Production In Powder Coating

Powder Coating Production And Quality

Powder Coating Production Thermoset Coatings are formulated by pigment, fillers and additives mixing in resin and hardener. Powder coating process involves 7 steps :

1. Weighing the ingredients based on the formulation.
2. Premix
3. Extrusion
4. Cooling and chipping
5. Grinding and classification
6. Sifting
7. Packaging

Primix

The weighed raw materials are put in a container and are well mixed during a predefined time to obtain a homogeneous distrubition. The container is brought to the extruder, after control on homogeneity. Any needed correction of coloring will be made during this process.

Extrusion Cooling and Chipping

The premixed ingredients are brought to extruder. In the extruder, ingredients are warmed up to a sort of paste, mixed and kneaded. The paste, leaving the extruder is immediately flattened between two cylinders and cooled down on a conveyer. This is done by cooling the welt by air and cold water. At the end of the cooling conveyer, the continuous powder plate is broken down into little pieces (named “chips”) that will be caught up in containers.

Grinding and Granulation

The containers with “chips” go to the grinding machine. The molten material is dropped onto chilled metal rollers, where it is pressed flat and cooled. The coating is then broken into flakes or granulated and fed to the grinder. The chips are ground to a optimum particle size by means of a centrifugal separator. Too small pieces are removed either to be discarded or reused later. Too big pieces finish in the grinding machine till they attain an acquired particle size.

Sifting and Packaging

The final structuring of particle size distribution is accomplished by passing the ground materials through sieves or cyclonic separators. When an optimum particle size is obtained, powder is packaged in airtight and dampproof boxes or bags.