This is because each batch of powder must be ground to order using expensive grinding equipment. Solvent born colors will continue to maintain their niche in the market because of the ease with which small batches can be mixed. Southern Aluminum Finishing also applies epoxy based powders for interior applications such as furniture. All the resins I have mentioned can theoretically be made in either solvent-born or powder coating formulations. The force of regulation weighs heavily on the construction industry, especially on solvent-born coatings.
Ozone is a major component of smog and can cause eye, lung and throat irritation.
If Southern California is an indicator of future environmental regulations for the rest of the country, it may soon be illegal in the U.S. to spray many solvent based coatings including PVDF without costly environmental equipment. This is driving up the cost of solvent-born coatings. Organic coating manufacturers may be forced to decide between recommending their applicators install costly pollution control equipment, or developing powder coating technology. In order to meet AAMA 2605-98 all organic coatings for architectural aluminum including solvent born and powder coatings require a hexavalent chrome pretreatment. This pretreatment is required for long-term adhesion for exterior use, but it requires that applicators have extensive water pollution control equipment.