During the manufacture of low basis weight tissue paper, it is difficult to efficiently use the dry strength agent (DSA) because a large amount of DSA adsorbed fines releases in forming roll by centrifugal forces. In this study, cationic polyvinylamine (C-PVAm) was used as a DSA in an environment where the retention of fines was weak. Addition of C-PVAm to the thermomechanical pulp (TMP) or TMP mixed with softwood bleached kraft pulp (SwBKP) improved the turbidity of filtrate from sheet former, however, the strength of handsheet paper was similar to that without C-PVAm. When C-PVAm was selectively added to SwBKP as much as 4 %, the tensile index could be improved by approximately 10.6 % without changing the retention of fines. In addition, C-PVAm added before the beating of SwBKP showed better results than C-PVAm added after the beating in terms of fines retention, tensile index, and formation. In particular, the tensile index was improved about 7.7 % by adding of C-PVAm 4 % as is before beating of SwBKP. Consequently, it was found that C-PVAm with a high reaction rate can be added before beating of SwBKP to improve the physical strength.

中文翻译：

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选择性添加C-PVAm以改善TMP混合薄纸的干强度

在低基重薄纸的制造过程中，由于大量的DSA吸附的细粉由于离心力而在成型辊中释放，因此难以有效地使用干强度剂（DSA）。在这项研究中，阳离子聚乙烯胺（C-PVAm）在细粉保持力较弱的环境中用作DSA。在热机械纸浆（TMP）或与软木漂白牛皮纸浆（SwBKP）混合的TMP中添加C-PVAm可以改善成膜剂中滤液的浊度，但手抄纸的强度与没有C-PVAm的强度相似。当将C-PVAm选择性地添加到SwBKP中达4％时，拉伸指数可以提高约10.6％，而不会改变细粉的保留率。此外，就细粉保留，拉伸指数和形成而言，在SwBKP打浆之前添加的C-PVAm显示出比打浆之后添加的C-PVAm更好的结果。特别地，通过加入4％的C-PVAm，如在击败SwBKP之前那样，将拉伸指数提高了约7.7％。因此，发现可以在殴打SwBKP之前添加具有高反应速率的C-PVAm以提高物理强度。