The build-up of detergent agglomerates in an auger filler

Powder build-up formation is a fouling process in which a small fraction of a powder becomes a coherent, non-porous, film adhered to a surface known as build-up. Build-up tends to form in auger fillers where particles undergo plastic deformation, leading to the formation of build-up on the internal surface of the tube within which the auger is housed. To develop an understanding regarding the process by which build-up is formed, a combination of macro scale auger filling experiments and laboratory scale characterisation of the virgin powder has been undertaken. This involved a comparison of results obtained via uniaxial compaction followed by tablet diametric compressions, with the results of macro scale auger filler experiments. From this work, it has been determined that the build-up forming powders have Kawakita b⁻¹ parameters of 0.5 MPa or less, and form disc-shaped tablets with strengths <0.5 MPa following compaction to 58 MPa.