Abstract: A process for the production of lignin in which lignin is precipitated from aqueous solution by acidification and agitation and the precipitated lignin is separated from accompanying liquid in which the lignin-containing solution and the acid are introduced by simultaneous cocurrent flow into an agitated mixing region, the precipitated lignin is separated not more than 60 minutes after precipitation and the separated lignin is subsequently washed. The process can form a step in a general process for the treatment of lignocellulosic materials to produce one or more products including lignin. The process enables the ash content of lignin to be reduced.

Abstract: Fibrous materials in the form of shaped articles such as paper are made from heat-cured amino-formaldehyde resin fibres having a degree of cure of at least 93%, optionally in admixture with other fibres. The amino-formaldehyde resin fibres are welded to one another and/or to the other fibres. The welding is brought about by subjecting the shaped article to pressure and to heat in the presence of water.