JPS6335980Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improved heat-shrinkable sheet,
In particular, the present invention relates to a heat-shrinkable sheet used for covering connections of pipelines or cables.

In general, heat-shrinkable tubes made of rubber or plastic take advantage of their heat-induced recovery properties to
It is used for waterproofing and protecting water pipelines and cable connections. In such cases, a heat-shrinkable sheet that can be joined at both ends to form a tube shape during use is easy to attach to the adherend, especially if the connection has already been completed or if the When repairs are required, it cannot be used unless it is in sheet form. Therefore, various heat-shrinkable sheets have been proposed in the past that have joint portions in which the end portions of the sheet are branched vertically and the branch portions at both ends are interlocked and joined.

However, in the vicinity of the joints of conventional heat-shrinkable end-branched sheets, the shrinkage rate is generally as high as that of the main body of the sheet, so the shrinkage stress during heat shrinkage may cause the mating joints to separate, or There were problems such as insufficient retention of the joint due to a decrease in mechanical strength due to thermal softening. For this reason, attempts have been made to reduce the shrinkage rate near the joint, but
This does not solve the problem of insufficient strength during thermal softening, and the result is that the joint must be held using auxiliary members or fasteners.

The purpose of the present invention was to eliminate such conventional drawbacks, and by reinforcing both ends of the sheet in advance and providing a fitting structure in these parts, the mechanical strength during heat shrinkage is reduced. It is an object of the present invention to provide a heat-shrinkable sheet that can prevent a decrease in strength and can be easily sealed by strong bonding.

As the embodiment of the heat-shrinkable sheet 1 of the present invention is shown in the drawings, one end 2 is reinforced with a mesh reinforcing member 4 therein, and the other end 3 is reinforced with a bias mesh reinforcing member 5. In a heat-shrinkable sheet 1 made of a polymeric material such as rubber or plastic that is reinforced by being embedded therein, a desired number of fitting holes 6 are formed at the end 2, and the other end 3 is provided with the end 2.
It has a structure in which fitting-locking protrusions 7' are re-stretched in number and shape corresponding to the fitting-locking holes 6 provided in the holes 6, and can wrap the desired adherend 12 in a tube shape. After fitting the covered and re-stretched fitting locking protrusion 7' into the corresponding fitting locking hole 6,
The locking joint portion 11 is formed by heating and shrinking and restoring.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1a shows a heat-shrinkable sheet serving as a base material, and a mesh reinforcement 4 is placed inside one end 2 of the heat-shrinkable sheet 1.
In the other ends 3, bias mesh reinforcements 5 are internally reinforced, each located approximately midway through the sheet thickness, as seen in FIG. 1b. The mesh-like reinforcing bodies 4 and 5 are inserted between each end of two heat-shrinkable sheets and bonded together by thermocompression, or when the heat-shrinkable film is wound around a core a required number of times and laminated and fused.
It may be molded by any method including inserting it into a predetermined position and press-molding it, or by other methods. The length of the mesh reinforcements 4 and 5 is preferably about a length slightly exceeding the insertion locking hole 6 or the insertion locking protrusion 7.
The heat-shrinkable base material is a commonly used material that can be given heat-shrinkable recovery properties by crosslinking, such as polyolefin.
During thermocompression bonding, the upper and lower layers may flow through the mesh of the mesh-like reinforcing bodies 4 and 5 and be cross-linked to such an extent that they are thermally fused, and the size of the mesh is also sufficient to allow fluid fusion. It's fine to use one. The mesh reinforcement 4 may be formed by punching a thin plate of metal, reinforced plastic, etc. into a mesh shape, or by knitting a single metal wire, a twisted wire shape, or an inorganic twisted wire shape into a mesh shape. . On the other hand, the bias mesh reinforcing body 5 may be made of a metal single wire, a stranded wire, or an inorganic strand that is knitted into a mesh shape and cut into a bias shape.

In Figure 2, a heat-shrinkable sheet 1 reinforced at both ends is shown.
A fitting locking hole 6 is provided on one end 2 side reinforced with the mesh-like reinforcing body 4, and a protrusion with a width larger than the width of the fitting locking hole 6 is provided on the other end side 3 reinforced with the bias mesh-like reinforcing body 5. A shaped portion 7 is provided. This protrusion 7 is heated and re-stretched in advance to a width that allows it to be inserted into the fit-in locking hole 6, and as shown in FIG. 3, a fit-in locking protrusion 7' with high shrinkage and recovery properties is provided. Here, since the reinforcing portion of the protrusion 7 has a bias shape, it can sufficiently follow the deformation caused by heating and re-stretching to form the fitting and locking protrusion 7'.
During heat shrinkage, the heat-shrinkable sheet 1 is given a property of being easily restored to a state close to that of the base material before stretching through the protrusions 7.

FIG. 4a shows a locking protrusion 7' that fits into the locking hole 6.
Fig. 4b shows a cross-sectional view. Here, it is preferable to apply a mastic 8 to the inner surface of the heat-shrinkable sheet 1 in order to make close contact with the adherend 12 and maintain waterproofness, and to further provide a mastic tongue-like portion 9 to fill in the step between the sheets. In addition, as shown in FIG. 4b, it is preferable to apply an adhesive 10 that melts and bonds at a temperature below the heating shrinkage temperature to the vicinity of the fitting locking protrusion 7' that contacts the fitting locking hole 6. The mastic 8 may be, for example, a butyl rubber mixture, and the adhesive may be, for example,
Examples include ethylene vinyl acetate copolymer and adhesive polyolefin resin.

A commonly used gas burner can be used for heating and shrinking. First, when the fitting portion shown in FIGS. 4a and 4b is heated, the fitting locking protrusion 7' is restored and deformed due to contraction, and the locking protrusion is form a shaped part 7'', and form a 5th a
A locking joint 11 is formed as shown in the figure, and a strong joint is obtained.

Next, the sheet 1 is heated and shrunk one after another, and the adherend 12 is
Closely contact. Here, when the fitting parts are heated and joined, the fitting locking hole 6 hardly shrinks and deforms even when heated because the mesh-like reinforcing body 4 is contained therein, and on the other hand, the fitting locking protrusion 6 Since the portion 7' has been re-stretched in advance, the deformation is large as described above, and when the portion 7' is heated and shrunk and restored, the width and thickness increase, and the effect is that it is in close contact with the insertion locking hole 6 with almost no dimensional change. With the addition of the effects of the bias mesh reinforcement 5 and the adhesive 10, a strong joint can be obtained.

The effects of the present invention are as follows.

In other words, the conventional problems such as detachment of joints due to shrinkage stress during heat shrinkage and difficulty in holding joints due to decrease in mechanical strength due to heat softening can be solved by reinforcing the joints in advance as in the present invention. The mechanical strength of the fitting portion is improved, and there is an advantage that a strong joint portion can be easily obtained without using any auxiliary members or fasteners for joining.

[Brief explanation of the drawing]

FIG. 1a is a front view showing the main part of the end reinforcement part of a heat-shrinkable sheet according to an embodiment of the present invention, FIG. 1b is a side view thereof, and FIG. 2 is a side view of the same. FIG. 3 is a plan view showing the insertion locking hole and the insertion locking protrusion at the end of the heat-shrinkable sheet according to the example, and FIG. 3 shows the re-stretched state of the insertion locking projection in FIG. FIG. 4a is a perspective view showing the entire fitting part of an embodiment of the present invention, FIG. 4b is a sectional view thereof, and FIG. 5a is a joint portion after heat shrinkage. FIG. 5b is a perspective view of the joint, and FIG. 5b is a sectional view of the joint thereof. 1...Heat-shrinkable sheet, 2...One end, 3...
Other end portion, 4...Mesh-like reinforcement body, 5...Bias mesh-like reinforcement body, 6...Insertion locking hole, 7...Protrusion part,
7'... Re-sharpened insertion locking protrusion, 8... Mastic, 7''... Locking protrusion, 9... Tongue-shaped part, 1
0... Adhesive, 11... Locking joint, 12... Adherent.

Claims (1)

[Scope of utility model registration request] In the heat-shrinkable sheet 1 made of a polymeric material, one end 2 is reinforced with a mesh reinforcing body 4 and the other end 3 is reinforced with a bias mesh reinforcing body 5. A desired number of fitting holes 6 are formed in the end portion 3, and a fitting hole 6 is re-stretched to have a number and shape corresponding to the fitting holes 6 provided in the end portion 2. A heat-shrinkable sheet characterized in that each protrusion 7' is provided.