ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Bleaching of semichemical pulp

I. Slávik and V. Masura

Slovak Academy of Sciences, Bratislava

Abstract: Deciduous wood cooked by an acid or neutral sulfite process is most suitable for bleaching because of low Cl requirements (I) and high yield. Poplar is the best in whiteness of unbleached cellulose. The semipulp used for bleaching should be cooked to a yield of 70-75% for beech and poplar and 65-70% for spruce without decreasing the yield of bleached cellulose. There is no difference in semipulp cooked by the mono- or bi-sulfite process because the amt. of lignin, I, and yields are the same. I are greatly affected by the condition of fiber. For high-quality bleached paper a 5-stage bleach with double chlorination is recommended.

Full paper in Portable Document Format: 91a44.pdf (in Slovak)

Chemical Papers 9 (1) 44–53 (1955)