Filterability of cellulose cuprammonium solutions through media with various pore sizes

Conclusions

The Cu/cellulose ratio in a cuprammonium spinning solution considerably affects the viscosity and filterability of the solution. On increase in this ratio, the viscosity of the solution is reduced, the rate of filtration is increased, and the filtration hold-up index is reduced.

On storage of cuprammonium spinning solutions for 5 days, the filtration hold-up index is essentially not increased.

Filtration of heated solutions, even with subsequent cooling, is impaired at temperatures over 40°C; this is connected with decomposition of the unstable cuprammonium complex and deposition of a precipitate of CuO, which leads to a gradual clogging of the filter medium holes.