Inspection efficiency on the incline


With a high rate of automation in its two Dutch cheese factories, Vepo Cheese prides itself on production efficiency. Slicing, grating, cubing, portioning and packaging millions of kilos of hard cheese a year, the business recently upgraded all of its production lines with a new incline layout comprising seven highly sensitive Interceptor Metal Detectors from Fortress Technology.

For its Oudewater site, high performance, future-proofing and an independent reject system on each line were important criteria to Vepo.

On approaching Dutch manufacturer Jansen Control Systems to design the compact incline inspection lines, the company’s Managing Director, Gerard Schuurman, explained the increased sensitivity of the Fortress Interceptor, and the advantages for cheese applications.

Recalling his conversation with the cheese giant, Gerard explained how these variations in density combined with the product effect could react in different ways in the magnetic field of a traditional food metal detector. “Not addressing product effect can lead to higher product waste. Vepo was especially taken by the Interceptor’s increased sensitivity. Keen to introduce a more fail-safe solution, Vepo wanted a metal detection solution which could increase the inspection pace to keep up with its growing production demands.”

Best solution for cheese

Explaining how the Interceptor machine works, Fortress European Managing Director, Phil Brown, commented: ”Inspecting wet products has for many years presented cheesemakers with a number of challenges. Water like metal is conductive. And cheese is inherently a wet and conductive product that also contains mineral content like salt. Accurate detection also depends on the size, shape and orientation of metal particles.”

The Interceptor overrides the propensity of ‘wet’ product effects that can drown out a signal, in particular the signals caused by a stainless steel contaminant. Software algorithms make this possible by distinguishing between signals specific to the product and those that flag up anomalies. By singling out low-frequency signals, the Interceptor leaves the signal from stainless steel more readily identifiable in the higher-frequency range.

As a result, the system can pinpoint metal fragments with dimensions half those detectable with the previous generation of equipment, with greater reliability. The result of separating these two readings is any metal signal as a result of genuine contamination isn’t swamped by product effect.

Maintaining automation efficiency

The ability to isolate rejected packs without interrupting the production flow was also important to Vepo. On previous inspection lines, Vepo didn’t have an automated reject system. If a contaminated pack was identified, the belt would stop, and an operative would have to intervene, remove the pack and restart the inspection process. For a busy, fully automated processing and packing facility, this business interruption impacted productivity.

To keep the footprint small and for smooth, seamless production, Jansen developed an incline conveyor that could be fully integrated with the Interceptor metal detector, vertical packing system and periphery equipment. Logistically, it was quite an engineering challenge, explains Gerard.

Other features comprised an easy to clean conveyor belt and a robust easy-to-empty bin trolley that could stand up to the weight of heavy packs dropping in. All of the inspection lines were installed within a day, ensuring minimal loss of production time.

Measuring just one metre at its widest point and just under three metres in length, Jansen also combined two conveyors into one which helped to reduce the number of controls. Within two hours of installation per line, the factory was running at full capacity accurately inspecting large quantities of grated cheese bags per shift. False positive rejects have also fallen since the systems went in.

Total traceability

Another advantage of the new, fully integrated packing system is the processing transparency. Each metal detector features Contact Reporter software. Data from each packaging line is collated in a common collection system, enabling quality assurance and production leaders to monitor processing and inspection performance from a centralised location.

This automated record keeper developed by Fortress also helps the factory to keep track of and record logs for rejects, tests and process settings.


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