Solid sodium silicate (commonly known as water glass or powdered metasilicate) offers several key benefits in paper manufacturing, enhancing paper quality, process efficiency, and cost-effectiveness. Below are its major advantages:
1. Enhanced Paper Strength
• Fiber Bonding: Hydrolyzed sodium silicate forms silica gel, which fills gaps between fibers, improving tensile strength and burst resistance (especially for kraft paper, corrugated board, and packaging paper).
• Partial Starch Replacement: Can substitute more expensive starch-based strengthening agents, reducing production costs.
2. Improved Sizing Performance • Rosin Sizing Aid: Works synergistically with alum (Al₂(SO₄)₃) to enhance rosin sizing efficiency, improving water resistance and printability (reducing ink penetration).
• pH Stabilization: Its alkaline nature helps maintain optimal pulp pH, reducing acid corrosion in papermaking equipment.
3. Filler Retention & Drainage Aid
• Microparticle Retention System: Combines with cationic polymers (e.g., CPAM) to improve filler retention (e.g., calcium carbonate, kaolin) via charge neutralization and bridging effects.
• Better Dewatering: Enhances wet-end drainage, increasing paper machine speed and reducing drying energy consumption.
4. Environmental & Safety Benefits
• Non-Toxic & Biodegradable: Unlike some synthetic chemicals (e.g., PAM), sodium silicate is eco-friendly, aligning with sustainable papermaking trends.
• Flame Retardancy: Adds fire resistance to specialty papers (e.g., fireproof boards, insulation papers).
5. Additional Functional Benefits
• Bleaching Stabilizer: Stabilizes hydrogen peroxide (H₂O₂) in alkaline conditions, improving brightness without excessive fiber damage.
• Anti-Corrosion: Protects metal components (e.g., wires, press rolls) from acidic pulp corrosion. Key Application Notes
• Optimal Dosage: Typically 0.5%–3% (excessive use may increase brittleness).
• Solubility: Must be dissolved into liquid silicate (modulus 2.0–3.2) before use to avoid clumping. Comparison with Traditional Additives Property Sodium Silicate Starch/PAM Cost Low (~1/3 price of starch) High Strength Effect Good for mid-high strength Best for ultra-high strength Eco-Friendliness Excellent (non-toxic) Some PAMs are non-biodegradable Multifunctionality Strengthening, retention, flame retardancy Single-function
Recommended Paper Types
• Packaging Paper (corrugated board, boxboard)
• Cultural Paper (improved surface strength)
• Specialty Paper (fireproof paper, filter paper) By leveraging sodium silicate, paper manufacturers can achieve cost savings, better process efficiency, and improved sustainability—making it a versatile choice for modern paper production.
Post time: Jun-04-2025