回用纤维表面的物理和化学变化

研究了硫酸盐浆、酸性亚硫酸盐浆、氢氧化钠浆、碱性亚硫酸盐浆1次回用后纤维的形态、纤维表面的物理及化学变化。结果表明,纸张经1次回用后,回用浆中细小纤维的含量明显增加,纤维平均长度变化不大,纤维的柔软性降低,卷曲指数和扭结指数下降;电镜分析显示,回用纤维的表面和原纤维的表面特征相似,密实光滑,但与原纤维表面相比,回用纤维暴露出较多的S2层,即纤维表面部分复合胞间层在回用过程中脱落;实验的4种浆料经回用后,纤维表面的O/C原子比均下降,氢氧化钠浆的O/C原子比下降得最多达22%,而酸性亚硫酸盐浆O/C原子比只下降3.4%。

Changes in the Surface Physical and Chemical Characteristics of Recycled Fibers

In this paper,the changes of the surface physical and chemical characteristics of recycled fibers!from four pulping processes-kraft,soda,bisulphite and alkaline sulphite were studied.The results indicated that fiber characteristics is changed after once recycling,the fine increases,the softness,curl index and kink index of the fibers decrease,but no significant change in fiber length.The observation of SEM showed that the surface feature of recycled fibers is similar to the virgin counterparts.However,the former seems to exhibit more exposed S2 surface,this is probably due to the partially detached CML which are released from fiber surface in the recycling process.There exists a general drop in O/C ratio for kraft,soda,bisulphite and alkaline sulphite pulp after once recycling.The soda pulp shows the most significant decrease with nearly 22% while the bisulphite pulp the least with 3.4%.