CORE OF FIBERGLASS REINFORCED PLASTICS

摘要

PROBLEM TO BE SOLVED: To provide a core of fiberglass reinforced plastics that shows high roundness in its external and/or internal surface and is inexpensive to manufacture. SOLUTION: A hollow cylindrical core body 14 formed from fiberglass reinforced plastics is provided with a thermoplastic resin layer 15, 16 on at least either of its internal and/or external surface. This raises the roundness of the internal and/or external surface, and uniforms the thickness of a formed film wound on the core.