Bulk Molding Compounds Inc. (BMCI, West Chicago, Ill., USA) announced on Aug. 5 the approval of thermoset material BMC 665 by Chrysler Corp. for use in cylinder head covers. BMCI developed the unsaturated polyester BMC 665 speciﬁcally for automotive powertrain applications.
“This material was speciﬁcally formulated to meet the long-term, demanding performance requirements associated with ever-increasing under-the-hood temperatures,” stated Len Nunnery, vice president global marketing. He added, “BMC 665 was chosen by Chrysler Corp. for its impressive physical properties, robust injection and compression procesability, and unrivaled cost effectiveness.”
Additional properties of this material include lower speciﬁc gravity (1.67) and good surface appearance for aesthetically critical engine parts. BMC 665 is inherently ﬂame resistant, offers a coeffcient of thermal expansion similar to aluminum, tight dimensional stability and a glass transition temperature nearing 200°C/392°F. This material is currently being used in breather cover and heat shield applications for Cummins Diesel engines.