Pectinase in papermaking: solving retention problems in mechanical pulps bleached with hydrogen peroxide

Area of Science:

• Pulp and Paper Science
• Biotechnology
• Materials Science

Background:

• Thermomechanical pulp (TMP) bleached with alkaline peroxide exhibits high cationic demand.
• This cationic demand can negatively impact the efficiency of retention aids in papermaking.

Purpose of the Study:

• To evaluate the efficacy of pectinase enzyme treatment on industrially produced, peroxide-bleached TMP.
• To assess the impact of pectinase on retention aid performance and pulp strength properties.

Main Methods:

• Industrial bleached TMP was treated with commercial pectinase preparations under mill-relevant conditions (15 min, typical temperature and pH).
• Cationic demand was measured before and after enzyme treatment.
• Dynamic drainage jar experiments were conducted to evaluate the effectiveness of retention aids with enzyme-treated and untreated pulp.

Main Results:

• Pectinase treatment significantly reduced the cationic demand of bleached TMP by approximately 50%.
• Enzyme treatment enhanced the performance of cationic retention aids in improving fines and filler particle retention.
• Pulp strength properties were not adversely affected by the pectinase treatment.

Conclusions:

• Pectinase is a viable and efficient enzyme for reducing cationic demand in industrial peroxide-bleached mechanical pulp.
• Incorporating pectinase into stock preparation systems can optimize the use of cationic retention aids, leading to improved retention and potentially reduced chemical costs.
• The enzyme treatment offers a promising approach for enhancing the papermaking process with peroxide-bleached mechanical pulp.