||Suspension solids are too high, creating viscous suspensions that are difficult to atomize finely.
- Decrease suspension solids content.
||Coating suspension is too foamy. Learn more.
- Improve mixing process by setting mixer height correctly.
- Choose mixer blade of correct size (about 30% of tank diameter).
- Choose optimal mixer speed, and incorporate powder into water quickly to avoid excessive viscosity build-up before all powder has been wetted out.
||Drying conditions are excessive for spray application rates.
- Decrease drying air temperature.
- Reduce turbulent airflow by ensuring optimal pan negative pressure is maintained.
- Increase spray rate.
||Spray gun operation is not ideal for process.
- Decrease atomizing air pressure, if excessive.
- Adjust gun-to-bed distance to maintain adequate spray coverage while minimizing drying of droplets prior to impact with the surface of the tablet bed.
- Check spray guns for optimal operation (replace any damaged parts; ensure “o” rings are properly lubricated; check for excessive material buildup on exterior surfaces of air cap). Learn more.