HEX Free Chem Films
Conversion Coating Process for Aluminum
Alpine Products and Metal
Finishing Company located in
Mil-DTL-5541 Type 2
Individuals long associated with the metal finishing industry immediately recognize the terms Iriditing and Alodining as nicknames for a process protecting aluminum with a yellow chromate conversion coating. The terms stem from the two most prominent proprietary products, Iridite and Alodine, of aluminum finishing since its inception in the early 1950s. However, recent European Union Directives such as End-of-Life Vehicles (ELV) approved in 2000, Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) both approved in 2003, now place restrictions on traditional hexavalent chromium containing finishes. The proposed OSHA limitation on hexavalent chromium exposure of 0.1 mg/m3, presently under review, has the American metal finishing and electroplating industries deeply concerned over the future of hexavalent bearing chemistries of any kind. The combination of these new governmental policies creates a need for a replacement of hexavalent chromium based finishes with technology that rivals the performance but remains hexchrome-free. This need has created the new name in chemical conversion coating technology.
Alpine
currently uses Alodine T
5900, which is a complex trivalent chromium conversion coating
formulated for treating aluminum and its alloys. The process
provides bare