STATIC VULCANISATION

The adhesion of cord, textile or metal, to rubber is a specialised measurement in that virtually all interest centres on tyres and to some extent belting. Most static tests consist essentially of measuring the force to pull a cord out of a block of rubber into which it has been vulcanised and it is apparent that the result is critically dependent on the efficiency with which the test piece was moulded. The measured force is also dependent on the amount that the rubber deforms during the test. 

For example ISO 1853, Conducting and antistatic rubbers, vulcanised or thermoplastic -Measurement of resistivity (in revision-DIS issued 1996). BS 2050. Electrical resistance of conducting and antistatic products made from flexible polymeric material. BS 2044. Determination of resistivity of conductive and antistatic plastics and rubbers (laboratory methods). An lEC standard is in draft giving comprehensive guidance. This is at present at the Committee draft stage—15D(Secretariat)37, Methods of test for the resistance of solid materials used to control static electricity. 

The Yerseley Mechanical Oscillograph supplied by ATS FAAR measures, according to ASTM D945 [142], the mechanical properties of rubber vulcanisations in the small range of deformation that characterises many technical applications. These properties include resilience, dynamic modulus, static modulus, kinetic energy, creep, and set under a given force. 

Automotive and electrical/electronics industries are the largest markets for engineering polymers which include Crastin PBT polyesters, Hytrel thermoplastic polyester elastomers, Rynite PET, high-temperature Thermx PCT (polycyclohexylene dimethyl terephthalate), Tribon composites and Tynex filaments, Vespel polyimide parts and shapes, Zenite liquid crystal polymers and Zytel PA resins. In July 2005, DuPont launched the DuPont Vespel SP-202 composition whose properties include the prevention of static charge build-up. Other products include Delrin acetal resins, engineering thermoplastic vulcanisates. Minion mineral reinforced PA resins and Teflon PTFE fluoropolymer resins. 

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