The Effect of Cooling Time on Properties of Thermoplastic Powder Coating Films for Telecommunication Plants

Thermoplastic polyester resin is known for the fact that the heating condition has an effect on the degree of crystallinity. Therefore it seems certain that the coating condition will also affect the degree of crystallinity of coated film. We focused on the relationship between the cooling time employed in the coating process and the degree of crystallinity as regards our developed thermoplastic polyester powder. The coating was formed by dipping the test pieces in fluidized polyester powder vessel. The test pieces were subsequently cooled in air to form the film and finally immersed in a water bath. We define this cooling time in air as the air-cooled time. As a result, when the air-cooled time increased, the degree of crystallinity increased. As the degree of crystallinity increased, the adhesion force and the specular gloss decreased. We therefore found that improvement in the film performance is related to the reduction in the air-cooled time.