Three Common Defects in Enamel RTU Powder Spraying Process and Avoidance Methods

During glaze spraying by manufacturers, three types of defects frequently occur. Targeted avoidance can greatly improve the pass rate:

1. Uneven Glaze Layer

Mainly caused by inconsistent spray gun movement speed, uneven spraying distance, or tilted spray gun.

Solutions: Provide regular training for operators and standardize operating procedures to ensure consistent movement speed and spraying distance; calibrate spray guns regularly to guarantee uniform glaze output without offset spraying.

2. Blisters in Glaze Layer

Mainly due to excessive air bubbles in the glaze slip or excessively high spray gun pressure.

Solutions: Let the glaze slip stand for 5–10 minutes after mixing to allow bubbles to dissipate naturally; strictly control spray gun pressure within the standard range to prevent excessive pressure from drawing in air.

3. Glaze Splashing and Missing Coating

Mostly caused by excessively high spray gun pressure or excessively fast movement speed.

Solutions: Reduce spray gun pressure to 0.3–0.4 MPa; adjust movement speed to the standard range to ensure full coverage of the product surface with glaze slip, free of splashing or missing coating.

In addition, manufacturers should clean spray gun nozzles regularly to avoid uneven glaze output caused by nozzle clogging. The spraying environment must be kept clean to prevent dust and impurities from mixing into the glaze slip, which would impair glazing quality.