JPH0337947Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heat-shrinkable sheet used for anticorrosion, waterproofing, insulation, etc., and particularly relates to a heat-shrinkable sheet with a structure in which both ends in the direction of shrinkage, that is, the joint parts, are reinforced. .

Conventionally, a cylindrical heat-shrinkable tube or a sheet-like heat-shrinkable sheet 1 has been used for purposes such as corrosion protection, waterproofing, and insulation. In the case of a heat-shrinkable tube, it is necessary to insert the sheath 3 in advance. On the other hand, the heat-shrinkable sheet 1 can be used in places where it is impossible to insert a tube, such as in the middle of a long object or in the repair of an existing pipe, by wrapping the sheet 1 around a covered object 3, fixing both ends, and heating it to shrink it. There are benefits that can be applied.

Conventionally, various methods have been devised for fixing both ends of the sheet 1 after it has been wound. For example, as shown in FIGS. 1a and 1b, as an example of the conventional method, chucks 2 are attached to both ends of a heat-shrinkable sheet 1 in the shrinking direction, and the sheet 1 is fixedly formed into a cylindrical shape by the chucks 2. There is a chuck type in which the covering body 3 is inserted into the cylindrical sheet, and then the sheet 1 is heated and shrunk to tightly cover the surface of the covering body 3.

However, with this chuck type, it is difficult to connect the chuck 2 and the heat-shrinkable sheet 1, and the chuck 2 may come off when buckled during shrinking work or after construction.

As another conventional example, as shown in FIGS. 2a and 2b, protrusions 4 are provided at both ends of the heat-shrinkable sheet 1 in the shrinking direction, and these portions are fixed with fixing fittings 5, so to speak. There are protruding types.

Although this has been widely used, it is necessary to prevent the fixed portion from shrinking due to heat, and it is necessary to adhere the protrusion 4 to the heat-shrinkable sheet 1. If the protrusion 4 is not present, it will come off and come off the fixture 5.

As still other conventional examples, FIGS. 3a and 3
As shown in Fig. b, a divided part 6 is provided in which both ends of the heat-shrinkable sheet 1 in the shrinking direction are divided into two layers in the thickness direction, and the covering body 3 is wrapped and wrapped, and then the divided part 6 is divided into two layers in the thickness direction. It is a so-called branch type in which 6 are engaged alternately.

This method is also relatively well-used, but since the divided portions 6 do not shrink much, the shrinkage rate as a heat-shrinkable sheet cannot be maintained very high.

Further, as still another conventional example, as shown in FIG. This is a type of 8-type adhesive tape.

This method is inexpensive, but the adhesive tape 8
Problems arise such as peeling over time and slippage due to a decrease in adhesive strength during heating during construction, so only those with a small shrinkage rate can be used.

As yet another conventional example, as shown in FIG. 5, both ends are penetrated and "crimped" with caulking metal fittings 9, similar to the method using the fixing metal fittings 5 described above. In this method, it is very difficult to prevent the fixing parts at both ends from shifting or coming off even when heated due to the stress generated during heat shrinkage. In particular, if the fixed portion is long, it is difficult to shrink that portion, so the shrinkage rate of the sheet 1 as a whole cannot be increased. Furthermore, in this through-caulking type, the through-holes 10 expand when the sheet 1 is heated and contracted, and tears may occur starting from the through-holes 10.

As described above, the conventional heat-shrinkable sheet 1 has many drawbacks during its construction, and its applications are also narrowed accordingly.

The present invention was developed to eliminate the above-mentioned drawbacks, and it is possible to securely fix both ends of the sheet, sufficiently withstand damage such as tearing and shifting due to shrinkage stress during heat shrinkage work, and also provide a sheet fixing section. The present invention relates to a heat-shrinkable sheet that has functions such as being able to have a very short length and increasing the shrinkage rate of the sheet as a whole.

As shown in the drawings, the present invention is directed to a porous material such as a mesh or a punched sheet having a large number of spaces 12 of at least 1 mm ² in both ends of a heat-shrinkable rubber or plastic sheet 11 in the shrinking direction. 1
3 is characterized in that the sheet flesh 11 on both sides is adhered to and integrated with each other through the holes or meshes 12 of the porous body 13, and is embedded approximately parallel to the sheet surface.

The present invention will be further explained below with reference to Examples.

Example 1 The net-like material 13 as a porous body used in the implementation was a brass wire with a diameter of 0.3 mmφ, and the grid spacing was 1 mm.
It's getting old. That is, as shown in FIG. 6, a wire mesh 13 provided with holes 12 was used.

The heat-shrinkable sheet 11 is made by stretching a cross-linked polyethylene film with a thickness of 0.3 mm to twice its length. After wrapping the film in three layers around a mandrel (not shown) with a diameter of 500 mm, the length is equal to the width of the film. Place the 10 cm net material 13, wrap three layers of the same polyethylene film 11 on top, and heat it at 200°C.
After heating for 1 hour to thermally fuse the layers of each film, the film was cooled and removed from the mandrel to obtain a cylindrical heat-shrinkable tube. The center of the tube where the wire mesh 13 was inserted and buried was cut open to obtain a heat-shrinkable sheet 11 as shown in FIGS. 7a and 7b.

The cut-out portion of the sheet 11 penetrated through the holes 12 of the lattice portion of the wire mesh 13, and the flesh of the polyethylene films on both sides were heat-sealed and integrated with each other, and the wire mesh was embedded in the polyethylene sheet.

This heat shrink sheet 11 is used as a covering body with a diameter of 250 mm.
It was wrapped over a pipe 14 of mmφ, and as shown in FIG. 8, the buried portion of the wire mesh was overlapped, and this portion was fixed by passing a fastener 15 such as a bolt through it.
Then burn the whole thing with a hand gas burner (not shown).
When it was heated and shrunk, no abnormalities such as tearing occurred at the fixed part, and it was able to be covered with a good appearance.

Example 2 A heat-shrinkable sheet 11 was obtained in the same manner as in Example 1, using a mesh 13 made of wire with a diameter of 0.5 mmφ and a lattice spacing of 10 mm ² as a porous body, and then
The thus obtained heat-shrinkable sheet was attached to a pipe with the same diameter as in Example 1, and when it was heated and shrunk,
Although the through holes of the bolts 15 were somewhat stretched in the longitudinal direction due to the shrinkage stress of the sheet and deformed into an elliptical shape, the bolts 15 did not come off and were successfully covered.

Comparative Example 1 A heat-shrinkable sheet was made in the same manner as in Example-1 except that the wire mesh 13 was used as a porous body, and when it was wrapped and heat-shrinked in the same manner as in Example 1, tearing occurred from the bolt through hole. However, the bolt came off and it was repairable.

Comparative Example 2 A heat-shrinkable sheet was made in the same manner as in Example-1 using glass cloth instead of the mesh material 13 as a porous body, and when this was placed on a pipe, the glass of the heat-shrinkable sheet was The cloth layer and polyethylene layer peeled off and coating was impossible.

The effects of the present invention are as follows.

That is, the feature of the present invention is that the heat-shrinkable sheet 11
A porous body 13 is embedded at both ends of the porous body 13 such that the fleshy parts of the rubber or plastic films 11 on both sides are fused together through the holes 12 or the meshes 12 of the mesh 13. (a) Therefore, even if the heat-shrinkable sheet 11 is fixed by penetrating both ends with a jig, no tearing will occur even if the heat-shrinkable sheet 11 is subjected to stress during heat shrinkage. (b) Also, this fixing method also uses, for example, one bolt
5 through the hole 12 and fixing, no special jig is required. (c) Furthermore, with other conventional methods, the fixing part is not very firmly fixed, so it is impossible to strongly heat the fixed part, so the shrinking work requires skill, but this does not happen with the present invention. . Next, (d) the fixed part is attached to the covered body 14.
Since it can be formed on the outside of the shrinkable sheet 11, it is possible to increase the shrinkage rate of the shrinkable sheet 11 as a whole.
4 can also be fully used. (E) Furthermore, even when covering different diameter portions of the sheathing pipe 14, due to its flexibility, no gap is generated between the sheathing body 14 of the fixed part and the shrinkable sheet 11, and the anticorrosion effect is improved.

[Brief explanation of drawings]

Fig. 1a is a schematic cross-sectional view showing an example of a conventional heat-shrinkable sheet, Fig. 1b is a schematic perspective view showing the state at the time of construction, and Fig. 2a is a schematic cross-sectional view showing an example of a conventional heat-shrinkable sheet. A schematic cross-sectional view, Figure 2b is a schematic cross-sectional view showing the state at the time of construction, and Figure 3.
Figure a is a schematic cross-sectional view showing still another example of the conventional heat-shrinkable sheet, Figure 3b is a schematic cross-sectional view showing the state at the time of construction, and Figure 4 is a schematic cross-sectional view showing still another example of the conventional heat-shrinkable sheet. FIG. 5 is a schematic cross-sectional view showing the state at the time of construction of an example, FIG. 5 is a schematic cross-sectional view showing the state at the time of construction of still another example of the conventional heat-shrinkable sheet, and FIG. Fig. 7a is a plan view showing an embodiment of the present invention, Fig. 7b is a sectional view thereof, and Fig. 8 is a perspective view showing an embodiment of the invention. FIG. 2 is a schematic cross-sectional view showing the state during construction. 1...Heat-shrinkable sheet, 2...Chick, 3...
...Object to be covered, 4...Protrusion, 5...Fixing metal fittings, 6...
... Divided portion, 7... Overlapping portion, 8... Adhesive tape, 9... Caulking metal fittings, 10... Through hole, 11...
...Heat-shrinkable rubber or plastic sheet (e.g. cross-linked polyethylene film), 12... Holes or mesh, 13... Porous body (mesh or punched sheet), 14... Covering body, i.e. pipe, 15 ……
A fastener like a bolt nut.

Claims (1)

[Scope of utility model registration request] A porous body having a large number of spaces of at least 1 mm ² is placed in both ends of a heat-shrinkable rubber or plastic sheet in the shrinking direction, and the sheet flesh on both sides is adhered or fused together through the spaces of the porous body. A heat-shrinkable sheet is characterized in that each sheet is embedded substantially parallel to the sheet surface in a curved state.