Hollow fiber membranes for dialysis were manufactured by dry-wet spinning of cuprammonium cellulose solution.
The composition of the dope was copper 5.87%, ammonia 11.63%, cellulose 9.19%.
The spinning was through a single hole needle-in-orifice hollow filament spinnerette.
In order to coagulate the inner wall of the hollow fiber, aquous acetic acid was used as an internal coagulant.
The effect of the internal coagulant, the coagulation bath composition, the coagulation bath temperature, the air drying time, the draw ratio, and the annealing temperature on the structure and properties of the hollow fiber membranes were studied.
The hollow membranes had homogeneous porous structure without the skin layer. It had inside diameter and thickness of 240μm and 37μm, respectively.