OCC回用处理过程对纤维孔隙结构与纸页强度的影响

选择OCC纸浆进行制浆造纸试验,研究了打浆以及抄纸工艺对二次纤维品质衰变的影响。结果表明：打浆过程使二次纤维在回用过程中已经封闭的细胞壁孔隙重新打开,当打浆度达到43°SR时,和未经打浆的纤维相比,纤维平均孔径上升了42.7%,孔容增加了126%,且打浆过程使得纤维的保水值和成纸的抗张指数分别提高了30.5%和37.1%。在施胶过程中保水值降低了5.2%,而成纸强度没有明显的变化。同打浆、压榨和干燥工艺过程相比,施胶对纤维品质的衰变影响较小。压榨和干燥过程使纤维发生了不可逆的角质化现象,和未处理纤维相比,压榨和干燥过程都使纤维细胞壁的孔隙在一定程度上发生了不可逆的关闭现象。压榨使得纤维的部分微孔发生了完全闭合,在此过程中二次纤维的保水值和成纸的抗张指数分别下降了11.7%和38.0%;而干燥则使纤维的中孔对应的孔容下降较为明显,保水值和抗张指数也分别下降了29.2%、34.9%。

Effects of recycling processes of OCC pulp on fiber pore structure and paper strength

The influence of beating and papermaking processes on the decay of fiber properties was studied by applying OCC pulp.The results show that beating process makes the pores re-opened,which closed in the recycling process.When beating degree reaches to 43°SR,the average pore size and pore volume of fiber increase by 42.7% and 126% compared with those of the fibers without beating.Beating can make WRV and tensile index increase by 30.5% and 37.1% respectively.Although sizing process makes WRV decrease by 5.2%,the paper strength has no obvious change.Unlike beating,pressing and drying,sizing have little effect on the decay of fiber properties.The press and drying process can make fibers to experience an irreversible hornification,both make the pores in fiber cell walls close irreversibly to some extents,press makes some micropores in fibers close completely.In press,WRV and tensile index decrease by 11.7% and 38.0% respectively,furthermore the average pore size of micropores decrease obviously in drying and then WRV and tensile index decrease by 29.16% and 34.9% respectively.