Custom Magnets and Magnet Assemblies
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Custom Magnets and Magnet Assemblies

About BUNTING Bunting is an industry leader in the design, manufacture, With a team of engineers using world-class, computer-aided and sales of cutting-edge magnetic equipment used in design equipment, we can customize and develop products applications such as magnetic separation, metal detection, to fit any application or production line. conveyor systems, custom manufactured magnets, and more. All of the products we sell are custom-designed by our Bunting-DuBois has a unique role as it is the only North engineering team. We work with customers to determine American manufacturer of...

Bunting ® Magnetic Technology for All Industries Separation, Detection, and Conveying Equipment for the Recycling Industries The unique benefits of magnetic technology can be utilized across a wide range of applications, and Bunting is always looking to the future regarding new challenges that present themselves in the many industries we work with. Bunting engineers are constantly working to develop new technologies and improve upon our existing product lines. Bunting custom designs, manufactures, and distributes a broad selection of magnets and magnetic assemblies for automotive, medical,...

Permanent Magnets: Permanent magnets are essential to virtually every type of modern technology and convenience. Being able to provide the optimum magnetic solution to the customer requires in-depth knowledge of the full supply chain. Bunting's team of magnet experts and engineers is fully equipped with this knowledge. Bunting entered the magnetics industry in 1959 as a magnet distributor and rapidly grew to a manufacturer of magnetic products, focused on custom design and customer-focused engineering. Today, Bunting is a leader in manufacturing and designing a diverse range of innovative...

• High-temperature neodymium magnets can safely be used at operating temperatures up to 300° F (149° C). Special grades are also available that can operate in excess of 392°F (200°C). • Injection molded magnets are available in both neodymium and ferrite varieties. • Injection molded ferrite magnets offer high durability and resistance to shock, as well as a low cost and extreme resistance to corrosions and conditions such as low density. Plastic Bonded Neodymium Magnets These magnets are-cost effective while offering high performance and tolerances in addition to low electrical...

Design Considerations Basic problems of permanent magnet design revolve around estimating the distribution of magnetic flux in a magnetic circuit, which may include permanent magnets, air gaps, high permeability conduction elements, and electrical currents. Exact solutions o f magnetic fields require complex analysis o f many factors, although approximate solutions are possible based on certain simplifying assumptions. Obtaining an optimum magnet design often involves experience and tradeoffs. FINITE ELEMENT ANALYSIS: Magnetic Design has become a critical feature of Bunting's growth and we...

Design Considerations PERMANENT MAGNET STABILITY: Irreversible but recoverable losses: The ability of a permanent magnet to support an external magnetic field results from small magnetic domains “locked” into position by crystal anisotropy within the magnet material. Once established by initial magnetization, these positions are held until acted upon by forces exceeding those which lock the domains. The energy required to disturb the magnetic field produced by a magnet varies for each type of material. Permanent magnets can be produced with extremely high coercive forces (Hc) which will...

RELUCTANCE CHANGES: Reluctance changes occur when a magnet is subjected to permeance changes such as changes in air gap dimensions during operation. These changes will change the reluctance of the circuit, and may cause the magnet's operating point to fall below the knee of the curve, causing partial and/or irreversible losses. The extent of these losses depends on the material properties and the extent of the permeance change. Stabilization may be achieved by pre-exposure of the magnet to the expected reluctance changes. ADVERSE FIELDS: External magnetic fields in repulsion modes will...

Assembly Considerations Affixing magnets to housings: Magnets can be successfully affixed to housings using adhesives. Cyanoacrylate adhesives which are rated to temperatures up to 180 C with fast cure times avoid the need for fixtures to hold the magnets in place while the bond cures. Adhesives with higher temperature ratings are also available, but these require oven curing and fixturing of the magnets to hold them in a vacuum. Potential outgassing of the adhesives should be considered. Permanent magnet materials are composed of small regions or “domains” each of which exhibit a net...

In general, permanent magnets are supplied with a simple 2 pole magnetization pattern: a North pole on one face and a South pole on the opposite face. However, by appropriate configuration of the magnetizing coils it is possible to construct a fixture that will magnetize a magnet with many pole-pairs, and for some materials, pole patterns on a single surface of the magnet. This is called multi-pole magnetization. Magnetizing Patterns Radial Through Arc Segment Prototype Magnetizing Fixtures/Tooling: For development projects, prototype fixtures can be built quickly after design. These allow...

The software utilized by Bunting can take full account of the true magnet properties achieved during magnetization and predict the surface or air-gap flux density waveforms of multi-pole magnets with the actual magnetizing fixture that will be used in production. This technique is not restricted to isotropic magnets and can also be applied to permanent magnet assemblies. This is an invaluable capability when it comes to moving from development to production phases within a project. In addition, it allows us to design magnets with specialized flux density wave forms to meet specific customer...