Problems in powder coating of aluminum. 1 2 poor fluidization poor fluidization causes slow and no transportation of powder from fluid container to guns store powder at or below recommended temp.
This method has its own challenges and we have detailed some of its problems and their causes below.
Aluminium powder coating troubleshooting. Powder coating problems can be caused by issues with pre treatment powder supply powder application curing or equipment. Typically pin holes occur due to inadequate preparation of the surface prior to applying your powder coating. When they do it is important to trace the cause of the problem as quickly as possible and to remedy it.
The most significant step in the process is applying the electrostatically charged powder to the aluminium. I don t know if 1700 hours will prove possible even with proper pretreatment chromate conversion coating and proper powder coating. By looking at the issue you have you can trace the problem back to a likely cause.
Happens when the ph level of the solution is not in the correct range. Powder coating defects and causes related to application are the easier issues to solve. After performing energy dispersive spectroscopy testing on the failed areas it was determined that a layer of magnesium was on the surface of the aluminum which became brittle after powder coating and separated so that the coating released from the substrate.
Increase line speed decrease oven temp. The positive charge of the powder allows it to bond to the aluminium. One of the common methods of pre treatment in powder coating use is phosphating the metal substrate.
And this bond is made possible as the aluminium will have been electrically grounded. I have recently had an issue with powder coating adhesion to aluminum processed through my single stage pretreatment system. Pin holes look exactly as they are described dimples and dots all over the surface of what should be a smooth glass like appearing finish.
You may need e coating before the powder coating especially if the powder coating can t cover well enough due to the shape of the parts. The heat of this oven melts the powder into a coating which melts uniformly over the surface of the aluminium. Heat and cure the aluminium.
Below are a few of the most common powder coating application problems. Powder coating finish problem 1 pin holes in your powder finish. Powder coating application problems.
The next step is to heat the aluminium extrusion in a curing oven. Blistering peeling edge breaking cloudiness. Very often problems arise here simply because equipment is on the wrong setting or has not been properly cleaned.
Different application methods will. Pretreatment of aluminium and problems in chromate conversion. Apply the powder.
Pre treatment problems and defects iron phosphate poor coverage.