摘要:
A plane plate of corrugated paperboard, which is produced by bonding a corrugated medium and at least one liner board with a thermoplastic resin, is shaped into a curved plate by means of a hot-press so that the resin fluidifies and allows the medium and each liner board to make individual and slipping movements during press-forming. The resin hardens upon subsequent temperature reduction and affords the curved heat and sound insulator plate a good shape retentivity.
摘要:
A plane plate of corrugated paperboard, which is produced by bonding a corrugated medium and at least one liner board with a thermoplastic resin, is shaped into a curved plate by means of a hot-press so that the resin fluidifies and allows the medium and each liner board to make individual and slipping movements during press-forming. The resin hardens upon subsequent temperature reduction and affords the curved heat and sound insulator plate a good shape retentivity. This is a continuation of application Ser. No. 686,314 filed May 14, 1976, now U.S. Pat. No. 4,093,482.