Trends in Adhesion Testing

There was an interesting article in Canadian Finishing and Coatings Manufacturing Magazine this month.  Adhesion in the coating industry is the strength of the bond between the substrate and coating material. It is very important to test adhesion to avoid coating failures. There are several different ways to test adhesion, including knife tests, tape tests, and scrape tests. A knife test is when you cut an X in the coating with a knife (making sure to cut all the way to the substrate) and gauging the amount of effort needed to remove the coating with the knife. A tape test is similar to the knife test, but instead of using a knife to life the coating, pressure sensitive tape is applied to the X cut and removed quickly, then inspected to see how much coating came off. Scrape tests are usually used in laboratory situations, where coated objects are forced under a weighted loop with increasing heaviness until the coating fractures. For more information, go to http://cfcm.dgtlpub.com/2013/2013-04-30/home.php (page 14).