What is the multi-pole magnet and single-sided magnet？

What is multi-pole magnet？

A multi-pole magnet is a magnetizing method of the magnet, it can be planar multi-pole or radiating multi-pole. However, the magnet still has only two poles which is the North pole and South pole, but the distribution is different. The strength of magnetism has nothing to do with the number of magnetizing poles, and the strength of magnetism is classified according to the national standard. Whether to use multi-pole magnets depends on the purpose.

What materials are generally used for multi-pole magnets？

According to different materials, multi-pole magnets can be divided into neodymium iron boron multi-pole magnets, ferrite multi-pole magnets, rubber magnetic multi-pole magnets, and samarium cobalt multi-pole magnets. The first three are more common.

Among the above-mentioned multi-pole magnet materials, the strongest magnetic force is the multi-pole magnet made of neodymium iron boron magnet material. Among the magnets, neodymium iron boron magnets are called "magnet kings" and have high remanence. Among the multi-pole magnetic rings, the magnetic force of the same specifications and magnetic poles is also the strongest. Mainly used in high-performance permanent magnet motors and sensors. In addition, according to different processes, NdFeB multi-pole magnets are divided into sintered NdFeB multi-pole magnets and bonded NdFeB multi-pole magnets.

The cost of rubber magnetic multipole magnets and ferrite multipole magnets is relatively low, but the magnetic force will be relatively weaker. 

The multi-pole magnet made of samarium-cobalt material is the most temperature-resistant multi-pole magnet. The maximum temperature of this material can reach 350 degrees, which is the best magnet currently used in high-temperature environments.

As for the number of poles of a multi-pole magnet, it also varies from customer to customer, and the maximum can be hundreds of magnetic poles.

With the development of home appliances and the information industry, permanent magnet synchronous motors and brushless DC motors have been widely used, and the application of multi-pole permanent magnets has become more and more extensive.

Currently， the most widely used products are magnetic grids, water pump motors, sweepers, loudspeakers, etc.

Why do some customers use single-sided magnet?

In fact, Monopole magnets do not exist. Because all shielding technologies cannot completely make one side of the magnetism refracted, all so-called "single-sided magnets" are only relatively strong single-sided magnets. Researchers of perpetual motion machines often ask magnet manufacturers whether there are monopole magnets. Someone tried to smash the magnet, and then got the south pole magnet and the north pole magnet. Maybe you will find that many products are named monopole magnets on online shopping platforms. The monopole magnet here refers to a magnet with magnetic on one side and weaker magnetic on the other side. The method is to wrap one side of the double-sided magnet with a specially treated iron sheet, so that the magnetism of the wrapped side will be shielded and the magnetic force will be refracted to the other side, The magnetism on the other side will be enhanced.

Application of single-sided magnets

It is widely used in the printing industry. There are single-sided magnets in gift packaging boxes, mobile phone packaging boxes, tobacco and alcohol packaging boxes, mobile phone packaging boxes, MP3 packaging boxes, moon cake packaging boxes and other products.

 It is widely used in the leather goods industry. There are single-sided magnets in leather goods such as suitcases, briefcases, travel bags, mobile phone cases, wallets and so on.

It is widely used in the stationery industry. There are single-sided magnets in notebooks, whiteboard buttons, folders, magnetic nameplates, etc.

The magnetic refraction of a single-sided magnet is like the refraction of the signal by a satellite pan or the refraction of light by a flashlight pan, and the effect is mainly determined by the following aspects:

Material: The choice of material and its thickness are closely related to the distance between the magnet and the material. Pure iron sheets are prone to magnetic leakage, and refraction will increase after special treatment. However, 100% of shielding materials have not been studied yet, but the effects of materials made by different manufacturers are different.

Angle: According to the principle of refraction, curved materials have the best effect, and right-angled materials have a greater refractive loss.

Space: The magnetic field lines are like mobile phone signals in the air, and they need space to be reflected. If the flashlight pot is completely wrapped on the bulb, the effect is not good, because a lot of light refraction is lost. How to use the above principles to maximize the effect of magnetic enhancement is a matter of finding the best among many parameters. This will greatly reduce production costs and save magnetic materials in the fields of packaging boxes and bags.

The pot-shaped magnet is a simple magnet assembly. Due to the special magnetic circuit design, the pot-shaped magnet can be given extremely strong pulling force. Some people think that one of the two poles is covered by a steel cap, also called a monopole magnet. NdFeB pot magnets are widely used in doors, car ceiling lights, cabinets and door stops, ceiling fixing, signs and banners, tight fittings, fixtures and fixtures, lighting, exhibition fixtures, industrial fixtures, etc.