Physical phenomena occurring in the process of physical–mechanical degumming of fiber from flax straw

Abstract

The study presents physical phenomena that occur in the physical–mechanical process of degumming of fiber from flax straw. Moreover, the effect of liquid flow through the straw has been determined by analysis of the mass exchange (motion) according to the principles of fluid mechanics.

It was shown that conditions of the degumming process, especially the temperature, have a significant effect on acceleration of the mass exchange.

The analyses of the results indicated that the developed model laboratory device allowed for evaluation of the mechanism of mass exchange by slow laminar liquid flow. The evaluation of the degumming process with convective mass motion at a higher speed of liquid flow was based on model tests of hydrodynamic washing of three types of gels: fruit pectin, animal gelatin and starch from linen fabrics. It was shown that temperature is a decisive factor affecting the washing out of gels. Better washing out was achieved by using diffusive penetration of water into the gel structure at the initial phase of the process. Using the dynamic washing out of the gels with a water stream of high flow speed (at the m/s range) shortened considerably the washing time.