Resistance of Rubber Covered Cable, Jacket, and Insulation Stocks to Weather and Artificial Aging

摘要

It was demonstrated that, by the use of four parts of wax, GR-S rubber can be compounded to experience practically no weather cracking when exposed unstressed for two years. GR-S can be so compounded as to undergo very limited weather cracking when exposed under stress for 24 months. However, the use of wax in itself is not adequate to ensure this characteristic; differences in types of wax, in compounding materials, and in methods of mixing and curing permit a wide range of results. Suitability of a specific type of rubber or formulation can be determined only by test. It was also demonstrated that low-temperature properties of military cables can be retained after exposure to desert conditions. A general correlation between tensile strength retention after exposure and weather cracking has been indicated. The results of this investigation emphasize the importance of developing a satisfactory accelerated weathering test which will more accurately predict outdoor suitability of rubber-like materials, and which can be used to compare correctly the merits of different materials.