Manufacture of fibreboard according to the wet method with closed backwater system

Abstract From the Canadian patent

The present invention provides in the manufacture of fibreboard according to the wet method and with closed backwater system which includes in sequence: defibrating lignocellulosecontaining material in at least one step dispensing the defi-, brated material in water serving as propellent liquid forming, wet sheets from the suspension mechanical separating and re-, cycling of the backwater to the suspension step and final drying by evaporation of water, the improvement that the entering lignocellulose-containing material prior to the suspension step is brought to a dry content exceeding the dry content of the wet sheet prior to said final drying, that formalin is admixed to the backwater and …