HIGH FREQUENCY FUSING METHOD FOR POLYPROPYLENE SHEET AND INSULATING MATERIAL USED THEREIN

摘要

PURPOSE: To simply fuse a polypropylene sheet of which the high frequency fusion is considered to be difficult by high frequency fusion and to provide an insulating material used in high frequency fusion. CONSTITUTION: An insulating material 5 obtained by impregnating a fiber base material with varnish of which the dielectric constant and dielectric loss are higher than those of polypropylene is placed on a base stand 1 and a plurality of polypropylene sheets 6 are placed thereon and a mold 2 heated to temp. higher than 50 deg.C but lower than the m.p. of polypropylene is pressed to the sheets from above to apply high frequency voltage across the mold and the base stand.