Rücksprühen in der Pulverbeschichtung: Ursachen und effektive Gegenmaßnahmen

Back-spray in powder coating – causes and effective countermeasures

Back spraying, also known as "back ionisation", occurs when too many charged powder particles accumulate on the surface of the workpiece during the coating process. This leads to repulsion of new particles, resulting in uneven layer thicknesses and surface defects.

Common causes of back spatter

• Excessive electrostatic voltage during coating
• Excessive powder flow rate
• Insufficient distance between the gun and the workpiece
• Insufficient grounding of the workpiece
• Coating of already coated surfaces without sufficient intermediate steps

How to avoid back-spray

To prevent back-spraying, reduce the electrostatic voltage to an appropriate level and adjust the powder flow rate accordingly. Make sure to maintain a sufficient distance between the gun and the workpiece and ensure that the workpiece is properly grounded. When recoating, the previous layers should be sufficiently prepared.