Technical Blog

Custom Magnets

Our sister company Phoenix America Inc. manufactures magnets using injection molding. This process can be used to produce either a simple or a very complex shape, depending on customer requirements.

These magnets can be used in various industries for many different applications.

Custom Magnets Manufacturing Process

One of the most important developments in magnetic materials is polymer-bonded magnets. These can be molded directly into, on or against other assembly components using the injection molding process, eliminating the need for subsequent assembly steps. In some cases it is less expensive to make an entire part from the magnetic material and magnetize only the part that requires magnetic output.

Materials Used

Magnetic powders include ferrite and neodymium-iron-boron (NdFeB). There are different alloy compositions of ferrite and NdFeB that offer many different magnetic properties.

Phoenix America has developed magnets that use a combination of the powders to meet specific application and environmental needs. In addition, Phoenix America works continuously to improve the physical strength, the recommended maximum use temperature, the corrosion resistance of the rare earth magnetic materials, the dimensional stability in the presence of water and solvents, and the ease of processing.

Temperature characteristics Of Custom Magnets

The maximum temperature usage is an important factor to take into consideration when selecting a magnet for use. Different products have different temperature limits.

The maximum usage temperature depends on both the magnet alloy powder and the binder. For example, ferrite powders in nylon 6 or PPS have tested satisfactorily at 150 ° C and 180 ° C, respectively. Nylon 12 melts above 170 ° C and is not recommended for use above 150 ° C. Magnetic material like the NdFeB grade with the highest energy and an intrinsic coercive force of 9,500 Oersteds (760 kA / m) suffers a significant irreversible magnetic loss above 120 ° C, regardless of which binder is used.

The maximum usage temperatures are listed on the datasheet for each product.

Tolerances

An important feature of injection molded magnets is that they adapt dimensionally to the precisely machined mold cavity, which leads to tight tolerances in the finished product. The low dimensional variability results from the shrinkage of the polymer during cooling. This depends on the part thickness and shape. Typical tolerances are +/- 0.003 in / in. Tighter tolerances for critical dimensions can be worked out on request.

The multi-pole magnetized target wheels Phoenix America Inc. consist exclusively of a proprietary mix of magnetic materials and engineering thermoplastics. The result is a uniform magnetic target wheel that generates a very precise, homogeneous magnetic field and has very tight mechanical tolerances. This results in a very cost-effective product compared to the conventional wheels with a high number of components, in which individual magnetic rods are glued in.

Contact us about your specific custom magnet application. We can offer you a tailor-made solution.

Article published on: 04/01/2022