Introduction

White Poly Aluminum Chloride (WPAC), a high-purity inorganic polymer coagulant, is gaining significant traction in the papermaking industry as a superior alternative to traditional additives like aluminum sulfate. Known for its low impurity content, stability, and eco-friendly properties, WPAC is transforming paper production by improving paper quality, reducing costs, and minimizing environmental impact.

Key Advantages of WPAC in Papermaking

1. Neutral Sizing Agent with Broad pH Adaptability
   WPAC has replaced aluminum sulfate as the preferred sizing agent in neutral or alkaline papermaking systems. Unlike aluminum sulfate, which is limited to acidic conditions, WPAC effectively functions across a wider pH range (5.0–9.0), reducing equipment corrosion and simplifying wastewater treatment. Its pre-hydrolyzed structure ensures minimal pH reduction in pulp, maintaining system stability.

2. Enhanced Paper Quality and Production Efficiency

   • Improved Retention and Filtration: WPAC’s highly charged polynuclear hydroxyl-aluminum complexes promote rapid flocculation and retention of fibers, fillers, and fine particles. This enhances the first-pass retention rate by up to 20% and accelerates dewatering, boosting production efficiency.

   • Superior Paper Properties: By enabling the use of cost-effective calcium carbonate fillers, WPAC increases paper whiteness, stiffness, and fold resistance while minimizing defects like spots and breaks.

   • Compatibility with Additives: WPAC synergizes with cationic starch, polyacrylamide, and other additives to further optimize sizing performance and reduce chemical usage.

3. Environmental and Economic Benefits

   • Reduced Chemical Consumption: WPAC’s dosage is only one-third of aluminum sulfate, significantly lowering operational costs.

   • Eco-Friendly Profile: With ultra-low iron content (<0.3%) and no heavy metals, WPAC minimizes environmental pollution and complies with stringent water quality standards. Its application in wastewater treatment also aids in removing phosphorus and fluoride, addressing critical environmental challenges.

   • Waste Valorization: Recent studies highlight WPAC’s potential in recycling hazardous aluminum ash, aligning with circular economy principles.

Case Study: Wuhan Paper Mill’s Success
A leading paper mill in Wuhan, China, reported a monthly consumption of 3 tons of WPAC, achieving a 15% reduction in production costs and a 30% improvement in paper strength metrics. The mill also noted easier handling of white water and reduced sludge generation.

Future Outlook
As the paper industry shifts toward neutral and alkaline sizing systems, WPAC is poised to dominate the market. Ongoing research focuses on optimizing its synthesis from secondary aluminum waste and expanding its applications in high-end paper grades and biodegradable packaging.