Top 10 Read Bunting Blogs of 2017

Which Magnetic Separator Articles Proved Popular in 2017?

In 2017, we have posted 48 articles and news stories on a wide range of subjects from metal contaminated food, environmental issues of plastic waste, and review of major trade shows such as Waste 17 and Interplas.

But which ones proved to be the most popular?

Here’s the top 10.

10 – Magnetic Separation Myths – You Can Block a Magnetic Field

The 8th of 10 myths on Magnetic Separation was published in February and highlighting how difficult it is to block out a magnetic field.

9 – Where are Metal Separators Positioned in a Plastics Plant?

This is one of the ‘Perfect Plant’ series of blogs, first published in March 2016, assessing a typical plastic plant and highlighting the best locations to remove metal contamination.

Perfect Plastics Plant

8 – ‘Ingesting Metal Fragments Can Cause Injury’ states FDA

On their website, the US FDA review the issue of metal contamination and highlight the dangers of consuming food products contaminated with metal.

7 – Cases of Metal Found in Food

For the UK’s Food Safety Week in June, we looked at recent high profile cases of metal being found in food and investigate how these problems could have been prevented.

6 – Magnetic Separation Myths – It Is Easy to Clean a Magnetic Separator

The 10th of the 10 Magnetic Separator myths was published in March, looking at the difficulties of cleaning high strength magnets and providing some simple solutions.

5 – Getting Metal Out of Recycled Tyres and Rubber

This article, assessing the best ways to remove metal from shredded rubber, was first published in April 2016, but still remains popular.

4 – How do you Separate Stainless Steel?

This article was published in April 2015 and highlights the challenges and solutions of separating stainless steel.

3 – 3 UK Waste and Recycling Facts

In the week prior to the UK’s recycling and waste show RWM17, we investigated three facts on how the UK handles and recycles our waste.

2 – Bunting Acquires Master Magnets

In January, we announced the acquisition of one of the UK’s leading manufacturers of Magnetic Separators and Metal Detectors, Master Magnets.

1 – What is an Axial and Radial Magnetic Field?

Radial Magnetic Field Bunting Magnetics

Despite the huge news coverage and interest in the acquisition of Master Magnets, the most read blog in 2017 was an article first published in August 2016.  The technical article explains the difference between an Axial and Radial Magnetic Field when used in a Magnetic Separator such as a Drum Magnet or Magnetic Pulley.

We hope that you’ve enjoyed reading our news and blogs in 2017 and please keep reading in 2018!

For further information on Metal Separation or to assess the right Magnetic Separator or Metal Detector for a specific application, please contact us on:

Phone: +44 (0) 1442 875081
Via the website

Top 10 Blogs Bunting 2017

Our 2017 Review

A Look Back at Our News & Blogs from 2017

2017 has been another busy and exciting time for Bunting Magnetics Europe with some great news stories.  In this blog we look back at the past 12 months and review the stories that hit our headlines.


bunting_master_magnetsWe started the year by announcing that Bunting had acquired leading UK Magnetic Separator and Metal Detection company Master Magnets.  This changed the Magnetic Separator landscape in Europe.

At the same time, the Bunting team was exhibiting at the Arabplast exhibition in Dubai.  The plastics focused event was attended and visited by plastics professionals across the region.  Sales were even made on the stand!

Our 7th of our 8 Magnetic Separator Myths examined the impossibility of achieving 100% metal separation.

To finish off January, we announced record sales in 2016 despite the backdrop of Brexit and political uncertainty.


We started the month with our 8th Magnetic Separator myth, asking if it was possible to block a magnetic field.

Bunting also joined the British Plastics Federation, reflecting our longtime involvement in the sector providing metal separation solutions.

Bunting at Exposolidos 2017

Our exhibition focus in the month was Exposolidos in Spain with our local representative SMED Tecnica.

In February, we also asked the question of whether our Environmental future is simple down to design?  This was written in response to the growing awareness of the environmental impact of waste that would gradually intensify through the year.

We finished off the month with the launch of the Teardrop Tube Magnet, ideal for use in fine powders where bridging might be an issue.


The strength of a Magnetic Separator is often expressed in ‘gauss’.  However, the vast majority of people are unable to measure gauss and so we showed a simple practical way to check the magnetic power using a simple spring balance.

Our 9th Magnetic Separator myth highlighted the dangers of strong Magnets and our 10th myth looked at ways to easily and safely clean captured metal off  Magnetic Separators.

We also investigated a US FDA report stating the ‘Ingesting Metal Fragments Can Cause Injury‘.

In March, we exhibited at the Southern Manufacturing and Electronics show in Farnborough UK.


Metal is commonly found in spices and we examined a typical plant and identified the best locations for Magnetic Separators and Metal Detectors.

We also reported that we sold a record number of Plate Magnets in 2016 for export to Indonesia and 28 In-Line Magnets to a German baby food producer.

New Bunting Sales EmployeesWith the continued growth of the business, we were thrilled to announce the appointment of two new sales engineers, Tom Higginbottom and Gordon Kerr.

In April, UK supermarket Morrisons was hit by a metal-in-food scare and we looked at how this could have happened and ways in which such a problem could have been prevented.


Our Food Safety theme continued in May when, during a metal separation survey, we found large amounts of metal safely captured when processing rice.  Our Perfect Plant review assessed the best methods and equipment location to ensure that metal is removed from Processed Vegetables.

Exports continued to proved successful with the shipment of a HFS Drawer Magnet to a Plastics recycling company in France.

Our technical review in May reviewed the effect of high temperatures on Rare Earth Magnetic Separators.


There was a political flavour to news in June after the UK’s general election and we investigated what the leading parties were promising with regards to the environment.  At the same time, Bunting and Master Magnets were jointly exhibiting at Waste 17, a major UK recycling show in Manchester.

The week after, Bunting supported local representative BMS France at the FIP Solution Plastique exhibition in Lyon, France.

To mark the UK’s Food Safety Week, we reviewed recent cases of ‘metal’-in-food’ and the potential implications for the manufacturer, sales outlet, and customer.


Denis_Elkins_Bunting_Magnetics_Europe-2176In July, we were thrilled to announce the successful transition to ISO9001 2015 Quality and the ISO14001 2015 Environmental Standards.

In the media there was increasing attention on the issue of plastic waste in the environment and we commented on the necessity of a global strategy for Plastic Waste.


The environmental theme continued in August asking if the UK could realistically increase their metal packaging recycling rate by 10% by 2020.


As a prelude to RWM17, the UK’s largest waste and recycling show, we looked at 3 UK Waste and Recycling Facts such as asking how much waste do we actually generate?

Bunting Master Magnets at RWM17

After exhibiting at RWM, there were many questions being asked by exhibitors and visitors about the future of the event despite the importance of recycling and the global waste problem.


Bunting Magnetics Europe at Interplas 2017

The UK’s leading plastics show, Interplas, is held every 3 years and, as in previous years, it was very well supported by both exhibitors and visitors.  The environmental issues associated with plastic waste was gathering momentum.

Removing metal from fine powders can be extremely difficult and we produced a technical report looking at the best techniques and ideal equipment.

Tom Higginbottom attended the successful Bulk Solids & Powders show SyMas in Poland with the local Bunting representative TEKPRO.


The Manufacturing and Engineering industries have been concerned about the lack of young engineers and hopefully initiatives such as Tomorrow’s Engineers Week will help address this issue.

We were also excited to report two consecutive record sales months in September and October.  2017 was proving to be as successful as 2016.

Our latest Perfect Plant review focused on the brewing of beer and ensuring that all metal is removed to protect delicate processing equipment and the taste of the beer.


Pantomine BlogThe BBC TV series Blue Planet had highlighted the global problem of plastic waste in our oceans.  However, as the pressure increased on the plastics sector, we asked whether Plastic was the Pantomime Villain of the recycling world?

We hope you have enjoyed reading our news and blogs in 2017.  If there are any topics that you would like reviewed, then please get in touch and send an email to Paul our press officer (

For further information on Magnetic Separators or Metal Detectors please contact the Bunting team on:

Getting Metal Out of Beer

Ideal Locations for Magnetic Separators and Metal Detectors in a Brewery

Thankfully, it is very unlikely that you will ever find a piece of metal in your glass of beer.  However, when tramp metal in the form of screws and nails is accidentally introduced during the brewing process, it damages processing equipment and can even affect the taste of the beer.  In this article we look at the best methods of ensuring that the brewing process is unaffected by tramp metal.


As with any food process, there are many locations where metal can be inadvertently introduced.  With raw materials being collected from the fields and then transported to the brewery in large trucks, contamination by metal and other materials is unavoidable.

Here we look at a typical brewery and identify where Magnetic Separators and Metal Detectors could be located to remove any metal contamination.

Location 1 – Malt In-feed Line

When the malt is delivered by truck or rail, it is commonly pneumatically transported into storage silos.  A Pneumatic In-Line Magnet and/or Metal Detector would ensure that any tramp metal in the raw material feed is removed prior to storage.

Bunting Magnetics In Line Magnet-2

A Pneumatic In-Line Magnet is designed to easily fit into a pipeline without causing any obstruction.  It has a magnetically strong Plate Magnet mounted on one side which attracts and holds any ferrous metal.  This is then manually removed on a regular frequency.

The Metal Detector identifies and then ejects any remaining metal contamination, both ferrous and non-ferrous.  As most metal contamination at this stage is ferrous, installing the Metal Detector after the In-Line Magnet reduces the amount of metal detection rejects and thus reduces the loss of product.

Location 2 – Prior to Milling

cartridge_magnetsGrate Magnets are commonly positioned in or above the in-feed hopper to the mill, especially if there has been no previous metal separation or detection.  A Grate Magnet is a series of Tube Magnets designed in a grid to fit inside a hopper.  For maximum protection of the mill, the Grate Magnet uses a set of high magnetic strength Rare Earth Neodymium Tube Magnets.  Such protection ensures that no tramp metal enters the mill where it can cause serious and expensive damage.

Location 3 – Hot Water Feed to Mash Tun

Bunting Magnetic Liquid TrapWater is a common source of metal contamination in food processing plants and is also the one in-feed material that is often overlooked.  The nature of water means that rust is common and a simple Magnetic Liquid Trap is used to attract and capture any rogue ferrous metal, even in a very fine form.  A Magnetic Liquid Trap is designed to be easily introduced into a pipeline, with flanges or any other connector.  Inside the body, high strength Rare Earth Neodymium Tube Magnets project down into the material flow, attracting and capturing any ferrous or weakly magnetic materials.  The Tube Magnets are removed from the process and manually cleaned.

Location 4 – Between Mash Tun, Lauter Tun and Brew Kettle

Magnetic Liquid Traps could also be located between the Mash Tun, Lauter Tun and Brew Kettle, especially is there has been limited protection earlier in the process.

Location 5 – Hops In-feed Line

Protection is important whenever raw materials are introduced into the process and Grate Magnets and a Quicktron Metal Detector will ensure that hops entering the brew kettle are metal-free.  This design of Metal Detector is for free-fall material.  As the material enters the metal detector, any metal is detected and then automatically rejected.  The Grate Magnet reduces the amount of material lost during the rejection process by removing any ferrous metal.

Location 6 – Between Brew Kettle and Whirlpool/Settling Tank

After the brew kettle , a Magnetic Liquid Trap, with special Neodymium magnets designed to withstand high temperatures, will provide final protection prior to settling.

Location 7 – Yeast In-feed Line

As on the hops in-feed line, a combination of a Grate Magnet and Quicktron Metal Detector will ensure that any metal does not enter the process.

Location 8 – Between Conditioning Tank and Filter

To protect the filter, a Magnetic Liquid Trap is often installed after the conditioning tank.

Location 9 – Prior to Bottling

p-TRON-GM-V2As in many food processing plants, it is good practice to install a Metal Detector (in this case a P-Tron) at the final stage of the process.  This provides a final stage of protection to ensure that any metal introduced into the process from damaged processing equipment such as the filter or in the pipes is detected and removed.

This is a typical example of a Brewing Operation.  However, each plant is unique and often a site visit is required to assess and recommend the best ways to ensure a metal-free end product.

For further information on removing Metal during the brewing process using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Other Food Plant Reviews include:





Getting Metal Out of Processed Vegetables

Ideal Locations for Magnetic Separators and Metal Detectors in a Vegetable Processing Plant

Processed vegetables are a vital part of the food chain.  Tens of thousands of bags of pre-cut carrots and freshly prepared kale are bought in supermarkets daily.  Frozen vegetables have been very popular since Clarence Birdseye invented the quick freezing method in 1924.  Also,  often-unnoticed processed vegetables are present in many everyday food items such as tinned soup, baby food, sauces, and ready-made meals.

However, processing vegetables takes a great deal of care and attention as the products are often delicate and can be easily damaged.

BUNT-2286 4 8.5x11 plants

As with all processed foods, there is always the risk of metal contamination.  Metal can be introduced at various stages in the process.  The design and positioning of the Magnetic Separator or Metal Detector has to also respect the delicate nature of the product.

Untreated Vegetables Feedstock

During the collection and transportation of the raw vegetables, there is always a high risk of metal contamination.  This can be remove using a Plate Magnet.  To avoid contact with the vegetables and eliminate the risk of damage, the Plate Magnet is suspended above the incline conveyor feeding the washer.  Metal is attracted up onto the face of the Magnet and held until cleaned.  This is ideal to remove larger metal items such as screws and nails.

Post Washing

The vegetables washing process frees dirt and other detritus including metal particles.  Prior to the washed vegetables being fed into a drier, a Permanent Magnetic Pulley, replacing the standard head pulley of a conveyor, attracts and automatically removes any free metal before entering the drier.  Again, there is no physical content between the Magnetic Separator and the vegetables.  After drying, the vegetables are fed into a dicing machine.

Prior to Dicing

Plate Magnet Tapered Step-9545
Plate Magnet Tapered Step

The blades on a dicing machine are delicate and expensive.  Metal contamination can cause significant damage.  To ensure that no metal is present, the dried vegetables are fed over the surface of a Plate Magnet.  This enables higher levels of separation that when the Plate Magnet is suspended as the material is passing closer to the area of maximum magnetic strength.  Any potential damage to the vegetables as they flow over the surface of the Plate Magnet is limited.  Metal is captured and then held under the lip of a tapered step on the surface of the Magnet.

Undersized Vegetables

Smaller sized diced vegetables are often taken on a different route.  They can be mixed with water, for ease of transportation, before being reintroduced into the process.  Immediately after dicing, the smaller particles fall through a Quicktron Metal Detector to remove any small ferrous and non-ferrous metals (including any broken blades from the dicer).  Water from the external source is passed through a Magnetic Liquid Filter Magnet to ensure that any rust or other ferrous metal contamination is not introduced into the process.  The Undersized Vegetables are mixed with the water and then re-introduced into the process.

Final Packed Product

Metron 05C Metal Detector
Metron Metal Detector

The final stage of weighing and packing includes 3 steps of Metal Removal and Detection.  Prior to weighing, the processed vegetables are passed over the surface of a Plate Magnet to ensure that all ferrous metal contamination has been removed.  After weighing, the vegetables fall under gravity through a Quicktron Metal Detector where any non-ferrous metals are removed.  Finally, after packing, the finished packed batch of processed vegetables are passed through a tunnel-type Metron C02 Metal Detector as a final check prior to shipment.

This is a typical example of a Vegetable Processing Plant.  However, each plant is unique and often a site visit is required to assess and recommend the best ways to ensure a metal-free end product.

For further information on removing Metal from Processed Vegetables using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009

Other Food Plant Reviews include:

Getting Metal Out of Spices

Ideal Locations for Magnetic Separators and Metal Detectors in a Spice Processing Plant

Most households have a collection of spices in one of their kitchen cupboards.  Adding spices to food when cooking is now a common practice, but how are they processed and prepared?

Most spices are grown in the tropical regions of the world, with some thriving in the cool misty highlands. Many of the seed spices come from more temperate areas, such as coriander seed, which is grown in Northern India, Africa and the wheat producing areas of South Australia and Western New South Wales.

BUNT-2910 Perfect Plants 5

The nature of the location and how the spices are collected mean that there is a high risk of metal contamination.  Most spice plants use a series of Magnetic Separators and Metal Detectors to remove and detect any problematic metal.  Indeed, many UK supermarkets and food retailers (eg M & S) have strict guidelines on the use of Metal Removal equipment.

The plant shown in the flowsheet is a generalisation of a typical spice producing operation and highlights suitable locations for both Magnetic Separators and Metal Detectors.

On Delivery

Ideally, it is always best to remove metal before it enters the process.  The metal tends to be larger in size and easier to separate.  At this early stage, the delivered spices can be passed over a High Intensity Rare Earth Drum Magnet.  This automatically removes magnetically susceptible metal prior to the spices moving on to storage.

Prior to Processing

Metal damages processing equipment and so it is always best practice to ensure protection by installing a Magnetic Separator.  The spices can be passed over a simple Plate Magnet prior to grinding, protecting the grinding plates from damage.Plate Magnet Bunting Magnetics-9805

After Grinding

The process of grinding may liberate entrapped metal and may introduce fine iron into the process.  A Plate Housing Magnet followed by a Quicktron Metal Detector removes any metal.

At this stage, the spice may be sent directly to bagging.  There are several types of Magnetic Separator that are often used to ensure a metal-free product including a Pneumatic In-Line Magnet on the pneumatic line, and a Grate Magnet or Plate Housing Magnet just prior to packing.  A FS Metal Detector can also be used to remove any non-magnetic contamination.

After MixingBunting Magnetics In Line Magnet-2

Once the spices are mixed into a blend, they can be passed through a Centre Flow In-Line Magnet and Quicktron Metal Detector prior to storage in drums or containers.  Prior to the spices being bottled, a final stage of Magnetic Separation is often used.  This is commonly a form of Grate Magnet followed by a Quicktron Metal Detector.  The final check on the bottled spice is often undertaken using a conveyor-type Metron C Metal Detector.  The bottles are then packed ready for despatch.

The multiple stages of Metal Separation may appear excessive, but are required due to the nature of the process.  Metal in a wide variety of forms can be introduced at any stage in the process, especially after grinding and mixing.  Installing different designs of Magnetic Separator and Metal Detector at different points in the process will ensure the best protection against metal contamination.

For further information on removing Metal from a Spice processing plant using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009

Other Food Plant Reviews include:






Getting Metal Out of Chocolate

A Guide to the Best Locations for Magnetic Separators and Metal Detectors in a Chocolate Production Line

Chocolate is made from the exceptionally hard cocoa bean and this means that metal gets introduced into the process, especially from equipment wear.  There have been a number of food safety alerts due to metal contamination in chocolate including the Raw Chocolate Company recalling chocolate goji berries because they may contain small pieces of metal.

However, a series of carefully selected and placed Metal Detectors and Magnetic Separators will remove any metal from the process before it becomes a bar that is loved by millions.

Magnetic Separator Location in a Chocolate Production Line
The locations for Magnetic Separators in a chocolate production process line

The Stages of Metal Removal

Stage 1 – When the cocoa beans are discharged from the delivery vessel, metal is removed by passing all the beans through a heavy duty Grate Magnet.  This captures any larger ferrous metal, like nails, nuts and bolts.

Stage 2 – After the cocoa beans have been cleaned and roasted, they are cracked with the shells being discarded and the nuts being fed into the process.  After cracking, the nuts can be fed on a conveyor through a Metal Detector (Metron C) before passing onto the grinder.  This protects the grinder from being damaged by metal freed in the cracking process.

Stage 3 – After the grinder, the nuts have been converted into a chocolate liquor.  The process of grinding will introduce fine metal into the process and this is removed with a Magnetic Liquid Trap followed by a P-Tron Metal Detector.

Liquid Chocolate Magnetic Trap
A Bunting Magnetic Liquid Trap with a Waterjacket

Stage 4 – The chocolate liquor passes through a hydraulic press where it is split into cocoa butter and cake for cocoa powder.  The cocoa cake is fed onto a grinder and screen with the packaged cocoa powder being passed through a Metal Detector Metron C on a conveyor as a final check.

Stage 5 – The cocoa butter is fed onto a mixer where sugar, milk and flavouring is added.  After mixing and passing through a series of rollers, the mixture is emulsified before being heated.  This molten hot mix is then passed through a Magnetic Liquid Trap with a waterjacket (the hot water in the waterjacket stops any material from cooling).   Care has to be taken in selecting the right magnets as high temperatures can irreversibly damage the magnetic field.  The magnets must be suitable for use in high temperature environments.  After the Magnetic Liquid Trap, the mixture is passed through a P-Tron Metal Detector to detect any non-ferrous metal that may still be present.  This joint protection is important to prevent damage to the next stage of the process (the moulds).

Stage 6 – After the chocolate is fed into moulds it is then cooled.  The final check is after cooling, when the moulded and formed chocolate is then fed on a conveyor through a Metal Detector (Metron C).  The metal-free chocolate is then packaging and despatched for sale to the millions of chocolate lovers all over the world.

Multi-stage Metal Detection and Magnetic Separation may appear excessive, but the best way to remove all metal from the process is to focus on areas where metal may be introduced or released as part of the production process.

For further information on ‘Getting Metal Out’ of Chocolate or any foodstuffs, please contact us on:

Phone: +44 (0) 1442 875081

Other Food Safety Articles



Getting Metal Out of Grain and Cereals

A Guide to the Ideal Location for Magnetic Separators and Metal Detectors in a Grain and Cereal Processing Plant

By the time grain and cereals have been collected and delivered to a Milling Plant, it is highly likely that there is metal contamination present.  Removing that metal to prevent damage to processing equipment and to produce the highest quality end-product is essential and achieved with a series of different designs of Magnetic Separators and Metal Detectors.

Grain Processing Plant Bunting Magnetics Europe Ltd
A plant flow sheet illustrating the ideal location for Magnetic Separators and Metal Detectors to remove metal contamination from Grain and Cereals

Metal can be removed at various locations within a plant, as this guide illustrates.

Step 1 – Whole Wheat Receipt

Material being discharged from the back of the transportation can be fed through a heavy duty Grate Magnet, to catch larger tramp ferrous metal.  The grain is then conveyed and fed into an elevator, where a Plate Magnet can be positioned on the side of the receiving hopper to capture smaller ferrous metals.  Another option is to install a Magnetic Separation Pulley on the end of the conveyor.

Step 2 – After Wheat Blending Silos

A second Plate Magnet can be positioned on the side of the receiving hopper of the second elevator after the wheat has been discharged from the blending silos.  This removes any ferrous metal contamination that has been liberated during the blending process.

Another option is to install a Hump Magnet, which comprises of two Plate Magnets offset inside a doglegged housing, as the elevated wheat is discharged from the elevator into the Mill Mix Silos.

Step 3 – After Mill Mix Silos

Before the wheat mix is fed into a series of screens, aspirators and the de-stoner, a Plate Housing Magnet is ideal to remove any potentially damaging ferrous metal.  Often a Plate Magnet is also installed after passing through this stage of processing and separation, on the side of the hopper feeding the next elevator.

Step 4 – After the Tempering Silos

After the tempering silos there is a stage of more delicate processing with expensive and delicate processing equipment such as roller mills, sifters and purifiers followed by reducing rollers.  It is critical that metal does not enter this stage and due to the importance a series of high strength, deep field, Plate Housing Magnets are commonly installed above the start of the process (ie the Roller Mills).

Step 5 – Fine Material After the Reducing Rollers

At this stage, the material has been significantly reduced in size and different designs of Magnetic Separator are required to remove smaller and weakly magnetic particles.  After the reducing rollers, a Drawer Magnet is commonly installed, with banks of high strength Rare Earth Tube Magnets.  After the material is bleached and whilst being pneumatically conveyed, In-line Magnets, either of a Center Flow or Pneumatic design, are connected into the pipeline.

Bunting Magnetics In Line Magnet-25

Step 6 – Coarser Bran after the Purifier

The purifier will separate the bran fraction which will be fed over a Plate Magnet prior to storage and then despatch.

Step 7 – Prior to Despatch and Packing

After enrichment, the various products are ready for despatch.  If the flour is being fed under gravity into a transport vessel, then a Drawer Magnet is commonly used as a last final stage of protection against metal contamination.  This removes any metal introduced during the process.  If the flour is being pneumatically transported into a transport vessel, then the Center Flow In-Line Magnet is commonly used.

Bunting Grate Magnet
Grate Magnets or Magnetic Separators to capture ferrous metal contamination from free flowing materials

Where flour is being packed on site, a Quicktron Metal Detector is used to detect and remove both ferrous and non-ferrous metal particles, with a final check of the packed material being undertaken using a Metron Metal Detector.

The sequence of different designs and types of Metal Separator ensures that metal being introduced as any stage of the process (ie with the original feed material and during the process) is identified and removed.  Removing metal at various stages reduces the damage to processing equipment and ensures productivity targets are met.

For further information on removing metal from a Grain Process or any food production plant, please contact the Bunting Technical Sales team on:

Phone: +44 (0) 1442 875081

Fax: +44 (0) 1442 875009

Getting Metal Out of Recycled Tyres and Rubber

A Guide to the Ideal Location for Magnetic Separators and Metal Detectors in a Tyre and Rubber Recycling Plant

Successfully removing the metal banding from rubber when recycling tyres is critical as rogue metal can cause injury to horses and children who run and play on the rubber crumb.  Although each tyre recycling plant is different, here is a guide to the types and location of Magnetic Separators to remove the steel.

The biggest challenge with removing all the steel wire from shredded tyres is to maximise separation whilst minimising product (rubber) loss.  This means that multi-stage Magnetic Separation is required.


As shown in the typical plant layout, the primary objective is to liberate the rubber from the metal and this is commonly achieved with a 2-stage shredding set-up.  This achieves optimum size reduction whilst also producing a rubber crumb material that is well liberated.  After the 2nd stage of shredding, it is then possible to focus on the separation of the steel.

Step 1 – Primary Magnetic Separation after the 2nd Shredder

At this stage, the objective is to separate the bulk of metal and this is achieved using a high strength Twin Pole Overband CBS Magnet.  The Twin Pole Overband produces a deeper and stronger Magnetic Field to lift and separate small wires and wire still entrapped in rubber (as explained in the blog The Benefits of a Twin Pole Overband Magnet);

Bunting Overband Single and Twin Pole Magnetic Field

Step 2 – Magnetic Separator Treatment of the Separated Metal Fraction

As there will be clean rubber product carried over into the separated metal fraction, the material can be passed over a Magnetic Drum Separator or Magnetic Pulley or the High Intensity Separation Conveyor (also known as the Stainless Steel Separator), all using high strength Rare Earth Magnets.  It is important that either of these has an Axial magnetic field (one that runs along the length of the Magnetic Separator) as this causes the material to tumble and release entrapped rubber.  If a Magnetic Drum is uses, then consideration is needed for either a manganese steel shell or wear cover as the strong magnetic characteristics of the steel wear can result in heavy wear;

Step 3 – Secondary Magnetic Separation

A second stage Magnetic Separation treatment of the primary rubber product prior to storage is recommended to remove any stubborn metal left after the first stage separation.  This is achieved using a second Twin Pole Overband CBS Magnet;

Step 4 – Magnetic Treatment of the Rubber Powder

For fine rubber material, that is fed onto a powder grinder, a final stage Magnetic Separator is needed to remove small fragments of wire.  As the volume of metal is low, a Plate Magnet suspended close to the product over the conveyor will lift and remove the fine wires;

Plate Magnets Bunting Magnetics

The 4 steps outlined are generalisations in line with work Bunting has conducted with tyre recyclers around the world, but each plant is often unique.  When considering metal separation, either from the start or to improve on the level of metal separation presently being achieved, a review of the plant by one of the Bunting or Master Masters Application Engineers will enable the recommendation of the optimum design and location of a Magnetic Separator.

For further information on removing Metal from Recycled Tyres using Magnetic Separators, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009

Metal Separation from Rubber Crumb

Getting Metal Out of Pet Food

A Guide to the Ideal Location for Magnetic Separators and Metal Detectors in a Pet Food Processing Plant

Ensuring Pet Food is metal free before it reaches the consumer is critical.  However, reports of foods being recalled due to metal contamination occur several times each year [Sainsbury warns of Metal in Bread, Jan 2016].  To assist processors and producers, Bunting has developed a series of typical plant flowsheets showing proposed locations for Magnetic Separators and Metal Detectors.  This blog reviews a flowsheet for a typical Pet Food Processing Plant.

BUNT-2910 Perfect Plants 5

The flowsheet shows material being fed into the plant through to packaging and shipment to retailers.  The type and location of the Metal Separation equipment is detailed as follows:

  1. Infeed Material
    • Dry Side – Dry materials are often fed into the plant from transportation via a pneumatic line.  To remove ferrous metals (eg nuts, bolts, nails, etc) then a Pneumatic Inline Magnet is recommended.  Additionally, after storage in the primary silo, the dry material is passed through a Plate Housing Magnet before being mixed with any other materials, such as meat;
    • Meat Side – After discharge from the transportation, material is commonly fed up a conveyor.  Positioned above the conveyor to lift and remove larger ferrous metal is a Suspended Plate Magnet and this is then followed by a Metron C Metal Detector to identify any non-ferrous metals such as stainless steel.  This ensures that no metal is fed into the grinder where is could damage equipment and also be fragmented into smaller parts that are more difficult to detect and remove;
  2. After 1st Stage Mixing
    • After mixing, when the material is now in a slurry form, a Magnetic Liquid Trap with high strength Rare Earth Magnets is ideal to remove any smaller ferrous metals and any metal that originates from the wear of processing equipment;
    • Bunting Magnetic Liquid Trap
  3. On the Wet Line prior to Canning
    1. To ensure a metal-free product prior to canning, a P-Tron-O Metal Detector can be used on the line to detect and remove smaller ferrous and non-ferrous metals;
  4. On the Dry Line prior to Bagging
    1. After extrusion and just prior to bagging or insertion into cartons or boxes, a Quicktron Metal Detector is ideal to detect and remove any smaller remaining ferrous and non-ferrous metals;
    2. As a final check, the filled and sealed bags are commonly passed through a Metron C Metal Detector which can detect metal inside a package;

The type and design of Magnetic Separator and Metal Detector and the recommended location has been determined following several decades of working with food producers and processors all over the world.  There are always variations to plant designs and layouts that mean different types of Metal Separation equipment is needed and an onsite review by a Bunting engineer will help ascertain the best solution.

For further information on removing Metal from a Pet Food processing plant using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009

Plate Magnet Bunting Magnetics-9805.jpg

Where are Metal Separators Positioned in a Plastics Plant?

A Guide to the ideal location for Magnetic Separators, Magnets and Metal Detectors

Determining the best location to remove metal in a Plastics Processing plant can be difficult and so Bunting has released a series of Typical Plant Flowsheets showing ideal locations for different designs and types of Magnetic Separator and Metal Detector.

Perfect Plastics Plant

On the flowsheet, the Plastics plant is divided into different areas and each has potential locations to remove metal.  In many cases, a combination of Magnetic Separator and Metal Detector is recommended as the Magnet captures and holds ferrous metal (the vast majority of metal contamination in any plant) leaving the Metal Detector to focus on removing the more difficult non-ferrous metals whilst minimising product loss and production downtime.  The type and suggested location of Metal Separation equipment is as follows:

  1. On the primary feed into the Bulk Storage Silo to remove metal before it enters the process:
  2. From the Bulk Storage Silo to capture any metal from the storage silo:
  3. On the Moulding Line to protect processing equipment;
  4. On the 1st Extruder to protect processing equipment
  5. On the Hot Runner System to protect processing equipment
  6. Molding (just in time material handling) to protect processing equipment
    • Torpedo Magnet to remove ferrous metal;
    • Machine Mounted All-Metal Separator to remove all metals;
  7. On the 2nd Extruder to protect processing equipment
  8. On the Regrind Line to remove metal introduced during reprocessing
  9. On the Cleaning Station as a final metal removal stage
    • Duplex Separator

The type and design of Magnetic Separator and Metal Detector and the recommended location has been determined following several decades of working with plastics producers and processors all over the world.  There are always variations to plant designs and layouts that mean different types of Metal Separation equipment is needed and an onsite review by a Bunting engineer will help ascertain the best solution.

For further information on removing Metal from a plastics processing plant using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009