JPS5896517A - Method of peeling off laminate tape - Google Patents

Abstract

PURPOSE:To peel off a laminated metal foil-rubber/plastic tape, which is welded to a covering layer of a cable by heating, without damaging the inner insulating layer when it is required to be peeled off, by previously heating the laminate tape layer. CONSTITUTION:The laminated tape of a rubber/plastic film and a metal foil covers longitudinally the covering layer of a rubber/plastic insulated cable, and is heated and welded by radiation heating to form a water barrier layer. When the laminate is peeled off to treate the ends of the cable, the laminate tape layer is previously heated to 60-150 deg.C using a gas burner, a band heater, an infrared heater, or the like, and then the laminate tape is peeled off. Thus the laminate tape can be peeled off readily and smoothly without lowering the electric properties of the cable.

Description

[Detailed Description of the Invention] The present invention applies a metal foil-rubber/plastic film laminate in which a water-blocking layer is provided by longitudinally fusing a metal foil-rubber/plastic film laminate tape onto a cable covering layer. The present invention relates to an improved method for peeling the bi-laminated tape of a cable.

Rubber/plastic insulation chamber cables have become widely used, but in recent years these cables have been fitted with laminated tape, which is a combination of rubber/plastic film and metal foil, to prevent water trees from forming, which can cause insulation breakdown. A method of forming a water-shielding layer is to form a water-shielding layer on any layer of a cable covering layer, such as on an insulating layer or an external semiconducting layer, by longitudinally applying radiant heat to fuse the cable covering layer.

However, this water-blocking layer made of metal-rubber/plastic and laminate tape, which is effective in preventing water trees, is tightly heat-sealed to the insulating layer or other coating layer so that no voids are formed. Therefore, it is difficult to remove the tape layer when processing the cable end, and conventionally the tape layer has been scraped off using a sharp piece of glass, but at the same time the tape layer is scraped off, the underlying coating layer is Situations that resulted in injury often occurred.

In order to solve these conventional problems, the inventors conducted extensive research on a method for peeling off laminated tapes, and as a result, they developed a method for peeling off laminated tapes using rubber/glasty, metal foil and rubber/plastic film that were vertically fused onto the coating layer of an insulated cable. It has been discovered that the laminate tape layer can be peeled off very easily and beautifully by heating the laminate tape layer to 60 to 150° C. in advance.

Next, the method of the present invention will be explained in more detail.

The metal foil-rubber/plastic film laminate tape layer vertically fused onto the rubber/plastic insulated cable coating layer is directly heated using a propane/gas burner, or a plate heater coated with silicone resin is heated. The laminate tape layer is wrapped tightly around the target area to be peeled and heated to a temperature of 60 to 150 by suitable heating means such as heating with electricity.
After keeping the rubber or plastic film layer of the laminate tape at a temperature of about 50°C for about 50 minutes until it is on the verge of melting, cut the laminate tape layer of the desired length to be peeled off with a cutter knife. The method of heating the laminate tape in the present invention is not limited to a gas burner, a band heater, an infrared heater, etc. The heating temperature for the heat treatment performed prior to peeling is limited to 60 to 150°C because if the preheating temperature is below 60°C, it will be below the softening temperature of the rubber/plastic of the laminate tape, making it difficult to peel off. In this case, the interface between the metal and rubber/plastic film layer that forms the laminate tape partially peels off, making it difficult to peel off the entire laminate tape as one piece.Also, when the cable approaches the melting temperature of the rubber/plastic, This is because there is a problem in that the coating layer is thermally deformed and the electrical characteristics of the cable are deteriorated after the laminate tape is peeled off.

Next, examples of the present invention will be described.

Example 1 A semiconductive composition made of an ethylene-ethyl acrylate copolymer base and a conductive carbon compounded on both sides of a lead tape with a thickness of 0.0 or 1 m was laminated to a thickness of 0.05 mm. A foil-semiconductive plasti laminate tape was wrapped vertically over the outer semiconductive layer of a cross-linked polyethylene insulated capeple with a total length of 20 (1 W+) and a conductor size of 250-, and was heat-fused by infrared radiant heating.

Next, in order to peel off the laminate tape layer heat-sealed onto the outer semiconducting layer, a Teflon tape made by Nitto Denko was applied to the metal foil-semiconducting plastic laminate tape layer. After wrapping Na920) in two layers with Shio wrap, a silicone insulated heater wire was wrapped on top of it and heated at 110°C for 30 minutes (Comparative Example 1), at 60°C for 30 minutes (Example 1), and at 150°C for 50 minutes. (Example 2
), 160°C for 0 min (Comparative Example 2), 200°C for 50 min
After heating for 70 minutes (comparative example 5), a circular cut was made in the circumferential direction with a utility knife at a point 70 fins from one end, and a single cut was made in the longitudinal direction at a length of 70 fins from the end. After attaching it, I used needle-nose pliers to pinch the notched end of the laminate tape and peel it off. The results were as shown in Table 1.

Table 1 If the plastic laminate tape is peeled off, it is possible to easily remove the ends without damaging the internal insulating layer and causing any adverse effects such as deterioration of electrical properties.

Claims (1)

[Claims] It is characterized by heating the laminate tape layer to 60 to 150°C before peeling off the laminate tape layer of metal foil and rubber/plastic film longitudinally fused onto the coating layer of the rubber/plastic insulated cable. How to peel off laminated tape.