In the production of PVC products, thermal stabilizers are essential for ensuring heat resistance and long-term durability. Two common types used in the industry are Calcium Zinc Stabilizers and Composite Lead Salt Stabilizers. While both serve to stabilize PVC under heat, they differ significantly in environmental impact, processing characteristics, and application range.
Calcium Zinc Thermal Stabilizers
Calcium zinc stabilizers are eco-friendly options that comply with global environmental regulations. They have become increasingly popular in various PVC applications due to their versatility and low toxicity.
Key Features:
Wide Applicability: Suitable for both transparent and opaque PVC products, including chemical building materials.
Cost Advantage: More affordable than organic tin stabilizers.
Excellent Compatibility: Can be used alongside other stabilizers such as lead, tin, cadmium, and antimony without sulfide pollution. Ideal for manufacturers transitioning from lead-based stabilizers.
Superior Weather Resistance: Products made with qualified calcium zinc stabilizers maintain color integrity and do not discolor over time.
Composite Lead Salt Stabilizers
Composite lead salt stabilizers are widely used, particularly in China, where they serve as the main thermal stabilizer in PVC manufacturing. Produced via symbiotic reaction technology, these stabilizers combine multiple lead salts and lubricants into a unified formulation.
Key Features:
Toxicity: Contains lead and poses health hazards, requiring careful handling and protective measures.
Transparency Limitation: Not suitable for use in transparent PVC products due to discoloration risks.
Electrical Insulation & Weather Resistance: Offers excellent insulation and outdoor durability.
Low Cost: Economical option with high cost-performance ratio.
Processing Versatility: Performs well in various processes such as extrusion and injection molding.
Comparison Table: Calcium Zinc vs. Composite Lead Salt Stabilizers
| Feature | Calcium Zinc Stabilizer | Composite Lead Salt Stabilizer |
|---|---|---|
| Environmental Impact | Low toxicity, eco-friendly | High toxicity, hazardous |
| Transparency Suitability | Suitable for transparent and opaque PVC | Not suitable for transparent PVC |
| Compatibility | Compatible with other stabilizers (Pb, Sn, Cd, Sb) | Usually used independently in composite form |
| Weather Resistance | Excellent, no discoloration | Good |
| Price | Lower than organic tin | Very economical |
| Processing Performance | Good, with clean processing profile | Excellent across multiple processes |
Choosing the right thermal stabilizer depends on application requirements, regulatory needs, product type (transparent vs. opaque), and cost considerations. While calcium zinc stabilizers are ideal for environmentally compliant production with excellent performance, composite lead salt stabilizers remain a cost-effective choice in traditional processing where transparency and toxicity are less of a concern.
