选取直立和倾斜欧美杨107杨为研究材料,根据正交试验确定正常木和应拉木最佳制浆条件,比较正常木和应拉木的制浆造纸性能,通过提高打浆转数对应拉木纸张性能的提高进行探讨。结果表明: 正常木的最佳制浆条件为用碱量15%、最高温度164 ℃、最高温度保温时间75 min; 而应拉木最佳制浆条件为用碱量13%、最高温度160 ℃、最高温度保温时间40 min。用碱量对正常木和应拉木制浆得率和卡伯值影响的通径系数在不同水平上显著。通过对正常木和应拉木制浆造纸性能比较发现,应拉木比正常木制浆得率高、卡伯值低、纸张力学性能均低,且抗张指数和耐破指数差距较大(约2倍),而撕裂指数差距较小。正常木和应拉木之间卡伯值、制浆得率、抗张指数、耐破指数均在0.001水平上差异显著,撕裂指数在0.05水平上差异显著。结合纸张断口形貌分析认为,胶质层的存在使得应拉木纤维成纸时不容易扁平坍陷,极大地阻碍了成纸时纤维之间的结合,因此降低了纸张力学性能; 但是,由于其胶质层纤维素含量很高,因此其制浆性能优于正常木。随着打浆转数的提高,应拉木纸张力学性能增强,且接近正常木纸张水平,但过高会降低纸张力学性能。
Both of straight and inclining poplar clone 107 tree were selected for studying materials in this paper. The optimal pulping conditions was established by orthogonal experimental design both for normal wood and tension wood, and the quality of pulping and paper-making between normal wood and tension wood was compared with each other. Finally, potential application for improving paper quality of tension wood through increasing beating revolutions was discussed. The result showed that the optimal cooking condition for normal wood was alkali concentration 15%, the highest temperature 164 ℃, time at highest temperature 75 min, and for tension wood it was alkali concentration 13%, the highest temperature 160 ℃, time at highest temperature 40 min. Path coefficient of effect of alkali concentration both on pulp yield and kappa value was significant at different levels. By comparison between average result of normal wood and tension wood in quality of pulping and paper-making, it was found that tension wood had higher pulping yield and lower kappa value than normal wood. Furthermore, for all mechanical properties of paper, normal wood hold higher value than tension wood, and even near two times than tension wood, such as burst index and tensile index. However, difference of tear index was quite narrow. Result of one way ANOVA showed that difference of burst index and tear index between normal wood and tension wood was significant at 0.001 levels, of tear index was significant at 0.05 levels. Based on observation of cross surface of paper, it was assumed that contribution of gelatinous layer to rigidity of single fiber had hampered collapse and compression of fiber during paper formation, which is essential for exerting combination between fibers in paper. So, mechanical properties of tension wood paper were decreased accordingly. However, owing to high cellulose content of gelatinous layer, tension wood was easier to pulping than normal wood. Mechanical properties of tension wood paper could be improved by increasing beating revolutions, the final value even close to normal wood paper. But, the increasing effect had a limit.