Osmosis Phenomena Based Degumming of Bast Fibrous Plants as a Promising Method in Primary Processing

Abstract

In this article the review of the methods of lignocellulosic plants

Characterization of Flax Water Retting of Different Durations in Laboratory Condition and Evaluation of Its Fiber Properties

“…Although water retting can produce fibers of good quality, the relatively long duration of 7 to 14 days and arising odor has made it less attractive (Foulk et al 2008;Tahir et al 2011). Warm water retting is performed at a temperature around 35 °C, and this can shorten the retting period to 100 hours, but, due to the high water consumption and unpleasant stench generated (Konczewicz et al 2013), it is only used in some developing countries; for example, over half of fiber production in mainland of China used this method (Daenekindt 2004). Chemical and enzymatic retting methods are used as well, and these offer more control than dew and water retting.…”

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

“…Generally, the substances containing mineral salts, pectin, bacteria and pigments are leached out from the stems in the process. The results of earlier, laboratory scale studies 3,4 confirmed the effect of degumming parameters, i.e. time and temperature, on the quality of the obtained fiber.…”

“…Mass exchange occurs under such conditions mostly by pure diffusion, and thus it is slow. Literature data reports that the wringing wastes are composed of: 1.5-5.0 g/dm 3 of dry mass, 0.54-1.1 g/dm 3 of soluble substances and 0.85-3.65 g/dm 3 of suspended matter. 8 The above can be presented as follows: if a flax stem is thrown into water without stirring, when the liquid remains still, only soluble substances are washed out: mineral salts, pectin, retting bacteria and pigments.…”

“…There are two physical phenomena involved in the fiber degumming process: diffusion and osmosis. [3][4][5] In this process, water penetrates inside the stem towards its woody part, according to the Fick's law, where the long bundles of cellulosic fibers are clustered in bundles by polysaccharides, see Figure 1.…”

Characterization of radio frequency assisted water retting and flax fibers obtained

“…Although water retting is easy to operate and can produce high quality fibers, the long duration, and stench and water pollution generated have made this method less attractive (Tahir et al, 2011). In order to eliminate these problems while guaranteeing the quality at the same time, many efforts have been put into optimizing the traditional retting methods by adopting new formulations and new bacteria/enzymes (Akin et al, 2007;Das et al, 2012), and into developing new retting processes that apply and/or combine different technologies (Konczewicz et al, 2013;Lavoie and Beauchet, 2012;Nair et al, 2014).…”