Factors determining the quality of bagasse mechanical pulps

Factors determining the quality of mechanical and alkaline chemi-mechanical pulps from bagasse are discussed. It is shown that intense depithing notably reduces silica content and metal ions, and improves bagasse brightness. Mechanical and chemimechanical pulps obtained at two working scales are compared. At a higher scale, properties of the cleaned RMP and CMP may allow these pulps to be used as a major component in a newsprint furnish. The mechanical pulp from wet bulk stored bagasse can reach the same quality by peroxide bleaching, provided alkaline effects are minimized. Papermaking trials using mixtures of mechanical and industrial semichemical pulp produce an acceptable 100% bagasse newsprint.