欧美杨107杨制浆造纸性能的径向变异

Radial Variation of Pulp and Papermaking Properties of Populus × euramericana cv.‘Neva'

逐生长轮对107杨木材进行硫酸盐法化学制浆,并制备手抄纸片测定纸张力学性能,进行制浆造纸性能径向变异的研究。结果表明:107杨制浆造纸性能均值分别为制浆得率48.39%,卡伯值22.16,抗张指数85.61N.m.g-1,耐破指数58.38 kPa.m2.g-1,撕裂指数13.72 mN.m2.g-1。制浆造纸性能径向变异模式分别为:制浆得率从髓心向外迅速波动上升,到第6生长轮后微弱下降;卡伯值从髓心向外开始逐渐降低,到第4生长轮时出现最低值,随后逐渐上升;抗张指数与耐破指数的径向变异模式较为类似,均从髓心向外波动增加,到第5生长轮后开缓慢下降;撕裂指数在生长轮初期保持一个较为平稳的缓慢上升的状态,到第4、第5生长轮之间基本不变,随后在第6生长轮后迅速攀升。综合考查制浆性能和纸张性能径向变异模式,认为从制浆性能出发,107杨纸浆林的轮伐期要长于6 a,而从纸张性能出发;107杨纸浆林轮伐期不能超过5 a;再综合考虑生长量等其它因素,107杨纸浆林最佳轮伐期应为6 a。单因素方差分析结果显示,不同单株之间撕裂指数差异在0.001水平上显著,卡伯值在0.01水平上显著,其余各指标差异均不显著。不同年轮之间,制浆得率、抗张指数、撕裂指数、耐破指数均在0.001水平上差异显著,而卡伯值差异不显著。

Poplar clone 107 trees （Populus×euramericana cv. ＇Neva＇ ） were selected as testing materials in this paper. Sulfate chemical cooking process was implemented for pulping. Unbleached paper was fabricated and its mechanical properties were measured accordingly. Finally, variation pattern of pulp and paper making properties was studied based on the data collected above. Result showed that the average values of all the properties of poplar clone 107 were obtained as pulp yield 48.39%, kappa value 22.16, tensile index 85.61 N ·m2·g-1, burst index 58.38 kPa·m2·g-1 , and tear index 13.72 mN ·m2·g-1. Radial variation patterns of all the properties were as follows： pulp yield increased from pith to outward, reached its maximum at the sixth growth ring, and then decreased. Kappa value increased from pith to outward, reached its minimum at the fourth growth ring, and then increased. Radial variation pattern of tensile index was quite similar to burst index, which increased from pith to outward, and reached their maximum at the fifth growth ring, and later gradually decreased. Tear index gradually increased in early age, and stayed stable at the fourth and fifth growth ring, and finally changed to an increasing trend after the sixth growth ring. Based on the comprehensive consideration of radial variation trend of the measured properties, it was suggested that the optimal rotation age for poplar clone 107 plantations should be longer than 6 years when high pulp yield was the final target. However, if the aim was to obtain high quality of mechanical properties of paper, tile rotation age should be less than 5 years. When other factors such as productivity of plantations were taken into account, optimal rotation age for poplar clone 107 should be 6 years. One-way ANOVA was applied to illustrate differences between different trees and different growth rings. An extremely significant difference in tear index was found between different trees （P〈0.001）, and a significant difference was also observed in kappa value （ P〈0.01 ）. No significant difference in other indexes was found between different trees. There were extremely significant differences in pulp yield, tensile index, tear index and burst index between different growth rings （P〈0.001）, and no significant difference in kappa value.