Projectile body coating is one of . In the painting process, some painting quality problems will inevitably appear.
1) The surface is uneven
Phenomenon: Point-like or block-like protrusions appear on the surface of the projectile .
Reason: After analysis and inspection, the reason is that the projectile body is bumped by other processes or the lumps adhering to the surface are not properly treated before painting, resulting in protrusions.
Solution: To perfect the surface treatment, polish the surface with a copper knife and fine sandpaper, and then wipe the surface with alcohol.
2) vertical flow and flow marks
Phenomenon: There are traces of paint flowing downward and downward droplet-like protrusions on the bottom of the projectile.
Reasons: 1) The atomization shape of the paint is bad; 2) The Spray Gun is too close the projectile; 3) The coating is too thick; 4) The viscosity of the paint is too low.
Solution: 1) Adjust the atomization shape of the Spray Gun; 2) Adjust the distance between the Spray Gun and the projectile to 20-26cm; 3) After repeated tests, reduce the number of times the Spray Gun reciprocates, and adjust it to 3 times; 4) After repeated tests , adjust the viscosity at 23~28Pa·s.
3) Exposed bottom and poor coverage
Phenomenon: There are places on the surface of the projectile that have not been sprayed or the color of the spray is too light, revealing the background color .
Reasons: 1) The moving speed of the Spray Gun and the projectile is inconsistent; 2) The distance between the Spray Gun and the projectile is too far; 3) The viscosity of the paint is too low; 4) The atomization shape of the paint is bad; 5) The coating is too thin; 6) The stroke of the Spray Gun is not enough; 7) The rotation speed of the projectile is too low .
Solution: 1) Adjust and check the in-position switch of the projectile body to ensure consistency, and fine-tune the moving speed of the Spray Gun and the speed of the conveyor chain, which are consistent at 925 mm/min; 2) Adjust the distance between the Spray Gun and the projectile body to 20-26 cm; 3) After repeated testing, adjust the viscosity at 23-28 Pa·s; 4) Adjust the atomization shape of the Spray Gun; 5) After repeated testing , increase the reciprocating times of the Spray Gun and adjust it to 3 times; 6) Increase the reciprocating stroke of the Spray Gun The height is 900 mm; 7) Accelerate the rotation to 28r/min.
4) Orange peel
Phenomenon: There are wrinkles similar to orange peel and grapefruit peel on the surface of the projectile, and the unevenness of the wrinkles is about 3 μm.
Reasons: 1) The viscosity of the paint is too low or too high; 2) The Spray Gun is too close the projectile; 3) The coating is too thick; 4) The solvent used is improper.
solution:
1) After repeated testing, adjust the viscosity to 23-28 Pa·s; 2) Adjust the distance between the Spray Gun and the projectile body to 20-26 cm; 3) After repeated testing, increase the number of times the Spray Gun reciprocates to 3 times; 4 ) using a solvent compatible with the paint
5) The paint is not dry
Phenomenon: The paint is not dry
Reason: The drying temperature is too low
Solution: Increase the drying temperature to (45±5)°C
