Analysis of paint adhesion failure on plastics

Objetive. Know why there is poor adhesion in some cases

Our client, a manufacturer of plastic parts for end users, wants to know why, depending on the plastic supplier, their parts have good or bad adhesion with the paint they subsequently apply. They need an agile solution since they leave out suppliers with whom they have poor adherence. They are looking for a solution so that adherence is good in all cases.

Solution. Analysis by confocal, DSC and surface energy

The first step was to learn from our client both the material and the production process. During the study we used pieces with good and bad adhesion, to be able to evaluate the properties, compare and know where the origin of this problem was.
As a second step, we worked on the selection and definition of the tests that could give us information about the problem.

We selected surface energy, confocal and DSC as characterization techniques. The client always uses the same paint and the same substrate, so we measure the surface tension of the paint to know its behavior with respect to the pieces. We demonstrated that the different roughness of the supplier of parts with poor adhesion negatively affected the adhesion of the paint on said substrate.

With all this information, our client was able to ask his supplier to correct the polishing of his pieces, so that he did not have any further incidents regarding adhesion with his paint.