MODUK DTD-5615A PDF

The materials covered by this specification are intended for the production of items such as sheets, mouldings and certain extrusions where high tear strength properties are of prime importance. They can be used for applications where incidental contamination may occur with heavy mineral or di-ester based liquids over the temperature range -60°C to 150°C for continuous operation or up to 200°C for short intermittent periods.

For applications in contact with-air they may also be considered for use up to 250°C but considerable reduction in the tear strength properties must be expected when these materials are exposed to high temperatures (150°C and above) for other than short periods of time.

They are unsuitable for use in contact with petroleum-based fuels, light mineral oils and greases made from them and phosphate esters. They have excellent ozone resistance.

Where prolonged contact with heavy mineral or di-ester based liquids is required, use should be made of materials complying with the requirements of D.T.D. 5582 - "Oil Resistant Vulcanised Silicone Rubbers for Aircraft".

NOTE. At ordinary temperatures and in the absence of hostile environments e.g. when properly stored, rubbers deteriorate only very slowly. For most practical purposes the effect is insignificant .for silicone rubbers and storage life may be considered indefinite.

However, the rate of deterioration increases markedly with increased temperature and the services life of the rubber therefore depends upon the operational temperature. Conversely, the maximum temperature at which the rubber may be used depends upon the useful life required.