Electrostatic powder coating is the most widely accepted method in coating industry. Electrostatic powder coating process is based on the principle of high-voltage electrostatic corona technology, charged powder is sprayed by an electrostatic powder gun, under the force of compressed air, and it is absorbed to a grounded metal workpiece.
The working principle of the fluidized bed is to circulate fine air flow that uniformly distributed through the powder, so that the powder particles turn into liquid state. After the balance between the air flow and the powder is established, maintain a certain height of the interface, then preheat the workpiece and put it into the powder to get a uniform coating film.
Advantages & Disadvantages
|Electrostatic Powder Coating:||Fluidized Bed Process:|
1) Can coat difficult shapes with high performance
2) Film thickness between 30-250μm
3) Automatic operation is simple and low coat4) Relatively easy color change
5) It's not required to pre-heat workpiece
1) Can apply very high film thickness (>250μm) in one application and curing cycle
2) Cost of initial equipment and maintenance is cheap
1) Initial cost of purchasing powder coating equipment is higher than fluidized bed.
1) Relatively large quantity of powder is required to charge the equipment.
2) The workpiece must be pre-heated.
3) The shape of workpiece should not be complex to avoid powder entrapment.
4) Color change is not convenient, must be achieved by additional beds.