AN APPLICATION OF THE "H" FACTOR TO SULFATE PULPING OF TROPICAL HARDWOOD

Abstract

This study was an attempt to determine whether the "H" factor could be used with tropical hardwood of Thailand because the previous research showed that the H factor could be employed with softwood and some temperate hardwood and obtained the same result Kraft pulping of tropical hardwood, Melia azedarach Linn., was done in laboratory digester using direct electrical heating. Fifteen cooks were carried out. Pulping condition established were active alkali 25% sulfidity 25% liquor to wood ratio 4 : 1 cooking temperature 170° C. Three different times to maximum temperature, 1 1 : 30 2 hours and equal H factor of 2500 were given under three conditions. The average screened yields, kappa numbers and physical characteristics- breaking length, burst factor, tear factor and folding endurance of Melia azedarach pulps were measured. Results were statistical analyzed and found that there were no significant difference existed among the yields, kappa numbers and physical characteristics of tropical hardwood pulps of varying time to maximum temperatures with equal H factor.