Polymer foreign body 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.

Further enhancements around the design of filler/additive systems lead to the introduction of modified polymers, detectable by conventional metal detection systems.  This still remains as probably the most common format of detectable polymer.  A typical balanced coil metal detector consists of three coils, where the induced currents in the coil arrangement are in balance and generate an electro-magnetic field within the detector.  This remains undisturbed until a metallic object passes through, causing a disturbance and triggering the sensor/alarm and rejection mechanism.  The required additive system in such polymers must be specifically engineered to achieve the optimum response to industrial metal detectors at the lowest possible addition rate, such that other properties are not too significantly affected.

Moving on from metal detection systems, X-ray detectors are becoming increasingly popular in the food industry.  Compared to metal detection systems, they have the advantage that they primarily rely upon density differences between food product and foreign body and hence are able to detect a range of additional foreign bodies such as glass, ceramic and bone.  Once again, it is possible to engineer polymers such that they are potentially detectable against a range of food products via X-ray systems, but a different set of additive systems are applicable and, for optimum performance, this requirement needs to be treated separately to metal detection.

Polymer materials are and will continue to be used extensively throughout machinery, equipment and products within food processing lines.  Components are typically manufactured by techniques such as injection moulding, compression moulding, extrusion or machining.  Fragments of these polymers falling into the food line is a real risk and, without due consideration, such foreign bodies could pass through existing on-line detection systems and into the consumer chain totally undetected.  There are potentially hugely negative implications to the food manufacturer should this happen.  It is possible to modify existing polymers such that they offer strong levels of foreign body detection via either or all of the commonly utilised techniques on existing food lines (principally visual, metal detection and X-ray detection).  However, there are many factors to consider up-front (type of polymer, final product, food products on the line, detection technique etc) and these need to be utilised fully and carefully when selecting or developing a well designed detectable polymer material.

If you are currently looking for a detectable polymer solution, please contact Chris Vince at chris@radicalmaterials.com or call us on 01495 211400.

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Konduct is the ultimate solution for all thermal management challenges

Introducing KONDUCT – A range of thermally conductive polymer compounds to solve all your thermal management challenges. KONDUCT can assist from design, prototype production, material testing (mechanical, physical and importantly thermal conductivity), through to full production of final compound.

Common applications include heat sinks for electronic devices and LED lights, geothermal pipes, thermally conductive pads, battery cooling systems among many others. In the automotive industry in particular, KONDUCT technology becomes an essential component. Fuel emissions are an ever-growing concern, and as a result we are seeing a significant rise in both hybrid and electronic vehicles hitting the roads. One of the key factors that plays a role in high emission rates is the weight of the vehicle itself. That’s where KONDUCT comes in. We are able to design bespoke thermally conductive compounds for your lightweight polymer components like battery housings and cooling systems, to ensure that all thermal management challenges are met.

In typical thermal management situations across all industries, materials such as metals and/or ceramics are traditionally utilised. The ability to use plastics and elastomers in such scenarios allow their additional benefits to be taken advantage of, for example lower weight, resistance to corrosion, toughness and ease/speed of manufacture. In many thermal management situations, most of the heat transfer is typically convection limited (free air cooling). In such cases, the convection can create a bottleneck and the high thermal conductivity of metals, for example, is unnecessary. A well designed thermally conductive polymer can potentially keep up with the convection rate and perform equally as well.

Chris Vince, Research & Development Manager for KONDUCT, had this to say: “Being able to utilise polymers for thermal management solutions offers proven benefits over traditional materials such as metals. At KONDUCT we have developed extensive knowledge of the various additive systems suitable for boosting thermal conductivity of polymer compounds. With this core knowledge and our extensive test facilities, we are able to support the development and production of polymer compounds for all thermal management challenges. This understanding is key to successful developments, as we are able to fully consider and characterise not just thermal conductivity but also processability, mechanical performance and costs.”

If you are currently looking for a heat management application for your polymer compound products, please contact Chris Vince at chris@radicalmaterials.com or call us on 01495 211400.

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