Enzymatic treatment of lyocell - Clarification of depilling mechanisms

We have characterized cellulose from the original structure of a lyocell fabric, from pills mechanically removed from the surface with a razor blade and from cellulose microfibrils removed from the surface and dispersed in the liquor during a cellulase depilling process. We find that cellulases first attack the cellulose from the microfibrils on the surface of the fabric because they are more externally exposed than the cellulose of the original fabric structure and have the same characteristics in terms of molecular weight, polydispersity, and crystallinity index as the base fabric. Cellulose from the microfibrils removed from the base fabric by the cellulase and recovered from the liquor shows significantly increased polydispersity, therefore indicating that the microfibrils have been widely attacked by the enzymes. Cellulases prove to be thorough surface finishing agents, since they change only the fiber surface, not the crystallinity.