4 documents found, page 1 of 1
Influence of dispersion of fibrillated cellulose on the reinforcement of coated...
Sanchez-Salvador, Jose Luis; Rasteiro, Maria da Graça; Balea, Ana; Sharma, Mohit; Pedrosa, Jorge F. S.; Negro, Carlos; Monte, M ConcepcionThe use of cellulose micro/nanofibrils (CMNFs) as reinforcement paper additive at industrial scale is delayed due to inconsistent results, suggesting a lack of proper consideration of some key parameters. The high influence of fibrillated nanocellulose dispersion has been recently identified as a key parameter for paper bulk reinforcement but it has not been studied for surface coating applications yet. This pa...
Use of New Branched Cationic Polyacrylamides to Improve Retention and Drainage ...
Antunes, Elisabete; Garcia, Fernando A. P.; Ferreira, Paulo; Blanco, Angeles; Negro, Carlos; Rasteiro, M. GraçaCationic polyacrylamides of very high molecular weight and with different charge densities and degrees of branching have been investigated as retention aids for papermaking. The effects of polymer charge density and polymer branching on drainage and retention of a suspension containing fibers and precipitated calcium carbonate have been correlated with flocs properties. Additionally, the effects of flocculant d...
Effect of Water Cationic Content on flocculation, flocs resistance and refloccu...
Antunes, Elisabete; Garcia, Fernando A. P.; Ferreira, Paulo; Blanco, Angeles; Negro, Carlos; Rasteiro, M. GraçaIn papermaking, mill water closure may result in a significant increase of inorganic salts in the white water. The effect of these contaminants on the performance of retention aids was evaluated, in this study, through flocculation of Precipitated Calcium Carbonate (PCC) with three very high molecular weight cationic polyacrylamides (C-PAM) of medium charge density and with different degrees of branching. Furth...
Modeling pulp fiber suspension rheology
Ventura, Carla; Blanco, Angeles; Negro, Carlos; Ferreira, Paulo; Garcia, Fernando; Rasteiro, MariaRheological properties of pulp suspensions play a very important role in the industry, mainly due to the consumption of energy for transporting pulp among the different parts of the paper mill. In this work, we determined the rheology of long- and short-fiber bleached kraft pulp suspensions by using a new rotational viscometer especially designed for their analysis. The experimental rheograms were adjusted to t...