In the cars of this world, they regulate the air flow of the heating and air conditioning system and thus ensure that the driver is nice and cool in summer and pleasantly warm in winter: Actuators. These important components are driven by stepper motors, for example, such as those produced by Johnson Electric International AG at its high-end production plant in Murten, Switzerland. Around 450,000 stators are stamped every day in production at the site near Bern. These stators (internal and external) are then assembled into stepper motors on the assembly lines. The two individual parts of the stepper motor must be perfectly degreased for the motor technology to work reliably in the vehicle and maintain a torque of up to 80 Nm. However, this was precisely the crux of the problem in the past: although the parts had been degreased, they were no longer able to withstand the required pull-out forces. Help came from Richard Geiss GmbH, the solvent specialist from Offingen, Bavaria, and its Swiss competence and distribution partner, Thommen-Furler AG from Rüti bei Büren. In close cooperation with Johnson Electric and the system manufacturer REK, the experts from Richard Geiss and Thommen-Furler got the degreasing problem under control. Johnson Electric can now not only rely on a stable degreasing process and high component cleanliness, but also saves around 50 percent on solvents - and therefore costs.
Johnson Electric International AG is part of the Johnson Electric Group, a leading global provider of innovative drive solutions, control systems and flexible circuits. According to the group, the Swiss site in Murten is one of its innovation and product development centers and employs 400 people. 75 percent of the components produced there go to the global automotive industry, including stepper motors, which are produced on three assembly lines. 36 million units leave the plant in Murten every year.
Perfect degreasing for 450,000 stators per day
"Every day, 450,000 individual parts for stepper motors pass through our production line. Two individual parts always make a motor," explains José Landeira, Metal Part Manager at Johnson Electric International AG. Later installed in the car, they control the heating and air conditioning flaps, for example. The more luxurious the vehicle, the more of these stepper motors it needs: "In a well-equipped S-Class, that's around 20 of them," Landeira continues. He has been working at the Murten site for 28 years, initially for the Swiss manufacturer Saia Burgess until it was taken over by Johnson Electric in 2005.
However, before the two individual parts are put together to form a stepper motor, they have to be perfectly cleaned. This is because even the smallest amount of dirt can have a negative effect on the pull-out forces of the stepper motor. The stators are degreased in Murten using two systems from REK Reinigungstechnik GmbH, which have been in use since 2015. For the solvent, Johnson Electric relies on the modified alcohol RG CLEANER 63 from Richard Geiss GmbH. The RG CLEANER 63 not only efficiently removes polar substances such as salts, dust or metal abrasion from the components, but also dissolves non-polar substances such as grease and oil.
Lower tear-out forces due to problems in the degreasing process
"However, the pull-out forces of our stepper motors became weaker and weaker over time. And we couldn't explain why. After all, we degreased the individual parts in our systems as usual," says Landeira. The stepper motors have to withstand pull-out forces of 80 Nm in order to meet the strict requirements of the international automotive industry. Johnson Electric operates the two REK vapor degreasing systems in three shifts, five days a week. "At the beginning of the week, the measurements were always OK, but towards the end of the week they got worse and worse," Landeira continues.
First thought: it could be due to oil ingress. This is because the two degreasing plants are shut down at the weekend and the solvent is distilled, which would have explained the better measurement results at the beginning of the week. "However, the analyses in our company laboratory showed that the two solvent samples that we took from the system at the beginning and end of the week did not show any major differences. On the contrary: the medium was clean," emphasizes Manuel Huihui, sales representative in international sales at Richard Geiss GmbH, who also supported Johnson Electric International AG on site.
Analysis showed: the system was foaming
How could it still be that the parts were apparently contaminated after they came out of the degreasing systems? To investigate the cause, the solvent specialists from Richard Geiss examined all the different process steps at Johnson Electrics in Murten, took samples from the individual washing baths and also measured the exhaust vapor residue in the degreasing systems. "This went far beyond normal service analyses," emphasizes Landeira. The comprehensive analyses were carried out in the company's own laboratory at Richard Geiss GmbH's headquarters in Offingen, Germany. In addition to the solvent, the entire system technology was also tested.
The result: the systems installed at Johnson Electric in Murten tended to foam under the set parameters and this foaming re-contaminated the parts after cleaning. This was due to the interaction between the oil introduced into the solvent bath and the pressure difference in the chambers of the vapor degreasing systems. The solvent vapor, which is deposited on the parts during the cleaning process, had drawn oil with it, and this oil was then deposited on the cleaned parts.
GEISS DISTIL breaks the foam
To solve the degreasing problem, the pressure difference in the systems was reduced and other system parameters optimized in consultation with a service technician who specializes in the systems. In addition, Johnson Electric now uses the GEISS DISTIL defoamer in its two vapor degreasing systems. The foam breaker prevents the formation of foam in organic solvents, which can be caused by surfactants, silicones or fluorocarbon resins. The contained defoamer component has a strong foam-breaking effect in distillation processes of organic solvents, preventing boiling over or foaming during distillation.
"This change has helped. We can now meet the strict requirements of the automotive industry again without any problems," Landeira explains. By this he means not only the international ISO standards, but also the recommendations and standards of the German Association of the Automotive Industry (VDA), the joint interest group of German car manufacturers and suppliers, as well as the IATF 16949 standard, which combines general requirements for quality management systems in the automotive industry, to which around a third of the more than one hundred car manufacturers worldwide have signed up. These include BMW, Chrysler, Daimler, VW, Fiat, Ford and General Motors.
Optimized degreasing process saves 50 percent solvent
Johnson Electric now not only has a stable degreasing process in Murten, but also an optimized one. Thanks to the system readjustment and the GEISS DISTIL defoamer, the technology leader in drive solutions for the automotive industry saves half as much solvent as before. Every week, José Landeira's team adds around 2 cl of the defoamer to the REK degreasing systems. That doesn't sound like much, but it has a big effect: "Whereas we used to have to replace almost 700 liters of solvent every three months, we can now get by with the solvent for six to eight months. This not only gives us a stable process, but of course also saves us considerable costs," emphasizes Ladeira.
In his eyes, the key to solving the degreasing problem lay above all in the close and constructive cooperation between all those involved: the solvent specialists at Richard Geiss GmbH, the system manufacturer REK and Thommen-Furler AG. The latter has been working with Richard Geiss GmbH as a distribution partner for the Swiss market since the 1990s. "If we hadn't had the exchange and support from all three sides, we might never have discovered the problem. The professionals at Richard Geiss in particular were there to support us with their expertise and help right from the start of the problem. The support from Geiss and the Thommen-Furler team is really great," emphasizes Landeira.
About the Johnson Electric Group: The Johnson Electric Group is a leading global supplier of innovative drive solutions, control systems and flexible circuits. It serves companies in a wide range of industries, including automotive, building automation and security, office equipment, defense and aerospace, ventilation and air conditioning, industrial equipment and medical devices.
Johnson Electric was founded in 1959 and supplies its products and solutions for a wide range of applications in more than 30 countries. Innovation and product development centers are located in Hong Kong, China, Switzerland, Germany, Italy, Israel, France, Canada, the UK and the USA. Johnson Electric employs 36,000 people in over 23 countries worldwide.
About Richard Geiss GmbH: Richard Geiss GmbH is one of Europe's leading specialists in the field of solvent recovery and is based in Offingen in the district of Günzburg. The company produces high-purity distillates from solvent waste by distillative reprocessing. Richard Geiss GmbH supplies solvents to industrial surface cleaning, textile cleaning and the chemical and pharmaceutical industries. Contract degreasing rounds off the range of services as a fourth business segment. Richard Geiss GmbH employs around 100 people in Offingen. The company has an approved processing capacity of 50,000 tons of solvents per year, which are processed into high-purity distillates and is certified according to ISO 9001, ISO 14001, OHSAS 18001 and as a waste management company. Richard Geiss GmbH was founded in 1959 by Richard Geiss. Today, Bastian Geiss and his sister Nathalie Geiss-Zinner are the third generation to run the family business.
