Class A Weather Stripping

Blemish-free surface appearance on extruded automotive profiles and window channels is a key requirement for automotive manufacturers.

This so-called "Class A" surface finish calls for an extremely low level of undispersed particles in the rubber compound to avoid visible imperfections on the extrudate surface, leading to part rejects or scrap. SPHERON®carbon blacks are designed to address surface imperfections, as they are produced using a specific process resulting in very low amounts of impurities and +120 mesh "grit" which is often responsible for visible surface defects.

SPHERON 5000A, SPHERON 6000A and SPHERON 6400A carbon blacks have a unique morphology as compared to traditional American Society for Testing and Materials (ASTM) series carbon blacks. This can considerably improve dispersion rates and ease of mixing when compared to the standard ASTM N500, N600 or N700 series carbon blacks.

In addition to our SPHERON A carbon black series, we offer several region-specific carbon black products for extrusion applications in order to meet the needs of our customers around the world, such as SPHERON SO carbon black in Greater China and STERLING® 5630 and STERLING 6630 carbon blacks in North America.