Stainless steel coating reduces fouling in food industry
15 Apr 2013
London – Researchers in the US have developed a way to modify stainless steel surfaces which, they claim, dramatically reduces fouling during food processing and improves efficiency.
Fouling is a common problem on surfaces that come into contact with food, such as heat exchangers and conveyors. This can lead to biofilm development, reduced heat transfer and a loss of product quality.
Jeffrey Barish and Julie Goddard from the University of Massachusetts, US, say that their technique can reduce fouling from proteins and minerals by 97%.
Barish and Goddard used an electroless nickel-plating process to co-deposit nanoparticles of a fluorinated polymer, polytetrafluoroethylene (PTFE), onto the surface of heat exchanger plates.
The modified heat exchanger plates were then used in an 8-hour process to pasteurise raw milk. The processing run was repeated a further nine times to test how robust the coating was.
After ten runs, the researchers found that around 0.5 mg/cm2 of fouling had built up on treated plates, compared to 13 mg/cm2 on the untreated plates.
The surface coating has a lower surface energy than untreated steel, and is much smoother, which helps to prevent build-up. According to the researchers, the coating process used can be easily scaled up.
The findings were published in Food and Bioproducts Processing, the official research journal of the European Federation of Chemical Engineering (EFCE).
