Improving drainage of OCC pulp slurry by enzyme

摘要

Enzyme treatment can enhance the freeness of OCC (old corrugated container) pulp without flocculation of fibers, it can improve machine speed and allow more dilution in the headbox, which leads to better sheet formations and better physical properties for the paperboard. OCC pulp slurry was incubated with complex cellulase AH, results shows that complex cellulase All has the obvious effect of improving drainage of OCC furnish. A lower dosage (0.10%, a commercial solution based on dry pulp) and a short reaction time (45 min), at pH 4.7, 50°C gain an increase in the drainage of OCC furnish by more than 6° SR (Schopper Riegler). Optimal conditions of enzyme treatment, such as temperature, enzyme dosage, pulp consistence, pH value, reaction times, have been decided by experiments, which is Complex cellulase AH dosage 0.032～0.40 IU/g, temperature 50～57 °C, pulp consistence 4.5%, pH 4.7～5.3, reaction time 45 min. Mechanical properties of enzyme treated and untreated OCC pulp sheets were also tested and compared. Handsheets treated by complex cellulase AH show that there are insignificant losses in tensile index and tear index compared with the control, burst index is improved a little.