plating, anodizing, & finishing Q&As since 1989
Automotive Organic Coatings
Hi, I am a Junior in college doing a presentation on Organic Coatings used in the Automotive Industry. I was wondering how often is this being used in the industry today especially with the Powder Coatings that seem to be coming much more popular. I am having a hard time finding that information. Also if there are any new improvemnts on applying the organic coatings, that would be helpful too.Barry Brandt
- Eagan, Minnesota, USA
I have the feeling that you don't know quite what an organic coating is, and that it's causing you confusion. I'm sure you know the difference between an inorganic chemical and an organic chemical. Well, practically all non-metallic coatings are organic coatings. All cars are painted, i.e., all cars have organic coatings. They can be applied by dipping or spraying, and they may be in powder form, dissolved in solvent, or waterborne.
There are a few simplifications in the above paragraph, but it should be a start.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
The organic coating's you refer are polymers dissolved in solvent with various pigments dispersed in them. The automotive industry uses to a large extent a three coat system. First there is an electrocoat primer which is applied by a dip process. A basecoat is applied next. This contains the colour. Thirdly a clearcoat is applied giving the glossy finish.
Electrocoat, also known as E-coat (Ford), ELPO (GM). The carrier for the polymer system is water and the polymer is epoxy based. Basecoats use acrylic based polymers with various pigment for colour. Mica or aluminum flakes are used to give the special optical effects.
Clearcoats are normally urethane polymers which are clear or in special cases dyed for special effect. The basecoat and clearcoat are sprayed on using robots in most cases. Powdercoating is restricted to under body applications due to technical limitations. Technical innovations include waterbased basecoats which some assembly plants now use. The inside track is I suspect coil coating, following the lead of appliance manufacturing.
I hope there is enough key words here to get you started.
Continuous Colour Coat - Brampton, ON, Canada