| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing process and equipment of seamless belt comprising mainly a polyimide which can reduce a poor appearance and increase accuracy of a thickness. SOLUTION: A manufacturing process of manufacturing a seamless belt comprises extruding at the same time a first polyamide acid solution (11) and a second polyamide acid solution (12) through a cyclic multi-layered die (20) into the inner part of a cylindrical die (30), whereby a multi-layered cylindrical body (18) comprising a first cylindrical layer (16) composed of the first polyamide solution (11) and a second cylindrical layer (17) covering an outer periphery of the first cylindrical layer (16) and comprising the second polyamide acid solution (12) is formed on the inner surface of the cylindrical die (30), wherein gas is introduced in an intermediate hollow part of a multi-cylindrical film (15) containing the first and the second polyamide solutions (11, 12), which is extruded through the cyclic multi-layered die (20). COPYRIGHT: (C)2010,JPO&INPIT |
