纤维表面润湿性能及其与纤维结合性能的响应关系研究

Study on the Fiber Surface Wettability and Its Response to the Fiber Bonding Performance

关键词:  木质纤维  润湿性  表面能  表面木素  结合性能

Key Words:wood fiber  wettability  surface energy  surface lignin  bonding properties

摘要:对南方松热磨机械浆纤维进行PFI磨浆处理，通过“液桥法”分析纤维接触角，进而计算表面能用于表征纤维表面润湿性能，最终建立纤维表面润湿性能与纤维结合性能之间的响应关系。结果表明，随着机械处理程度的加深，纤维表面木素含量从87.13%降低到77.51%，纤维表面润湿性能得到改善（表面能从46.63 mJ/m²上升到54.45 mJ/m²，表面电荷从48.382 mmol/kg上升到60.382 mmol/kg），结合强度指数从4.63 N·m/g提升到10.9 N·m/g。实验发现，纤维表面润湿性能与结合强度指数以及纸张的松厚度之间存在二次函数关系，且相关系数均大于0.9。从表面润湿性能与松厚度之间的关系方程可知，纸张松厚度随纤维表面润湿性能降低而降低的较小，在整个机械处理过程中从4.95 cm³/g下降到3.57 cm³/g，这表明可通过改善纤维表面润湿性能来达到在不显著影响纸张松厚度的前提下提高纤维结合性能的目的。

Abstract:In this study， the southern pine thermo-mechanical pulp fibers were refined by the PFI mill. The contact angle of the fibers was analyzed by the ‘liquid bridge method’， and the surface energy was calculated to characterize the surface wetting behavior. Finally， the response relationship between the surface wetting performance and the fiber bonding performance was established. The results showed that with strengthening the mechanical treatment， the lignin concentration on fiber surface reduced from 87.13% to 77.51%， and the fiber surface wettability was improved（the surface energy increased from 46.63 mJ/m² to 54.45 mJ/m ²， and the surface charge increased from 48.382 mmol/kg to 60.382 mmol/kg）， and the bonding strength index increased from 4.63 N·m/g to 10.9 N·m/g. The experiment found that there was a quadratic function relationship between the fiber surface wettability and the bonding strength index and the bulk of the paper sheet， and the correlation coefficient was greater than 0.9.The equation between the fiber surface wettability and the bulk of paper indicated that the bulk of the paper sheet decreased with the wetting performance of the fiber surface， and decreased from 4.95 cm³/g to 3.57 cm³/g during the refining. It suggested that the fiber bonding performance could be enhanced by improving the fiber surface wettability without sacrifice of the bulk of paper sheets．