Application of Anionic PAM in Papermaking

Anionic polyacrylamide (APAM) is widely used in papermaking, mainly for retention aid, drainage aid, strength improvement, white water recovery and sludge dewatering, suitable for neutral/alkaline systems.

1. Core Functions

• Retention Aid: Increases retention rate by 20–30%, saves 20–30kg pulp per ton, reduces white water turbidity.
• Drainage Aid: Accelerates dewatering by over 30%, increases machine speed and reduces drying energy consumption.
• Dry Strength Agent: Improves tensile, burst and tear strength by 10–20%, enhances printability.
• Formation Improver: Optimizes fiber dispersion and paper smoothness.

2. Surface Sizing & Specialty Paper

Compound with starch as surface sizing agent for newsprint/coated paper; applied in food/tea packaging paper to meet hygiene and strength requirements.

3. White Water & Wastewater Treatment

Medium-molecular-weight APAM (6–8 million) recovers over 90% fine fibers from white water; combined with PAC for sludge dewatering.

4. Key Parameters

• pH: 6.5–9.0 (neutral to alkaline)
• Molecular weight: 8–12 million (retention/drainage); 3–6 million (strength/sizing)
• Dosage: 0.05–0.2% (based on oven-dry pulp); 2–5mg/L (wastewater, with PAC)

5. Notes & Difference

Avoid mixing with cationic additives; control dissolving temperature (≤60℃) and stirring speed (≤200rpm). Unlike cationic PAM (for acidic/neutral systems, COD removal), APAM is for neutral/alkaline systems, focusing on retention, drainage and strength.