Abstract

As the important part of liquid packaging board, the middle layer is generally produced from a mixed pulp furnish by unbleached softwood kraft pulp and high-yield pulp (HYP). However, the addition of HYP would bring unsatisfactory properties (e.g. hydrophilicity) to liquid packaging board. Herein, in this study, the sizing performance of middle layer of liquid packaging board was evaluated by varying the kraft pulp to HYP ratios of middle layer, the dosage of sizing agent and cationic additives etc. It showed that the edge penetration value and Cobb value of middle layer illustrated a better liquid repellence with the addition of sizing agent. The improved sizing performance of the middle layer of liquid packaging board can be ascribed to the excellent performance of the added cationic additive (polyethyleneimine (PEI), alums) for trapping anionic trash via neutralization/flocculation effects. In addition, a binary cationic additive system (Al₂(SO₄)₃-PEI) was proposed to study the improvement on the sizing performance. It was found that a desirable liquid repellence ability can be successfully achieved at a binary additive system containing 1.5% of Al₂(SO₄)₃ and 0.2% of PEI, even when dosage of rosin sizing agent was reduced to 0.5%. The study put forwards a practical approach to improve the sizing performance, especially the liquid repellence ability of liquid packaging board when containing HYP.

Graphic abstract

摘要

作为液体包装板的重要组成部分，中间层通常是由未漂白的针叶牛皮纸浆和高产量纸浆（HYP）制成的混合纸浆配料制成。但是，添加HYP会给液体包装板带来不令人满意的性能（例如亲水性）。本文中，通过改变牛皮纸浆与中间层的HYP比例，上浆剂和阳离子添加剂的用量等来评估液体包装板中层的施胶性能。结果表明，边缘渗透值和Cobb值中间层的涂层说明了上浆剂的拒液性更好。液体包装纸板中间层尺寸的改善可归因于所添加的阳离子添加剂（聚乙烯亚胺（PEI），（明矾）用于通过中和/絮凝作用捕获阴离子垃圾。此外，二元阳离子添加剂体系（铝_{提出了用2}（SO ₄）₃ -PEI）研究上浆性能的改进方法。已经发现，即使将松香上浆剂的量减少至0.5％，在包含1.5％的Al ₂（SO ₄）₃和0.2％的PEI的二元添加剂体系中也可以成功实现所需的拒液性。研究提出了一种提高施胶性能的实用方法，特别是在添加HYP时提高液体包装纸板的拒液能力。

图形摘要