Directional Effects in Dielectric Properties of Molded Rubber

During the COllrse of an inves tigation of differentlv compounded rubber-filler systems. it was obs;rved that specimens of the sarno composition som etimes showed large differences in their values of both dielectric constant and of diss ipa tion factor. Tho most likely explanation was that these electrical properties wero affected by the amount of flow in a given direcLion produced during manufacture of th e samples. A study was therefore made of tb e eHect of flow during molding upon the dielectri c constant and dissipation factor of a number of rubber-filler mixtures. The thermal expansivity of the samples was also obtained in order to determine correlations that might exist. The results show that flow during molding may produce large differences in th e dielectric constant, dissipation factor, and expansivity of certain rubber-filler mixtures.