Effect of detergent on powder triboelectrification.

Triboelectrification of pharmaceutical powders during processing and manufacture may cause adhesion/cohesion effects, reduce fill and dose uniformity, affect powder flow and packing behaviour and even obstruct the manufacturing of the product. This paper presents the results of an experimental study on the triboelectrification of microcrystalline cellulose in contact with stainless steel pipes washed with several different detergents. Detergents and their concentrations were chosen to be similar to typical industrial manufacturing stages. The adhesion of powder to the surface had a considerable effect on the triboelectrification process. Therefore, polystyrene spheres were also charged in a similar way and the results were compared with the powder charging results. The results clearly indicate that detergent contamination on the pipe surface has a considerable effect on the generated charge. The detergents and powders used could be arranged in a triboelectric series with only one exception.