Bread remains one of the UK’s favourite foods, with households buying the equivalent of nearly 11 million loaves each day. With large bakeries accounting for 85% of UK bread production, switching from a single conveyor metal detector to a multi-lane, multi-aperture system that allows operatives to run different product batches side-by-side, can boost efficiency and total cost of ownership (TCO).
The Benefits of Multi-Lane Metal Detector Systems
That’s certainly been the case for one large baker in the Netherlands, which is now accurately inspecting 3,600 loaves per hour. As one of the first companies to install Fortress Technology’s space saving, multi-lane, multi-aperture metal detector systems, Borgesuis opted for a twin-lane conveyor that feeds product in single file through two smaller apertures encased within a single Stealth metal detector.
Before the installation, bakery operatives manually loaded bread loaves onto a conveyor for inspection by a single metal detector. It was a slow, labour-intensive process, causing packing bottlenecks at the factory.
Rather than commission one large metal detector to span two lanes, the company wanted to identify metal contaminants in the individual line and separate rejects. However, installing two metal detectors would have prohibited the bakery from running two conveyors so closely together. Sensitivity was also key – Borgesuis requested a minimum of 1.8mm ferrous, 2.8mm non-ferrous and 4.0mm stainless steel.
Fortress proposed installing a twin aperture Stealth metal detector, mounted across two conveyor lines. Each aperture measures just 200mm by 450mm and the loaves pass right through the centre point, allowing the system to better cope with orientation and product effect. The dedicated aperture for each lane is also more sensitive to smaller metal particles, detecting 0.8mm ferrous, 0.8mm non-ferrous and 1.2mm stainless steel.
To reduce product effect, the bread loaves, which are all baked on the premises, are inspected individually after rotating around the expansive cooling tower and before packaging.
The Future of Bakery Metal Detectors
Until now, bakeries and food manufacturers wanting a multi-lane system to inspect items had limited options, emphasises Fortress Technology’s Phil Brown. “You could either install a much larger single aperture spanning all lanes or insert standalone metal detectors between the conveyors. Neither option suited this specific application at the Borgesius bakery, as it would have meant a bulkier machine, multiple systems to maintain and a wider footprint, or conceding on metal detection sensitivity.”
To maintain a small footprint, the metal detector was integrated with a new section of conveyor (measuring 1.7m by 5m) that slots alongside the bakery’s existing cooling tower. This bespoke conveyor system splits into two infeed lanes. If the metal detector identifies a contaminated loaf, the conveyor on that lane dips, dropping the bread loaf into an individual lockable BRC-approved reject bin for each lane.
The bakery is now able to inspect different products side by side, boosting efficiency and total cost of ownership. Within 12 hours of installation by Dutch manufacturer Jansen Control Systems, the bakery was running at full capacity, accurately inspecting 14,000 loaves per shift.
Plant manager, Willy Boneschansker from Borgesius, comments: “To keep pace with the growing number of supermarket and convenience store orders, and continue meeting the stringent retailer codes of practice, we needed an efficient automated inspection process. Our twin aperture metal detector from Fortress is integral to this effort and has proven reliable and easy to operate.”