Autodeposition of Organic Films - Some Unique Applications 862020
An autodeposition process applies an organic coating to cleaned-only metal surfaces without the use of an external current. Major advantages include lower floor space requirements than other high-quality finishing methods and the absence of Volatile Organic Compounds (VOC) when using the chemicals employed in the most widely adopted process version. Of perhaps even greater importance is the energy efficiency of the process combined with its excellent throwing power. To achieve adequate film thicknesses in a 90 to 150 second immersion time, it is only necessary for the chemical coating bath to be able to wet any recessed area.
An example of a commercial part suited to a low-cure autodeposition process is an automotive leaf-spring assembly which is a composite of heavy-gauge steel plates plus plastic and rubber components, the performance of which could be adversely affected by exposure to temperatures in excess of 200°F. An autodeposition system has been designed which is capable of providing quality under this constraint.
Enclosed structures, such as automotive fluid filler tubes and rectangular “tube-type” lateral arms for a newly designed axle system, have also been successfully coated with autodeposition processes. These and other examples will be discussed in the presentation.