Abstract:Filler modification by encapsulation-preflocculation was carried out by sequentially adding anionic polyacrylamide, cationic starch and cationic polyacrylamide, which formed mulitiple polyelectrolyte complexes.The modified filler was used for papermaking and compared with the filler modified only by preflocculation.The results showed that compared to the single preflocculation treatment, the encapsulation-preflocculation treatment resulted in significantly larger particle size and higher surface charge potential of the fillers which led to higher filler retention.At the same level of paper ash content, the encapsulation-preflocculation modified filler had more advantage in improving the paper tensile index, internal bonding strength and tearing index than the preflocculated filler, and its application also led to the better paper formation. |