摘要
麦草化学机械浆不仅得率高、强度性能好,而且纸浆生产成本低。但在造纸过程中存在纸浆水化程度高、滤水性差及纸干燥能耗大等突出问题。研究结果表明:在草片磨成浆进行消潜-筛选净化-浓缩-贮浆过程中,由于制浆残碱和温度的作用,纸浆中的半纤维素一直在持续溶出,表现在水相中阴离子物质的阳离子需要量增大、纸浆纤维表面的羧基含量增加,导致水化程度上升;溶解进入水相的半纤维素分子片段通过高价金属离子能重新回吸到纤维表面,进一步增大了纸浆的水化程度。采用羧甲基淀粉模拟半纤维素,在钙离子环境下重现了半纤维素的回吸现象验证实验。因此,在麦草化学机械浆生产过程中,半纤维素溶出与回吸不仅导致纸浆的水化程度加重,而且导致了纸成形时滤水性变差、干燥能耗高的重要原因。
Wheat straw chemical mechanical pulp not only has high yield and good strength performance,but also has low production costs.However,there are prominent problems in the papermaking process,such as high degree of pulp hydration,poor water filtration,and high energy consumption during paper drying.The results showed that hemicellulose in the pulp had been continuously dissolved due to the residual alkali and temperature during the process of straw chip pulping,which included the increase of cation demand of anionic substances in the water phase and the increase of carboxyl group content on the surface of pulp fiber,leading to the increase of hydration degree.The hemicellulose molecular fragments dissolved into the aqueous phase can be re-absorbed to the fiber surface through high valence metal ions,further increasing the degree of pulp hydration.The carboxymethyl starch was used to simulate hemicellulose,and the desorption phenomenon of hemicellulose was reproduced in the calcium ion environment.Therefore,during the production of wheat straw chemi-mechanical pulp,the dissolution and desorption of hemicellulose not only aggravate the degree of hydration of the pulp,but also lead to the important reasons of poor drainage and high drying energy consumption during papermaking.
出处
《中华纸业》
CAS
2023年第11期69-74,I0008,共7页
China Pulp & Paper Industry
基金
“十三五”国家重点研发计划项目(2019YFC19059003)。
关键词
麦草
化学机械浆
保水值高
原因分析
wheat straw
chemical mechanical pulp
high water retention value
reason analysis
