NSSC pulp from planted populus and hardwood sawdust for flutting production
This research was performed with the goal of using neutral sulfite semi chemical pulp (NSSC) from populous instead of all or part of MWPI’s NSSC pulp for producing fluting paper. Firstly, NSSC pulp was prepared from populous species and hardwood sawdust under the mill’s cooking conditions. Then, the two mentioned pulp samples were replaced with the mill’s NSSC pulp in a variety of mixing ratios. Next, handsheets with 120 g/m2 were produced of mixed pulps and the properties were measured. The results showed that both raw materials could supply the pulp properties in acceptable way in comparison with control pulp (NSSC pulp of Mazandaran mill).
THE EFFECT OF SURFACTANTS APPLICATION ON SODA PULPING OF WHEAT STRAW
This paper details the effects of two non-ionic surfactants, ELA-7 and PEG 1500, on the soda pulping of wheat straw. The results showed that application of either surfactant improved the pulp yield and decreased the screen rejects. The increase in pulp yield at similar kappa number may be due to higher selectivity of delignification affected by surfactant, which can act as a co-solvent. Addition of ELA-7 to cooking liquor didn’t have significant effect on paper properties. But a significant effect was observed with PEG 1500. In fact, it caused a decrease in burst and tensile index but increased the tear index, probably because of a debonding effect of the surfactant. In addition, application of both surfactants improved brightness for both unbleached and bleached pulp samples.
Peg-based aqueous biphasic systems as improvement for kraft hardwood pulping process
Aqueous biphasic systems (ABS) represent wholly aqueous systems that are safe, nontoxic, nonflammable, and relatively environmentally benign as extraction media. We have studied detailed phase diagrams and partitioning data currently used in wholly aqueous solvent extraction or reactive extraction processes that may be applicable to the delignification of cellulosic materials at elevated temperature. The study results indicate that increasing the concentration of salt improves the degree of phase divergence. The partitioning results of different lignin species in PEG/salt ABS show that lignin prefers the polymer-rich phase of ABS. Four complete time-at-temperature (130-160°C) batch-cooking experiments were made using a Kraft pulping solution with and without PEG. The results for wood chips composed of a mixture of southern hardwood indicate that the use of PEG results in a pulp with lower Kappa number, lower lignin content, higher residual pulp yield, and reduced alkali consumption.