Abstract
Regarding the process of microstructure formation of viscose fiber, the fundamental study was done with Na-xanthate model filaments which contained Dithizone (Diphenyl-thiocarbazone) as indicator of Zinc. When the filament was immersed in various H2SO4-ZnSO4 baths or H2SO4-ZnSO4-Na2SO4 baths, on the cross-section of the filament clear periodic ring, which consisted alternately of Zn-xanthate layers and directly regenerated layers, was observed.
This periodic ring formation is influenced intricately by diffusion velocity of H2SO4 and ZnSO4 and regeneration reaction velocity. In case that any of them is predominent, periodic ring does not appear. There is optimum combination of these factors.
The mechanism of this ring formation, which is related to the microstructure of the fiber, is considered from the view point of diffusion phenomena of reagents.
