The electrostatic powder coating technology for building aluminum materials is a surface treatment technology that has been developed rapidly recently. It is characterized by that the powder can be recycled, does not contain solvents, does not pollute the environment, is easy to realize automatic manufacturing, and is simple to use. The coating can meet different weather resistance requirements, and has diversified colors. Some defects often appear in the electrostatic powder spraying of aluminum profiles, resulting in poor appearance quality and use performance of products.

The following are the causes and control measures of several common coating defects:

Defect name: particle

Cause analysis: there are burrs, aluminum chips and graphite marks on the surface of the base material, and the pretreatment is poor; The residue of pre-treatment tank liquid adhered to the surface of the profile, which could not be washed in place; Before painting, the chromizing material is placed for a long time, and dust is adsorbed on the surface; Improper use of newly fired hangers leads to ash falling on the surface of chromizing materials; The powder and recovered powder may contain impurities; The spraying site and curing furnace are unclean and have suspended solids.

Control measures: polish the blank surface or sand blast before the upper row to ensure that the pretreatment is in place; Regularly reverse the tank, clean the residue, and extend the pure water washing time; Carefully blow dust after chrome chemicals are discharged; Spray a thin layer of coating on the newly fired hanger before use; Recycled powder should be used after sieving; The workshop implements 6S management, keeps the spraying site clean, and regularly cleans the curing furnace.

Defect name: exposed bottom

Cause analysis: poor coverage of powder coating; The complex sectional structure of profile is easy to cause electrostatic shielding effect; Improper hanging method; The spray booth workers have weak sense of responsibility, poor business ability and improper judgment of coating thickness; There is too much powder at the nozzle, which is blocked; The spray gun moves too fast or the chain speed is too fast; The profile decorative surface is not clearly understood.

Control measures: strictly control the quality of powder coating; Manual powder feeding for profile groove and inner corner; Adjust the angle of profile hanging; Improve the skills of the spray booth worker, and the spray booth worker should try to measure the film thickness of the cured profile as soon as possible; Clean the nozzle regularly to keep it unobstructed; Adjust the moving speed of the spray gun and appropriately reduce the chain speed; Understand the requirements of customers for painting and recognize the decorative surface of profiles.

Defect name: Heather

Cause analysis: when the spray booth workers were changing colors and cleaning the spray booth, the cleaning was not thorough enough and the powder infiltration caused the mottled color; The powder (recycled powder) is not baked in time, and the color is corrected; The environment around the spray booth is not clean.

Control measures: When cleaning the spray booth, the spray booth worker should carefully clean every detail, especially the powder pipe of the spray gun. The big cyclone should be carefully blown clean. After cleaning the spray booth, the spray booth must be baked to confirm whether there is any color before painting; The recycled powder must be used after the baking board is confirmed to be qualified, and the surrounding of the spraying room must be kept clean at all times.

Defect name: uneven coating

Cause analysis: improper hanging mode and arrangement of chrome chemicals; Poor aluminum grounding (poor conductivity of some hangers); The conveyor chain speed is uneven, or the chain speed is inconsistent with the lifting speed of the spray gun, and the powder coverage times of the profile decorative surface are inconsistent; Improper powder output and powder atomization of spray gun; The pressure of compressed air is unstable; The voltage of high voltage electrostatic generator is unstable, and the static electricity is high voltage.

Control measures: strengthen the communication between the foreman in the spray booth and the spray booth worker, and select the hangers corresponding to the profiles; Check whether the hanger is conductive; The spray booth worker strengthens the function and improves the hanging density and chain speed during spraying

Guangzhou Tuoshen Surface Treatment Co., Ltd., the spraying manufacturer, is preferred for purchasing spraying, Spray processing Factory, trustworthy