Spray pattern defects – material application too heavy in the centre
Excessive material application in the centre of the spray jet can significantly impair the uniformity and quality of the paint job. This problem often occurs when the pressure and material settings are not optimal. In this article, we will examine the causes and provide tips for how to fix it.
What does it mean when there is too much material application in the middle?
An uneven spray pattern with excessive material application in the middle leads to paint build-up and an unclean finish. The aim should always be to achieve an even application across the entire spray width.
Possible causes
- Atomiser pressure too low: The air pressure at the horn bores is insufficient to distribute the material evenly.
- Viscosity too high: The pressure setting is not sufficient to finely atomise highly viscous material.
- Damaged paint nozzle tip: A defective nozzle leads to uneven material dispensing.
- Incorrect round and wide jet regulation: When the regulation is closed, the material application is concentrated in the middle.
Remedy
- Optimise pressure setting: Use tools such as SATA adam, SATA DIGITAL or a SATA air micrometer with a pressure gauge to set the correct atomisation pressure.
- Check viscosity: Check the material properties and, if necessary, select a different nozzle size.
- Replace damaged parts: Replace damaged nozzle sets.
- Check the regulation: Make sure that the round and wide jet regulation is open.
Frequently asked questions
Question: Why is the material application too heavy in the centre of the spray jet?
Answer: Excessive material application in the centre of the spray jet can be caused by an atomiser pressure that is too low, a viscosity that is too high or a damaged paint nozzle.
Question: How can I fix the material being applied too thickly in the middle?
Answer: Adjust the atomiser pressure, check the viscosity of the material and make sure that the round and wide jet regulation is correctly opened. Replace damaged nozzle sets if necessary.
For more tips on spray pattern problems and how to solve them, check out our daily blog series.
