Non-Bearding Two-Fluid Spray Nozzle Design For Tablet Coating Applications

Two-fluid spray nozzles are commonly used in tablet coating applications to provide a finely atomized spray, which adheres to the tumbling tablets to form a thin, uniform coating. In aqueous film coating, coating uniformity is critical. Slight changes in coating uniformity or thickness can cause adverse effects to product quality and potential for substandard product. Hence any discrepancies in coating uniformity must be quickly corrected. These corrections often require shutdowns and cause a loss of productivity and profitability. Two-fluid spray nozzles used in tablet coaters are prone to collect deposits on the nozzle exit orifice, this phenomenon is known as bearding. This buildup can block liquid and air orifices, resulting in a distorted spray distribution. Frequent cleaning is necessary to ensure coating quality.

The purpose of this work is to develop and validate a two-fluid spray nozzle design that would eliminate bearding. By preventing this build-up and blockage, downtime and production costs would be greatly reduced.