ANALYSIS OF WATER INGRESSION INTO RUBBER-SEALED SYSTEMS.

A mathematical method has been developed and used to evaluate the rate at which water enters an elastomer-enclosed system. This can be done for an internal atmosphere of any composition (air and castor oil reported) and with the presence or absence of desiccant. Initially one observes a rapid increase in internal relative humidity with an asymptotic approach to 100%. The permeation rate simultaneously decreases rapidly and asymptotically approaches zero. For systems which are water sensitive, such as electronic devices, this method of analysis can be utilized to estimate useful lifetime expectancy.