(Certified Best Practice by BMPCOE)
Rockwell Collins Avionics and Communications Division - Cedar Rapids, IA
Rockwell Collins Avionics and Communications Division (CACD), Coralville uses an alternate conformal coating process that satisfies environmental requirements while realizing many other advantages. Since 1993, Rockwell CACD has used a customized, automated conformal coating system from the Nordson Corporation to eliminate problems associated with the traditional spraying application method such as required masking, increased solvent release to the atmosphere, and substantial labor efforts.
Rockwell worked with Nordson to customize the system to Rockwell requirements. The Nordson Select Coat is an in-line workcell comprised of a coating workstation, workcell system controller, and in-line ovens for pre- and post-coating processes. The coating workstation includes a five-axis gantry robot that moves in the x, y, and z directions, as well as 30-degree tilt and a 90-degree incremental rotation. Operations such as coating gun movement, actuation of pneumatic valves, conveyor speed, temperature control, time duration, and overall operations are controlled by the workcell controller.
The system uses laminar flow as the application method. Although similar to spraying, the application method virtually eliminates overspray by using lower pressure (10 psi versus 30 psi). Lower application pressure removes the atomization experienced at higher pressure levels. Because of the ability to control overspray, masking is not required and cleanup is simplified. Labor and cycle time savings are achieved by eliminating two production steps, masking and unmasking. Because the system has a heater, higher viscosity materials can be used with the advantage of being more environmentally friendly since less solvent is required. The application head is also positioned closer to the product (< 0.5-inch) using laminar flow.
This system, which also has an oven preheat and an infrared and convection curing oven, is a complete workcell and has proven to be a good investment for Rockwell CACD production while remaining environmentally friendly.