JPS608039A - Manufacture of thermo-shrinkable tube - Google Patents

Abstract

PURPOSE:To simply obtain a high-quality thermo-shrinkable tube suitable for connection of communication cables, etc., by a method in which halved metals are fitted on the periphery of a long material to form a cylindrical frame, and a thermo-shrinkable tape wound around the frame is integrally bonded in a tubular form by heating. CONSTITUTION:Halved metals 11 formed by dividing a thin metal cylinder into two parts longitudinally are fitted on the periphery of a long material, e.g., communication cable 1, etc., for example. The four corners of the halved metals 11 are joined with a spacer 12 into a cylinder. A thermo-shrinkable tape 14 is wound around the cylinder and heated until the tape 14 is integrally bonded to the cylinder to form a thermo-shirnkable tube. The thermo-shrinkable tube is cooled, the spacer 12 is removed out, and the halved metals 11 are removed to obtain an aimed tube. EFFECT:Many kinds of thermo-shrinkable tubes can be simply produced in small numbers with good operability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a heat shrinkable tube that fits on the outside of an elongate body.

This kind of heat-shrinkable tube that fits perfectly into the outer housing of a long body is used, for example, in the connecting part of a communication cable as shown in FIG.

In other words, 1 and 1 in Figure 1 are communication cables.

la, la is the cable jacket, 2 is the communication cable 1,
1, the heat shrink tube 3.3 is connected to the communication cable 1 along with the auxiliary lead pipes 4, 4 and the main lead pipe 5.
．． It is strangely aligned with the outside of 1. Then, together with the heat-shrinkable tubes 3, 3, the cable is wrapped so as to be located between the cable jacket [aIIa] and the heat-shrinkable tube 3.3, and between the heat-shrinkable tubes 3, 3 and the auxiliary lead pipe 4.4.
, by heating the hot melt adhesive tape 6, the cable jackets 1a, 1a, the heat shrinkable tubes 3.3 and the auxiliary lead pipes 4.4 are bonded to each other.
4 and the main lead pipe 5 are joined to each other by a leadwork part 7.

By the way, in the connection part of such a communication cable, for example, the existing communication cable 1 that is routed through a manhole
If it becomes necessary to provide such a connection in the middle of the
3. Circular heat shrink tube as usual. Main lead pipe 5. The auxiliary lead pipe 4 cannot be connected to the existing communication cable 1. Therefore, in such a case, the main lead pipe 5. The auxiliary lead pipe 4 is first cut with a saw or the like to make it vertically split, and then fitted to the outside of the communication cable 1, and each vertically split part is worked with lead on the communication cable l to return them to their original cylindrical shape. When repaired and applied, a constant vertical connection method is used. It is also necessary to cut the heat shrink tube 3 vertically in the same way.

Therefore, as such a heat-shrinkable tube 3, a bonded heat-shrinkable sheet 8 as shown in FIGS. 2 and 3 has come to be used. The heat-shrinkable sheet 8 shown in FIG. 2 has both ends joined by zippers 9, and the heat-shrinkable sheet 8 shown in FIG. 3 has both ends joined by slit fittings 10.

However, in such a bonded heat-shrinkable sheet 8,
Connections of communication cables that require complete airtightness and water-tightness because the joints have complicated shapes, are prone to deformation during shrinkage, variations in heating temperature, and poor adhesion of hot bath adhesives. There was a problem that it could not be applied for commercial purposes.

On the other hand, there is a method of wrapping a heat shrink tape on the auxiliary lead pipe 4 instead of the heat shrink tube 3 and shrinking it by heating. However, in this method, the outer side of the heat-shrinkable tape wrapping layer shrinks first and its outer diameter is reduced during heating, so wrinkles occur in the inner layer between the heat-shrinkable tape layers or at the contact interface with the heat adhesive tape 6. There was a problem in that air bubbles were generated that impaired airtightness and watertightness.

The present invention has been made in consideration of the circumstances described above, and is made by fitting a half metal fitting on the outside of a long body such as a communication cable to form a cylindrical shape, and using this cylindrical body as a jig. By wrapping a heat-shrinkable tape around the outer circumference and then heating it, a heat-shrinkable tube that fits on the outside of a long object such as a communication cable can be made easily and with high quality. The purpose of the present invention is to provide an unprecedented method for producing heat shrinkable tubes.

The present invention will be explained below based on FIGS. 4 to 6.

Figure 4 shows an example of a jig for manufacturing a heat shrinkable tube used in the practice of the present invention, which is a thin half-split cylinder with a metal body having heat resistance of 11 degrees, heat resistance up to about 200'C, and mechanical strength of 9 days. It is a set of two half-shaped metal fittings. In addition, 12 in the same figure is a spacer having an H-shaped cross section and having the same heat resistance and mechanical strength as the half fitting 11, and 4
Each piece is a set. As shown in FIG. 4, this spacer 12 is fitted between the abutting portions of the two halves 11 and assembled into a cylindrical shape with a constant spacing P9r between them.

FIG. 5 shows how the present invention is implemented using such a half metal fitting 11 and a spacer 12. In carrying out the present invention, first, a protective glass tape 13 is wrapped around the communication cable 10 to a thickness of about 1 mm, for example, to avoid thermal effects on the communication cable 1, and then the circumferential surface is sandwiched. Place the two halves 11 together so that they fit together, join their four corners with spacers 12, and connect them to a cylindrical body. Then, the cylindrical body is wrapped with heat shrink tape 14 on the outer circumferential surface of the two halves 11, and the heat shrink tape 14 is wrapped around the outer circumferential surface of the two halves 11 using a heating device such as a gasoline torch lamp, a propane burner, or an electric hot plaster. Until the wrapped layer becomes transparent (approximately 110
~130'c) Heat evenly. After that, natural cooling or forced cooling using air blowing is performed, and when the heat shrink tape 14 has cooled to a temperature that can be removed by hand, the spacer 12. Half metal fitting 11. Remove the protective glass tape 13. In this way, a heat shrink tube is produced by integrating the heat shrink tape 14.

After winding the heat-shrinkable tape 14, if the tape end at the end of the winding is fixed with adhesive glass tape O lengthwise, the heat-shrinkable tape 14 can be prevented from unraveling and the finished product can be neatly finished.

In this way, the heat shrink tape 14 is tightly wound around the cylindrical inner frame formed by the half metal fitting 11, and the heat shrink tape 14 is integrated. A high-quality heat-shrink tube that does not contain air bubbles between the shrink tapes 14 can be produced on the outer sheath la of the communication cable 1.

By the above method, a heat shrink tube with an inner diameter of 40 to 80 mm and a thickness of 2 to 3 mm is produced using a leaf material such as a cross-linked polyethylene tape and a gasoline torch lamp.As a result, the time required for production is as follows: It was extremely short and efficient, taking 4 minutes to 10 minutes including the natural cooling time, and had a clean finish with almost no bubbles. By the way, when the wall thickness of the half-split metal fitting 11 is increased, the dipping time during which the heat capacity increases increases. -! Ta,
The lighter the half metal fitting 11 is, the more convenient it is to operate and trim during manufacturing work. On the other hand, when the heat-shrinkable tube that has been heated to a high temperature is cooled and hardened, it generates an extremely large shrinkage force, and if the half fitting 11 becomes too thin, there is a risk that it will be deformed. For this reason, for example, when the material of the half fitting 11 is made of brass, it is appropriate that the wall thickness is about 1 mm.Also, when the heat shrink tube in a high temperature state is cooled, the diameter is 2 mm. mm, so the outer diameter of the half-split fitting 11 after assembly must be larger than the inner diameter of the heat-shrinkable tube to be manufactured by the amount of shrinkage.Also, when assembling the half-split fitting 11, spacer 1
If the height of spacer 2 is set to 2 mm or more, that spacer 1
2 is removed and disassembled, a sufficient gap is created between the half metal fitting 11 and the heat shrinkable tube 1, which is convenient because the half metal fitting 11 can be easily taken out.

FIGS. 6 and 7 show other examples of the half fitting 11 and the spacer 12 used in carrying out the present invention. In this example, the spacer 12 is a metal piece having a dumbbell-shaped cross section, and grooves 15 are formed at the four corners of the half-split fitting 110, and the spacer 12 is placed in each of the mutually opposing grooves 1fJj. By inserting a total of four
The two halves 11 are joined together at a predetermined interval. According to such a connection, the half fittings 11 are connected to each other, making it easier to manufacture the heat shrink tube.

It should be noted that as for the half fittings 11 and the spacers 12, it is possible to use various structures other than the above-mentioned ones on the valley side.

As explained above, according to the method for manufacturing a heat-shrinkable tube according to the present invention, a heat-shrinkable tape is wrapped around the outer periphery of a long body such as a communication cable using a half metal fitting and a space f-. Then, by integrating the heat-shrinkable tape into a tube shape using heat, mt.
In order to make heat-shrinkable tubes that match each other, for example, you can place heat-shrinkable tubes on the outer periphery of a long body such as a communication cable installed at the site at a temperature of ℃. This method is also ideal for easily producing high-quality heat-shrinkable tubes in small quantities.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a connection part of a communication cable using a heat-shrinkable tube and a hot melt adhesive, Figs. 2 and 3 are cross-sectional views showing different examples of bonded heat-shrinkable sheets, and Fig. 4 is A perspective view showing an example of a half-split metal fitting and a spacer used in carrying out the invention, FIG. 5 is a conceptual diagram shown to explain the implementation status of the invention, and FIG. FIG. 7 is a perspective view showing another example of the spacer, and FIG. 1... Communication cable, 3... Heat shrink tube, 11
... Half metal fitting, 12 ... Spacer, 14 ... Heat shrink tape. Applicant Japan' Kameshin Telephone Public Corporation Figure 4 11 Figure 5 I 194-

Claims (1)

[Claims] A method for producing a heat-shrinkable tube that fits on the outside of a long body, in which a half-split fitting made by vertically dividing a thin metal cylinder into two is fitted on the outside of the long body, and the half-split fittings are assembled. They are joined to each other via a spacer on the longitudinally divided surfaces of the metal fittings, and a heat shrink tape is wrapped around the outer circumferential surface of the circular body formed by joining the 70-half metal fittings, and then the heat shrink tape is used as a heat shrink tube. The heat shrink tube is heated until it is integrated, and after cooling the integrated fire heat shrink tube, the spacer and the outer knife are disassembled and removed to produce a heat shrink tube. How to make heat shrink tube.