It's not something we usually think about, but it's true that sometimes we need to cut or puncture a magnet. It is not advisable to drill or saw magnets, but if we must cut or pierce them, we must do it the right way so that they do not lose magnetism.
Ferrite and Neodymium magnets are hard materials, but at the same time, they are very brittle, so we do not recommend working on them with common tools such as the drill, as it can overheat and general a large amount of dust that is very inflammable, as well as that usually demagnetizes the magnets. For this reason Neodymium magnets and Ferrite magnets are worked, cut or perforated, before they are magnetized. If we have to pierce or cut the Neodymium and Ferrite magnets we must use suitable diamond tools, as well as having a system that allows us to cool with water from time to time.
Actually, even if we don't believe it, there are many reasons why we may need to cut a magnet. For example, it occurs to us that you need to replace it or one that doesn't work for a project. If in this case you only have a large magnet and you need to decrease its size there are several ways to do it.
But we warn you that the way you select from the ones we propose must depend on the type of magnet you are trying to pierce or cut. Some magnets are more flexible than others. In any case, regardless of the type of magnet, we want to make some recommendations that you must take into account.
Use work gloves, as handling a magnet, even a magnet is dangerous as splinters can be generated. Work gloves will also protect you from the tools you are going to use.
You must mark the route on the magnet you are going to follow whenever you want to make a cut.
We recommend cutting the magnet with a metal shear, following the guide mark.
Wear a nose and mouth mask, gloves and goggles. Not only is there a danger of cuts with the blade in your hands, but piercing these magnets will produce dust in the air that is harmful if inhaled and can easily reach the eyes. For any cut you should always wear protection.
Place the magnet on a vise, which will make it easier for you to use a metal saw. This method prevents the magnet from moving, which favours the conservation of its magnetic properties. The excessive vibrations favor the evasion of the magnetic electrons of the magnet, diminishing or losing the magnetic properties. By controlling this you avoid losing the magnetization.
You can also cut the magnet with a saw, following the route you have traced to help you.
You can also place your diamond-plated lathe on your dremel. Once in place, press it into place. Then start the device. As the lathe rotates, place it over the mark you made on the magnet, pressing as you do so. Take care not to put excessive pressure on the dremel or you can bend the lathe. - You can also use a chisel on the mark to orientate yourself on the magnet. Holding it with one hand and using a hammer you can hit the handle. This can break the magnet in two if the cut fails. But remember that this will be your last option, as it has the greatest chance of damaging the magnetic properties of the magnet, as indicated above. You can reduce them or lose them in the cutting or punching process.
If the material of the 19th century was steel, there is no doubt that the material of the 20th and 21st centuries is plastic. This material has many properties and is one of the most moldable that exist; allowing its use in applications of the most diverse from plastic film papers to much thicker and more resistant materials such as polymers. Plastics, whose manufacture involves magnets, occupy a very important place in the global production system and play a fundamental role in the economy.
In order to make plastic, it is necessary to process the oil that is extracted in wells and then refined in a specific way to create plastic. Depending on the type of plastic that is created, the process of refining and manufacturing will be totally different. Thus, this petroleum derivative is produced in high-tech centres where the manufacturing process can vary from one plastic to another. In general, both moulds and magnets are used to achieve, throughout the production chain, a high quality product with the precise characteristics for its intended use.
Throughout the production process of plastic materials we can observe the presence of calenders, as well as cutting shredders. This type of machines, indispensable for the manufacture of plastic, are protected along the production chain by various sets of magnets that are in charge of their defense. Thus, injection moulding machinery, extruders, granulators or mills can carry out their work in complete safety and without the risk of any type of interruption due to misuse.
On the other hand, during the plastic production process, magnets play a fundamental role - just as in the mass production processes of other materials and components - as a tool for effectively fixing, handling and transporting moulds.
In addition to separating moulds, magnetic separation magnets have other applications.
As a mechanism to separate the parts of molds that may have broken and thus free of damage to the entire production, cleaning the assembly line and manufacture of this type of impurities.
To eliminate metallic contaminants or adhered metallic particles that could be present in the feeding belt.
All this cleaning function is obtained thanks to the installation of specific magnets throughout the entire process or production chain. Thus, in a manufacturing plant, treatment or modification of plastic we can see that there are magnets of various models such as magnetic grills, magnetic filters or magnetic separators, also present in manufacturing plants of other types of products such as food products.
It should be noted that if magnets are not present throughout the production process, the plastic produced in this type of centres and manufacturing plants could have impurities that could harm its use or make it impossible, as well as, on the other hand, could damage the manufacturing mechanisms and devices with the presence of impurities or unwanted magnetic elements that could compromise the safety and integrity of the components of the assembly line, preventing the adequate and sustainable production of the plastic.
We call injected magnets those that have been manufactured through ferrite magnetic powders and also rare earths that have previously been incorporated into what we call thermoplastics, among which we highlight, above all, polyamides. They are a type of magnet much more resistant to any type of corrosion than those synthesized materials. We should not overlook the fact that maximum temperatures between 100 and 120 degrees Celsius are achieved.
Magnets can be injected or manufactured in special plastic polymers with particles that we have incorporated of ferrite or neodymium. Doing so will allow us to use all the usual possibilities of models for plastics to make designs with shapes and also with a special type of magnetization. Everything made from the needs of the client.
It is because of the different, unique possibilities offered by this technology that we cannot speak of standard sizes, and it is also what allows us to customize the magnet as much as possible according to customer requests and the specific needs of the application that is going to be given to it.
In the injection moulding process, a type of solid binder is used, such as plastic, to which the magnetic type material is attached, providing us with a large number of shapes. The resulting material is isotropic.
Among the main advantages that we can find in magnets that have been moulded by injection we can highlight the following: possibility of making more complex shapes and structures; they are magnets that have low conductivity and also low eddy currents; they are magnets with good tolerance and are more resistant to jumping to compression in situations of servitude; and they allow hybrid versions with combined properties; versions of NdFeb, SmCo, alloy steel and ferrite and also Overmold, mould insert.
Among the main disadvantages of an injection molded magnet are the following. The main disadvantage is that these magnets will have a lower magnetic performance than those that have been made by compression in bonded conditions. This happens because the magnetic load is lower.
At present we find injection moulded magnets in many everyday uses of which we are often not aware. From motors, to sensors, magnetic components, etc.
We would like to highlight the injected Neodymium magnets, as they are currently the most used and requested by customers. These, in addition, are produced using the design and special needs of the customer, so they have an exclusive use.
We must remember that it is currently possible, through the process of stamping, both injection and compression, the mixture of plastic materials with powders with a greater or lesser load of Praseodymium-Neodymium. For this reason, it is possible to create, at the customer's request, a type of mixture with very personalised characteristics according to the required indications, both with very small tolerances and quite the opposite.
These types of magnets have magnificent mechanical properties that will make it possible to reach precise and adjusted tolerances for each need, which makes it possible to achieve a perfect balance and, furthermore, they allow for complicated geometries that adapt perfectly, as the peculiarities and needs of the customers have been taken into account for the realisation of this. At IMA we manufacture plastic magnets for many companies in different fields, such as manufacturers of electric motors, household appliances or automobiles. Maximum temperatures of between 100ºC and 120ºC are obtained and allow us to solve the specific needs of each client.
Permanent magnets are those that can provide a magnetic flux without the need for electricity, as is the case with electromagnets.
They are made from ferromagnetic materials, which, after being magnetized, retain these magnetic properties for an indeterminate time, that is, until they are demagnetized.
From the material with which they are made we can define the types of permanent magnets:
Neodymium Magnets
Ferrite Magnets
Samarium Magnets
Alnico Magnets
At IMA we explain your features and applications in this infographic.
If you have any questions or need to know which is the best magnet for your needs, contact us.
Magnets are used in many different fields, such as manufacturing, in the automotive industry, in security systems and electronic devices, in everyday life and even planet Earth itself is a gigantic magnet, but how does heat affect magnets? It is an answer that we will get in this article.
To understand how heat affects magnets, it is necessary to look at the atomic structure of the elements that make up the magnet. Temperature affects magnetism by either strengthening or weakening the attractive strength of a magnet. A magnet subjected to heat experiences a reduction in its magnetic field as the particles inside the magnet move at an increasingly faster and more sporadic speed.
Heat affects the magnets because it confuses and misaligns the magnetic domains, causing magnetism to decrease. On the contrary, when the same magnet is exposed to low temperatures, its magnetic property improves and strength increases.
In addition to the resistance of the magnet, the ease with which it can be demagnetized also varies with temperature. Like the strength of the magnet, heat affects the magnets in terms of resistance to demagnetization, which generally decreases with increasing temperature. The only exception are ceramic (ferrite) magnets, which are easier to demagnetize at low temperature and more difficult to demagnetize at high temperature.
Different magnetic materials react differently with temperature. Alnico magnets have the best resistance stability, followed by SmCo, NdFeB and then ceramic. NdFeB magnets have the highest resistance to demagnetization (coercitivity), but experience the greatest change with temperature. Alnico magnets have the lowest resistance to demagnetization, but the smallest change achieved with temperature. Alnico has the highest operating temperature followed by SmCo, ceramic and then NdFeB.
But not everyone is aware of how a magnet affects its maximum usable temperature. This is especially important for NdFeB magnets, because they have the greatest change in resistance to demagnetization with temperature. As the length of the magnetized shaft increases, so does its resistance to demagnetization.
It's a fact that heat affects magnets, a fact that makes them permeable. For example, the effect of temperature on neodymium magnets is one of the most interesting phenomena to observe and evaluate. Indeed, there is an experiment with magnets, which specifically explores how they react when exposed to extreme heat.
In principle, it is an experiment not suitable for children and, in addition, it must be carried out with the maximum safety measures and it will bring us as a result how heat affects the magnets. For this, we will need the following elements:
A 100°C thermometer
Plastic tweezers
2 bars of neodymium magnets
Safety glasses and gloves
Water
Stove
Bread
Plastic container
100 clips
Heat affects the magnets in two simple steps. The first of them is a test of ambient temperature and for it the paper clips must be poured in a plastic container, to then submerge one of the magnets of bar of neodymium in the container of clips and to remove it, registering the collected number. The paper clips are then removed from the magnet and set aside.
When doing so with hot water, gloves and goggles should be worn. Heat about one-third of the cup of water in a small saucepan until it reaches 85°C or 100°C. At boiling point, the water should be near or within this temperature range and the thermometer is used to verify that the grade is appropriate.
Using the plastic clips, gently place the neodymium magnet in the water and leave it there for about 15 minutes. The magnet is then removed with the plastic clips and placed in the container with clips. Once there, you will see how many clips are collected.
The result will be obvious. The heated magnet will not lift the clips or, in any case, it will lift very few, depending on the temperature and the moment at which it was heated, which makes it evident that the heat directly affects the magnets.
It is possible to re-magnetize a magnet that has lost its magnetic properties, but as long as the alignment of its internal particles has not been modified for any reason, such as, for example, the exposure of these elements to high temperatures.
It is a reality that, with the passage of time, a magnet can be magnetized again, above all because these elements can forget, in some way, the properties that allow them to function optimally.
In fact, it is possible to re-magnetize a magnet with one whose force is greater, such as the powerful neodymium magnets, which are made of neodymium, iron and boron; also with a rare earth magnet or with the sum of several old magnets, however, the polarity (south and north) must first be determined and the correct pole magnetized.
Finding a magnet to remagnetize another is not too complicated task. In fact, you can simply locate an old discarded computer somewhere with an old 400MB hard drive or some other relatively small capacity drive that is no longer in use. When you open it, there will be a powerful magnet inside.
Now, for the first step before continuing the remagnetization, the first thing to do is to remove any protector the magnet may have. Then, find the poles of the magnet in good condition with the help of a compass.
Which one should be magnetized? That side to which the needle points, which will be the south pole (since opposites attract) and, in that way, you can magnetize the old north with the new south pole of the magnet that, contrary to popular belief, these two poles are normally found on the long and flat sides of the magnet, not on both.
A magnet can be re-magnetized by rubbing a neodymium pole, for example, against the opposite pole of the old magnet, thus repeating with the other side and achieving the desired effect. Evidently, the parts that are attracted are those that can be recharged among themselves and this would allow us to magnetize them again and thus use them, without the need to discard them.
A magnet can be re-magnetised, too, if it has been hit or stored incorrectly, which makes them lose their attraction capacity. Even a magnet in its best condition can be demagnetized during its useful life. An example of this is a cobalt samarium magnet that has been shown to naturally lose 1% of its magnetic capabilities over a period of 10 years.
After this process, any magnet that has lost its magnetic properties can become fully functional again.
In a previous publication, we learned how to magnetize a magnet, because, in general, these elements are not magnetic from their early stages of production, so that they have the properties they need and, maintain them over time, a fundamental action is to store it correctly to maintain the magnetism for much longer.
After re-magnetizing a magnet, it must be stored in such a way that its poles alternate, that is, the north pole of one magnet against the south pole of the next. Magnets naturally attract each other in this orientation, and storing them in this way helps preserve their magnetic strength.
On the contrary, by storing them in a random jumble or with similar poles against each other (facing north to north), the magnets will deteriorate relatively quickly and, again, it will be necessary to repeat the process to re-magnetize a magnet early.
A magnet that has lost its magnetic properties can be re-magnetized if the alignment of its internal particles has not been modified.
Electromagnets were created with the aim of testing, measuring and recreating electromagnetic fields, as electromagnetism is one of the fundamental forces of the universe, responsible for everything from electric and magnetic fields to light.
Electromagnets are devices that use electric current to induce a magnetic field. And, since their initial invention as a scientific instrument, electromagnets have become a common feature of electronic devices and industrial processes.
Electromagnets are distinguished from permanent magnets because they only show a magnetic attraction to other metallic objects when a current passes through them. This has numerous advantages, as the power of their magnetic attraction can be controlled, and turned on and off at will. It is for this reason that they are widely used in research and industry, wherever magnetic interactions are required.
There are three basic types of electromagnets: the robust ones, the superconductors and finally the hybrids.
Resistant: A resistive magnet produces a magnetic field with copper wires, this executes electricity through the wire and electrons produce a weak magnetic field. In this sense, if a wire is twisted around a piece of metal such as iron, it helps to concentrate that magnetic field around the plate, so the more the wire twists, the stronger the field.
Superconductors: Superconducting electromagnets operate by reducing electrical resistance: when a current passes through a copper plate, atoms in the copper interfere with electrons in the current. Therefore, superconducting magnets use liquid nitrogen or liquid helium to produce very cold temperatures. The cold keeps the copper atoms out of the way, and these electromagnets keep working, even when the power is disconnected.
Hybrid: Hybrid electromagnets combine resistive electromagnets with superconductors. The design of hybrid electromagnets varies, but, for example, at the University of Florida there is one that weighs 35 tons, represents more than 20 feet in height, and contains enough copper wire for an average of 80 homes. Deionized water, or water without an electrical charge, keeps this hybrid magnet running along more than 200 degrees C below freezing point.
Uses of electromagnets in industry
Today there are countless applications for electromagnets, ranging from large-scale industrial machinery to small-scale electronic components.
Due to their ability to generate very powerful magnetic fields, low resistance and high efficiency, superconducting electromagnets are often found in scientific and medical equipment. These include magnetic resonance imaging (MRI) machines in hospitals and scientific instruments such as nuclear magnetic resonance (NMR) spectrometers, mass spectrometers and also particle accelerators.
Electromagnets are also widely used when it comes to musical equipment. These include loudspeakers, headphones, electric bells, and magnetic recording and data storage equipment, such as tape recorders. The multimedia and entertainment industry relies on electromagnets to create devices and components, such as VCRs and hard drives.
Electric actuators, which are motors responsible for converting electrical energy into a mechanical torque, also rely on electromagnets. Electromagnetic induction is also the medium through which power transformers operate, which are responsible for increasing or decreasing alternating current voltages along power lines.
Induction heating, which is used for cooking, manufacturing, and medical treatment, is also based on electromagnets, which convert electrical current into thermal energy. Electromagnets are also used for industrial applications, such as magnetic elevators that use magnetic attraction to lift heavy objects or magnetic separators that are responsible for classifying ferromagnetic metals from scrap.
They are also used in the application of Maglev type trains. In addition to using electromagnetic force to allow a train to levitate over a track, superconducting electromagnets are also responsible for accelerating trains at high speeds.
In short, the uses of electromagnets are virtually unlimited, driving everything from consumer devices and heavy equipment to mass transit. Electromagnets have become a common feature of electronic devices and in-line processes.
Magnets have a multitude of uses, from the most important to the most banal; from the most industrial to the most personal. Magnets are present in our lives in the form of parts of a motor, mechanisms of a personal computer or as part of the assembly line that has built our car or assembled the parts of our wardrobe.
Of all these uses, one of the most prominent of the magnets for their familiarity, are the personalized magnets. This way of adapting the magnets to everyday life is one of the best known by all. Who has not made tourism and has taken as a souvenir a fridge magnet with an image of Paris, London or New York? However, there are many more occasions when it is possible to have personalized magnets in addition to the typical souvenir stall.
In fact, the adaptability of the magnet is very great. A fridge or magnetic mural magnet - a much cleaner alternative to cork panels - is a most useful element in our professional and personal lives and can have many more uses than the mere tourist purpose. Therefore, in this article we propose to make you discover all the ways to adapt a magnet to different sectors or products through personalization or customization.
In the 19th century, the great economic transformation was the arrival of steam and, with it, of railways and chain production machines. The last decades of the 20th century and the first two decades of the 21st century have brought us a boom in robotic systems that have transformed the way we do things and have placed magnets at the centre of all new production processes.
Things as simple as transporting a package and organizing it in a warehouse; an appendicitis operation or driving an automatic car are many of the robotic processes that are becoming fashionable and increasingly popular in those involving magnets. These robotic processes now touch virtually every sector of the market (from food production to automotive) and seem to have come to stay.
In this article, we wanted to analyze some of the many robotic systems in which one or more magnets of different characteristics and power intervene. Of course, the list is not exhaustive because the variety of robotic systems in which magnets are used are innumerable. Here we present some of the most relevant ones.
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