Papermaking properties of aspen ultrahigh-yield mechanical pulps

Abstract

Eleven types of aspen ultra-high-yield (90% and above) mechanical pubs were evaluated for their chemical compositions (including sulfur), handsheet strength, and optical properties, fiber length indices, and fiberizing energies. The pulping processes were stone groundwood, pressurized stone groundwood, refiner mechanical, thermomechanical, chemimechanical (alkaline sulfite), chemithermomechanical, bleached chemithermomechanical, peroxide chemimechanical, steam explosion, and biomechanical. Data were obtained from USDA Forest Service reports and other literature. Pulps made using chemical pretreatments of the chips gave considerably higher handsheet strength properties than those produced from the groundwood types. This difference was not explained by chemical compositions. Chemical Sulfonation composition changed little, except for sulfonation of those pubs pretreated with sulfur-containing compounds. The light-scattering coefficients and fiberizing energies were reduced in the pulps from chemically pretreated pubs. The biomechanical pubs showed lignin loss with improved handsheet strength properties.

Citation

McGovern, J. N.; Wegner, T. H. 1991. Papermaking properties of aspen ultrahigh-yield mechanical pulps. Tappi journal. Vol. 74, no. 8 (Aug. 1991): Pages 157-161.