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 involves 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.
Below is Powder coating manufacturing process step:-
Extrusion Process:-
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.
Extruders can be of a single or twin screw design. But Rapid coat division using totally Twin screw extruders operate on a similar principle. however, they use the shearing action of two co-rotating screws encased in a smooth barrel. Work is exerted into the mixture by the kneading blocks on the screws. The coordinated rotation of the screws pushes the material from screw to screw as it travels the length of the barrel. The heat generated during this process allows the resinous components to melt, and the shearing action affords the distribution raw materials and dispersion of the pigments. The cooling process typically involves introducing the moving extrudate into a set of chilled rolls, which then convey a ribbon of material onto another cooling surface, such as a continuous belt or rotating drum. After the extrudate is sufficiently cooled, it is broken into flakes that are suitable for feeding into a pulverizing process.