| 摘要 |
PURPOSE:To provide a separation membrane support having a uniform layer, free from raising and having the good adhesiveness with a separation membrane, by using a nonwoven fabric having a double structure consisting of a surface layer comprising a thick fiber and having a large mesh size and large surface roughness, and a dense back surface layer comprising a fine fiber and a small mesh size. CONSTITUTION:When a polyester fiber is used, a thick fiber is used in a layer 2 and a fiber mixture consisting of fine fiber and a copolymer fiber having a slightly low m.p. and a medium thickness is used in a layer 3. These layers 2, 3 are formed into a uniform sheet according to a wet process using a papermaking machine and a thick fiber sheet and a fine fiber sheet are processed by a heating roll to form a separation membrane support comprising a nonwoven fabric having a double structure. By this method, the raising of the outer surface of the surface layer 2 can be suppressed and a coarse structure having a degree improving the adhesiveness of a separation membrane 1 by anchor effect is obtained and, at the same time, the back surface layer 3 can be formed into a dense structure capable of preventing the permeation of a cast solution. |
