a process for preparing a metal plastic composite comprising prime coating at least a portion of a metal substrate with one or more layers of an adhesion primer powder consisting of a solid thermosetting resin using a conventional powder application technique , heating the thus coated substrate to a temperature sufficient to melt a surface coating powder to be subsequently applied , immersing the thus coated substrate into a fluidized bed of a surface coating powder for a time sufficient to give the thickness of surface coating desired .