Coating Process Guarantees Precise and Uniform Results with Minimal Losses

With the Bohle Uni Cone BUC process, L.B. Bohle Maschinen + Verfahren provides a new, patented method for the precise coating of particles. “We have shown that our new method works much more accurately and evenly than the conventional Wurster process said CEO Lorenz Bohle.

The Wurster process is used in the pharmaceutical industry when small particles must be coated. Most of today’s coating systems are based on this method, which was developed by the American Pharmacist Dale Wurster in 1959. “The biggest weaknesses are hardly calculable setting parameters and the spray nozzles being at the bottom,” explained Bohle.

With the Wurster process, the adjustment parameters must be re-tested in long tests for each product. This approach runs more on the basis of experience rather than on verifiable data. Losses in production and large fluctuations in the coating uniformity are the results.

“We have developed two major changes that solve both problems of the Wurster process,” continued Bohle. “A sloping floor and a conical tip in the centre provide a uniform turbulence of the product. Simultaneously, the coating substance is sprayed from lateral nozzles. We therefore achieve a hitherto impossible coating uniformity. Using this process, customers can coat products containing an active substance with the highest precision. The losses are under one percent in a very complex process.”

The tangential nozzles have also enhanced handling. If a nozzle is blocked, it can be cleaned with aqueous operation during the process.

“Because of the tremendous benefits, we have secured a utility patent protection for the process and have protected the BUC as a European brand,” concluded Bohle.

L.B. Bohle Maschinen + Verfahren GmbH , +49 2524 9323 150, t.borgers@lbbohle.de, www.lbbohle.de.