Optimal use of flocculants on the manufacture of fibre cement materials by the Hatschek process

This paper is focused in the description of a new real-time methodology for flocculant selection in the fibre-cement manufacture based on studying flocculation and floc properties with a focused beam reflectance measurement (FBRM). Results were supported and confirmed by particle vision and measurement (PVM) analysis. Opposite effects of polyacrylamides characteristics on fibre cement flocculation and on final product were found: charge density resulted in increased product strength when dosage of polymer was low but decreased it at high dosages. The feasibility of using artificial neural networks (ANNs) to predict mechanical properties of fibre cement composites from the flocculation data obtained by in-line measurement in a Hatschek machine by the FBRM sensor is reported. (C) 2009 Elsevier Ltd. All rights reserved.