Novel polymer enables metal-detectable products to be moulded

Paul Boughton

Manufacturers in the food, beverage and pharmaceutical industries have to ensure that their products are not contaminated. Alistair Rae reports on a grade of polymer that enables the injection moulding of plastic implements such that, if damaged, any fragments will be detected and rejected by standard in-process metal detectors.

Within the food and pharmaceutical industries there is an ever-present risk of contamination that, if undetected, can result in damage to equipment, costs incurred through product recalls, harm to the company's reputation and, in the worst case, serious injury to somebody inadvertently consuming the contaminant. A relatively straightforward measure that can be taken is to use only metal implements - such as spatulas, scoops and scrapers - and install an inline metal detection system that can detect any metallic contamination of the product and automatically reject it.

However, there are drawbacks with this approach. For instance, metal implements are costly, especially if manufactured from stainless steel, they can be heavy, and the geometries that can be created at a reasonable cost are somewhat limited. In some cases, therefore, plastic implements are used, with the polymer grade selected so as to minimise the chance of breakage. Nevertheless, using plastic implements carries with it a risk that small fragments could contaminate the product and remain undetected.

New EU hygiene legislation is due to take affect on 1 January 2006, with the primary objective being to optimise public health protection by improving and modernising the existing EU legislation. The new legislation maintains, and sets out more clearly, the duty of food business operators to produce food safely. This is a requirement that is contained in current legislation and is underpinned in general food law. Requirements for food business operators are laid down in the new EU Regulation 852/2004.

It is intended that the more risk-based and flexible procedures will better match the needs of individual businesses and enforcement agencies. This will be facilitated by the introduction of food safety management procedures based on the application of Hazard Analysis and Critical Control Points (HACCP) principles. HACCP-based principles are widely regarded throughout the EU and in most developed countries as crucial to the management of food safety and, in turn, consumer protection. On 1 January 2006 it will become a legal requirement for all food businesses (except primary producers) to put in place, implement and maintain a permanent procedure or procedures based on HACCP principles.

These principles prescribe a certain number of requirements that must be met throughout the cycle of production, processing and distribution in order to permit, via hazard analysis, identification of the critical points that need to be kept under control in order to guarantee food safety: identify any hazards that must be prevented, eliminated or reduced to acceptable levels; identify the critical control points at the step or steps at which control is essential; establish critical limits beyond which intervention is necessary; establish and implement effective monitoring procedures at critical control points; establish corrective actions when monitoring indicates that a critical control point is not under control; implement own-check procedures to verify whether the measures adopted are working effectively; and keep records to demonstrate the effective application of these measures and to facilitate official controls by the competent authority.

Detectable plastic

A novel material has recently been developed that could help food and pharmaceutical manufacturers comply with the new Regulations and, more importantly, give them the opportunity to use cost-effective, functional, ergonomic plastic implements that are approved for food-contact use. A key feature of products manufactured from this material is that fragments are detected and rejected by standard in-process metal detection equipment.

Known as Detectamet, these products from E-Components and Chains are injection moulded a specially formulated, non-toxic, non-fibrous grade of polypropylene that has a metal-based additive so that fragments as small as a 2mm cube (weighing 0.01 g) can be detected and rejected, depending on the metal detection equipment used and its operating parameters. Moreover, the high-impact material is described as 'shatterproof and virtually unbreakable', which, in itself, helps to reduce the risk of any fragments entering the food or pharmaceutical product, and the finished articles are approved for direct food contact under EU Directive 90/128/EEC rules from the FDA (the USA Food and Drug Administration). Detectamet products are available in red, green and yellow in addition to the standard blue.

The most popular product developed so far is Detectamet pens. These are available as a stick design or retractable, with a choice of four colours for the pen and three colours of ink. Clips are reinforced to reduce the chance of them becoming detached, and the stick pen can be supplied without a clip if preferred.

Numerous other Detectamet products have also been developed, usually in conjunction with a customer following a specific request. Examples of Detectamet products include a stylus for use with PDAs (personal digital assistants), scoops, scrapers, stirrers, shovels, buckets, cutters, knives, cups, clipboards, sticking plasters (dressings), earplugs and vinyl gloves (Fig. 1). For machinery and process applications, there areDetectamet rubber sheeting, rubber extrusions, O-ring seals, belting, suction cups, retaining clips and cable ties. In addition, test sticks, pucks and balls are available for verifying the correct operation of metal detectors.

Clearly the food and pharmaceutical industry offers enormous potential for this innovative material, but there are other possibilities as well. Already there has been interest in military applications that can take advantage of the high-impact, corrosion-resistant, easily-formed material. In the medical sector, surgical instruments could be moulded from the Detectamet material, which would help to avoid instances of instruments – or parts thereof – being inadvertently left inside a patient following an operation. Other possibilities range from anti-counterfeit measures and security tags to any application where small, corrosion-resistant components or markers could benefit from being detectable without being visible, especially if their function requires them to be of a shape that is most cost-effectively manufactured by injection moulding (Fig. 2).

As well as receiving enquiries from within the EU, E-Components and Chains has been contacted by companies in the USA, Australia and New Zealand, as the innovative metal-detectable plastic products believed to be unique inasmuch as they are also approved for direct food contact in accordance with EU Directive 90/128/EEC and FDA rules. The company is now actively seeking distributors around the world to promote and sell Detectamet products.

Recent Issues