Sheet composition for pipe connection, and sheet for electrofoaming fusion and connecting apparatus for underground pipes using the sheet composition

A method for producing a sheet for electrofoaming fusion using the sheet composition, comprising:

• a) weaving a heater line having a zigzag or net shape using a raschel machine;
• b) incorporating a master batch comprising 30 to 50% by weight of low-density polyethylene, 5 to 20% by weight of high-density polyethylene, 10 to 30% by weight of a metallocene polyethylene-based elastomer, 20 to 40% by weight of a maleic anhydride graft copolymer, 1 to 10% by weight of a foaming agent and 0.1 to 5% by weight of an additive, with respect to 100 parts by weight of a base resin comprising 30 to 50% by weight of low-density polyethylene, 5 to 20% by weight of high-density polyethylene, 10 to 30% by weight of a metallocene polyethylene-based elastomer, and 20 to 40% by weight of a maleic anhydride graft copolymer, into an extruding machine, and melt-extruding the master batch at a foaming temperature or less to produce a non-foamed sheet;
• and
• c) laminating the extruded non-foamed sheet on one or both surfaces of the woven heater line, followed by pressing to integrate the non-foamed sheet with the heater line.