The present study aimed to evaluate the effect of active alkali charge, in kraft cooking of Eucalyptus globulus wood, on the properties of the laboratory-produced tissue paper. Eucalyptus wood chips were cooked under similar conditions at four different active alkali (AA) levels of 16, 19, 21, and 23 % and DEDED sequence was used for subsequent ECF bleaching. Pulps were analyzed for their intrinsic viscosity, chemical composition, and fiber morphology, while the corresponding papers (20 g/m2) were examined for their strength properties, absorptivity, and softness. It was demonstrated that changes in the AA upon cooking, not only affected the chemical composition of the obtained pulps and their intrinsic viscosity, but also the fiber’s shape (e.g., curl and kink). These changes caused variations in the properties of laboratory-produced tissue papers. Thus, the increase in AA led to paper with lower tensile strength, but with better softness. Even though the increase of AA in cooking led to bulkier papers, their absorptivity was not significantly enhanced. This was explained, at least in part, by the lower water retention of the pulps obtained from cooking with higher AA.

中文翻译：

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碱电荷对生活用纸用蓝桉牛皮纸浆性能的影响

本研究旨在评估活性碱在硫酸盐蒸煮中的效果蓝桉木材，关于实验室生产的薄纸的特性。桉树木片在相似的条件下以 16%、19%、21% 和 23% 四种不同的活性碱 (AA) 水平进行蒸煮，并使用 DEDED 序列进行后续的 ECF 漂白。分析了纸浆的特性粘度、化学成分和纤维形态，同时分析了相应的纸张（20 g/m2）检查了它们的强度特性、吸收率和柔软度。结果表明，蒸煮时 AA 的变化不仅影响所得纸浆的化学成分及其特性粘度，而且还影响纤维的形状（例如卷曲和扭结）。这些变化导致实验室生产的薄纸的性能发生变化。因此，AA 的增加导致纸张的拉伸强度较低，但柔软度较好。尽管烹饪中AA的增加导致纸张体积变大，但它们的吸收率并没有显着增强。这至少部分是由于用较高的 AA 蒸煮获得的纸浆保水性较低。