纤维分级对漂白云杉木浆纤维悬浮液屈服性能的影响

Impact of Fiber Fractionation on the Yielding Properties of Bleached Spruce Pulp Fiber Suspensions

采用沉降和流变实验,研究了纤维分级对漂白云杉木浆纤维悬浮液屈服性能的影响,并分析了压缩屈服应力和剪切屈服应力的耦合相关性,通过Froude数(剪切屈服应力与压缩屈服应力的比值)表征。结果表明,分级前后各长度组分纤维(4种纤维悬浮液)的凝结集聚因子介于26.1~37.8之间,其与纤维长径比近似呈线性关系;所有长度组分纤维悬浮液的压缩屈服应力和剪切屈服应力均随集聚因子的增大而呈指数式增大;对同种纸浆,Froude数随集聚因子的增大而降低,并逐渐达到稳态值。

In order to study the influence of fiber fractionation on the yield stress of bleached spruce pulp fiber suspensions,the compressive and shear yield stresses of fiber suspension were measured by sedimentation and rheological methods,and their coupling correlation was also analyzed.The results showed that the gel crowding number of pulp samples before and after fractionated ranged from 26.1 to 37.8,and increased approximately linear with the fiber aspect ratio.Compressive and shear yield stresses of all suspensions of fiber fractionations increased exponentially as increasing of the crowding number.Moreover,Froude number decreased gradually with increasing crowding number,and finally approached a stable value.