Looking deeper

The inspection market continues to evolve as manufacturers are placed under pressure to adhere to increasingly stringent levels of food safety compliance. Whether responding to individual corporate standards or the latest requirements set out by the British Retail Consortium and other global institutions, manufacturers must demonstrate tight control.

EU legislation and regulations dictate that all confectionery manufacturers implement a documented food safety management system based on the principles of Hazard Analysis and Critical Control Point (HACCP) which must show adequate inspection processes are in place to prevent and inspect for dangerous contaminants and foreign bodies.

To inspect for foreign contaminants, manufacturers have two main choices: metal detection or x-ray inspection.

Metal detection
Previously, the main limitation of metal detection was that each detector had to be factory set to a fixed operational range. However, the latest developments in ‘variable frequency’ technology mean that detectors can operate at any frequency between 40kHz and 900kHz and have the ability to autoselect the ‘correct’ operating frequency in seconds, eliminating the past restrictions caused by single and ‘limited’ frequency detectors. Changing product and packaging no longer requires the expense and inconvenience of engineer set up and production downtime is minimised. This flexibility is ideal for confectioners, as many processing sites are inspecting a variety of different products and many lines are used for multiple product inspection.

The latest advances in metal detection technology mean that systems are now even more sensitive to metal contaminants, as well as being more user friendly and designed with features to meet the increasing demands of food manufacturers.

When products are made with only the finest of ingredients and thousands of pounds spent on glossy adverts promoting an image of luxury and quality to justify premium pricing, manufacturers realise that they cannot afford their product to be less than perfect every time.

X-ray inspection
The major change to foreign body detection over the past few years has been the introduction of x-ray inspection. X-ray inspection systems work on the principal of density analysis of the product and the contaminant. As an x-ray penetrates a food product, it loses some of its energy. A dense area, such as a contaminant, will reduce the energy even further. As the x-ray exits the product, it reaches a sensor. The sensor then converts the energy signal into an image. Foreign matter appears as a denser area enabling the technology to identify the foreign contaminant.

The main advantage of an x-ray machine is that it can find other contaminants in addition to ferrous, non ferrous and stainless steel metals. These include ceramic, glass, bone, plastic and stones. An important feature of an x-ray machine is its
capability to detect more than just contaminants, most systems can also detect for missing, underweight or improperly packaged product.

Inspecting confectionery
Consumers do not want to open a box of chocolates only to find their favourite flavour missing. X-ray systems can scan every individual package to identify any missing or incomplete chocolates, as well as contamination, in boxes containing single or multiple layers. Typical production anomalies could include large sugar crystals or a simple product lump in the sweets.

Confectionery manufacturers are in intense competition with each other and luring consumers through innovation and catchy packaging is still the key to success. One aspect of packaging that provides significant benefit for extending shelf life and continues to thrive in the snacks industry is the growing trend to use metallic/foil packaging materials which offer convenience to the consumer and lends itself to the supplier to use innovative packaging design to stand out on the supermarket shelf. This material determines that an x-ray will have to be used to verify the products as a traditional metal detector will struggle due to the high conductivity of the packaging.

With a growing number of manufactures in the confectionery sectors, where x-ray detection systems are becoming more prevalent, particularly when the brand is positioned at the top end of the market.

Many leading European supermarkets are seeing this benefit and are driving through x-ray inspection as the ‘Code of Practice’ for foil or  metallised product packaging. As a result, x-ray technology is increasingly in demand.

Checkweighing
As important as contaminant detection is for quality, weight analysis is also critical to ensure total customer satisfaction. A checkweigher is a system that weighs items as they pass through a production line, it protects against unacceptable under or
overweight packages ever reaching the customer.

A reliable, accurate checkweighing system is crucial to adhere to consistent product quality and again current EU legislation protects consumers against short measures and puts even greater pressure on food producers to accurately measure their products and ensure that prices and weights are correct and that incorrect weight products are kept to a minimum.

Checkweighers are generally located at the end of a production line, normally manufacturers use a checkweigher after a filler to verify proper fill levels, or as a counter after a bagger to ensure there are no missing or extraneous parts.

Checkweighers have evolved over time from the simple grading checkweigher, which just accepted or rejected each pack on the basis of a single set point, to average recording checkweighers which calculate and display statistical information about the production process.

The majority of automatic checkweighers produced today are average recording checkweighers. These machines inspect each pack and deal with non-standard and inadequate product, calculate and record the average weight for a given batch size. Also they are fitted with a suitable alarm if the average weight falls below the nominal net weight. With optional features such as ‘automatic mean weight correction’ they prevent a defective batch by controlling the average weight.

Since the accuracy of an automatic checkweigher is highly dependent upon the package and the environmental conditions, the packer must assess the performance of each checkweigher on each processing line. Maintaining high quality standards while increasing throughput and reducing downtime costs are the key considerations to choosing the right checkweigher solution.

Today’s technology makes checkweighers more reliable and accurate than ever before. The information that a quality team had to collect by hand can now be collected in the blink of an eye by the checkweigher operating system.

By utilising the latest advances in inspection equipment, food processors can stay ahead of regulation and streamline production. Most importantly, by implementing contaminant detection techniques, processors can protect their brand and reputation.

James Chrismas, global marketing manager, Loma Systems