Stability of Photographic Film: Part VI—Long-Term Aging Studies

Abstract

Predictions of the life expectancy of photographic film have been based on the extrapolation of high temperature incubation results to practical storage temperatures using Arrhenius-type treatment of the data. On the basis of such tests, estimates have been made of the storage life of photographic motion picture films on cellulose triacetate, cellulose nitrate, and polyester supports. Incubations reported in earlier papers in this series have been extended, and property measurements have now been made on the film after ten years at temperatures of 50°C. Longer term, lower temperature incubations provide greater confidence in the accuracy of extrapolations of film life expectancy to lower temperatures, and the data now reported are the longest term incubations published thus far. Analysis of the extended-term data supports previously reported predictions and indicates that triacetate support has good stability for at least 40 years and polyester support for as long as 1,000 years when stored at room conditions. Nitrate base is highly variable: some materials have a life of 500 years and some show degradation in less than a decade.