Research on Deinking of Toner Printed Paper during Recycling

(1)调色剂对纸张表面的粘附性采用简单的纸张与聚合物调色剂热粘合的连接强度测量来评估纸张与聚合物的粘附性是否足够。结果表明，纸张-聚合物界面的粘合强度强烈依赖于施胶处理。随着烷基烯酮二聚体施胶剂用量的增加，胶接强度先增加后大幅度下降。结合强度的变化与纸的表面自由能的变化相关，特别是分散力分量，如通过两种液体接触角方法测量的。(2)采用氧碱法对墨粉印刷废纸进行脱墨研究。与常规浮选脱墨工艺相比，70 ℃氧碱法脱墨效果更好。氧碱处理后的纸浆白度可达82%以上，油墨去除率可达96%以上。此外，超过60 μ m的可见大油墨斑点基本上通过氧-碱脱墨过程去除。(3)墨粉印刷废纸的干法碎解常规的脱墨方法如洗涤和浮选不能满足再生无斑点浆的要求。采用实验室粉碎机“涡轮磨”对干燥状态下的墨粉印刷废纸进行纤维化处理。结果，纤维化纸浆中的调色剂也被粉碎成约40 μ m的细颗粒。然而，强度性能，如拉伸，撕裂和折叠显着降低干崩解方法。

(1) On the adhesion of toner to paper surfaceA simple joint-strength measurement of paper heat-bonded to polymeric toner was used to evaluate whether the paper-polymer adhesion is sufficient. It was demonstrated that the bonding strength to the paper-polymer interface strongly depends on the sizing treatment. The bonding strength once increased with amount of alkyl ketene dimer sizing agent, followed by a large decrease. The change in bonding strength correlated with change in surface free energy of paper, particularly dispersive force component, as measured by the two liquid contact angle method.(2) Deinking of toner printed waste paper using oxygen-alkali treatmentThe oxygen-alkali treatment was investigated for deinking toner printed waste papers. The oxygen-alkali treatment at 70ﾟC peformed a higher deinkability of toner printed paper compared with the conventional flotation deinking process. The oxygen-alkali treated pulp showed over 82% in brightness and over 96% in ink removal efficiency. Also visible large ink specks over 60 mum was substantially removed by the oxygen-alkali deinking process.(3) Dry disintegration method of toner printed waste paperConventional deinking processes such as washing and flotation are not satisfactory to produce pulp clean enough for reclaiming speck-free pulp. A laboratory pulverizer "Turbo-mill" was employed to fiberize the toner printed waste paper in dry state. As a result, toners in the fiberized pulp were also pulverized into fine particles around 40 mum. However, strength properties such as tensile, tear and folding were considerably lowered by the dry disintegration method.