Abstract Increasing the filler content of sheet tends to decrease filler retention and paper strength properties. To overcome this problem and make better use of fillers, development of new methods on filler modification has never been stopped. In this study, filler modification was carried out by sequentially adding an anionic polyacrylamide, a cationic starch and a cationic polyacrylamide. It is believed that in this process, multiple polyelectrolyte complexes are formed which can not only encapsulate filler particles but also preflocculate the particles. The results showed that, compared to the single preflocculation treatment, the sequential encapsulation and preflocculation (SEP) treatment brought significantly larger particle size and higher surface charge potential of the filler, thus higher filler retention was achieved. When the modified fillers were used for papermaking and paper ash contents were controlled at the same level, the SEP modification was better in improving the tensile index, internal bond strength and tearing index of paper than the single preflocculation method, in addition, it maintained better paper formation, caused insignificant change on opacity of paper. It is believed that this newly developed SEP method is worthy of being applied to industrial scales in making various grades of filled paper.

中文翻译：

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连续包封和预絮凝法改性的填料及其对纸张性能的影响

摘要 增加纸张的填料含量往往会降低填料保留率和纸张强度性能。为了克服这个问题，更好地利用填料，填料改性新方法的开发从未停止。本研究通过依次加入阴离子聚丙烯酰胺、阳离子淀粉和阳离子聚丙烯酰胺进行填料改性。据信，在该过程中，形成了多种聚电解质复合物，其不仅可以包封填料颗粒而且可以使颗粒预絮凝。结果表明，与单一预絮凝处理相比，连续包封预絮凝（SEP）处理显着增大了填料的粒径和更高的表面电荷电位，从而实现了更高的填料留着率。当改性填料用于造纸且纸灰含量控制在同一水平时，SEP改性比单一预絮凝法在提高纸张的拉伸指数、内结合强度和撕裂指数方面更好，并且保持更好纸张形成，导致纸张不透明度的微小变化。相信这种新开发的 SEP 方法值得在工业规模上应用于制造各种等级的填充纸。