Hollow fibres, process for their manufacture and their applications especially in the field of separations using membranes

摘要

Hollow fibres based on fibre-forming polymeric substances, characterised in that they are of asymmetric structure in the sense that they have a relatively dense layer (''skin'') H of very small thickness < 1 mu m at their outer periphery, which is connected to a so-called ''open'' structure J whose porosity increases in the direction of the inner wall, the said open structure underlying the said skin consisting of a microporous layer directly in contact with the said skin and characterised by the presence of pores of dimensions greater than 0.1 mu m and smaller than 2 mu m and of a macroporous layer exhibiting macrovoids I which have a main dimension greater than 2 mu m, the proportion of these macrovoids representing at least 10 % by volume of the wall. <IMAGE>