Accidents often occur, especially when removing and s […]
Accidents often occur, especially when removing and storing large magnets. In many cases, plastic partitions are used to store magnets, but even so, the magnets will fly up and stick to each other, usually carrying some skin.
In order to manage, pack and store large magnets, appropriate methods must be used, especially certain safety aspects must be considered.
In fact, some receiving or storage departments of some factories are not familiar with the strength of permanent magnets, which may cause personal injury or damage to parts. All persons who may come into contact with this alloy should be aware of the dangers of handling these magnets. If the magnets are allowed to collide with each other or on a solid surface, the brittleness of the alloy will cause flying debris.
In this sense, if the necessary precautions are not taken, storing large magnets may become a great danger.
What are the safe storage methods for large magnets?
The main way to store large magnets is to use wooden boxes. Many times, these products must be transported or packaged just for safety, but this protection must be provided because it is considered a dangerous product (because of its size) because the field density emitted from the side of the package exceeds the specified value.
Therefore, for the storage of large magnets, as well as their use and cleaning, they must be mainly protected from the influence of three factors, which are conducive to waste banknotes and even destruction. These aspects are:
Mechanical protection. They should not be hit, so it is convenient to put the "closed magnetic circuit" connecting them with the iron sheet in a box with a padded inner surface. Even if the blow is not strong enough to break them, they can very effectively reduce the magnetization of the magnet. This is most noticeable when the magnet is at a higher temperature (for example, in certain industries where the magnet is cleaned by steam jet).
Chemical protection. The magnet must not come into contact with corrosive or humid environments. Therefore, it is convenient to put them in a sealed box, which contains desiccant (such as silica gel) particles. Rare earth permanent magnets such as samarium and neodymium magnets (such as SmCo5, Sm2Co17 or Nd2Fe14B) are easily oxidized only when they are in contact with oxygen in the air. Therefore, in general, the surface is plated with nickel.
Thermal Protection. Magnets should be stored and used at the lowest possible temperature, as this will accelerate their demagnetization. Therefore, for a given application, a magnet should be selected whose material has a critical temperature Tc approximately 3 times the operating temperature. For example, from a temperature perspective, the magnet with the best magnetism is the worst. In fact, Nd2Fe14B has a Tc = 310 degrees Celsius, so it is not recommended to place it at a temperature much higher than 100 degrees Celsius.
On the other hand, special attention must be paid to metal shelves with small spacing, as they can cause the magnets to jump or move when they are in contact. Therefore, the recommended safe distance should be maintained between the device and the magnet, and large magnets should not be stored near devices with cathode ray tubes (CRT) or magnetic storage media. Due to the demagnetization effect, magnets of different alloys may need to buffer each other.
In short, in order to eliminate accumulated waste, magnets should be stored in a closed, clean container. The magnet must remain attracted and all the spacers are intact.
why is that? I have no idea. Because this attracts air and iron particles on the surrounding surface. These particles will accumulate and appear as tiny "hairs" on the surface of the magnet or packaging.