Effect of vulcanization on cable insulation

During January the Rubber Section of the Bureau of Standards carried out some work on the effect of variations in vulcanization on the electrical properties of rubber insulating materials for cables. A number specimens of the compound, smoked sheets, 92 percent and sulphur 8 per cent, were prepared for the purpose of determining the effect on the electrical properties of conducting vulcanizing at different temperatures and for different lengths of time. The results indicate that for a givenstate of cure the electrical properties are practically independent of the means by which that cure was effected, whether by vulcanizing for a long time at a low temperature or a shorter time at a high temperature.