Compounding white sidewall compounds is a difficult process. The difficulty comes not from the formulation or mixing procedure but from potential contamination. Since white sidewall compounds are mixed in locations where a significant amount of carbon black, antioxidants, incompatible polymers and other potential contaminates exist, the potential for discoloring and foreign material is extreme. The other problem with mixing white sidewall compounds is the dust generated by using powdered titanium dioxide.
This white powder is quite fluffy and is easily lost into the air and dust collection systems. Using dispersions of titanium dioxide can eliminate the dust level and save significant waste to the dust collectors and floor. This study will examine the physical and processing properties of a typical white sidewall compound using both rutile and anatase titanium dioxide and compare the results of powdered versus the dispersions of each.