| 摘要 |
PURPOSE: To efficiently and continuously produce a PVA type porous sheet relatively large in surface voids by laying a fabric or nonwoven fabric on the metal plate of which the surface is coated with fluoroplastic of a belt conveyor. CONSTITUTION: The fabric 11 trained over rotary drums 12a, 12b, 12c to be rotated is arranged above a belt conveyor 1 so as to cover the upper surface of the reaction soln. spread over the belt conveyor l in a sheet form and moved and rotated at the same speed as the moving speed of the belt conveyor 1. The belt conveyor 1 is composed of a metal plate 1a of which the surface is coated with fluoroplastic. Further, a fabric 1c composed of an extremely fine fiber is laid and fixed on the fabric. The projected parts 14 for limiting the spreading of the reaction soln. so as to prevent the overflow of the reaction soln. are provided in the vicinity of both side end parts of the surface of the belt conveyor 1 over the entire periphery of the conveyor 1. A reaction product 20 is peeled from the fabric 11 and the belt conveyor 1 and, after cooling, a void forming material is removed by washing to obtain a PVC type porous sheet. |
