Porous cuprammonium cellulose fibre produced with annular orifice and central coagulating stream

Abstract From the Canadian patent

A porous regenerated cellulose hollow fiber obtained by a micro-phase-separation method is described. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5 x 104 each of, the average pore diameter D1 on the inner wall surface of the hollow fiber and the average pore diameter D2 on the outer wall surface is 0.02 to 10 µm the in-plane, porosity Pr on the outer wall surface is at least 10% and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length. The hollow fiber is prepared by a process …