Bunting Magnetics Review of Southern Manufacturing 2017

Southern Manufacturing 2017 News and Views

The 2017 Southern Manufacturing & Electronics Show held at FIVE in Farnborough, UK (21st to 23rd March) proved to be a great place to showcase Magnets, Magnetic Assemblies, and Magnetic Separators.

The 2017 Show was of a similar size to 2016 with a good number of visitors.  One of the highlights of the Show was the wide range of 3D printers.  They included UV curing systems, double material heads, and fibre impregnated polymers.

On the Bunting stand, we found that people were looking for inspiration and one of the most common questions was ‘How can we use Magnets to fix a problem?’

“Being at the show gave us the opportunity to talk through potential applications with customers,” explained our Technical Sales Engineer, Matthew Swallow.  “One customer involved in mouldings was looking for high temp magnets that could operate above 300 degrees.  We talked to them about Samarium Cobalt (SmCo), which is specifically designed for use in high temperature applications up to 350 degrees.  We are now working with them on the project.”

“We also met a company who were searching for an alternative to a bonded radially magnetised magnet with the objective of giving their motorbike more power.  They were not aware that the new radial sintered Neodymium Magnets are over 4.5 times more powerful.”

Bunting Teardrop Tube MagnetThere was a great deal of interest in the recently launched Teardrop Tube Magnet.  The new Magnetic Separation is used in processing plants to capture fine magnetic contamination.  The ‘Tear’ design is ideal when processing fine powders that have a tendency to bridge.

“We simply would not have got some enquiries if we were not at the show,” said Matthew.  “On one project, we were generally speaking with an existing customer who then mentioned the need for a much stronger sintered Neodymium Magnet.  However, they were really concerned about the subsequent assembly difficulties and safety implications.  They were unaware that we build Magnetic Assemblies and we are now in the process of arranging for the customer to send us the metal work for us to assemble.”

As a showcase for UK manufacturing, the Show proved to be a great success.

For further information on Magnets, Magnetic Assemblies, or Magnetic Separators, please contact our Technical Sales Team on:


It Is Easy To Clean A Magnetic Separator

10th of 10 Magnetic Separation Myths

The Magnetic Separator has done its job and captured that potentially damaging item of ferrous metal.  Now it is time to remove the captured metal from the surface of the Magnetic Separator.  It should be easy, shouldn’t it?  However, due to the high magnetic power cleaning metal off a Magnetic Separator is becoming increasing difficult and a health and safety concern.

So, is it possible to make the cleaning process easier?

One of the most used Magnetic Separators is the Cartridge or Tube Magnet.  The diameter of the tube is commonly 1 “ or 25.4mm and the length can vary enormously.  They are used in a wide range of Magnetic Separator designs such as Drawer and Grate Magnets and can be supplied in a range of strengths for different applications such as:Bunting Cartridge Tube Magnetic Separators-6256

  • Ferrite – The lowest strength and good for general tramp iron such as nuts and bolts
  • Rare Earth – The strongest magnet and is ideal for fine ferrous contamination and abraded stainless steel;

As already mentioned, the most common problem for users of high strength, Rare Earth Tube Magnets is cleaning.  The magnetic field is so strong that removing captured metal from the surface of the Tube Magnet can be very difficult and a health and safety risk.  So how can the captured metal be removed?  Here are a few examples, some of which may be a little unorthodox:

  • Use a heavy cloth and push the captured metal along the tube surface to the non-magnetic end where it will then discharge. A heavy cloth is recommended as shards of metal may penetrate the cloth;
  • Use heavy duty gloves and a similar technique to the heavy duty cloth, although using PPE for such applications should be discussed with your Health and Safety Officer;
  • Use putty or a similar substance as the metal on the surface of the Tube Magnet becomes embedded in the putty. You may need to move the putty along the Tube surface from points of high to low magnetic intensity;
  • Fit a rubber sleeve over the Tube Magnet before installing into the process line.  Metal is captured on the outside of the rubber sleeve and when it is rolled off the Tube Magnet, the metal is removed at the same time;Bunting Cartridge Tube Magnetic Separators Putty & Gloves


Techniques that are not recommended are:

  • Using high pressure water. This may move metal around the surface of the Tube Magnet from the point where the water is striking the surface to the opposite side, but does not effectively clean the magnet;
  • Using high air pressure, where the same problem as with high pressure water occurs;
  • Using high pressure water and air also poses health and safety risks;
  • Rubbing metal off with an unprotected hand. This can result in injury with metal becoming embedded in the surface of the skin;

Cleaning the Cartridge or Tube Magnet is important as it ensures that optimum separation performance is maintained.  Any cleaning process will need discussion with your Health & Safety Officer and we provide free help and support.  For further details on cleaning or on the range of Magnetic Separators and Metal Detectors supplied by Bunting, please contact our technical sales team on:

Other Magnetic Myths reviewed in this series include:

  1. Should You Always Use the Strongest Magnet?
  2. All Rare Earth Magnets are not the Same;
  3. The Highest Gauss Magnet is not always the Best;
  4. Stainless Steel Isn’t Magnetic, or is it?;
  5. Do Magnets Lose Strength Over Time?
  6. Is a Magnetic Field Uniform Across the Surface of a Tube Magnet?
  7. We Guarantee 100% Metal Separation
  8. You Can Block a Magnetic Field
  9. Magnetic Separators are Not Dangerous?!!?

Ingesting Metal Fragments Can Cause Injury states the FDA

Solving the Problem of Metal Contamination in Food

In a 10 page document, the US Food and Drug Administration (FDA) declares that metal fragments in food may cause dental damage, lacerations of the mouth or throat, or laceration or perforation of the intestine.  They do not mention the untold damage to a company’s reputation and the subsequent financial damages.  Only last month (February 2017), PetSmart in the USA recalled dog food over a potential metal choking hazard.

It is nearly impossible to stop metal fragments entering a process line.  Processing equipment will wear, especially with metal-to-metal contact, and there will be equipment failures (e.g. valves, screens, conveyors, etc.).  Once that fact is accepted, then a solution to the problem of removing and detecting that metal before it reaches the consumer can be found.

Tube Cartridge Magnets Bunting Magnetics-7

Several methods of metal removal are employed of which Magnetic Separation and Metal Detection are the most common.  The effectiveness of this equipment is dependent on the nature of the product, the location of installation and the maintenance.  Well-planned and executed maintenance, especially with planned Magnetic Separator cleaning schedules, will ensure that metal separation levels are maintained for the long term.

Magnetic SeparatorsBunting Magnetics In Line Magnet-16

Magnetic Separation is commonly used to remove metal from liquids and free flowing solids or powders.  By positioning the Magnetic Separator in the process (i.e. inside a pipeline or chute), magnetically susceptible metal (such as ferrous metal and abraded or work hardened stainless steel) is attracted by the magnetic field and then held on the surface of the magnet.  There are many different designs of Magnetic Separator and strengths of magnet to suit different applications and locations.

Quicktron05A_Sodium Bicarbonate 2Metal Detectors

Metal Detection can also be used as part of a separator, whereby metal is detected and then rejected immediately.  This is often used in free fall locations, but can result in high losses of product.  More commonly, Metal Detection is installed at the end of the process either just before or/and after the product has been packaged and packed.

Guidance to Address Metal Contamination

The FDA document is very helpful and even outlines ways to determine if the potential metal contamination hazard is significant.  Continuous monitoring and verification form key parts of the metal contamination management plan.  Regular and planned checks on the Magnetic Separators and Metal Detectors are vitally important to ensure that the level of separation and detection performance is maintained over time.

The US Food and Drug Administration (FDA) give specific guidance on the issue of metal inclusion or contamination on their website. 

Typical Food Process Line

To assist food manufacturers assess the optimum ways to address metal contamination, we have produced a series of Flow Sheets.  These show typical locations for both Magnetic Separators and Metal Detectors.

For more information or a metal contamination site survey by our trained sales engineers, please contact our team on:

Phone:  01442 875081

Email:  sales@buntingeurope.com

Via the website

Magnetic Separators Are Not Dangerous!??

9th of 10 Magnetic Separation Myths

In school science, we learn about magnetism by playing with small permanent magnets.  It is fun, seeing how iron filings are affected by the magnetic field.  Our bodies are also constantly exposed to the Earth’s Magnetic Field.

So how can Magnets be dangerous?

In the 1980s, the concept of permanent magnetism changed with the development of the ‘Rare Earth Magnet‘.  The new permanent magnets produced a Magnetic Field and Force far higher than traditional Ferrite or Ceramic Magnets.

Since the 1980s, the magnetic strength of Rare Earth Magnets, like the Neodymium Iron Boron type, has increased.  Tube or Cartridge Magnets (as used in Magnetic Separators like Grate Magnets and Drawer Magnets) commonly use Rare Earth Magnets.  The high permanent magnetic force enables the attraction and capture of very fine or weakly magnetic materials.  This is vitally important when processing and producing plastics, foodstuffs or pharmaceuticals.

Bunting Magnetics Europe Ltd FFS Magnet-0095

But are they dangerous?

A strong Tube or Cartridge ‘Rare Earth’ Magnet has a surface magnetic reading of around 12,000 gauss.  The ‘Ferrite’ type has a surface field of 1,500 gauss.  In terms of magnetic force, the difference is enormous.

However, the real test comes when using a spring balance to pull a small steel ball bearing off the surface of the Tube Magnet.  When the steel ball is pulled off the Ferrite Tube Magnet, the force needed is negligible.  On testing the Rare Earth Tube Magnet, over 2kg of force is required.

Now we know that magnets attract.  So if two Rare Earth Tube Magnets are placed near each other, they will naturally want to go together.  The speed of the two items moving towards each other increases until they meet and the resultant collision is substantial.  If a hand or finger is in between the two Tube Magnets, the force of the attraction could result in serious injury.  People have been known to break or badly bruise fingers just by having them caught between two attracting Rare Earth Magnets.

So, the answer is a loud yes.  Magnets can be dangerous.  Luckily, advice and guidance is provided when advising users about Magnetic Separators.  And many Magnetic Separator designs include excellent safety features.

For further information on Rare Earth Magnets, Magnetic Separators, and Safety Advice, please contact us on:

Phone: +44 (0) 1442 875081
Email: sales@buntingeurope.com
Via the website

Other Magnetic Myths reviewed in this series include:

  1. Should You Always Use the Strongest Magnet?
  2. All Rare Earth Magnets are not the Same;
  3. The Highest Gauss Magnet is not always the Best;
  4. Stainless Steel Isn’t Magnetic, or is it?;
  5. Do Magnets Lose Strength Over Time?
  6. Is a Magnetic Field Uniform Across the Surface of a Tube Magnet?
  7. We Guarantee 100% Metal Separation
  8. You Can Block a Magnetic Field

Testing a Magnetic Separator with a Spring Balance

A Practical Method of Checking Magnet Power

Regularly checking that a Magnetic Separator has not lost any magnetic strength is good practice and is a key part of many companies’ annual equipment checks, but how easily can it be done?

A Magnetic Field can be measured by using a gauss meter, but due to the design of Magnetic Separators and the variable shapes of the fields, taking accurate and meaningful measures can be extremely difficult.  Training and regular use is needed to use a Gauss Meter correctly and get meaningful measurements.

magnetic-pull-test-kit-bunting-magneticsThe best meaningful method of measuring and recording the strength of a Magnetic Separator is relatively simple.  Magnetic strength can be measured by testing the force required to remove a steel object from the magnet surface.  The technique has been used by Bunting Magnetics for many years and provides information that is easily understood and recordable.  The force (in kgs) required to detach a specified steel object from the Magnetic Separator can be recorded and then checked as frequently as required.  Unlike measurements of gauss, no interpretation of the data is needed as it is a simple physical test.

The Bunting Magnetic Test kit includes a Spring Balance, 3 sizes of steel ball, a steel plate and a non-magnetic spacer plate.  When conducting a test, the steel ball or plate is attached to the hook on the end of the Spring Balance and then placed on the surface of the Magnetic Separator.  Simple physics takes over as the steel is attracted to the strongest magnetic point or points (i.e. the magnetic poles).  Force is then applied to the other end of the Spring Balance to remove the steel from the surface of the Magnetic Separator, with the amount of kg force being applied being measured by the Spring Balance.  When enough force is applied, the steel becomes detached from the magnetic field, with the amount of force being recorded on the side of the Spring Balance.  This test is repeated 3 times and an average fo
rce reading (in kgs) is calculated to give the recorded reading.

Where the Magnetic Separator has several high points of magnetic force (i.e. magnetic poles), tests at recorded points are taken to check the uniformity of the field.


For many companies, Bunting conduct the tests on a regular annual or twice-yearly basis, providing an independent analysis of their Magnetic Separators.  The tests are not limited to Bunting equipment and are summarised in a report that is kept for reference, often as part of the quality or health & safety management system.  It provides companies with the knowledge that the Magnetic Separators installed are operating to the best of their ability, protecting product quality, delicate processing equipment, and the company’s reputation.

This simple and yet effective method of testing the strength of a Magnetic Separator is used by companies in a wide range of industries including food production, pharmaceuticals, plastics and recycling.  The technique can also be used when assessing different suppliers of Magnetic Separators by asking for the Magnetic Detachment Force to be stated along with the Gauss figure.  As Gauss is often difficult to quantify (how does a customer check if a Tube Magnet actually has 12,000 gauss on the surface?), asking for a physical figure that can be easily checked when the Magnetic Separator is delivered ensures that what has been supplied meets the same specification as that quoted and ordered.

Further information on the Bunting Magnetic Test Kit and the Spring Balance test can be found on our website as are details of a Free Magnetic Separation Audit.  You can also contact us on: