| Abstract:In this study, unbleached kraft softwood pulp was used to explore the effects of Valley blade on the morphology and paper properties of fiber before and after beating. The results showed that different types blade had a great effect on the beating performance of fiber. Under the same beating conditions, with the increase of bar width, the rubbing effect of blade on fiber was enhanced, which aggravated the change of fiber morphology, and the phenomenon of fiber fibrillation was more obvious, which accelerated the improvement of beating degree and water retention value. When the pulp consistency was increased, the influence of blade type on the beating effect was weakened. Under the same pulp consistency and similar beating degree, the paper properties of different types blades were little different. The paper properties of the 2# blade with 2 mm bar width were best when the pulp consistency was 2.0%. Its tensile index, burst index and tear index were 104 N·m·g-1, 6.93 kPa·m2·g-1 and 11.5 mN·m2·g-1 respectively when the beating degree was 56 °SR. |