I would like to know what are the factors that determines the migrations of the charge (CaCO3, silicates) on the rubber surface? This film reduces the ability of the rubber to adhere on the other elements when joined.
Minerals do not migrate. Liquid ingredients can migrate. However, mineral dust on the surface of rubber can definitely interfere with the ability to bond to the rubber. Any dust would indicate inadequate mixing, or that dusting was used to prevent the rubber from sticking during handling. Dust can also be washed off of surfaces.