Membranes made of synthetic or regenerated polymers in form of films, hollow fibers, tubings and pipings for separation processes; bundels of the aforesaid hollow fibers, tubings and pipings in combination with textile threads and with the aforesaid membranes or bundles equipped modules for use in medical apparatus, especially hemodialysers, hemofiltration modules, hemodiafiltration modules, endotoxin filtration modules, plasmapheresis modules, hemoconcentration modules, modules for removal of toxins from blood or blood plasma, modules for removal of blood constituents from blood or blood plasma, all aforementioned goods included in this class