Method of compounding low-gravity sponge rubber for automotive weatherstrip

摘要

The invention relates to automotive weatherstrip material. More specifically, the invention utilizes thermo-expandable microspheres in the sponge bulb member of the weatherstrip to produce a microcellular structure which provides a lower weight weatherstrip material with improved surface appearance and comparable stiffness to known materials for use in the automotive industry, and exhibiting a blown specific gravity of less than about 0.60 g/cc.