Peroxide or platinum silicone: how to choose the right catalyst for your industrial application?
Introduction
In our workshops in Luberon, the question comes up every day: “What catalyst for this project?” Behind this apparently simple technical question lies a strategic choice that determines the performance of your final part, its regulatory compliance and its industrial feasibility. At PROGRESS Silicones, we transform silicones on a daily basis for sectors as demanding as the medical,Agri-food And thelighting. Between peroxide and platinum, the choice is never trivial. Here's what our teams learned over the course of the projects.
Understanding silicone cross-linking: the basics
Cross-linking transforms a soft silicone gum into a stable and efficient elastomer. Without this chemical process, silicone would remain a paste without industrial interest. Two main families dominate hot vulcanization: peroxide systems and platinum systems. They are not two interchangeable solutions, but two philosophies of transformation, each with its own areas of predilection. These two complexes can be used in moulding And in extrusion.
The peroxide system: proven industrial robustness
How does it work
Peroxide triggers cross-linking through thermal decomposition, creating free radicals that form carbon-carbon bonds between polymer chains. The reaction is generally activated between 160° C. and 200° C.
The benefits of peroxide
This historic technology has remarkable industrial robustness. Peroxide silicone tolerates less stringent storage conditions and is naturally integrated into high-speed processes such as continuous extrusion. The parts obtained offer excellent thermal resistance and proven mechanical stability. For industrial seals, technical profiles or lighting applications, peroxide is often the most economical and reliable solution.
The constraints to be controlled
Peroxide cross-linking generates decomposition by-products that remain trapped in the room. Post-cooking (generally 4 hours at 200°C) is necessary to eliminate these residues and guarantee the absence of odor or migration. This additional step requires rigorous logistics that our teams master perfectly. Peroxide also has incompatibilities with certain additives and can complicate regulatory compliance for critical medical or food applications.
The platinum system: the requirement for purity
How does it work
Platinum crosslinking, or hydrosilylation, uses a platinum complex to catalyze the reaction between vinyl and Si-H groups. This addition reaction does not generate any by-products: it is clean, total and perfectly controlled.
The benefits of platinum
The platinum catalyst offers exceptional chemical purity: no by-products, no mandatory degassing, no residual odor. That is why it dominates medical, pharmaceutical, and food applications. The parts have excellent optical transparency, recognized biocompatibility (ISO 10993, USP Class VI) and homogeneous mechanical properties. For LSR injection or complex parts, platinum allows short cycles and high dimensional accuracy.
Technical challenges
The platinum catalyst is extremely sensitive to catalysis poisons. Minimal traces of sulfur, amines, or certain plasticizers are sufficient to inhibit the reaction.
Result: the mixture does not vulcanize.
This requires cleaning protocols, environmental control and constant vigilance on the materials in contact. In general, the cost of platinum is slightly higher, and will require more stringent storage conditions.
Concrete use cases: the PROGRESS Silicones experience
Case 1 - Medical devices
Requirements: Biocompatibility, absence of migration, prolonged contact with body fluids
Choice: Bi-component platinum silicone
Our added value: Full process qualification, regulatory documentation, total traceability
Case n° 2 - Large series industrial joints
Requirements: Mechanical strength, thermal resistance, optimized cost
Choice: Peroxide silicone with controlled post-cooking
Our added value: Optimization of molding parameters, repeatability over millions of parts
Case 3 - LED optics
Requirements: Maximum transparency, optical stability, premium aesthetics
Choice: High transparency platinum silicone
Our added value: optical quality control, complex geometries, adapted cycles
How to choose: the right questions to ask yourself
Our teams systematically ask these questions:
Environment of use: Food contact? Human body? Industrial atmosphere?
Regulatory constraints: Medical standards, food standards, internal requirements?
Expected performances: Transparency, mechanical strength, dimensional stability?
Volume and budget: Prototyping, small series, large series?
Level of finish: Hidden technical part or showcase of your product?
At PROGRESS Silicones, we are not just transformers. We are an industrial partner made in Luberon that masters both technologies with the same requirements.
Our teams analyze your specifications to:
- Define the optimal reticulation system
- Qualify manufacturing parameters
- Optimizing the material/process combination
- Secure your approvals and costs
This tailor-made approach, rooted in our culture of precision and our family spirit, allows us to support complex projects from prototypes to large-scale industrial series.
Conclusion: whether your projects are extrusion or casting, these two catalysts can be used, only expertise will make the difference.
There is no “good” or “bad” catalyst, only a system adapted to your context. Peroxide excels for robust and economical industrial applications. Platinum is essential for purity, biocompatibility and optical performance.
Our role: to help you ask the right questions in advance to secure your project. Because behind each technical choice, there are women and men who bring French industry to life with passion and rigor.
👉 Are you hesitant about choosing your catalyst? Let's talk with our technical experts.
