YOUNG WOOD OF SPRUCE AND BIRCH – COMPLETE RAW MATERIAL FOR PULP AND PAPER INDUSTRY

Abstract

The work is devoted to increase in complexity of use of wood raw materials – one of the most important directions in solution to complying with the modern requirements of rational environmental management and environmental protection.Features of impregnation by bisulfite sulfite cooking acid and regularities of bisulfite delignification of young and ripe fir-tree and birch wood have been investigated. It is shown that young thin wood of both breeds becomes impregnated by bisulfite sulfite cooking acid much quicker, than ripe. The nature of delignification processes for young and ripe wood are identical, however intensity of processes is much lower for young wood.It has been established that cellulose derived from young wood is ground easier and has higher mechanical strength rates than from ripe. However cellulose from young wood is dehydrated slightly more difficultly and has the increased water-retaining what is connected with differences in sizes and properties of fibers of young and ripe wood.Cellulose yields of young and ripe wood differ insignificantly. Cellulose from young birch wood characterized by a somehow lowered owing due to the higher content of knots of this wood.Young wood is dignified by bisulfite cooking liquor without difficulties, but slightly more slowly in comparison with the corresponding ripe wood breed. The research results showed that the young (thin) fir-tree and birch wood of which is formed at cleaning cutting is the considerable reserve stock of wood raw materials which can be successfully utilized fibrous semi-finished products production, in particular in bisulfite cellulose.