat-recoverable tube according to the present invention cut into a semi-cylindrical shape along its length, and Fig. 2 is an A-A of Fig. 1. 4 is a sectional view taken along line B--B in FIG. 3, and FIG. 6 is a sectional view taken along line C--C in FIG. 5. DESCRIPTION OF SYMBOLS 1...Adhesive layer, 2...Tube body, 3, 4...Protection sheet, 5...Heat seal portion.

Claims (1)

[Scope of utility model registration request] The entire inner and outer walls of the heat-recoverable tube body are each covered with a long protective sheet, and both ends of the two protective sheets are layered on the outside of both openings of the tube body. Resilient tube.