JPH01125216A - Production of elastic self-shrinkable tube - Google Patents

Abstract

PURPOSE:To easily produce an elastic self-shrinkable tube with a rolled body supported on the outer periphery of a tubular body, by feeding a liquid under pressure into an elastic tube under a sealed condition to enlarge the tube radially, restricting the tube to a desired outside diameter, freezing the liquid present inside the tube, rolling back the elastic tube on the outer peripheral surface of the resultant frozen columnar body to form the rolled body, and transferring the rolled body onto the outer periphery of the tubular body. CONSTITUTION:A sealed part is provided at one end part of an elastic tube 1a, a pressurized water sealing hole is provided at the other end part, and the tube 1a is inserted into an outer shape restricting means 3 capable of being split into two in the axial direction thereof. Pressurized water at a desired pressure is fed in through the sealing hole under a sealed condition to enlarge the tube 1a in diameter to the inside diameter of the restricting means 3, thereby obtaining an elastic tube 1b having a desired diameter, and the pressurized water present inside the tube 1b is appropriately frozen to be a frozen columnar body 2b. The elastic tube 1b enlarged in diameter at a desired expansion ratio on the columnar body 2b is rolled back at one end part thereof on the outer peripheral surface of the columnar body 2b so that the inner and outer peripheral surfaces of the tube 1b are disposed on the outer and inner sides, respectively, to form a rolled body 4a. The rolled body 4a is transferred onto the outer periphery of a tubular body 5a coaxially fitted over the other end part of the columnar body 2b.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing an elastic self-shrinking tube that can easily protect and insulate connecting parts of electric wires, cables, pipes, etc. .

[Conventional technology]

In recent years, elastic self-shrinkable tubes that can be shrunk without using heat have been used to protect, insulate, or repair connecting parts of electric wires, cables, pipes, etc. This elastic self-contracting tube is made by expanding an elastic tube made of a material having rubber-like elasticity in the radial direction and supporting it as it is on a rigid hollow support that can be removed. The elastic self supported on the support is expanded by expanding the diameter from the inside with pressurized gas, and holding it under reduced pressure with an outer mold. A method of obtaining a shrinkable tube, etc. has been adopted.

[Problem that the invention seeks to solve]

However, in the above method, if the circumferential force at the desired expansion magnification is larger than the vacuum suction force, it cannot be maintained, and there are problems such as being subject to restrictions such as the material of the tube, the cross-sectional size, and the expansion magnification. was there. In addition to this method, there is also a method of mechanically expanding the diameter, but there is no suitable method that allows the hollow support to be easily supported by inserting it inside the hollow support in the expanded diameter state.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems.A liquid is pressurized and sealed inside an elastic tube made of a material having rubber-like elasticity, and the liquid is expanded in the radial direction. an outer diameter regulating step for regulating the outer diameter to a desired outer diameter; a freezing step for freezing the liquid contained within the elastic tube that has been regulated to the desired outer diameter in the regulating step; and a freezing step for holding the liquid on the frozen cylindrical body through the freezing step. a winding step in which the rolled elastic tubes are turned over and stacked on the outer peripheral surface of the frozen cylindrical body so that the inner peripheral surface is on the outside and the outer peripheral surface is on the inside to form a rolled body; The method is characterized by comprising a transition step of transferring the rolled body to the outer periphery of the cylindrical body and supporting it.

The present invention will be explained in detail below with reference to FIGS. 1 to 6a and 6b. FIG. 1 shows a cross-sectional view of an elastic tube la made of rubber-like elasticity, and FIG. 2 shows a sealing part (not shown) provided at one end of the elastic tube la, and It is inserted into the outer shape regulating device 3 which can be divided into two in the axial direction with a pressurized water sealing hole (not shown) provided therein. Next, pressurized water 2a at a desired pressure is sealed through the sealing hole and expanded to the inner diameter of the outer shape regulating device 3 to be regulated to form an elastic tube lb with a desired diameter.Then, the pressurized water contained therein is appropriately frozen. It is assumed to be a cylindrical body 2b. 3rd a
Figures 3 and 3b show that the outer shape regulating device 3 that has regulated the outer diameter in the above process is removed, and an elastic self-shrinking tube 6a is manufactured from the elastic tube 1b held at a desired length on the frozen cylindrical body 2b. FIG. FIG. 3a shows the outer circumferential surface of the frozen cylindrical body 2b so that the inner circumferential surface of the elastic tube lb shown by the broken line is on the outside and the outer circumferential surface is on the inside when the elastic tube lb is expanded to a desired magnification on the frozen cylindrical body 2b. The rolled body 4a is turned over at one end and laminated to form a rolled body 4a, and the rolled body 4a is transferred to the outer periphery of a cylindrical body 5a that has been coaxially inserted into the other end of the frozen cylindrical body 2b. FIG. 3b shows a cross-section of an elastic self-shrinking tube 6a made of a wound body 4a having one laminated portion produced by the above-described process.

Figures 4a to 4c illustrate another embodiment in which an elastic self-shrinking tube 6b consisting of a rolled body 4c having two laminated parts A and B is manufactured from an elastic tube lb held in the same manner as above. It is a diagram. FIG. 4a shows a wound body 4 in which the elastic tube 1b held on the frozen cylindrical body 2b is indicated by a broken line.
b, and then unwind the adult body 4b by an amount corresponding to approximately half the length of the elastic tube 1b around the outer periphery of the cylindrical body 5b coaxially inserted into the frozen cylindrical body 2b. It shows the state where the laminated part B has been arranged after the transition,
Next, as shown in Fig. 4b, the other end is turned over to form a laminated part A to form a rolled body 4c, which is transferred to a cylindrical body 5b and then extracted from the frozen cylindrical body 2b as shown in Fig. 4c. two laminated portions A disposed on the outer periphery of the cylindrical body 5b;
.

An elastic self-shrinkable tube 6b with B is obtained.

The elastic chain la used here is made of a material with rubber-like elasticity, and is made of rubber such as natural rubber or synthetic rubber, or a mixture of two or more of them, as well as reinforcing agents, softeners, anti-aging agents, cross-linking agents, and cross-linking aids. A composition obtained by appropriately blending the following is formed into a predetermined shape, and subjected to chemical crosslinking, electron beam irradiation crosslinking, etc.
In addition to being obtained by crosslinking by appropriate means, it can also be obtained by molding thermoplastic rubber or rubber-like soft plastic into a predetermined shape. In order to enclose pressurized water 2a inside the elastic tube 1a obtained in this way and expand the elastic tube 1a to a desired outer diameter, a cylinder is used to uniformly regulate the outer diameter of the expanded elastic tube 1b. shaped outer diameter regulating tool 3
The outer diameter regulating device 3 is a cylindrical body that can be divided into two parts in the axial direction for easy removal, and is obtained by appropriately molding a rigid plastic or metal, but there are some problems in terms of heat conduction during freezing. Metals such as iron, aluminum, and copper are preferably used. The temperature at which the pressurized water 2a is frozen at a temperature below the freezing point while being regulated by the outer diameter regulating device 3 thus formed to form the frozen cylindrical body 2b is as follows:
However, the temperature is such that it can maintain flexibility to the extent that the rolled bodies 4a, 4c can be made by turning and stacking them, and the temperature is such that the ice does not melt until the rolled bodies 4a, 4c are transferred to the outer periphery of the cylindrical bodies 5a, 5b. It is desirable that the elastic tubes 1b are turned over and stacked on the outer peripheral surface of the frozen cylindrical body 2b to form rolled bodies 4a, 4c.
If the strength of the frozen cylindrical body 2b is insufficient in the process of making the rolled bodies 4a, 4c and transferring them to the cylindrical body 5, the frozen cylindrical body 2b should be positioned coaxially approximately at the center of the frozen cylindrical body in advance. Reinforcing rods can be placed as appropriate. The cylindrical body 5 that transfers and supports the wound bodies 4a and 4c thus formed is formed into a desired shape from a polyolefin resin such as polyethylene or polypropylene, or a rigid plastic such as polyvinyl chloride resin. The resulting roll is 4
In order to facilitate the removal of the cylindrical body 5 after transferring a and 4c to the covered object, it is recommended to make cuts in the cylindrical body in advance to make it easier to disassemble or to make it easier to crush by impact. is desirable.

FIGS. 5a, 5b, 6a, and 6b are cross-sectional views showing the state in which the elastic self-shrinking tubes 6a, 6b obtained as described above are coated on a covered object. Fifth
Figure a shows an elastic self-shrinking tube 6a consisting of a rolled body 4a having one laminated portion placed on a covering object 7 to form a rolled body 4a.
Fig. 5h shows a state in which the rolled body 4a is being transferred from the cylindrical body 5a in the direction of the arrow and placed on the covered object 7, and FIG. The state in which the elastic coating layer 8 is formed is shown.

FIG. 6a shows an elastic self-shrinking chain member B consisting of a rolled body 4C having two laminated parts, placed on a covered object 7, and first, one laminated part A is unwound and rolled out onto the covered object 7. Fig. 6b shows a state in which the other laminated part B is moved onto the covering object 7 while being rolled up on the cylindrical body 5b. The state in which the elastic coating layer 8 is formed on the coated object 7 by being expanded is shown.

〔Effect of the invention〕

As described above, the method for manufacturing an elastic self-shrinking tube of the present invention involves supporting the rolled body on the outer periphery of a cylindrical body by turning over the elastic tube so that the inner peripheral surface is on the outside and the outer peripheral surface is on the inside. Compared to conventional manufacturing methods, the elastic self-shrinkable chain can be manufactured easily with fewer steps.
Its industrial value is extremely large.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the elastic tube, Figure 2 is a sectional view showing the elastic tube expanded in diameter and regulated in outer diameter, and Figures 3a and 3b are elastic tubes consisting of a wound body with one laminated part. A cross-sectional view illustrating a method for manufacturing a self-shrinkable tube, FIG. 4a,
Figures 4b and 4c are cross-sectional views illustrating a method for manufacturing an elastic self-shrinkable tube consisting of a winding body with two laminated parts, and Figures 5a and 5b are cross-sectional views of a winding body with one laminated body. FIGS. 6a and 6b are cross-sectional views showing a state in which a covered object is covered with an elastic self-shrinking tube made of an adult body. FIG. 3 is a cross-sectional view showing a covered state. la, 1b~elastic tube, 28~pressurized water, 2b
~Frozen cylindrical body, 3~Outer diameter regulating device, 4a, 4b,
4c. 4d~rolled body, 5a, 5b~cylindrical body, 6a, 6b~
Elastic self-shrinking tube.

Claims (1)

[Claims] an outer diameter regulating step in which a liquid is pressurized and sealed inside an elastic tube made of a material having rubber-like elasticity to expand in the radial direction, and the outer surface of the tube is regulated to a desired outer diameter with an outer diameter regulating device; A freezing step of freezing the liquid contained in the elastic tube whose outer diameter is regulated to a desired outer diameter, and a freezing step in which the inner peripheral surface of the elastic tube held on the frozen cylindrical body is on the outside and the outer peripheral surface is on the inside. A winding step of forming a rolled body by turning over and stacking layers on the outer peripheral surface of the frozen cylindrical body so that the rolled body is transferred to the outer periphery of the cylindrical body and supported A method for producing an elastic self-shrinkable tube, comprising a transition step of