What role does surface finish, expressed as the Ra value, play for cleanability and product residues in food mixers?
The Ra value is a central hygiene factor in food mixers. The smoother the product-contact surface, the fewer residues adhere to it and the easier cleaning becomes.
For standard applications, Ra values of up to 0.8 µm often apply, and for sensitive products frequently up to 0.4 µm. What matters, however, is not only the Ra value but also a dead-space-free construction without crevices, scratches or poor welds.
How amixon® solves surface finish and material selection for hygienic powder processes
The Ra value is a central hygiene factor in food mixers. The smoother the product-contact surfaces are, the less product residue adheres and the more easily the mixing chambers can be cleaned.
amixon® therefore attaches great importance to hygienic design, smooth surfaces and joint-free constructions. For particularly demanding applications, mirror-polished surfaces, fully welded mixing chambers and readily cleanable components are used. Product residues, carry-over and microbial risk are thereby effectively reduced.
The surface roughness can be selected project-specifically, typically with Ra values of 0.8 µm, 0.6 µm, 0.4 µm or 0.2 µm; beyond this, amixon® can lap to a mirror finish and electropolish. The required Ra value is established as a one-off in accordance with the URS and documented.
Special mixing tools additionally ensure a very good residue-free discharge and a self-cleaning effect. This markedly facilitates cleaning and supports stable, hygienic production processes.
What matters here is not the surface finish alone, but its interplay with the construction. Dead-space-free geometries, readily accessible inspection doors, complete emptiability and reliable WIP/CIP capability are equally decisive.
Practice shows that the better the surface quality and the cleaner the hygienic design, the faster, more reproducibly and more economically cleaning can be carried out. This lowers the cleaning effort and the consumption of water and chemicals, and increases product safety.