Method of and apparatus for forming seal portion of tubular body of synthetic resin

摘要

When a tubular body containing a synthetic resin material of a high gas-barrier quality is heated and fused, heat may decompose and foam the material. A projecting end portion (3) of an end (2) of a tubular body (1) is heated and fused, and is compressed and diminished in volume to be compression molded into a seal portion (5) of a desired shape whereby the seal portion (5) is increased in density and formed into a desired shape.