With the development of powder coating technology, electrostatic powder coating has been widely used in the field of surface treatment of aluminum profiles. The main features are as high as 95% recycling rate, no pollution to the environment, no preheating at room temperature can be powder coating, can form a thicker film, will not occur hang current phenomenon and so on. Powder coating includes air spraying, fluidized bed dipping, electrostatic fluidized bed dipping, electrostatic powder spraying, flame spraying and electric halo spraying, etc.
Each coating method has different characteristics and applicable conditions, the following brief analysis of these coating methods and characteristics.
A: air spraying method
Puts powder coating spray gun, using the adsorption force of compressed air to coating adsorption on the surface of preheated aluminum in advance, by melting on the surface of aluminum powder, thermoplastic and thermosetting powder, can be used if the type is thermosetting powder, even inside the oven curing, the spraying method is suitable for small aluminum surface.
Production bench
Two: fluidized bed dip coating method
Aluminum preheating first, then into powder fluidized bed, make the fused to the surface of the aluminum powder, thermoplastic and thermosetting powder, can be used if they are thermosetting powder, also want to put into the oven curing, the spraying method is suitable for the small film thickness aluminum surface, as well as medium-sized pipe or metal mesh, can be a full range of dip coating.
Three: electrostatic powder spraying
This is the most widely used a powder coating method, which USES the principle of electrostatic adsorption, made by the electrostatic induction respectively take the opposite charge of powder coating and adsorption onto the surface of the aluminum, thermal spray and cold spray can, spray into the baking furnace after drying, the spraying method is suitable for different size and shape of aluminum surface, using thermoplastic and thermosetting powder can be.
Four: electrostatic fluidized bed dip coating method
This spray method combines fluidized bed dip coating with electrostatic powder spraying, using thermoplastic and thermosetting powder, suitable for mass production of small aluminum profiles with film thickness below 150 m.
Five: electric field halo coating method
Place thermoplastic or thermosetting powder between two parallel electrodes to electrify the powder coating. Pass the coating between the electrodes to adsorb the powder on the surface. Place the device under a fluidized bed and spray the material out of the nozzle of the injector.
Six: impact coating method
This spraying method, also known as mechanical spraying method, will be different particle size powder and glass beads in accordance with a certain proportion of the mix together, ejected by the nozzle of the injector, powder under the impact of the glass beads deposited on the surface of aluminum profiles, this method is suitable for spraying film thinner (2-10 m) aluminum profiles.