The chain-on-edge method of coating is used for applications, wherein, the coating requirement may be just on the inside or the outside diameter of the part. An example of this would be a bushing that would require an adhesive coating on the outside so that the rubber could be bonded to the bushing. Similar applications would also apply to certain inside diameters. This method could also be used on brake drums and brake rotors.
The Chain-On-Edge Process
A typical chain-on-edge line would be approximately 100 to 200 feet long. Work holding fixtures would be placed on sprockets 3" to 12" apart. Parts would be placed on the fixtures. The chain-on-edge conveyor line runs at 6 to 20 feet per minute. Hi-Tech Coatings' lines 1, 2, and 3 have 2 paint booths and 2 curing ovens for prime coat and top coat applications. This process is fast and eliminates the need to mask parts. As the line approaches the prime coating booth, the work holding fixture sprockets engage a chain which spins the fixtures and parts in front of a spray coating gun which automatically sprays as the parts travel through the spray mist. The parts then go through a curing oven and past the top coat booth and then into the final curing oven. Parts are normally pre-treated utilizing PFG phosphate coating or shot blasting processes.
PFG has 9 high volume chain-on-edge lines in place which are capable of running a wide variety of parts and coatings. Hi-Tech specializes in applying adhesives, Teflons®, and dry film lubricants. These four lines compliment our dip/spin and spray coating lines. Three of the lines are new state-of-the-art machines that can do I.D. only or O.D. only.
Our Michigan Hone & Drill division manufactures a complete line of chain-on-edge work holding fixtures for Hi-Tech Coatings and other companies that utilize chain-on-edge equipment.