ACCELERATED ACID ETCH FOR AUTOMOTIVE CLEARCOATS PART 2: A REFINED TEST PROCEDURE PROVIDES LAB FIELD CORRELATION

摘要

In 2002, BASF and Q-Lab Corporation (formerly Q-Panel Lab Products) developed a new procedure to reproduce acid etch in the laboratory. This procedure, known as the BASF Accelerated Acid Etch Test (BAAT), was the first of its kind to provide excellent correlation with the coatings' actual service performance. This unprecedented level of correlation was achieved by incorporating all the critical stresses including humidity, UV, moisture, appropriate acid solution, and horizontal specimen orientation into the exposure cycle. Since its inception, the BAAT procedure has been used as a screening tool for automotive clearcoats.rnThere has been ongoing research to improve and substantiate correlation with field results and to optimize the test procedure. First, temperature settings from the original BAAT have been adjusted to improve practicality. Next, new evaluation techniques using modern instrumentation were performed to further quantify exposure results. Finally, additional outdoor exposures determined the following: results do not differ significantly between sites on Blount Island, coated panels can be used interchangeably for actual automotive hoods, and a horizontal orientation provides the best etch results. Cumulatively, this research provides the automotive industry with a practical, viable test method to replace Jacksonville exposure testing, without sacrificing correlation.