TO INVESTIGATE THE EFFECT OF USING DRY DEFIBRATED FIBERS IN INCREASING BULK AND BENDING STIFFNESS OF THE MULTI-PLY PAPERBOARD

Abstract

Aim of the work is a simultaneous improvement of the production process and of properties in multilayer board production by application of dry defibrated fibre materials, especially in the middle layer. Background of the project idea are the characteristic properties of dry defibrated fibre materials, enabling an essentially faster dewatering compared to conventionally wet defibrated fibres. Furthermore, the use of dry fibres results in significantly higher sheet thicknesses. Especially this potential for increasing the specific volume is conform to development targets of board manufacturers. The planned investigations are focusing on dry defibration of several recovered papers and the subsequent application of these materials in the middle layer of a three-layer laboratory model board. By replacing wet defibrated material with dry defibrated fibres increased drainage rate, sheet thickness and a higher bending stiffness is expected compared to the reference board from completely wet defibrated raw material