January 1, 2002
BASF Corp., Southfield, MI, announced the commercial introduction of DynaSeal, a dual-cure (UV and thermal) sealer for coating sheet molded composite (SMC) materials used in automotive applications. The company said the product prevents porosity defects in automotive coating layers by sealing the SMC surface. The technology involves curing of the sealer with UV light and heat, which allows the SMC surface to be sealed by the UV-induced polymerization before the part is subjected to the thermal cure. The polymerized film prevents out-gassing from the SMC part when subsequent paint layers are cured, the company says. SMC is extensively used in automotive applications because of its favorable weight-to-strength ratio and ability to be molded into complex parts, but BASF says the SMC has been difficult to paint with standard automotive coating systems due to out-gassing of volatile materials from the substrate during the curing process.