Case Study – Walkers


Pepsico is a leading global food and beverage company with brands that are respected household names throughout the world. MDS has been working with Pepsico across their UK sites for 10 years, providing new metal detectors as well as validating their existing food metal detection methods to ensure that they operate to required standards for HACCP and CCP control.

For this particular topic, we were called to their Walkers crisps site in Leicester.

The Challenge – Food Metal Detection

Walkers ran a promotion in early 2017 which would allow the public to win sums of money, select packets had instant win £5 notes inserted in the crisp packets, and others had codes which could be redeemed online to see if you had won. However, due to ‘orientation effect’, the £5 notes were being picked up by the metal detectors, causing a massively increased number of detections compared to a normal run. This was the same for all models within the factory.

Previous to beginning the campaign, Walkers had carried out trials to ensure the £5 notes would run through the throat detectors smoothly, all appeared fine. Once the promotion went live there was a large increase in the number of false detections, the main cause of the issues being that the pre-packaged notes have been folded differently, creating a different ‘orientation effect’ that had not been tested for beforehand.

Walkers contacted us as soon as they realised this was not a problem they could solve on their own.

food metal detection

Throat Detectors as used by Walkers

The Results

Due to the nature of the promotion and the timescales, MDS responded rapidly and an engineer was promptly dispatched to site. Once our food metal detection engineer had confirmed that the issues were due to the way the £5 notes had been folded he was able to adjust the phase angle and sensitivity of the metal detectors that were being used. After this, there were fine adjustments to the high-level parameters which would allow the £5 notes to pass and not disrupt the detectors ability to operate to required levels of detection; thus ensuring due diligence was maintained at all times regarding the operation of the metal detector and CCP requirements.

This was done over 3 visits in priority order, which had been decided with Walkers. Adjustments were made in a new program, and when the promotion ended we resupplied a food metal detection engineer to the site in order to re-set all of the detectors to their original set up, ensuring that at all times food metal detection levels were maintained.

Due to the strict nature of Advertising Standards Agency (ASA), if this promotion had continued with a number of prizes not making it out to stores due to metal detection, the customer faced the promotion being cancelled and the threat of a fine. Fortunately, MDS was able to quickly and efficiently solve their problem in a way which did not affect their ability to run the promotion.

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