Nuremberg, Germany – Munich-based chemical group Wacker’s presentations at DKT2018 included a new solid silicone rubber for sealing profiles and tubing used at temperatures of up to 300°C for several days.
Elastosil R plus 4350/55 is described as a silicone rubber for formulating heat-resistant, addition-curing silicone elastomers that attains optimum properties when combined with heat stabilisers.
“The type of stabiliser and the amount used have a significant influence on the heat resistance of the cured rubber, which is easy to process in extruders,” explained Wacker.
Heat-aging tests, it added, show that mechanical properties, such as Shore A hardness and elongation-at-break, change very little at temperatures above 200°C even after 2,000 hours.
After it has cured, Elastosil R plus 4350/55 achieves a Shore A hardness value of 55 and is said to be suitable for manufacturing heat-resistant profile gaskets, such as for oven and stove doors or for engine-compartment parts.
Post-cured grades, noted Wacker, comply with the requirements of the German Federal Institute for Risk Assessment and the US Federal Drug Administration for food contact.