Lime mud CaCO3 for use as a filler material in papermaking: Impact of its preflocculation with cationic polyacrylamide

摘要

Cationic polyacrylamide with different molecular weights were used to preflocculate the lime mud (LM) before it was added to the paper stock for handsheet preparation. The particle sizes, potential, and morphology of the unpreflocculated and resulting preflocculated LM were studied. We found that high-molecular-weight cationic polyacrylamide (H-CPAM) led to larger LM flocs with a more positive potential. The scanning electron microscopy images indicated that the morphological structure of the filler hardly changed during the preflocculation process. The effects of the preflocculation on the filler retention and paper properties were also investigated. The results show that the handsheets filled with preflocculated LM had better hydrophobicity and strength properties compared to handsheets filled with unpreflocculated LM, especially for H-CPAM-preflocculated LM. The paper formation was also improved, and the optical properties nearly remained the same. In addition, the LM preflocculated with H-CPAM had the highest filler retention. At a filler loading of 30, the filler retention of the H-CPAM-preflocculated LM was higher than 86; it was less than 82.5 in other cases. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41640.