In the design of modern micro-motors and small actuators, magnets must not only deliver a stable magnetic field but also accommodate compact spatial constraints and complex assembly requirements. As a composite functional material, injection-molded magnets have become a viable option in specific application scenarios due to their relatively high design freedom and good dimensional accuracy.

      Injection-molded magnets are typically produced by blending magnetic powder with thermoplastic engineering resins, followed by injection molding. Based on the type of magnetic powder used, they are primarily categorized into neodymium-iron-boron (NdFeB)-based and ferrite-based types. According to the binder system, common variants include PPS (polyphenylene sulfide) and PA (polyamide). The PPS system generally offers better thermal resistance, while the PA system exhibits favorable toughness and flow characteristics during processing. This material combination allows the final product to possess both magnetic functionality and mechanical properties typical of engineering plastics—such as moderate impact resistance, dimensional stability, and corrosion resistance.

      Compared to traditional sintered magnets, a notable feature of injection-molded magnets is their near-net-shape forming capability. Complex geometries—such as multi-pole rings or asymmetric rotors—can be molded in a single step, eliminating or reducing the need for secondary machining or adhesive bonding. This helps minimize assembly errors and improves batch-to-batch consistency. Additionally, since the magnetic particles are fully encapsulated within the polymer matrix, these magnets demonstrate better long-term stability in humid or mildly corrosive environments than exposed metallic magnets.

      It should be noted that the magnetic energy product of injection-molded magnets is generally lower than that of sintered counterparts of the same material system. Therefore, their applications are mostly concentrated in medium-to-low power scenarios where high integration density and operational smoothness are prioritized—such as in micro-motors for household appliances or drive units in office equipment. Material selection should take into account factors including operating temperature, rotational speed, spatial limitations, and cost to ensure appropriate system matching.

      Ningbo Buer Magnetic & Electric Technology Co., Ltd., established in 2018, engages in the R&D and manufacturing of various types of magnets, including injection-molded magnets. The company’s core team has over twenty years of experience in the magnetic materials field and possesses a solid understanding of material systems, processing methods, and application contexts, enabling them to provide customers with selection guidance based on actual operating conditions.