SNB’s Blog

Many manufactures benefit from using metal detectors. They prevent contaminated food escaping through factory doors and aid businesses in complying with COP’s. However, whether you have bought metal detectors for production lines before or you have never bought a unit, it is crucial that the correct metal detector is chosen for you site. The thought buying a new metal detector can seem like a large task. This blog will run through the different type of metal detectors available and which may suit your product.

Metal Detector on Conveyor

One of the most common type of metal detector is a standard head attached to a conveyor. These types of metal detectors can be seen often in the meat, confectionery, bakery and packaging industries.

Most metal detectors have three coils within the head. They contain one transmitter coil and two receiver coils. Each product will be set up on the metal detector so that when a metallised product runs through the head, it will give a different signal, upset the coils and therefore the product will reject.

Conveyor metal detectors can come in all shapes and sizes with different reject systems fitted to automatically take products off the line.

Customers running foiled products could also use an FIF metal detector. The difference between an FIF head and standard metal detector is an FIF can only detect Ferrous metal. Whereas a standard head is able to detect Ferrous, Non-Ferrous and Stainless Steel.

Top tip – if you are looking for a metal detector on a conveyor, to get the best head for the job, select one only 50mm higher than your tallest product. For example a cake that stands 150mm tall would be perfect for a metal detector with an aperture of 200mm. This will help your product have the best sensitivities.

Pipeline

A pipeline system unit is basically a pipe that can be attached to the end of your pipeline production. The pipe pushes product through past the metal detector. On detection of metal
contaminated product this is taken out of the pipe via a reject flap.

These types of metal detectors tend to be used by customers that run products such as wet pet food, jams, soups, sauces, slurries and dairy products.

These systems tend to be placed just before a packaging unit or vacuuming filing machines.

Vertical Fall, Drop Through, Gravity Metal Detectors

There are a few names for these metal detectors, but a vertical fall metal detector is what it says on the tin. Your product falls down through a pipe or funnel and through a metal detector.

This system is integral for checking certain products during or towards the end of the production line.

This type of metal detector is suitable for bulk products and powders/granules such as sugar.

Pharmaceutical

Pharmaceutical metal detectors are intended to be used by those manufacturing tablet formed products such as drugs or supplements.

Compared to the other metal detector types, pharmaceutical metal detectors offer the highest levels of sensitivity. These sensitivity levels are obtainable as the aperture sizes are small and the heads have high operating frequencies. The only limits with this type of metal detector are the amount of throughputs, product materials and product dimensions.

Twin Head Metal Detector

Similar to a metal detector on a conveyor, a twin head encompasses a standard head and FIF metal detector on the same conveyor belt.

This system is suitable for customers that need to run foil wrapped products as well as other packed products. Customers use one metal detector head during the run of production.

This type of metal detector is perfect for metal lidded products such as yoghurts or ready meals.