Plastic Bonded Magnets are manufactured by compounding magnetic ferrite or rare-earth powders with a thermoplastic binder. They can then be made by compression or injection molding and can be isotropic or anisotropic.
They have the advantages of precise dimensions, consistent magnetic properties, low manufacturing costs, and excellent surface quality.
Bonded magnet applications are primarily motors and sensors used in many of products such as computer and office equipment, consumer electronics (e.g., personal video recorders and mp3 music players), automotive and industrial applications (e.g., instrument panel motors, seat motors and air bag sensors) and home ventilation systems (e.g., ceiling fans).
Compression Molding
Compression molded magnets involves mixing magnetic powder (such as NdFeB, SmCo or AlNiCo) with a thermosetting epoxy resin binder, mechanically pressing that compound in a die, and then curing the epoxy in an oven. To improve the corrosion resistance of the product, these components are often finished with a surface treatment such as Epoxy resin/Parylene after the curing process.
Injection Molding
Injection molded magnets involves prepearing the feedstock which mainly consists of magnetic powder(such as Ferrite, NdFeB, or SmCo) with a variety of thermoplastic material (such as Nylon 6,Nylon 12,PPS and etc.), injecting the feedstock into mold cavity under high pressure. Once the part has cooled down, it will be ejected from the mold.