Paint adhesion problem on plastic
Paint adhesion problem on plastic
Problem
The customer has a paint adhesion problem on plastic samples. Depending on the supplier you receive the samples from, the parts have good or poor adhesion. When the customer receives the parts from the supplier, he reintroduces the parts to his polishing process and paint adhesion improves.
Objective
Know the cause of the paint adhesion problem in samples from different suppliers.
ATRIA Solution
Different tests were carried out to characterize the surface of the samples from both suppliers in order to compare them with each other and find out if there are differences. The surface energy of several samples was analyzed and it was observed that the energy of the supplier’s parts was lower, therefore, depending on the surface tension of the ink, the adhesion could vary.
The roughness of the surface was also observed using confocal equipment and it was possible to see that the surface, after polishing, was different depending on the supplier of origin. DSC tests were carried out to rule out possible problems due to the injection of the parts.
The client always uses the same ink and the same substrate, so the surface tension of the ink was measured to know its behavior with respect to the pieces. It was shown that the roughness, detected to be generated by the supplier, negatively affected the adhesion of the ink on said substrate.
The origin of the problem was in the polishing of the supplier, since, as shown in the photos of this project, it generated different roughness, affecting the adhesion of the ink.
