Coating-Technology Turbo-Charging the Coating Process

Author Anke Geipel-Kern

Featuring a range of finely tuned enhancements, a new drum coater speeds up the coating process by 30 percent — The proven GCC range now has an equal in terms of process technology: the GCSmart, which is designed to make the coating process significantly faster. An optimized nozzle arm and consistent air guidance with reduced turbulence promote reproducibility, even with minimal charging, while a WIP automatic system, integrated exhaust air chamber, and automatic discharging simplify handling for the user.

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Discharging of GC Smart
Discharging of GC Smart
(Source: Glatt)

When tablets, capsules, or pellets emerge from the coating process, they need to be smooth, uniform, taste masked and with a defined degree of solubility. Not only that, but the results need to be reproducible and the process time short. A true classic, the drum coating method used in the production of solid materials is absolutely indispensable and represents the procedure of choice for coatings containing sugar, those with aqueous and organic solvents, and coatings with a delayed release.

High Degree of Production Availability

Around 40 years ago, Glatt developed the very first coater of this type with a fully perforated drum. Now, its experts have revised the proven GCSmart and made a range of finely tuned adjustments to increase the coating speed and productivity even further. The air guidance system and handling in particular have been improved considerably. The changes were made in response to demands from the pharmaceutical industry for quick and reproducible processes, says Bernd Looser, Head of New Technologies at the Innovation Center. “Our customers see the GCS as a real workhorse on the market, with a high degree of production availability,” he explains.

The GCC’s little brother was always fast, but since the improvements to its process technology, the system can now achieve a coating time of just one hour from charging to coating and discharging. The process technology featured in the two coater series are now on an equal footing: The design size, drum geometry, mixing elements, number and type of nozzles, as well as the air guidance and available air flow are the same for both machine types, meaning that they can both be operated using the same process parameters.

Integrated exhaust air chamber

The Glatt developers invested a great deal of time in completely overhauling the coater’s air guidance system (inlet and exhaust air). One of the goals was to simplify cleaning and inspection by removing the need for time-consuming processes — for instance, by integrating an exhaust air chamber in the coater housing. The distance between the spray arm and the tablet bed can be varied, and the angles of the spray arm itself can be manually adjusted across five axes based on the degree of charging, meaning that the spray nozzles are always positioned at exactly the right distance from the tablet bed. This means that the degree of charging can be varied between 100 and ten percent. A guide plate can also be used for filling volumes of less than 30 percent to ensure that the air guidance perfectly matches to the filling level.

“The guide plate ensures that the drying air is drawn through the tablet bed exactly as required and doesn’t simply leave the processing chamber without being used,” explains Head of Marketing Axel Friese. The trapezoidal discharge channel is also a new feature. It is now firmly integrated in the housing, meaning that the tablets are transported to the collection hopper quickly and gently. All of these features demonstrate the work the developers have done to improve a whole range of aspects, making it possible to significantly reduce processing times even further.

* Contact Glatt: Phone +49-7621-664-145