New silicones for gaskets
The new Fermasil 91 and Fermasil 93 two-component silicones produced by Sonderhoff are characterised by cross-linking times of just a few minutes at ambient temperature. Both products are dry to the touch after 10-12 minutes, without need for a furnace, thereby saving on both process time and energy costs.
Fermasil 91 has a lower viscosity (of up to 25,000 mPa·s) and has been developed for groove applications, while the Fermasil 93 thixotropic system, with a viscosity of 80 to 130,000 mPa·s, is intended for applications on even or inclined surfaces without grooves. The sealant is applied directly onto the parts by means of a dynamic mixing and dosing system with FIPG (Formed In Place Foamed Gasket) technology, developed by the same company.
The new silicone sealants have a closed cell structure that makes them hydrophobic, resistant to a wide range of temperatures (from -50 to +180°C, with peaks of up to 350°C), stable under UV-ray exposure, and with a low compression set (less than 15% for Fermasil 91 and less than 10% for Fermasil 93). Even after repeated compressions and at a temperatures above 180°C, compressibility is retained, ensuring that a perfect sealing effect is maintained over time.