Polymer foreign body contaminant detection in the food processing industry
Foreign body contamination in food products is a major area of concern for food processors/manufacturers. Examples of foreign body inclusions are fragments of metal, bone and glass as well as plastics and rubbers, which find their way into the food production chain from products/equipment/machinery used as part of the processing line. Should such foreign bodies pass through into the consumer chain, then there is significant risk to consumer health as well as huge financial and reputational implications to the manufacturers. Such incidents are reported in systems such as FSA (Food Standards Agency) report and RASFF (Rapid Alert System for Food and Feed).
To combat the issue and comply with HACCP (Hazard Analysis and Critical Control Point) requirements, production lines will employ detection systems at critical control points, these commonly being metal detectors and/or X-ray systems. The difficulty with commonly utilised standard plastics and rubbers is that they possess neither the electrical/magnetic properties to be detected by metal detectors, nor typically the density to be differentiated from food products by an X-ray system. Standard plastics and rubbers are used extensively in machinery and products within food production lines and, as foreign body particles, are often totally undetectable by conventional systems.
It is possible to enhance the detectability of standard polymers, but early revisions relied purely on visual detection to try and prevent foreign body contamination. Polymer products were (and commonly still are) coloured blue to render them easier to visually detect on a food line due to the lack of naturally occurring blue in the bulk of food products.
