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          Measuring Properties          Measuring Hardness          Tensile Strength          Elongation          Modulus          Compression Set          Permanent Set (Tensile Set)          Density (Specific Gravity)          Resilience          Chemical Resistance          Fluid Resistance          Weather Resistance          Ozone Resistance          Electrical Properties          Tear Strength          Abrasion Resistance          Electric Strength          Flame Resistance          Low Temperature          Staining          Accelerated Ageing      Glossary of Terms      Request A Copy Contact Information

Ozone Resistance   Property: Ozone Resistance Method of Measurement: Ozone causes cracking in rubber. Test pieces are usually placed under a small degree of tension e.g. by bending round a mandril or stretching by 5%. The sample is exposed under static conditions to a controlled atmosphere containing ozone (typically 50 pphm). These cracks are graded by standard photographs, by measurements or by description, e.g. visible under "10 x magnification", "visible to the unaided eye" etc. Results may be recorded as the time taken to reach a particular grade of cracking, or by the grade of cracking apparent after a fixed period of time. ASTM REFERENCE: D1149 BS REFERENCE: BS903 PartA43 ISO REFERENCE: ISO1431/1** * technically equivalent ** identical