Application

Supply Problems

Fluidisation is good, but the powder is not being fed to the gun in a smooth continuous flow.  These problems may be caused by blockages in the feed system, including hoses, venturi and spray gun equipment.

Blockages

Powder can build up around corners of hoses and in other equipment, restricting the flow of the coating through the system.

  • Potential Cause

    Worn parts from normal wear and tear of the coating process.

    If you believe the parts are wearing prematurely, it may indicate that the air feed pressure is turned up too high.

  • Solution

    Clean and replace aprts according to the equipment manufacturer's recommendations, paying attention to any changes in shift patterns or extra working hours since the equipment was installed and taking account of the extra working time load.

  • Potential Cause

    Impact fusion caused by air pressure being too high, or the powder coating type being more susuceptible to impact fusion.

  • Solution

    Check the feed air pressure.  The pressure should be reduced to the minimum level required to achieve a steady even flow of powder to produce an electrostatic cloud that is attracted to the earthed part.  Powder coatings are not designed to be blasted onto parts.

    Some powder chemistries are more prone to impact fusion than others, contact us to discuss.

    If the air feed needs to be turned up to achieve sufficient powder film thickness, it may be that the system is performing beyond its maximum efficient output.  Consider reducing the line speed, or adding more spray guns

  • Potential Cause

    Kinked feed hoses

  • Solution

    Kinks, or sharp bends that flatten the hoses and restrict powder flow should be prevented.  Replace any that are permanently deformed and take measures to reduce the occurence.

< Back to Knowledge