Search

Hardwood bleached Kraft pulp was treated with an endoglucanase prior to Valley beating. The Valley-beaten pulp slurry was further ground with a particle grinder in order to evaluate the effect of enzyme beating on preparation of microfibrillated cellulose (MFC). The time required to make 100 mL Canadian Standard Freeness pulp slurry was greatly reduced by enzyme pre-treatment. The viscosity of the enzyme-beaten MFC slightly increased with grinder pass number; however, the rate of change in viscosity was much lower than that of non-enzyme-beaten MFC. The crystallinity of MFC decreased with grinder pass number for both cases. The drainage of the pulp slurry containing enzyme-beaten MFC was higher than that of the pulp slurry containing non-enzyme-beaten MFC. Further, the enzyme-beaten MFC subjected to the 10 passes grinding had the same tensile index as the MFC subjected to the 15 passes grinding. Thus, the mechanical energy for MFC manufacturing can be greatly reduced with enzyme beating.

Agricultural cultivation papers treated with water repellent were investigated in order to analyse mechanical properties and durability. The water repellency was optimal when papers are treated with Wb and Sa water repellents. Also, WCPs with 5% water repellent were more effective than those of 3 and 10%. In addition, water repellency of WCPs with Wb and Sa water repellents were kept constant in correlation with aging time. Finally, WCP with Wb water repellent possesses efficiency in terms of mechanical properties and durability.

In this study, we evaluated properties of pulp treated with swelling agent and swelling concentration. We used swelling agent, such as NaOH, DMSO, urea. One of them, pulps treated with NaOH from 0 to 5% measured WRV, beating efficiency, crystallinity and as-pect ratio. We identified that NaOH when freeness reaches 100mL CSF was the shortest, on the other hand, WRV didn’t change. Because NaOH is good beating efficiency, when pulp treated with various concentration of NaOH from 0 to 5%, pulp treated 1% NaOH was best beating efficiency. However, WRV, crystalline structure and crystallinity didn’t change. The more NaOH concentration increased, the more aspect ratio increased, but when NaOH concentration exceeds 3%, aspect ratio decreased. As a result, pulp treated with 1% NaOH was the greatest beating efficiency and WRV, chemical structure didn’t change.Keywords: Microfibrillated cellulose (MFC), swelling agent, beating efficiency, WRV, crystallinity http://dx.doi.org/10.7584/ktappi.2015.47.3.003Journal of Korea TAPPIVol. 47. No. 3, 2015, 3-10pISSN(Print): 0253-3200Printed in Korea