Rapid Powder Coating Extrusion Process

The extrusion process of the high-quality powder coating step can be described as the paint-making process and is where the powder coating formula is compounded. The extrusion process basically consists of a feeding mechanism, a compounding section, and cooling. The material is fed into a rotating mechanism, which is usually a screw device encased by a barrel. Making powder coatings is a multi-step process, essentially composed of batching, premixing, extrusion, and particle size reduction. It can be described as being semi-continuous because it begins as a batch process (weighing and pre-mixing) but evolves into a continuous process (extrusion and milling).

Manufacturing high-quality powder coatings also involve dispersing pigments throughout the resin system, which entails the de-agglomeration of the pigment. Most pigments naturally exist as agglomerates. The powder coatings manufacturing process, and more specifically the extrusion process, endeavors to disperse these agglomerates to achieve a more consistent and intense color. Incomplete pigment dispersion results in uncontrolled color consistency. Finally, the particle size of the extrudate must be reduced from flakes to a particle size distribution usable with the customer’s application equipment.