Produce various powder coated surfaces with stable metal shine via microwave energy

Metallic pigmented powder coating, composed of metallic pigments and coating particles, provides coatings with metal shine and functional protection, while causes much less emission of organic solvents, unlike the traditional paint. The greatest challenge of the manufacturing step is binding the two incompatible ingredients together. However, the present industrial binding method, thermal bonding, has some inherent issues, such as pre-curing, pigment bending and high-temperature bonding. Hence, in the present work, a novel approach, microwave bonding, was studied and tested to address these shortcomings. Aluminum flakes were bonded with three types of powder coatings: polyester, hybrid, and polyvinylidene fluoride (PVDF). Microwave bonding shows a more stable metal shine over the non-bonding, obtains a lower bonding temperature than the glass transition temperature, and has a much higher heating rate (∼17 °C/min) over the thermal bonding method. Therefore, microwave bonding is trusted to have great potential to produce coatings with highly stable metal shine efficiently.