Extraction of sunnhemp fibre and its properties

Abstract

An effort has been made to extract sunnhemp fibre from stalks of sunnhemp plants which are considered as agriculture waste after harvesting seeds. Sunnhemp (Crotalaria junceae) stalks have been rippled and stacked for about 20-30 days to dry the stalks. The dried stalks are then pre-treated with different retting agents, viz. urea and compost culture. Fibre is extracted by water retting (tank) method. Physico-chemical properties, microstructure and solubility tests of extracted sunnhemp fibre are performed. It is revealed that the urea treated stalks produce higher fibre yield with lower retting period. Urea treated sunnhemp stalks give relatively longer, finer and stronger fibres than the compost culture treated and control stalks. Lower per cent of lignin is observed in compost culture treated stalks. Sunnhemp fibre constitutes oblong shaped cross-section with elongated lumen. Like cellulosic fibres, sunnhemp fibre is soluble in concentrated acids and is least affected by solvents.