JPS5613003A - Production of tubular semipermeable membrane - Google Patents

Abstract

PURPOSE:To enable the product of high grade to be easily obtained by suspending a continuously formed self-supportable and permeable pipe, sending it downward, coating a film-forming material-solution layer on the inside wall of said pipe and letting said layer solidify. CONSTITUTION:A permeable strip 1 (e.g. ''Tetoron '' fabric) is unrolled continuously from a spool, not shown, is sent downward, is continuously formed to a pipe 1a by a funnellike forming member 2 and is closed by e.g. an adhesive agent. Thence, a weight 4 is attached to the bottom end of this pipe 1a and the pipe 1a is suspended. While the pipe 1a is being sent downward, the solution 6 of a film- forming material is coated on the inside wall of the pipe 1a from a ring nozzle 3e, and the solvent of the solution 6 coated thereon is partly evapotated in the portion (b) where it goes to a solidifying bath 7; further it reaches the solidifying bath 7, where the film-forming material in the solution 6 solidifies on the inside wall of the pipe 1a and this yields a tubular reinforced semipermeable membrane. If necessary, the atmosphere on the inner side of the pipe containing solvent vapors at a high concentration is forcibly substituted by the atmospheric air outside the pipe.