When structural designers choose to use permanent magnets as functional parts, they usually need to evaluate the assembly or disassembly of the permanent magnets with other parts , and ensure that the structure is stable and reliable. So what assembly methods are used when permanent magnets are used with other plastics, hardware, wood or glass?
Lock screw fixed permanent magnet
NdFeB alloy materials are brittle and fragile. When processed into magnets, threaded holes cannot be drilled. Generally, through holes or countersunk holes are drilled , and then bolts are used to fix the magnets on the hardware. This fixation method is commonly used in magnetic suction cups, fishing magnets, tool storage, etc.
Hot melt or injection molding to secure permanent magnets
In-mold injection molding is usually used to embed NdFeB magnets in plastic. The permanent magnet completed by in-mold injection molding has at least one effective surface exposed for adsorbing or sensing Hall components. This fixation method is commonly used in precision instruments such as automotive sensors , mechanical switches , electronic valves , small electromagnetic suction structures, and industrial pump valves .
Press-fit fixed permanent magnet
Usually, an interference fit is used to press small or simple-structured powerful NdFeB magnets into the inner holes of plastic parts. This kind of fixation is used in electronic cigarettes, POGO PINs of charging nodes and other places with small load-bearing capacity.
The permanent magnet fixed by dispensing glue
You can choose UV glue, anaerobic glue, AB glue, etc. to bond the NdFeB permanent magnets with other hardware. This method of fixing magnets is common in Halbach arrays and the assembly of various motor rotor magnets (gluing rare earth permanent magnets to silicon steel sheets or gluing rotor magnets to the motor casing)
Double-sided tape fixed magnet
Stick 3M double-sided tape on the back of the NdFeB powerful magnet. When using it, just tear off the strap and press the sticky side against the items to be adhered. There are many models of 3M adhesive, the commonly used ones are 437, 486, 4612 and so on. It is widely used in various fields such as gifts, household appliances, automobiles, mobile phones, packaging, toys, electronic instruments, and mechanical equipment.
Laser welding Fixed
the magnet during the welding process will cause demagnetization. Affect magnet performance. The welding temperature is as high as 600℃-700℃. During the welding process, the temperature will exceed the Curie temperature of the NdFeB powerful magnet, which may cause the magnet to lose its magnetic over a long period of time. Therefore, this fixing method is rarely used for magnet fixing.
