Thermally Expandable Microspheres | Physical Blowing Agent for Addition-Cure Silicone, Packed in Drum
Short Description
Manufacturers working with silicone calendering, silicone coating and foam silicone gaskets often struggle with inconsistent cell size, surface pinholes, unstable expansion ratio, high shrinkage, poor resilience, strong odor from chemical blowing agents, or platinum poisoning that stops silicone curing. Thermally expandable microspheres are high-performance physical foaming particles customized for platinum-cure addition silicone systems. Each microsphere has a thermoplastic shell filled with low-boiling hydrocarbon. When heated, the shell softens and the core expands to form regular closed cells. No chemical decomposition, no harmful by-products. We supply neat microspheres in drums. You can compound them on your own line, or use them as raw material to produce foam master paste. Compatible with our three pre-formulated silicone foaming pastes: low-temperature foam paste, calendering foam paste & coating micro-cell foam paste.
✅ Solve Your Common Production Pain Points
❌ Pain 1: Conventional chemical blowing powders create irregular, large cells and poor surface finish
✅ Benefit: Microspheres produce fine, uniform cells, smooth surface and fewer pinholes
❌ Pain 2: Chemical foaming agents leave residues, bring strong odor and fail low-VOC requirements
✅ Benefit: Pure physical expansion, low VOC & low odor, REACH and RoHS compliant
❌ Pain 3: Some foaming additives poison platinum catalyst, leading to tacky, under-cured silicone
✅ Benefit: Platinum-safe, no curing inhibition, stable crosslinking for addition silicone
❌ Pain 4: Foamed parts shrink heavily, rebound poorly and have high compression set
✅ Benefit: Stable closed-cell structure, excellent resilience and low compression set
❌ Pain 5: Uncontrollable expansion ratio causes big density variation between batches and low yield
✅ Benefit: Predictable expansion rate, consistent quality from batch to batch
❌ Pain 6: Foaming agents break easily under high shear during coating or calendering
✅ Benefit: Good shear resistance, reliable for continuous knife coating and calendering lines
Key Features
- Physical foaming, no gas generated by chemical decomposition
- Fine and uniform closed-cell structure
- Fully compatible with platinum addition-cure silicone
- Wide processing window: coating, calendering, compression molding
- Supplied in drums, samples and bulk orders available
Main Applications (Silicone Focus)
- Addition-cure silicone foam sheets by calendering, new energy silicone foam gaskets
- Silicone coating on fabric, fiberglass, PET substrate, matte & non-slip microcellular coating
- Low-temperature molded silicone foam, cushion & sealing sponge
- Raw material for compounding: low-temp / calendering / coating foam master paste
- Other uses: lightweight ink, artificial leather, adhesive foaming
Technical Guide
- Appearance: White fine particles
- Onset expansion temperature: 80–130°C (multiple grades for different processes)
- Recommended dosage: 0.8–3 wt% (adjust according to target density & expansion ratio)
- Packing: 25kg per drum
- Note: This is solid physical blowing agent, NOT gas for supercritical foaming. It can also work with peroxide-cured silicone, while our main recommendation is for platinum addition silicone.
Inquiry CTA
Free samples, TDS, MSDS/SDS and dangerous goods documentation are available. Please send your inquiry with details: silicone type, process (coating / calendering / molding), target foaming temperature and desired density, we will match the right grade for you.
- Hi, Winstar Silicone company, we are interested in your product silicone color masterbatch, could you please offer some free samples to us？ Our company address: ***LA,USA
- Hello Winstar, our product is compression molding product,could you advise which peroxide curing agent to use ?
- Hi friend, we have some problem in silicone to PVC bonding, that bonding strength is not well at all, how to improve it please ?
