(A.) Discoloration (gloss loss) is often caused by excessively long curing times or high curing temperatures during powder coating curing. Because the pigments in red, yellow, and blue powders are not heat-resistant, prolonged high-temperature curing beyond their curing range can easily cause the powder to yellow. Excessive high-temperature curing can also cause resin degradation and brittleness.
(B.) Varying gloss levels between batches of powder coatings from different manufacturers can also cause an artificial appearance of gloss loss. Mixing powders of varying gloss levels can also result in varying gloss levels. This can be due to issues with the pigments, matting agents, brighteners, or fillers.
(C.) Mixing powder coatings from different manufacturers can also cause discoloration and gloss loss due to differences in resins, pigments, and additives.
