Ann, actually, I have found many applications for food processing prefer stainless steel enclosures. I know that this is for clean rooms, but I wonder if the painted surfaces have something to do with issues presented by flat surfaces that are unpainted.
You got it, Beth. Although it's more like materials that don't generate particles in the first place, as any particles in the air are a bad thing. Smooth surfaces with tough paint covered by a clear coat so it doesn't chip and is easy to clean with a non-particle-producing type of cloth, paint on flat areas but not in holes or stops, where there's a lot of wear, and special glue seals. I didn't ask about the white color, but white is pretty common in cleanroom equipment and clothing, probably because it's much easier to spot contaminants on white surfaces.
I would imagine there is a lot of demand for specialized clean room versions of robots. Is the non-painted surfaces and some of the other special considerations what make it "clean" as they prevent the attraction of particles?