Powder coating technology is commonly described as the art of applying a pulverized resin to a substrate and heating the powder so that it melts and creates an even coating on the substrate. This simple technology can be very successful in providing impact, corrosion and abrasion resistance, as well as ensuring gloss retention and surface protection. In short, powder coatings are durable. They are also chosen for their versatility and savings potential. Powder coating technologies are nowadays seen as a sustainable option, in particular for industrial coating applications. While they are most widely used to coat metal substrates, numerous efforts have been put into developing solutions that allow their application to more highly temperature-sensitive materials such as wood and plastics. New opportunities for powder-coating-based technologies are arising as a result of expansion and growth in construction markets, and through increasing demand for more sustainable solutions. Raw material suppliers and coating formulators are responding with the development of new powder coating technologies that can be produced and applied more efficiently, exhibit improved performance, and have a greater range of potential end uses.
A typical powder coating formulation contains ingredients ranging from binders, fillers, pigments and crosslinkers to various types of additives. The combination of components and their fine tuning at different ratios allow the final powder and coating properties to be determined once the coating is applied. The ingredients are dry-mixed, fed into an extruder and heated to produce a homogeneous mixture. The heat involved in the melting/extrusion process is not high enough to induce a reaction or to initiate curing. The mass produced during this melting/extrusion process is pushed through chilled rollers, flattened, fed onto a belt to cool down, and then shaken at the end of the belt so that the hardened material breaks into small pieces. Afterwards, the material is reshaped to the required size and sieved, and is then ready to be packaged and shipped out or stored. Powder coatings differ from other types of coatings in that they are solid at ambient temperature, and they melt quickly to become low-viscosity mixtures that can form a continuous film. This 100% film-forming mixture completely covers the substrate or the part to be powder coated. The uniform coating provides superior durability and aesthetic appeal, and further fine tuning of the formulations allows customers’ specific color and performance needs to be met.