TRIGON Snacks – a supplier of nuts and snacks to the licensed trade, retailers and food service operators – commissioned a horizontal metal detection concept for its new honey roasted nuts line.
Retailer COPs specified that as ‘naked nuts’ the new honey-coated range must be inspected for metal contaminants prior to own-label packaging. Trigon also required a supermarket spec metal detector sensitive enough to adapt to the fine oil and sugar tolerances.
The business opted for a wide-head Stealth metal detector with a specially adapted linear conveying system from Fortress Technology.
Fortress explained that factoring in the conveying and reject system was ‘critical’ to guarantee reliable operation and avoid false readings. Given the tight footprint, it was decided a customised solution was the best way to ensure metal detector performance was not compromised.
The low profile nuts combined with the inspection speed meant a kicker would be incompatible, Fortress added. The manufacturer said it is also ‘virtually impossible’ to isolate and divert contaminated products with naked products. With insufficient space to accommodate a flap style reject, Fortress engineered a retracting band conveyor and reject mechanism.
The rollers on Trigon’s food-grade belt are rounded. The metal detector, which sits at the front of the conveyor, calculates how long the contaminated nuts will take to reach the end of the conveyor band, communicating via the control system. The belt retracts back on a sliding rail, rolling the rejected nuts into a dedicated bin located beneath the conveyor.
Capable of detecting ferrous and non-ferrous particles as small as 1mm and stainless steel particles down to 1.5mm, Fortress sales manager Jaison Anand attributes the level of sensitivity to the aperture dimensions. He said, “Aperture size is critical to optimal operation. If aligned to the size of the product being inspected it delivers the best performance. That’s why we installed a wide yet low profile metal detector head on the Trigon honey nut line.”
