The strength properties of pulps from red lauan produced by different pulping methods.

Abstract

This investigation was carried out to study the effects of various chemical pretreatments and different chemical pulping methods on the strength properties of corresponding chemithermomechanical pulp (CTMP) and chemical pulps from red lauan.In CTMP, chips were pretreated with cold soda, hot soda, alkaline sulfite, bisulfite and neutral sulfite prior to fiberization. The strength properties of CTMP increase in the order of cold soda<hot soda<alkaline sulfite<bisulfite<neutral sulfite pretreated chips.In chemical pulping, chips were cooked by means of the following cooking methods: kraft, alkali-methanol and cresol-water pulping. It showed that at the cooking temperature 170°C, there was no difference between the strength properties of alkali-methanol and kraft pulps except tear factor. The cresol-water pulping on the other hand, produced pulps with inferior strength properties but more effective in dissolving alcohol-benzene extracts compared to those of the alkali-methanol and the kraft pulping.