Effects of Filler Morphology and Loading On Tire Innerliner Permeability: A Computational Study

The loss of air pressure in tires is known to degrade tire performance, specifically causing higher rolling resistance and reduced fuel economy.  Tire innerliners incorporate solid fillers that help minimize permeability by obstructing the path of migrating air molecules.  The effects of spherical filler particles on permeability of rubber are investigated via computational modeling of diffusion in 3D composites of solid spheres (assumed to have no gas permeability) within rubber (through which gas molecules are assumed to diffuse).  Biased random-walk diffusion was used to characterize permeability properties as functions of filler aggregation, morphology, and loading.  The effects of these parameters on modeled permeability properties are discussed.