The fully saturated hydrocarbon backbone of EPDM rubber results in outstanding weatherability, ultraviolet stability and low/high temperature resistance. Therefore, EPDM rubber has been established as the primary polymer choice for automotive sealing applications (both dense and sponge weatherstrip).
A typical manufacturing process of automotive dense weatherstrip involves profile extrusion followed by continuous vulcanization. Excessive porosity in extruded and fully cured dense profiles remains a big challenge to many automotive weatherstrip tier suppliers.
In this study, we systematically studied the mechanism of porosity formation in EPDM dense profile. The major factors for porosity in EPDM dense profile were summarized as compound formulation; extrusion conditions; and vulcanization conditions.
A porosity-free technical solution for EPDM dense profile also was presented.