The coating has a lower flexibility, hardness and/or impact resistance than expected directly after application
A change has been made in the substrate or pre-treatment system without making changes in the process.
Contact suppliers to ensure no changes to the substrate have been made. Ensure that the pre-treatment system is appropriate to the substrate.
Under cured films will have lower flexibility, hardness and impact resistance
Modify cure conditions by increasing temperature and/or dwell time.
The film thickness is too high
Optimise the thickness of the film. Most coatings are designed for application between 60 and 100 microns; consult the technical data sheet for the coating.
Different resin chemistries will have different physical properties. Many standard coatings are a balance of properties to achieve a recognised standard such as Qualicoat. Often, improving one coating attribute will have a negativel impact on another attribute. For example, increasing the UV-weathering resistance of a polyester coating will reduce its flexibility and impact resistance.
Contact us to discuss your specific requirements. We may have an off-the-shelf alternative, or we can custom build a product to your requirements.
The coating has a lower flexibility and/or impact resistance than expected some days or months after application.
Flexibility deteriorates over time. Powder coatings will naturally lose a little flexibility and become more brittle over time. This can be confirmed using a reverse impact test (falling weight) and is is a consequence of the binder system becoming more crystalline.
If long term flexibility is an issue for post-forming work, we can tailor-make coatings that are more flexible and retain their flexibility for longer.