Extremes of Temprature
Apart from Silicone, rubbers are essentially hydrocarbon materials and perform within a limited range of temperatures. Where working temperatures are quoted, these represent the range within which the rubber’s properties are maintained more or less indefinitely. Temperatures lower than the minimum will always stiffen the material (although it will relax as the temperature rises) and extremely low temperatures may turn it brittle. Temperatures higher than the maximum will degrade the rubber, ultimately destroying it.
Where service temperatures are known, the best types of material can be selected to provide adequate life under those conditions. Temperature guidelines are provided in the DataChart, covering the range from – 80°C to + 300°C.
In vehicles, under-bonnet components are required to perform reliably in a high temperature environment while being exposed to hot oil, brake fluid and other chemicals. In other countries, the same components must function even when subjected to high wind chill factors – in Scandinavia for example sometimes reaching – 50°C.
Examples Of Components
- Telescopic eyepieces which must remain flexible and comfortable even in Arctic conditions.
- Furnace rod control seals, operating at continuous temperatures of 250°C