Pulsation in powder coating: identifying and eliminating causes
A uniform powder output is crucial for high-quality coating results. Pulsation, i.e. an irregular powder flow, can lead to uneven layer thicknesses, surface defects and increased material consumption. Below, we explain common causes and provide practical solutions based on GEMA recommendations.
1. Clogged or worn injectors
Contaminated or worn injectors can impede powder flow and lead to pulsating discharge.
Solution: Clean the injectors regularly and replace worn parts to ensure a constant powder flow.
2. Improper hose routing
Too small cross-sections or tight radii in the powder hose layout can disrupt the powder flow and cause pulsation.
Solution: Ensure that the radii of the powder hoses are at least 150–200 mm and use hoses with a suitable diameter.
3. Pressure fluctuations in the air supply system
Fluctuations in the compressed air system can destabilise the powder flow and lead to pulsating discharge.
Solution: Check the air supply system for constant pressure conditions and install pressure regulators or accumulators if necessary to compensate for fluctuations.
4. Unsuitable powder properties
Powder with poor flowability or high moisture content can impair uniform discharge and cause pulsation.
Solution: Use powder with good flowability and store it under suitable conditions to prevent moisture absorption.
By observing these points and regularly maintaining your equipment, you can increase the efficiency of your powder coating processes and avoid quality problems.
