About Harboro Rubber Engineering in Rubber      Contents      Introduction      Uses of Rubber      Processing Rubber      Designing With Rubber      Selecting / Specifying Rubber      Quality In Rubber      Rubber Directory      Health & Safety          Material Data          Fire and Explosion Hazard          Health Hazard Data          Company Statement          General Guidelines              Storage              Crystallisation              Low Temperatures              High Temperatures              Burning              Rubber Dust              Servicability              Resistance              Bonded Rubber Parts              Friction              Electrical Properties              Radiation      Measuring Properties      Glossary of Terms      Request A Copy Contact Information

High Temperatures   Rubbers deteriorate as their temperature is raised. Each compound has a maximum safe continuous working temperature which depends upon the formulation, service conditions and level of properties required. This temperature may sometimes be exceeded for short periods if some deterioration of the properties can be safely allowed. Rapid bending or stretching of rubber parts may also lead to a damaging build-up of heat (hysteresis) within the part - for example, a flat tyre. Rubber which has been overheated will have severely reduced properties and parts may be unable to function as designed. It can also produce unpleasant or dangerous substances, depending upon the base rubber and additives used in the compound. The typical temperatures for continuous and intermittent duty listed in "Engineering in Rubber" are based on simple laboratory air ageing tests. The only way to ensure totally satisfactory operation is to test the actual rubber compounds under normal (and abnormal) conditions of use.