DIFFUSION OF SOLVENT IN WET SPINNING OF ACRYLIC FIBER

Abstract

In this report, using acrylonitrile-vinylacetate copolymer-dimethylacetamide system, diffusion of solvent in wet spinning of acrylic fiber has been investigated quantitatively in connection with various spinning conditions. Furthermore, the effect of diffusion phenomena on spinnability and on microstructure of fiber were studied, and it was recognized these were closely related.
The diffusion constant of solvent in filament during the spinning was approximately 5×10^-6 cm²•sec^-1 at 40°C; the activation energy was 8.5 K cal/mol.
The above value was about twice the diffusion constant of triacetate-acetic acid system (the previous report) under the same temperature condition. Temperature rising of spinning bath made the diffusion constant higher moreover. That is, the coagulation induced by solvent diffusion from filaments was very rapid in this system, and therefore, the optimum spinning conditions were found in the direction which opposed to coagulation.