About Harboro Rubber Engineering in Rubber      Contents      Introduction      Uses of Rubber      Processing Rubber      Designing With Rubber          Designing For Minimum Costs          Producing A Specification          Prototyping          Designing Components          Tooling Design          Cost          Colour          Surface Finish          Materials              Request Material Samples          Tolerances          Quality      Selecting / Specifying Rubber      Quality In Rubber      Rubber Directory      Health & Safety      Measuring Properties      Glossary of Terms      Request A Copy Contact Information

Materials   Harboro is happy to advise on the most economic materials for any application. The company will supply free samples of materials in 4" x 3" (approx.) sheets to allow different compounds and hardnesses to be trialed. Of course, any material proposed should be well tested before production commences. You can Request Material Samples from this site. Some materials are very expensive, but on small complex parts the material cost may not be that significant. However, on tiny, thin parts, the weight of flash, sprues and runners may be large compared with the component itself. Each mould is made to allow for the shrinkage of a specific compound. Rubber compounds of the same type have similar shrinkages - harder compounds shrink slightly less. It is possible to change compounds in a mould but the finished dimensions may vary if the shrinkage is different.