Influence of H factor on mixed hardwood kraft pulping

The kraft pulp properties of mixed hardwood under different H factor were discussed and the optimization of kraft pulping processing conditions was also made.The results showed that:good pulp properties can be got under the conditions of H factor more than 800,the dosage of alkali ranging from 16%～20%,the temperature 165℃.Pulp strength properties is the best when H factor is 900,effective alkali dosage 16%.Pulp yield,breaking length,bursting strength and tearing index can reach 44.27%,8.18km,4.81 kPa·m2/g and 12.7mN·m2/g respectively.But pulp brightness is only 25.8%ISO and kappa number 26.4.The kraft pulp with better strength properties can be obtained in pulping conditions at high H factor and low dosage of effective alkali.