Silicones for Vacuum Bagging & Composite Production Vacuum bagging is an essential technique in the professional composites industry for producing high-quality carbon fiber, fiberglass, and aramid laminates. Silicones play a crucial role in this process: as a reusable vacuum bag, as a sealing material, and as a protective coating. At...
Silicones for Vacuum Bagging & Composite Production (1)
Silicones for Vacuum Bagging & Composite Production
Vacuum bagging is an essential technique in the professional composites industry for producing high-quality carbon fiber, fiberglass, and aramid laminates. Silicones play a crucial role in this process: as a reusable vacuum bag, as a sealing material, and as a protective coating. At Silicones and More, we supply specialized silicones from Wacker and CHT that are specifically suitable for these demanding applications.
Videos: Vacuum Bagging in Practice
See how silicone vacuum bags are made and applied in composite production:
Why Silicones for Vacuum Bagging?
- Reusable – silicone vacuum bags last for tens to hundreds of cycles, unlike disposable nylon film
- Temperature resistant – suitable for autoclave processes up to 200°C+
- Chemically resistant – resistant to epoxy, polyester, and vinylester resins
- Excellent elongation – adapts to complex geometries without tearing
- Vacuum tight – no leakage, consistent pressure build-up across the entire laminate
- Cost-effective – lower material costs per cycle with repeated use
Wacker – Elastosil C 1200 A/B
Wacker ELASTOSIL® C 1200 A/B is the reference product for casting reusable silicone vacuum bags. This 2-component platinum-cure system is specially developed for composite production and offers:
- Excellent temperature resistance – stable up to 200°C, suitable for autoclave curing
- High elongation and resilience – adapts to complex shapes and returns to its original form
- Long lifespan – resistant to repeated thermal cycles without degradation
- Low viscosity – easy to pour over molds for uniform bag thickness
- No shrinkage – platinum-cure system for dimensionally accurate bags
- Resistant to resins – no inhibition by epoxy, polyester, or vinylester
Applications: Reusable vacuum bags for autoclave, out-of-autoclave (OOA) processes, RTM (Resin Transfer Moulding) membranes, and press bags for composite presses.
CHT – Silicones for Vacuum Bagging & Composite
CHT Group offers an extensive range of silicones specially developed for composite production and vacuum bagging applications:
- QVB 701 – 2-component platinum-cure molding silicone especially for vacuum bags and composite production. High temperature resistance, excellent elongation, and long lifespan during repeated autoclave cycles. Reusable for tens to hundreds of cycles.
- SilSo Lite 21025 / 21030 – lightweight silicone foams for gap-filling, thermal management, and sealing in composite structures. UL94-V0 flame retardant (21030), ideal for aerospace and EV applications.
- ALPA-SIL 97116 – fast-reacting platinum-cure system (pot-life 2 min) for rapid prototyping of vacuum bags and composite molds. Demolds in 2–3 hours for high productivity.
- CHT Release Coatings – silicone release agents and release coatings for molds and tools in composite production. Ensure problem-free demolding of epoxy and polyester parts.
- Silicone sealants (AS-series) – for sealing vacuum lines, connections, and edges in vacuum bagging setups. Resistant to high temperatures and chemicals.
Applications in Composite Production
Aerospace & Aviation
- Autoclave curing of carbon fiber panels
- Reusable bags for complex geometries
- RTM membranes for structural components
Wind Energy
- Vacuum infusion of rotor blades
- Press bags for large composite panels
- Seals for vacuum setups
Automotive & Motorsport
- Carbon fiber body parts
- Out-of-autoclave (OOA) production
- Prototyping of composite components
Marine & Sport
- Ship hulls and deck components
- Surfboards, skis, and sporting goods
- Lightweight constructions for boats
Processing Tips for Silicone Vacuum Bags
- Prepare mold: use a suitable release coating on the mold for easy demolding of the silicone bag
- Pouring: pour the silicone calmly and in thin layers to minimize air entrapment; vacuum degassing recommended
- Thickness: a bag thickness of 3–6 mm offers the best balance between flexibility and durability
- Curing: allow to cure fully at room temperature or accelerate at elevated temperature (post-cure)
- Maintenance: clean with isopropanol after use; check for tears or damage before reuse
Why Choose Silicones and More?
- ✓ Wacker and CHT silicones directly available from the Netherlands
- ✓ Smaller packages and samples available for R&D and prototyping
- ✓ Technical support and customized advice
- ✓ Scaling to bulk possible for series production
- ✓ Full TDS and SDS documentation available
Do you have questions about the right silicone for your vacuum bagging application? Contact us for expert advice!