As automotive paint spray processes have adopted cleanroom philosophies in the past several years, it has become increasingly apparent as to the impact of indirect materials on the final product.
Historically, less reliable methods such as panel tests and tape tests were utilized to determine product cleanliness. These methods suffered from environmental interference, with an inability to isolate variables unrelated to the product’s cleanliness. As a result, new test methods for particle release have evolved, which are more reliable, and scientifically repeatable. Some examples are Readily Releasable testing and Bidirectional Shake Testing for particulates.
Though originally intended for testing of particle release of wiping materials, automotive OEMs have expanded the use of these tests for Cleanroom-type coveralls, wipes, gloves and automation covers. The test criterion encompasses both new and reusable products.
The laundry can no longer rely solely upon test methods such as ASTM F51-68, or Helmke Drum testing as a means to determine particulate release for an individual batch of product. Though the tests are both effective and acceptable for other critical manufacturing environments.
The ensuing paper will investigate these test methods, and the impact and the validity to measure contamination from indirect materials on automotive paint finishes.