PROCESS OF PRODUCING THERMOPLASTIC POLYESTER SERIES RESIN FOAMED MATERIAL

摘要

A process of producing a thermoplastic polyester series resin foamed material is disclosed, which comprises heating and further foaming a thermoplastic polyester resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water or steam of at least 60.degree.C and then heating the foamed material by bringing into contact with a heating medium other than water of at least 100.degree.C to further foaming the foamed material. A process of producing a thermoplastic polyester series resin foamed material is also disclosed, which comprises heating and further foaming a thermoplastic polyester series resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water to steam of at least 60.degree.C, heating and further foaming the foamed material by bringing into contact with a heating medium other than water of at least 100.degree.C, and molding the foamed material by a mold.