Soft Foam Injection Technology (S-FIT)
S-FIT for the first time offers the opportunity to gate true flexible-foam seals (e.g. of polyurethane or silicone foam) in one process step (one-step process) directly into plastic parts. The process presented at the K-Fair 2007 as a world first, combines the advantages of thermoplastic base carriers with thermoset sealing properties, wide freedom of design with adjustable flexibility and high long-term leak resistance. By using pre-vulcanized thermosets, processing is safe and simple. The plant investment is kept within manageable limits. Probably the most significant aspect: the cycle times compared to standard injection moulding increase only marginally, because the waste heat from the thermoplastic material is used directly.
Benefits
- Plant investment is kept within manageable limits
- High process reliability and short cycle times
- Thermoset seal (i.e. good chemical and heat resistance)
- Flexibility freely adjustable (low resilience, air serves as a gaseous medium)
- High freedom of design regarding sealing geometry
- Sealing face instead of sealing line à Compensation of moulding tolerances possible
- Integrated external outer layer with closed-cell foam structure
- Small moulding tolerances, approx. +/-0.1 mm
Process cycle
1. Injection moulding of thermoplastic base carrier
2. Providing a three-dimensional space for the sealing contour (core-back, rotary platform,
transformation technology, etc.)
3. Introducing the thermoset sealing material
4. Curing the seal by making use of residual heat and temperature
Typical applications
- Automotive components (door modules, cowl plenum chambers, headlights, roof antennas, etc.)
- Electronics (insulating components, fuse boxes, battery covers, etc.)
- Sanitary ware (fittings, toilet flush system handles, interior parts, etc.)
- Domestic appliances (vacuum cleaner bags, coffee machines, refrigerators, etc.)