Injected Magnets
Injected magnets are made out of magnetic ferrite powder or rare earth which are incorporated in thermo-plastics. The mechanic and magnetic values change according to the materials used. These materials used in injected magnets are usually polyamides (PA6-PA11-PA12). They allow to reach maximal temperatures, 100ºC for PA12, and about 120ºC for PA6. For working temperatures at 200ºC, polyphenol is used, which makes for a high resistance extent whith high temperatures. For magnets injected in rare earth, epoxy resins are used; they can work until 120ºC. These type of magnets have a stronger resistance against corrosion than sintered materials, therefore, they can be used in most of the applications without special coatings.Things We Should Know
One of the main advantages of plastic magnets is the moulding variety that the injecting process offers. This is why the coating with plastics, shafts, sockets, pivots, dented wheels and other functional elements can be carried out. The combination of shafts, bearing sockets and traction shafts with extrusion coating in a working cycle are usually done. It is also possible to do a pressing of the back shaft thanks to the tolerance of the injection and the elasticity.Injected Ferrite Magnets
They offer a great resistance against mechanic impacts and they are less fragile than sintered ferrite magnets; thanks to their great density, their magnetic characteristics are slightly lower than those of sintered ferrite. This type of material does not have a predefined magnetising (axial, radial, multipolar). The specific energy is higher when the particles are oriented during the injection process.
Rare Eart Magnets (Neodymium-samarium)
Magnetising can be carried out after the injection process (isotropics) or magnets can be oriented and magnetised during the injection process (anisotropic),
The great coercitivity of these type of magnets enables the moulding of many different shapes. It is also important to have in mind that the isotropic magnets can be magnetised in any direction (axial, radial, multipolar).