Process for the treatment of the short fibre fraction after separation from the long fibre fraction in a secondary fibre mixture in particular for the production of folding box board

摘要

To remove disturbing wax particles and for increasing the specific volume the short fiber fraction is subjected to a thermal treatment, especially by application of water vapor or steam, in a heater, such as a worm heater throughout a defined residence time and a defined temperature. With relatively low energy expenditure the distrubing wax particles are eliminated in such a manner that no wax spots or speckles can be discerned in the finished product. The specific volume of the short fiber fraction is appreciably increased while obtaining a predetermined strength.