Hygienic Mixing Systems

Hygienic finish mixing systems and vessels

Good hygiene in mixing systems depends on several factors:

  • Use of durable materials and components that are easy to clean
  • Design and manufacture to eliminate traps where product can accumulate
  • High polish finish for ease of cleaning
  • Effective cleaning processes

To ensure optimum quality of finish, Greaves has its own in-house metal finishing department with calibrated testing systems and certification.

A high grade finish is achieved using a range of techniques including passivisation, pickling and electro-plating, Greaves can offer mirror finishes down to 0.01 Ra µm.

Hygienic Mixing FAQ’s

  • Essentially, this refers to the “Cleanability” of the vessel and all contact parts within the process zone. The objective is to achieve a standard that can be considered Bio Safe – i.e. removal of all traces of microbial contamination.
  • Maximum “Cleanability” is achieved through careful design, taking into account the following factors: –
    • Avoidance of “traps” – ie. any enclosed volume where process material (and bacteria) can remain and prove difficult to remove.
    • Construction with materials that can be polished to a fine smooth surface finish.
    • Use of construction materials that will not corrode, even with the use of aggressive cleaning agents and conditions.
    • Finishing techniques that result in smooth finish that can be easily cleaned.
  • Greaves offers popular standards such as 0.5Ra or 240 grit finishes to mirror polished or electro-plated finishes to the inside and outside of the vessel.
  • We have a UKAS calibrated & certified surface roughness tester and can certify the finish of both vessels and mixing tools.
  • Passivation is a chemical process that creates a surface coating on a material so that it becomes “passive”, that is, less readily affected or corroded by the environment or any chemicals it comes into contact with.
  • With stainless steel, the passivation process uses nitric acid or citric acid to remove free iron at its surface and create a protective oxide layer, or passivation film, that is less likely to chemically react with air and cause corrosion.
  • 304 & 316L stainless steel
  • 316 Ti stainless steel
  • Greaves can supply CIP cleaning systems as required.
  • Careful system design is crucial to ensure avoidance of traps, shadows and difficult edges which could compromise the effectiveness of cleaning.