The film has poor resistance to a chemical, such as a solvent, an acid or alkali, a detergent or a chemical in gaseous form.
The poor resistance may be apparent as a change in gloss or colour; may be a softening or degradation of the coating; or may be blistering and delamination from the substrate.
Powder coating chemistries have differing chemical resistance properties. The coating being used is not appropriate to the environment.
Consider what aggressive chemicals the coating needs to withstand. If in doubt, discuss your requirements with us. We’ll carry out a chemical resistance test specific to your requirements. Many powder coatings can be custom-made to maximise resistance to certain chemicals.
Under-curing of the coating. The chemical resistance of a coating is one of the last attributes to develop in the cure cycle. Often near-full cured films will show adequate or good adhesion, so that the coating appears to be fully cured, whereas the chemical resistance has not been fully developed.
A full cure is required to realise the coating’s potential. Modify cure conditions by increasing temperature and dwell time.