6 Metal in Food Safety Scares in 2017

UK Food Standards Agency Reports 6 Metal-in-Food Problems in 2017

Six warnings of UK food being contaminated with metal fragments were reported by the UK Food Standards Agency in 2017.  The food safety warnings ranged from sweets to meat products.

Metal In Food Safety Warnings 2017

Greencore recalled various brands of Chicken and Bacon Caesar Wraps because of concerns that the products contained metal fragments (20 December 2017).  Greencore, as precautionary measure, recalled various brands of Chicken and Bacon Caesar Wraps.  The products, manufactured by Greencore, were sold in Aldi, Co-op Food and Morrisons retail stores.

Athole Tablet Ltd recalled tablet products because of possible contamination by small pieces of metal (31 August 2017).

William Santus & Co recalled Uncle Joe’s Liquorice & Aniseed Extra Strong Mints (35g tins) as there were concerns that the sweets may have contained small pieces of metal (15 May 2017).

Morrisons recalled Trimmed Beans because of the reported presence of small pieces of metal (20 April 2017).

Metal Found In Morrisons Green Beans

Quorn Foods Ltd recalled a batch of its frozen Quorn Meat Free Mince because of the presence of small pieces of metal (2 March 2017).  The affected product was only on sale at Tesco from 27 February 2017 to 1 March 2017.

Lotus Bakeries UK Ltd recalled Lotus Biscoff Crunchy Biscuit Spread because of small metal contamination concerns (2 March 2017).  This product was sold at Tesco, Sainsbury’s, Morrisons, Asda, Waitrose, Ocado and Nisa stores.  In addition, batch number 7005109 with ‘best before’ date 5 February 2018 has also been sold through East End Foods.

How Does Metal Get Into Food?

Metal In Food-1136All of the foods listed have been processed and it is during that process that metal can contaminate the product.  Food entering a process plant will potentially go through stages of washing, size reduction (e.g. cutting, mashing, slicing), mixing, forming, cooking and packaging.  Metal can be introduced from the wear or failure of processing equipment, or through human error.  In fact, it is not uncommon for metal to contaminate food.  However, it is unusual that metal contaminated food reaches the end consumer.

All food companies use a combination of Magnetic Separators and Metal Detectors to separate and detect the metal.  When metal contaminated products are found to reach the consumer, it can be concluded that this safety equipment failed.

Reviewing the performance of the Magnetic Separators and Metal Detectors on a regular basis is important to ensure that any metal contamination problem is identified and dealt with at the factory.  Regular audits will check the integrity of the Magnetic Separators, assessing and recording the magnetic strength and reassessing the location.  Audits for Metal Detectors will check the application, assessing detection sensitivities.

Often such audits find that changes in the process or product (including packaging) mean that the performance of the Magnetic Separators and Metal Detectors is no longer optimised.

Thankfully, metal in food safety alerts remain relatively infrequent in the UK, although each one causes significant financial and reputation damage to the producer and food retailer.

For more information on preventing Metal Contamination Food Safety Scares, or to arrange a free onsite survey and audit of a particular plant or process, please contact the Bunting team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

 

 

 

Fish Cakes Contaminated with Metal

Youngs Seafood Recalls Metal and Plastic Contaminated Fish Cakes 

In February 2018, Young’s Seafood Ltd recalled its Chip Shop Fish Cakes 6 pack due to the possible presence of pieces of metal and plastic in some packs.  The presence of metal and plastic makes this product unsafe to eat and presents a safety risk. The affected product is sold in some Farmfoods and Heron Foods stores.

Youngs is a leading British producer and distributor of frozen, fresh, and chilled seafood, supplying approximately 40% of all the fish eaten in the United Kingdom every year.  However, this product recall damages their brand and customer confidence.

Where Does Metal Contamination Come From?

Metal contamination is commonly found in food processing plants.  It can be present in the food or ingredients delivered to the processing plant, or introduced during the production process.

Food producers use a combination of Magnetic Separators and Metal Detectors to ensure that the metal contamination is removed before the final packaged food is despatched to supermarkets and sales outlets.

So How Could This Latest Food Scare Happen?

Youngs is not the first or last major food producer to face a product recall due to metal contamination.  Most food producers have installed suitable Magnetic Separators and Metal Detectors.  However, often the contamination issue is a result of old equipment no longer adequate for the application, a failure of equipment, or a change in the process.

Magnetic Separators do not lose magnetic strength over time unless they are damaged or subjected to high temperatures.  However, it is important to annually check the magnetic strength and integrity of the Magnetic Separators.  This can be easily done using a Magnetic Pull Test Kit as part of a Magnetic Separator Audit.

Bunting Magnetics Pull Test Kit

The Magnetic Separator Audit also reviews changes in the production process and may propose the relocation of some equipment to ensure that maximum protection is maintained.

Metal Detectors are often used later in the process, once the product is made and after packaging.  The settings of the Metal Detector need to be regularly checked, especially if there are changes in the production process, product or packaging.  Also, settings on the Metal Detector may be accidentally altered, reducing the sensitivity and resulting in metal contamination being missed.  Again, an annual Metal Detector Audit will review the performance and settings and ensure that there is maximum protection.

Unfortunately, reports on metal contaminated food are not unusual.  Other examples include:

For more information on preventing Metal Contamination Food Safety Scares, or to arrange a free onsite survey and audit of a particular plant or process, please contact the Bunting team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

42 In Line Magnets Ensure Baby Food Is Metal Free

Magnetic Separators Remove Metal During Baby Food Production

A Baby Food producer based in Germany has purchased a further 14 In Line Magnetic Separators to guarantee a metal-free product.  The latest 14 In Line Magnetic Separators are in additional to 28 already supplied and installed as they equip their food manufacturing plants across Europe.

Bunting Magnetics In Line Magnet-9528In Line Magnetic Separators are designed to easily fit into an existing pneumatic or gravity fed pipeline transporting food stuffs.  Both ends are fabricated to connect with the installed pipework.  The central body of the In Line Magnet has a strong Rare Earth Neodymium Plate Magnet.

A key feature of the In Line Magnetic Separator is that there is no restriction to the product flow.  In this particular project, baby food passes through the body of the In Line Magnet and any ferrous or weakly magnetic materials are attracted by the strong magnetic field and then held against the face or the Plate Magnet.

The Plate Magnet has a tapered step, which intensifies the magnetic force and also provides an area to collect rogue metal contamination.

As the Baby Food has chucks of vegetables and meat, it was important that there was no restriction to the product flow where the food could be damaged or blockages could occur.  The Magnetic Liquid Filter, which uses Rare Earth Neodymium Tube Magnets, would not have been suitable for this application.

Bunting Magnetics In Line Magnet-9552Periodically, the captured metal is cleaned off the face of the Plate Magnet.  Access is designed to be simple and quick, with the Plate Magnet swinging away from the body on hinges.

All 42 In Line Magnetic Separators are designed for use in pneumatic pipelines up to 15 psi.  They are manufactured from Stainless Steel there are a range of standard sizes available.

For more information on the Pneumatic In-Line Magnet or any Magnetic Separator, please contact our team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

Reviews of typical food processing plant layouts with suggested locations for Magnetic Separators and Metal Detectors include:

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.

January

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.

February

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.

March

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.

April

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.

May

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.

June

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.

July

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.

August

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

September

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.

October

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.

November

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.

December

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 (press@buntingeurope.com).

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.

Bunting_Magnetics_Europe_Brewery_Plant

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:

Bunting_Magnetics_Europe_Brewery_Plant

 

 

 

The Challenges of Removing Fine Iron from Powders

Magnetic Separators Designed for Processing Powders

Removing metal contamination when the tramp metal and material is granular is far more straightforward than when in a powder form.  To determine the best solution to remove fine iron contamination from powders, it is necessary to have a good understanding of the way the fine materials behave.

Powders are produced and used in a wide variety of industries including food, pharmaceuticals, refractories, and chemicals.  It is estimated that 80% of materials used in industry are in a powdered form.

flour-791840_960_720A ‘powder’ is defined as fine dry particles produced by the grinding, crushing, or disintegration of a solid substance.  The nature of a powder means that the handling and processing tends to be problematic as powders exhibit similar properties to both solids and liquids.

Metal contamination, commonly in an iron form, can be introduced into a material at any stage within a process.  Tramp metal that is undetected and remains in the product before the powder production stage, becomes significantly reduced in size and, subsequently, increasingly difficult to extract.

Magnetically susceptible metal contamination (i.e. iron) is commonly removed using Magnetic Separation Equipment, which traps metal using Ceramic Ferrite or Rare Earth Neodymium Iron Boron (Neodymium) Magnets.  Although there are Magnetic Separators where the magnetic field is produced via an electrical current, the vast majority utilize permanent magnets such as Ceramic Ferrite and Rare Earth Neodymium Iron Boron (Neodymium).  Ceramic Ferrite Magnets produce low strength but deep magnetic fields, while Neodymium Magnets create the strongest permanent magnetic presently commercially available.

Where Does The Metal Originate?

Metal contamination commonly originates in a powder from two sources:

  1. Primary large tramp metal, such as a nail, screw or bolt;Tube Cartridge Magnets Bunting Magnetics-5
  2. Primary or Secondary fine tramp iron. Primary fine iron or magnetic particles are often present in the raw material.  This originates from primary processing, transportation, or even naturally occurs in the original material.  Secondary fine iron originates from a larger tramp metal source that has been reduced in size during the process.  Typically, this could be from a nail, screw or bolt that has been through a size reduction process, or from damaged or worn processing equipment.  Another common source of secondary fine iron contamination is rust, falling into the process from weathered and worn processing equipment such as chains, hoists, and building cladding.

The separation and detection of tramp metal is easier when the metal contamination is in a larger form and can be successfully removed using a wide range of suitable Magnetic Separators and Metal Detectors.  Magnetic Separators using standard strength Ceramic magnets, with deep magnetic fields, are ideal.  A good example is the Plate Magnet, often installed in a chute, in a housing, or as part of an In-Line Magnetic Separator.

Quicktron05A_Sodium Bicarbonate 2

Larger metal contamination is also easier to detect on a Metal Detector.  Metal is detected as it passes through the coil of the Metal Detector and an automatic reject system removes it from the flow.  For detection, the magnetic field generated by the Metal Detector has to see a state change.  Finer sized metal produces a lesser state change and thus increases the difficulty in detection.

In a project in Pakistan, a processor of fine Sodium Bicarbonate is using a Quicktron Metal Detector to remove the larger tramp metal.

Removing larger tramp metal with a Magnetic Separator and Metal Detector prior to the processing stage not only prevents the metal from being reduced in size (e.g. converted into a secondary source of fine iron contamination), but also protects delicate processing equipment such as granulators, shredders, and mills from being damaged by the metal.

Once in a powder form, there are processing parameters to consider when assessing the optimum method to remove fine iron contamination.

How Does a Powder Flow?

When a powder is sprinkled, it remains light and free.  However, when the same powder is vibrated or compressed, it may become very dense and even lose the ability to flow.

Individual grains in a powder cling to each other in clumps, in accordance with the Van der Waals force.  This coagulation often results in the fine iron being trapped in among clean product.  The ability of any Magnetic Separator to attract, hold and separate the fine iron is dependent on the iron being as close to the magnetic field as is physically possible.  If the fine iron contacts the surface of a Magnetic Separator with a high strength magnetic field, it will be held.  However, when the fine iron is held inside a coagulation of powder, then it could be held out of the reach of the maximum magnetic force.  Thus, it will not be separated.

The way a powder flows impacts on the design of the Magnetic Separator.  Powders flowing in a hopper may experience classic flow problems such as ratholing, bridging or flooding, all of which could be exacerbated by the design of Magnetic Separator.

Different Designs of Magnetic Separator

Plate Magnets Bunting Magnetics-9797High strength magnetic fields, as produced by Neodymium, are needed to capture fine iron metal contamination.  There are four main magnet configurations suitable for handling powders.

  1. Tube Magnets (also known as Rod Magnets and Cartridge Magnets), often in a multi-rod Grate configuration;
  2. Flat-faced Magnetic Plates;
  3. Cone-shaped Magnets;
  4. Magnetic Drums with a curved magnetic arc;

Although occasionally a Tube Magnet may be used on its own, it is more commonly part of a larger multi-cartridge Grate system.  The Magnetic Grate is designed to fit inside a hopper, or can be supplied complete with a housing (i.e. as a Drawer Filter Magnet).ff-neo-4

In operation, powder falls freely onto the surface of the Tube Magnet where fine iron strikes the surface and is held by the strong magnetic field.  To ensure that the powder makes contact with the Cartridge surface, deflectors are often deployed above the gaps between the Cartridges.

Powder build-up on the surface of a Magnetic Cartridge will reduce the separation efficiency.  Also, in severe cases, a slight build up on the surface of the Cartridge may quickly cause a blockage of the whole housing.

Such blockages can be prevented by ensuring that there is optimum space between the Magnetic Cartridges.  Also, in some cases, the mounting of an external vibrating motor on the side of the hopper or housing will provide enough disturbance to prevent any material coagulation.  The frequency of the vibration needs careful consideration as it could affect the flow ability of the powder.  Additionally, when vibrators are used, the Magnetic Cartridges need to be manufactured to withstand prolonged periods of vibration.

Bunting Teardrop Tube Magnet

‘Teardrop’ shaped Tube Magnets are specifically designed to stop the build-up of fine powder on the surface.  The sharp edge of the teardrop faces up into the product flow and allows material to flow around the edge and into the magnetic field.  Magnetic particles are captured and held underneath the Tube Magnet.

Flat-faced Magnetic Plates are ideal when it is possible for the material to flow over the surface.  For fine iron removal, the Magnetic Plates would use high strength Neodymium Magnets.  This magnetic field is further enhanced when a Tapered Step is added to the face of the magnet.  Captured iron migrates behind the step and away from the material flow, reducing the risk of re-entering the cleansed product.

As well as being fitted into chutes, Magnetic Plates are incorporated into housings.  The Plate Housing Magnets resist bridging and choking to remove tramp iron and ferrous fines from flow-resistant bulk materials.  The stainless steel housings mount easily to enclosed spouting or directly on processing equipment.

There are optional square, rectangular, and round adapters for easy connection to existing chute work.  A baffle at the top of the housing helps break up clumps and directs product flow over the unit’s two powerful Plate Magnets.

Bunting Magnetics In Line Magnet

Plate Magnets are also used in In-Line Magnets and there are two designs:

  1. Gravity In-Line Magnets (GIM) – The Plate Magnets are positioned in round, sloping spouting where material is under gravity flow.  For effective tramp metal capture, the spouting should be angled no more than 60° from horizontal;
  2. Pneumatic In-Line Magnets (PIM) – These designs are for use in dilute phase pneumatic conveying systems (up to 15psi). They can be installed easily with optional factory-supplied compression couplings and work best in horizontal runs with the plate magnet down to take advantage of material stratification;

Another design of In-Line Magnet is the Center-Flow, although the magnetic field is generated in a Cone configuration instead of a Plate.  The Magnetic Cone is positioned in the center of the housing, allowing the powder to flow in the space left between the housing.  Center-Flow In-Line Magnetic Separators are commonly used in dilute-phase pneumatic conveying lines up to 15psi.

To achieve optimum contact with the product flow, a conical magnet is suspended in the center-line of the housing.  This tapered, exposed-pole cartridge has a stainless steel “nose cone” to direct the flow of materials around the magnet.  The tapered poles of the cone magnet allow ferrous fines to collect out of the direct air stream.  Additionally, the trailing end of the magnet is an active magnetic pole and holds any tramp metal that is swept down the cone.

Both types of In-Line Magnet are designed with clamps and doors to enable easy access for cleaning.

drumIn specific applications, a high strength Neodymium Drum Magnet will enable the best level of separation.  The Drum Magnet is gravity-fed, usually via a Vibratory Feeder.  The Drum Magnet has a stationary high-strength magnetic arc positioned inside a rotating outer shell.  When material flows onto the drum magnet, the magnetic field projected by the stationary magnetic assembly inside the shell captures fine iron and holds it securely to the drum’s stainless steel surface.  With contaminants removed, the good product falls freely to a discharge point.  As the drum rotates, the captured fine iron travels along the drum surface and out of the magnetic field, where it is discharged.

There are various magnetic field configurations possible, but the most suitable for removing iron from powder is one that produces a Radial Magnetic Field.  This ensures that once captured, the fine iron does not leave the Drum surface until it moves out of the magnetic field.

Processing powder on a Drum Magnet presents more difficulties that other designs of Magnetic Separators.  Firstly, it is recommended that the Vibratory Feeder has an air bed to produce a consistent feed of powder.  Standard Vibratory Feeders may deliver powder in clumps, significantly affecting the separation performance.

Secondly, the shell of the Drum Magnet should be rotated at high speeds.  This will result in some of the powder pluming, and this can be minimized by keeping the distance between the end of the Vibratory Feeder Tray and the rotating surface of the Drum Magnet to a minimum.

The high rotation speed of the Drum Magnet significantly reduces the amount of product lost to the magnetics.  This is because there is less material on the surface of the Drum at any one time, reducing the chance of entrapment.

The use of Drum Magnets operating at high rotational speeds has been very successful in removing fine iron from abrasives, refractories, and other applications where the material has a high specific gravity.

Ensuring Powder is Metal-Free

As the demand for finer and purer powders increases, so does the need to remove even the finest iron.  Understanding the properties and behavior of the powder is vitally important when considering the optimum method of fine iron separation.  Often the ultimate solution is a series of Magnetic Separators and Metal Detectors located at strategic points within the process.

For further information on removing fine metal contamination from powders with Magnetic Separators and Metal Detectors please contact us on:

Cases of Metal Found In Food

A Food Safety Nightmare

To mark the start of the UK’s Food Safety Week (19th – 23rd June 2017), we are looking at recent cases where there has been an issue with food safety with specific reference to metal contamination.

Metal_Physical_Hazard

Metal contamination is commonly found in foods as they are being processed.  Metal can be introduced at a number of stages including:

  • Originating in the raw food product prior to arrival at the processing plant;
  • During transportation of the foodstuffs to the processing plant;
  • In the process from process machinery wear or failure;
  • Accidentally by workers or during maintenance;

In the vast majortity of food processing plants, there will be a series of Magnetic Separators and Metal Detector to remove and identify any metal contamination prior to the finished food product leaving the factory.

However, if the Magnetic Separator or Metal Detector is not operating to the optimum efficiency, or if there are no systems to remove metal installed, then metal end up in the food product being purchased by the consumer.

Recent Metal Found In Food Cases

These are some recent cases where metal has been found in food.

  1. In May 2017, William Santus & Co announced that Uncle Joe’s Liquorice & Aniseed Extra Strong Mints (35g tins) were recalled because there were fears that the sweets may contain small pieces of metal;
  2. UK supermarket Tesco faced a ‘metal-in-food’ safety warning in March 2017 when there were fears that the vegetarian product, Quorn Meat Free Mince (300g pack), was contaminated with small bits of metal;
  3. Lotus Bakeries UK Ltd recalled Lotus Biscoff Crunchy Biscuit Spread because the product may contain small pieces of metal.  This affected most of the supermarkets in the UK in March 2017;
  4. Metal Found In Morrisons Green BeansThe food company OK Food Inc (Oklahoma, USA) recalled more than 466 tons of breaded chicken because of possible metal in the food in March 2017;
  5. In the USA, Blue Buffalo dog food had to be recalled in March 2017 after a Lakeland woman reported that she had found metal.
  6. UK supermarket Morrisons was hit by a food safety scare in April 2017, when metal wire was found in green beans;

In all cases, the cost of recalling the product was significant, but for many it was not as high as the damage to the company’s reputation.

Other Food Safety reports relating to Metal-in-Food include:

For more information on preventing Metal Contamination Food Safety Scares, or to arrange a free onsite survey and audit of a particular plant or process, please contact the Bunting team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

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
Email: sales@buntingeurope.com
Web: http://www.buntingeurope.com

Other Food Plant Reviews include:

Metal Found In Rice

Magnetic Separator Ensuring Food Safety

There are a lot of negative Food Safety reports about metal being found in food (e.g. Morrisons’ Green Beans, Sainsbury’s Bread), but there is also a great deal of good practice.

Whilst undertaking an annual Magnetic Separation Survey at a rice processing factory, we were able to see the importance of installing metal separation equipment.

Fine Iron on Bunting Grate MagnetThe Food Processor had installed Bunting FF Drawer Grate Magnets at the base of hoppers holding Basmati rice prior to packing.  For maximum fine iron removal, the Grate Magnets were constructed with high strength Rare Earth Magnets with magnetic fields of approximately 11,200 Gauss on the surface.

A schedule had been established for the Grate Magnets to be cleaned on a weekly basis.  During the Survey, the amount of fine iron captured and held onto the surface of each of the Tube Magnets was found to be  substantial.  Subsequently, one of the recommendations was to increase the cleaning frequency.  This would then ensure that the Magnetic Separators were working optimally as performance can drop if the Magnets are laden with captured metal.

Where Does the Metal Come From?

Fine Iron on Bunting Grate MagnetThe majority of rice processed in the UK is imported from South-East Asia.  The process of collection, storage and transportation results in fine iron being introduced.  Additionally, very small amounts of fine iron may be introduced during the handling of the rice at the UK plant.  This could be from the wear of processing equipment.

Does the Amount of Metal Vary?

The UK food processor has very little control on the amount of metal present in the delivered rice and even working closely with the rice grower to improve Food Safety standards does not ensure a metal-free product.  As with all food imports, there are many stages of handling and storage where metal contamination occurs.  The amount of metal can vary significantly and, subsequently, the frequency of cleaning the Magnetic Separators will alter.

Good Food Safety Practice

As demonstrated at this rice processing plant, Magnetic Separators will separate magnetically susceptible metal (including work-hardened stainless steel) prior to any product reaching the consumer.  Annual reviews with the suppliers of the equipment will provide assurance of metal-separation performance.

For more information on good Food Safety practices and removing metal contamination, or to request a Magnetic Separation Audit, please contact the Bunting team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

Fine Iron on Bunting Grate Magnet
Fine iron captured by a Bunting Magnetics Europe Rare Earth FF Drawer Grate Magnet

28 In Line Magnets Remove Metal from Baby Food

Record Sales for In Line Magnets in 2016

A record 28 Pneumatic In-Line Magnets (PIMs) have been supplied to a major global Baby Food products company in Germany.  The Magnetic Separators are installed into food processing lines to attract and remove any magnetically susceptible materials.

Pneumatic_InLine_Magnet_Bunting_Europe-1608
2 PIMs ready for despatch to Germany

Metal is commonly found in food during processing.  The metal can originate from a breakdown of processing equipment (e.g. failure of a screen or pump), or even be delivered with the food raw materials.  The vast majority of food producers use Magnetic Separators and Metal Detectors to remove and detect any rogue metal before any food product leaves the production plant.

Pneumatic In-Line Magnets (PIMs) are specifically designed for installation into pneumatic conveying systems.  The 28 supplied for the Baby Food application are fitted with extremely powerful Neodymium Iron Boron Rare Earth Magnets.  These produce the highest magnetic field and capture even small shards of metal and work-hardened stainless steel.

The internal design of the PIM ensures that the product flow is not compromised.  The powerful flat-faced magnet with two tapered-steps is mounted on one side of the PIM and swings out from the body for easy cleaning.  To ensure there is no leakage during operation, the flat-faced magnet is held firmly into place by long-threaded bolts.

Bunting Magnetics In Line Magnet-10

The key design features of the PIM are:

  • Designed for unobstructed product flow;
  • Compression couplings speed in-line installation;
  • For dilute phase conveying up to 15 psi;
  • Best suited for horizontal installation;
  • Optional portable cart available for easy handling;
  • Powerful Rare Earth magnetic field covers entire cross-section of product flow;
  • High-energy Rare Earth tapered step plate magnets are standard;
  • Magnet swings out for easy cleaning;
  • All finishes available including food and sanitary;

Other articles discussing ‘Metal In Food’ include Green Beans Found Contaminated with Metal at Morrisons and Metal found in Sainsbury’s Bread.

For more information on the Pneumatic In-Line Magnet or any Magnetic Separator, please contact our team on:

Phone:  +44 (0) 1442 875081

Email:  sales@buntingeurope.com

Via the website

Bunting Magnetics In Line Magnet-25