Q: What is the basic difference between polyester powder coating and antimicrobial powder coating? Can polyester powder coating resist mildew, bacterial attack, acids, alkali, and oils?
A: You ask about coating resistance to several different agents. Allow me to break this down. “Polyester” refers to the resin type used in the powder coating formulation. Antimicrobial behavior is achieved by incorporating an additive that kills bugs, namely bacteria, viruses, and fungi.
Therefore, a well-formulated powder coating can resist acids, alkalis, and oils; however, it most probably will not kill microbes like mildew and bacteria. That said, antimicrobial powder coatings are quite common, and they can be based on a variety of powder coating chemistries (e.g., polyester, polyurethane, epoxy, and epoxy-polyester (hybrid)).
The most common antimicrobial powder coatings rely on the incorporation of a low concentration of silver ions. These ions kill a high percentage of bacteria that can be encountered on the surface of a coated item. By the way, the most common antimicrobial test protocol is JIS Z-2801 (Japanese Industrial Standard).