针叶木和阔叶木硫酸盐浆PFI打浆性能的研究

Comparative Study on PFI Beating Response of Hardwood and Softwood Kraft Pulps

研究了针叶木和阔叶木硫酸盐浆PFI打浆对各自纤维性质及浆张性能的影响。结果表明,打浆使两种浆纤维长度下降较小,纤维粗度下降较多,同时纤维被拉伸,纤维的卷曲和扭曲系数降低;两者游离度的变化趋于一致;打浆可不同程度地提高两种浆的零距裂断长和抗张指数,而对于撕裂指数,随打浆的进行,针叶木浆的撕裂指数为降低趋势,而相应的阔叶木浆却增加;打浆降低浆料的光学性能如白度、不透明度、光散射系数。

The influence of PFI beating on fibre and handsheet properties of hardwood and softwood kraft pulps was investigated. The results indicated that improvement in strength properties by beating is accompanied by deterioration in optical properties. The hardwood fibre response differently to PFI refining when compared to the softwood counterpart. The drop in fibre length is relatively small for both pulps when they are beaten to 17,000 revolutions, but the softwood fibres experience a greater reduction in coarseness （26%） when compared with the hardwood counterpart （ 14% ）, at the same time, beating straightens fibres by reducing the curl and kink indices. The rate of drop in free- ness is similar for both pulps. When beaten to about 17,000 revolutions, the increase in dry zero-span tensile is greater for softwood （47%） than for hardwood fibres （28%）, but the softwood fibres experience a net loss in tear index, while the hardwood counterpart shows about two folds gain. When beaten to freeness about 450 mL, the softwood fibres show a greater decrease in brightness （4% -points） than the hardwood counterpart （2%-points） ; opacity and light scattering coefficient are substantially higher for the beaten hardwood fibres than for that of beaten softwood fibres.