Enhanced Reactivity of Kraft-based Viscose-grade Dissolving Pulp by Hollander Beating Treatment

The reactivity of rayon-grade dissolving pulp is an important parameter in the subsequent production of viscose fiber. It can determine the processability and the quality of the viscose fiber. This study focused on improving the reactivity of kraft-based rayon-grade dissolving pulp through a mechanical treatment with mechanical refining, which could induce more fiber ends and channels or reactive sites via fiber cutting and fibrillation. Results showed that the Fock reactivity of a softwood kraft-based dissolving pulp increased from 54.4% to 68.4%, and the viscose filterability improved from 3743 s to 11 s when the beating degree of dissolving pulp was increased from 9 degrees SR to 16 degrees SR. Such a treatment also led to increases in the fines content, pore diameter, water retention value, and specific surface area while decreasing the fiber length. Meanwhile, it was beneficial that the intrinsic viscosity of dissolving pulp fiber was almost unaffected by the beating treatment.