Polyester powder coatings exhibit good weather resistance, toughness, adhesion, and good leveling and film fullness. However, using polyester powder coatings alone cannot produce anti-graffiti powder coatings with good stain resistance, as their stain resistance, solvent resistance, and surface free energy do not meet the requirements for anti-graffiti coatings. The choice of hydroxyl polyester directly affects the anti-graffiti performance of the coating film; coatings made from hydroxyl polyesters with higher hydroxyl values exhibit better anti-graffiti performance.
According to the standard "Environmental Testing for Electrical and Electronic Products Part 2: Test Methods and Guidelines" (GB/T 2423.16-2008), mold growth tests can be conducted on polyester powder coatings. Test species include Aspergillus niger and Aspergillus terreus, with evaluation levels ranging from 0 to 3. Polyester/TGI and polyester/HAA powder coating sheets, under conditions of 28 days, humidity >90%RH, and temperature 28℃, both showed a mold growth level of 0 (no mold).