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Master the silicone vulcanization process with this 2026 detailed guide. Learn exact temperature, time, pressure parameters for peroxide and platinum curing systems, differences between molding and extrusion vulcanization, post-cure recommendations, and troubleshooting tips.
Vulcanization is the most critical step in silicone rubber manufacturing. It transforms soft, sticky raw silicone compound into a durable, elastic, heat-resistant final product. Proper vulcanization parameters directly determine the mechanical properties, heat resistance, compression set, and service life of the finished silicone parts.
This comprehensive 2026 guide covers everything you need to know about the silicone vulcanization process — including detailed parameters, curing systems comparison, equipment settings, and practical troubleshooting for both peroxide and platinum systems.
Table of Contents
1. What is Silicone Vulcanization?
Vulcanization (curing) is a chemical cross-linking reaction that connects linear silicone polymer chains into a three-dimensional network. This process gives silicone rubber its elasticity, high-temperature resistance (-60°C to +200°C+), chemical stability, and mechanical strength.
2. Two Main Vulcanization Systems: Peroxide vs Platinum
Peroxide Curing (Organic Peroxide)
Uses peroxides such as DBPMH (double 2-4) or DCBP (double 2-5). Lower cost, widely used in extrusion and general industrial products.
Platinum Addition Curing
Uses platinum catalyst (Pt). Cleaner, no by-products, faster curing at lower temperatures. Preferred for medical, food-grade, and high-purity applications.
3. Detailed Vulcanization Parameters
Peroxide Curing System
- Temperature: 160–180°C (commonly 170°C)
- Time: 5–15 minutes (increase ~1 minute per additional 1mm thickness)
- Pressure: 10–15 MPa (100–150 kg/cm²)
- Vulcanizing Agent Dosage: 1.5–3.0 phr
Platinum Curing System
- Temperature: 120–200°C (recommended 150–180°C)
- Time: 30 seconds – 5 minutes (very fast, especially for LSR)
- Pressure: 50–150 bar for injection; lower for compression
- Catalyst Level: 5–20 ppm platinum
4. Vulcanization Methods by Process Type
Compression Molding
Typical: 170°C × 5–10 minutes at 10–15 MPa. Good for O-rings, gaskets, and complex shapes.
Extrusion (Continuous Vulcanization)
Hot Air Vulcanization (HAV) tunnel at ~180°C. Peroxide systems commonly use DBPMH. Residence time depends on line speed and tunnel length.
Injection Molding (LSR)
Platinum cure at 150–200°C with very short cycle times (seconds). Ideal for high-precision medical parts.
5. Post-Cure: When and Why It’s Needed
Post-cure (secondary vulcanization) at 180–200°C for 2–4 hours is highly recommended for:
- Medical and food-grade products
- Improving compression set resistance
- Removing residual volatiles and by-products
- Enhancing long-term heat aging performance
6. Key Factors Affecting Vulcanization Results
- Product thickness (thicker parts need longer time)
- Filler loading (high silica slows heat transfer)
- Vulcanizing agent type and dosage
- Mold venting and pressure control
- Environmental contaminants (especially for platinum systems)
7. Common Vulcanization Problems & Solutions
- Under-cure (sticky surface, low strength) → Increase time/temperature or agent dosage.
- Over-cure (brittle, reduced elongation) → Reduce time or temperature.
- Scorching in extruder → Lower barrel temperature or use slower peroxide.
- Platinum catalyst poisoning → Avoid sulfur, amines, and tin compounds.
8. Best Practices for 2026 Production
- Use precise PID temperature control (±2°C accuracy)
- Always perform small-batch trials before full production
- Monitor t90 cure time with rheometer (RPA)
- Implement post-cure for high-performance or regulated products
- Keep detailed records of batch, parameters, and test results
9. FAQ – Silicone Vulcanization Process
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"text": "For peroxide systems: 160–180°C. For platinum systems: 120–200°C, commonly 150–180°C."
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Conclusion
Mastering silicone vulcanization parameters is essential for producing consistent, high-performance silicone rubber products. Whether you use peroxide or platinum systems, compression molding or extrusion, following the correct temperature, time, and pressure settings — combined with proper post-cure when needed — will dramatically improve product quality and reliability.
By applying the detailed parameters and best practices in this guide, you can reduce defects, meet strict industry standards, and deliver better silicone components to your customers in 2026 and beyond.
Have questions about your specific vulcanization setup? Drop a comment below with your process type (extrusion, molding, LSR) and product application. Our technical team will reply with tailored advice.
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Published: March 26, 2026 | Author: Silicone Technical Team
Original technical content. Feel free to share with proper attribution.
