Tablet tooling surface treatment

摘要

A method of surface treating the tip of a tablet pressing tool. A mirror finish is applied to provide an Ra of between 0.025 and 0.1 μm. The surface of the pressing tip is then textured by shot blasting to provide an Ra of between 0.35 and 0.55 μm. The textured surface is then coated, and the coated textured surface is then further treated to provide an Ra of between 0.2 and 0.5 μm. The shot blasting may use particles of 0.074 and 0.105 mm at an angle of between 45 and 90 degrees. The coating may be chromium nitride preferably using a physical vapour deposition process, although chemical vapour deposition and electroplating may alternatively be used. The further treatment may be post-polishing using a drag finishing process through particulate media, preferably walnut having a particle size of 0.2 to 0.4 mm and impregnated with a polishing paste. The surface treatments may be applied to the punch tip.