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      Measuring Properties      Glossary of Terms          A-B          C-D          E-G          H-O          P-S          T-Z      Request A Copy Contact Information

H-O   HEAT (see "Lift") HEAT AGEING Also known as "accelerated ageing". Rubber materials are often tested for shorter times at higher temperatures to predict what will happen over longer times and at lower temperatures. HYSTERESIS The difference between the amount of energy absorbed when a rubber is stretched and the amount of energy released when the rubber is relaxed. High hysteresis indicates a high loss of energy (and so is good for energy absorbing applications). Low hysteresis rubbers are more resilient. LIFT The set of rubbers resulting from a single mould cycle or pressing. Also called a "heat". MODULUS The relationship between stress (force) and strain (extended length). Modulus is usually given as the stress (or force) required to extend a rubber (e.g. 100%, 200% extended).