| |
>
About
us
>
Magnet-Products
>
Magnet
technology
>
Measuring
magnetism
>
Demagnetizers
> Degaussing
services
> Degaussing technology
> Technical
cleanliness
ISO
16232/VDA19
> White
Papers
> References
> Representations
wanted
> Magnetizers
>
News
& Media
> Sales
/ adresses
> Contact
>
Terms
of delivery and
Sales
(pdf)
>
Imprint
>
Job
vacancies
|
Maurer
Degaussing – a leap ahead in the field of industrial demagnetization
Maurer
Degaussing-Technology
History
The procedure "Maurer Degaussing" has been invented in the year
2001 during the development of a complex degaussing solution for a large
Japanese customer. Existing demagnetizing technologies were not able to
fulfill the requirements for process safety, quality and productivity.
By using the latest power electronics, innovative ideas, and years of
experience in the field of magnetism, Maurer Magnetic AG developed an
advanced pulsed demagnetization method. Maurer-Degaussing technology is
meanwhile protected by various international patents. Based on this process,
Maurer Magnetic AG supplies international customers with an comprehensive
product range for the demagnetization of ferromagnetic parts.
Purpose
With Maurer Degaussing parts in all sizes and combinations can be demagnetized.
Examples include large units with a weight of several tons, tungsten carbide,
packs of needles, baskets with parts, sintered parts, fully assembled
parts, technical springs, parts in steel containers, etc.
Demagnetization with the Maurer Degaussing method is suitable for automated
manufacturing processes as well as for manual operation. The demagnetization
takes place by a brief pulse of a few seconds duration. The controlled
alternating field profile, the high productivity and reproducibility of
the process make Maurer Degaussing perfect for modern industrial applications.
Features
of Maurer Degaussing
Demagnetization
by alternating electromagnetic field
Industrial demagnetization, as it is known, is done generally by a decreasing
alternating field. The source of the field is a standard copper coil.
The reduction in amplitude is achieved by pulling away the workpiece (eg
by a conveyor belt) from the coil. Due to the decaying alternating field,
the magnetic moments inside the workpiece become oriented randomly. With
proper implementation of this process, virtually no residual magnetic
fields remain in the demagnetized workpiece.
The process Maurer Degaussing is based on a magnetic field generated in
a coil. The intensity of the field is initially raised to a maximum value,
and then reduced within a few seconds on a controlled curve to zero amplitude.
The power electronics makes this pulse completely reproducible and through
that, the outcome of the demagnetization gets absolutely process safe.
The key elements of the Maurer Degaussing process called are explained
here in more details:
Brief, maximum field strength
Parts of magnetically hard materials, such as Nickel-chromium alloys,
ball bearing steels, carbides, etc., need a strong magnetic field to overcome
the coercive force. The same applies for the demagnetization of bulk materials
or multiple parts in containers. Screening effects of the ferromagnetic
material reduce in such cases the penetration depth of the alternating
magnetic field. High field strength helps to increase the penetration
depth of the alternating field into the ferromagnetic material. The outer
hull of the material becomes magnetically saturated and consequently the
alternating magnetic field penetrates deeper into the material. The energy
consumption of the demagnetization process is minimized, by the short
time spent at the maximum field strength. The penetration depth is further
enhanced by demagnetizing with lower frequencies. Demagnetizing with low
frequency suppresses the disturbing eddy currents induced in the material.
This is a crucial element for productivity and a feature of the Maurer-Degaussing
demagnetizers.
High number of oscillations with decreasing amplitude
The quality of the demagnetization depends predominantly on the number
of oscillations with decreasing amplitude. This is particularly the case
when parts with high geometric complexity or bulk materials are demagnetized,
in order to cover all the magnetic moments. The duration of the pulse
defines the number of these decreasing oscillations. The form of the pulse
sets the intensity drop between the oscillations. These parameters are
preset and guarantee a smooth demagnetization. Power modules with Maurer
Degaussing-technology perform a reproducible degaussing pulse, which results
in high quality and process safe demagnetization.
Accurate decay to zero current
The sudden interruption of a magnetic field inside a part leads in almost
each case to a measurable residual magnetism. For this reason, the final
decay of the degaussing pulse must go as accurately as possible to zero
current for a good quality demagnetization result. Industrial current
sources work properly with a certain minimal current. Below that threshold,
the current controller completely interrupts the electrical current. Maurer
Magnetic AG uses power sources, which can be regulated at lower minimal
currents. The dynamics that has to be handled (maximum / minimum current)
is about 60 dB or better, comparable to a hi-fi audio system.
Field
Multiplicator Technology FMT®
Maurer Magnetic AG
is making efforts to manufacture energy efficient demagnetizers. Degaussers
with AC field principle are using coils for generating the magnetic field.
Larger standard coils typically need big amounts of reactive power, often
at levels above 50A at 400VAC. Generally, standard degaussing coils consume
a lot of reactive power and produce low field strength. Maurer Magnetic
AG has found a solution for this challenge and uses for coils which have
to generate high field strengths, the innovation FMT ®.
Constant Field Technology CFT®
To demagnetize a part, it must pass through a coil, or it must be placed
near a coil. Ferromagnetic material near a coil causes a decreased flow
of current through the coil because of change in inductance. The field
strength is proportional to the current, and thus the demagnetization
is weakened. This physical effect is more pronounced with dense filling
of the coil. Maurer Magnetic AG has developed and patented the innovation
CFT ® to eliminate this field reducing effect. Demagnetizers with CFT
® Technology are particularly suitable for applications with dense filling.
For example this is particularly important for the demagnetization of
long tubes or bars.
<<
back to main page demagnetizing
|
