This specification covers an elastomeric silicone insulating and sealing compound, supplied as a two-component system. The compound may be either an addition- or a condensation-cure type.
This specification covers an elastomeric silicone insulating and sealing compound, supplied as a two-component system. The compound may be either an addition- or a condensation-cure type.
This SAE Aerospace Standard (AS) provides dimensions and procedures for a standardized test fixture used to evaluate the static performance of O-rings and other seal types in glands per AS4716 and AS5857.
To ensure success in design of elastomeric parts for use at low temperature, the design engineer must understand the peculiar properties of rubber materials at these temperatures. There are no static applications of rubber. The Gaussian theory of rubber elasticity demonstrates that the elastic characteristic of rubber is due to approximately 15% internal energy and the balance, 85%, is entropy change. In other words, when an elastomer is deformed, the elastomer chain network is forced to rearrange its configuration thereby storing energy through entropy change. Thermodynamically, this means that rubber elasticity is time and temperature dependent (Reference 25). The purpose of this report is to provide guidance on low temperature properties of rubber with the terminology, test methods, and mathematical models applicable to rubber, and to present some practical experience.