To clarify what hysteresis is, we must first look at the term itself. The hysteresis comes from the Greek histeros (ὕστερος), which can be translated as "posterior". Hysteresis is translated into German as "aftereffect".
This is exactly what hysteresis is all about. Therefore, a general definition of the term is: "It is the tendency of a material to retain one of its properties, in the absence of the stimulus that has generated it".
Consequently, the principle of hysteresis can be applied to a wide variety of areas, from electronic phenomena to economic phenomena and ferromagnetism.
Ferromagnetic materials can be magnetically charged by external magnetic fields. This magnetisation increases much faster than it decreases when the external magnetic field is switched off again.
It is precisely this effect that we owe to hysteresis, which is measured by the hysteresis curve. The magnetic force that remains when the external magnetic field is completely off is what we call remanence.
Let's look at an example of a non-magnetized ferromagnetic material.
For example, through an electric coil, we can magnetize this material. The external magnetic field is denoted (H) and the resulting magnetic field inside is the magnetic flux density (B). Here we are dealing with two variables, the magnetic field strength (H) and the magnetic flux density (B), with hysteresis being the relationship between the two.
If both values were previously at zero, i.e. the coil has not yet been electrified and the material to be magnetized does not yet have its own magnetic energy, a hysteresis curve is formed, which we call the new curve. As the magnetic field strength (H) gradually increases, the magnetic flux density (B) slowly increases at first and eventually reaches a saturation point. Even if (H) increases more, (B) will not increase more.
Consequently, the external magnetic field can be deactivated again and the intensity of the newly created magnetic field will not decrease with the same speed, but only gradually, since we are now talking about the remanence of the material to be magnetized.
Now there are different hysteresis curves: the soft one and the hard one. Soft magnets have narrower curves, smaller remanence and coercive field forces. In contrast, with hard magnets we can observe wider curves, as well as higher remanence values and coercive field forces.
The topic of hysteresis is extensive and can be seen from both the physical and mathematical sides. In this article, however, we initially wanted to clarify the basic principle and general definition of hysteresis. If you have further questions, you can contact us at any time and our experts will be happy to help you.
Electric and magnetic charges are closer to each other than some might have thought. Maxwell's 4 equations describe exactly this fact. That is, the generation and therefore also the size or strength of the magnetic and electric fields. They were defined by James Clerk Maxwell in 1864 and still provide the basis for electrodynamics today.
Maxwell's equations are a summary of Ampere's law, Faraday's law of induction, Gaussian law combined with an addition for Maxwell's displacement current. Maxwell's equations are therefore an extremely complete theory that has been experimentally tested to provide a solid foundation for the whole.
One can imagine that both electric and magnetic fields influence each other in an electromagnetic wave. Now there are the independent and time-dependent Maxwell equations.
The time-independent equations are based on a given static charge and currents in the approximate airspace. Electric fields and magnetic flux density are described with these basic requirements. This means that an electric field has sources and sinks called positive and negative charges. So-called field lines emanate from these.
In this case, the strength of the electric field is as strong as the charge. When this electric field is active, the currents cause vortices that activate the magnetic flux density or magnetic field. The strength of this field is also the same as in the included current.
In addition to the factors of the time-independent equations, the time-dependent equations also contain, as their name suggests, electric and magnetic fields that vary over time. This interferes with a time-varying magnetic flux density acting on the electric field. It causes additional vertebrae.
Conversely, the same is true of eddies in the magnetic field that originate in the electric field. Here the interaction between these two factors becomes clear.
red H = D + j
red = rotation
H = magnetic field strength
D = electrical flux density
j = current density
red E = - B
red = rotation
B = magnetic flux density
E = electric field strength
div = divergence
D = electrical flux density
q = electric space charge density
div B = 0
div = divergence
B = magnetic flux density
Injected plastics are parts that would be manufactured using injection moulds. The advantage is that these parts are completely customized and can therefore be created for a wide variety of applications.
At IMA we offer exactly this service to our customers. Thanks to our experience, we can advise our clients from the beginning and meet their requirements. When it comes to producing injected plastics, we first sit down with our customers and let them explain their needs to us. With this information, the project is analysed by our experts and we produce a 3D simulation of the planned plastic injection moulding. If it meets the customer's expectations, we go on to manufacture the mould with the shape of the injected plastic parts to be created.
In this case there are two options. The customer can order only the injection molds because he produces the injected plastics himself, or he can also order moulds plus manufacture of the plastic parts. Both variants are offered by IMA.
This manufacturing method is very advantageous for several reasons such as:
Not only the shape, but also the material used to make the pieces you want can be customized to meet your needs. For example, different plastics can be injected, including: thermoplastics, polymers and polyamides.
Plastic injection is an extremely economical method of production. Even if the desired parts have a complex structure, they only need to be produced once for the prototype and with this, an infinite number of parts can be produced in the same way without further problems. This means a saving in time and money.
In addition, the desired parts, however complicated they may be, are produced in a single manufacturing step. This significantly reduces the error rate. It is more important that the injection mould is manufactured under strict controls to produce perfect parts afterwards.
The injected plastic can be produced in a fully automated manufacturing process, which saves additional costs and labor.
Unlimited number of parts can be produced quickly
Therefore, if you need injected plastics or want to use an injection mould in your production process, you can contact our team of experts and get advice without obligation.
Injection moulding technology is a manufacturing method with which parts can be produced in a variety of ways for all industries. In this process, the plastic is liquefied and put into a mould. As soon as the plastic has cooled and hardened again, it can be removed from the mold and the part is ready for use.
The advantage of these injection moulds is that they can be manufactured individually and offer an economical solution for producing many identical parts relatively quickly. For this reason, it is important that the injection mould used to manufacture the finished parts is of the highest quality so that the production process runs smoothly and also delivers high quality parts as a final product.
At IMA, we specialize in the production of injection molds. This means that, on the one hand, we have the most modern machines that are necessary for this process and, on the other hand, we can count on the experience of trained personnel, which guarantees the quality of our products.
The process used is:
The customer explains to us all the details of the project, what he needs the pieces for and what shape he imagines. With this information, we create a 3D design to present to the client and compare if it meets their needs. When this process is completed, we start producing a prototype for the injection mould.
We care about choosing the best materials and guarantee a constant control and revision of the process. This is how we ensure that the injection mould is finished smoothly and in perfect condition. During this process, we offer total transparency and let the client participate and be involved from the beginning.
Finished injection molds can be used to easily manufacture individual parts for a wide variety of industries. This saves costs and guarantees a smooth production process, ensuring that each part is identical.
If you also need injection moulds or plastic injected parts, you can contact our specialized staff at any time and get good advice.
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