Using PVA and PVA & Cationic Starch to Improve the Strength of High-Yield Pulp

Abstract

Dry strength additives play an important roll in papermaking process. In this work, we aimed at analyzing the performance of poly vinyl alcohols (PVA) and PVA & cationic starch (CS), as dry strength additives, on the properties of high-yield pulp (HYP). Various dosages of PVA were applied on HYP under various conditions and the corresponding pulp properties were evaluated. It was observed that PVA increased the strength properties of the HYP significantly, and the enhanced strength properties can be kept even after refining, which gave a promising application of this method in conventional pulping process. The best conditions of PVA for dosage, pH, pulp consistency and time was 20 mg/g, 6.0, 3% and 10 min, respectively. The application of CS, combined with PVA, can further improve the final physical strength properties of HYP. The results obtained from using PVA & CS were more effective than those obtained from using only PVA.