Tag Archives: FST

A New Generation of Conductive Seals

Freudenberg Sealing Technologies is developing a new generation of conductive seals designed to ensure a durable electrical connection between housings and shafts while preventing bearing damage caused by electricity and electromagnetic radiation.

In many operating conditions, the shafts used in electric powertrains are electrically insulated from their housings. The insulation is created by the lubricating films in the contact zones for the bearing and the shaft seals. Lubrication is necessary to promote long-term system functionality. Alternating current and its electromagnetic fields produce changes in the electric potential between the rotor and the stator and the rotor becomes charged. The current can only be drained off through a grounded system that allows the electricity to travel from the shaft to the housing. If there is no grounded pathway, the current flows to the area of least resistance – the bearing – and produces an abrupt discharge when electricity flows from the inner ring to the outer ring across the bearing. Discharge flashes cause surface burns and material compromises that permanently damage the system. The result: The contact surfaces in the rolling bearing are steadily and systematically destroyed. The mounting becomes noisy and the bearing must be replaced to prevent powertrain failure.

Finding the conducting element

conductive simmeringDamage from electric current must absolutely be avoided. The simple solution is to develop a lasting, reliable electrical contact between the shaft and the housing that facilitates a continuous flow of electricity and prevents excessive build up and sudden discharges. The more difficult challenge is to find a system element that can conduct the current via ongoing contact with both the housing and the shaft. As a rule, seals are made of insulating materials and are not suited for this purpose.

For several years, Freudenberg Sealing Technologies has been producing an electrically-conductive nonwoven disk as a series- production system element. The advantage: It is firmly connected to the shaft seal ring and requires almost no additional installation space. The conductivity of the nonwoven is achieved with special fibers that are embedded in a matrix. The system has been used in regular-production electric vehicles for years and reliably prevents bearing damage. The electric resistance in this approach is already at a very low level, but the sealing specialists at Freudenberg continue to develop the solution further.

Power densities continue to grow in upcoming electric powertrains, increasing current, voltage and disruptive electromagnetic fields. To offer a robust solution for these situations, the company is now developing a new generation of conductive seals. The first validated, functional models in this category will be available within a few months. “Our goal is to achieve constant resistance values over a long period of operation – even in adverse conditions,” said Dr. Tim Leichner, who is responsible for Strategic Product Advance Development at Freudenberg.

A new dynamic testing procedure

To fulfill the new requirements for seals in electric powertrains, Freudenberg Sealing Technologies has developed the appropriate test procedure to evaluate and compare the functioning of current dissipation elements. Test stand trials have shown that static measurements of the elements’ electrical resistance are not adequate to predict electrical conductivity during actual dynamic use. So development engineers in Germany developed a dynamic testing procedure that delivers alternating-current flows in the frequencies found in automobiles.

“There is the possibility of doing even more with conductive seals,” said Francois Colineau, who is in charge of the development of this product line at Freudenberg Sealing Technologies. “High electrical conductivity lends itself to possible shielding of disruptive electromagnetic radiation.” The exit point of the shaft from the housing, in particular, is normally a location where “impermeability” is only achieved with difficulty. At this location on every electric motor, there is a shaft seal that could help handle the shielding. It would be possible to combine the sealing of oil and other media with impermeability to electromagnetic radiation – without necessarily adding another nonwoven layer. “Perhaps we will even find an entirely new electrically conductive sealing material. We’re working on it,” Colineau said.


The original article can be found on Freudenberg’s website.

For more information about this new generation of conductive seals, contact Gallagher’s engineering department.

Freudenberg Announces New VMQ Materials

When it comes to food, Freudenberg wants to be sure that its sealing materials are free of harmful substances.

In the food processing industry, in order to guarantee food safety, both the food and the hardware that come into contact with it must meet particularly stringent criteria. These guidelines also apply to sealing materials.

picture of food processing plantIn China, specific standards were created in 2016 with the two standards GB 4806 and GB 9685, which deviate from the existing relevant American and European regulations for food-grade materials. To meet the stringent Chinese regulations, FST has now successfully tested two proven VMQ materials: 70 VMQ 117055 and 60 VMQ 117117 for their conformity with Chinese guidelines.

The Chinese standard GB 9685 specifies which ingredients may contain materials that come into contact with food in a so-called positive list. A large number of seal-relevant ingredients that conform to 21 CFR 177.2600 of FDA (U.S. Food & Drug Administration) and European EU (Reg.) 1935/2004 are not listed here. This applies to elastomers. For a global food release, new material compositions must therefore be developed or proven materials tested for their conformity with the specifications.

Global food approvals require extensive testing

The basic requirements for gasket materials as well as sensory tests and migration tests are defined in standard GB 4806. Two of Freudenberg’s newly developed EPDM materials have successfully passed the tests: 75 EPDM 386 and 85 EPDM 387. 

After extensive testing, FST’s two new VMQ materials now meet the requirements of the Chinese standards. As an example: the silicones in the migration measurement in mg/dm2 had a result of <1, and are far below the specified limit of ≤10.

In addition to the EPDM materials which are characterized by media resistance, good processing behavior and a long service life, FST’s new silicones, 70 VMQ 117055 and 60 VMQ 117117 provide grease-resistant material selection for use in contact with food in the Chinese market.


Gallagher Fluid Seals is a preferred distributor of Freudenberg sealing. For information about Fruedenberg, or if you have needs for a custom solution, contact our engineering department.

The original article or press release can be found on Freudenberg’s website.

The Future of Seals – Identifying and Communicating Levels of Wear

Seals do their jobs tirelessly, usually behind the scenes. Until now, machines mostly had to be dismantled to check the condition of these parts. That’s expected to change: At Freudenberg Sealing Technologies, a cross-disciplinary team is testing seals that identify and communicate their level of wear. They are based on a novel material that functions as a sensor.

It’s time for maintenance at a beverage bottling facility. Different components of the equipment are opened up, and the seals on tubes, pumps and valves are checked. If they are worn out, they have to be replaced. But if they are still intact, the check itself – a common yet expensive process – is superfluous. What would happen if the seals themselves could autonomously measure and transmit information about the level of their wear? And determine the exact point – no sooner and no later – when little of the seal lip is left and the seal has to be replaced? The future of seals may lie in self-identifying seals.

Seals Identifying Wear Automatically

A cross-disciplinary research team at Freudenberg Sealing Technologies addressed this question. Working with a customer from the process industry, experts developed a seal that measures its own wear. The key benefit: The maintenance of processing equipment – filling equipment in this case – could be performed based on actual need. Moreover, the service staff would have the opportunity to time the maintenance perfectly for the equipment’s operating schedule. Unplanned stoppages due to leaks would become a thing of the past.

Measurement Principle
The seal lip serves as an insulator. If it is worn, the capacity between the electrically conductive seal body and the housing changes.

Electrically Conductive Rubber

Seals are mostly made of elastomers that, in their pure form, are unable to process signals. To arm them with intelligence, it is possible to integrate a sensor or a microchip into a seal. But since the integrated element is a foreign body, it could impair the seal’s functioning. “So we focused our attention on approaches where the intelligence comes from the material itself,” Dr. Boris Traber, who is in charge of the development of new materials at Freudenberg Sealing Technologies. The researchers equipped a sealing material with special fillers to make the elastomer electrically conductive. At the same time, the material had to have qualities that are just as functional as those of a conventional seal. And, since the seals come into direct contact with the food during the filling process, they can only contain components that are on the positive list approved by the EU and the FDA.

Electric Signal Points to Leakage

The design and measurement principles that the seal uses to convey the level of its wear are just as important as its material mixture. In this particular application, an external transducer sends an electric signal over a lead to the seal. This creates voltage between the electrically conductive portion of the seal and the external housing, and the seal lip in-between insulates the two surfaces from one another. The greater the wear of the seal, the less it can effectively insulate the two electrodes from one another. As a result, the electrical capacity changes. If you measure the change, you can draw conclusions about the condition of the seal lip.

Development to Production Readiness

This smart seal is now due to be developed to production-readiness for specific applications. The effort involves material developers, product developers, process specialists and sensor experts who are working hand-in-hand with colleagues from operating areas, the Freudenberg Sealing Technologies sales organization and the customer’s application experts. Of course, it would take a good many experts to actually make seals that were talkative. But it would be possible – that much is clear, and the future of seals is looking bright.


For more information about sealing technologies, and to find out which seal might be a fit for you, contact Gallagher’s Engineering Department.

The original article was featured on Freudenberg’s website and can also be found in the May 2019 edition of their ESSENTIAL magazine.

Tackling Flavor Transfer with Seals Made from Globally-Certified Materials

The popularity of multi-flavor drink dispensers, those touch screen wonders that offer dozens of beverage and flavor options to consumers, has grown during the past decade. Manufacturers are installing these complex machines in venues and locations throughout the world.

Elastomers and flavor transfer

But what’s great for an individual customer – a cherry-ginger-lime cream soda, for example – can play havoc with the elastomer seals inside the machine. Add in hygienic cleaning requirements and proper food contact certifications and equipment manufacturers can find themselves spending months chasing challenges like flavor transfer, leaks and material compliance approvals.

Freudenberg-NOK Sealing Technologies, a leading specialist in advanced sealing applications, has a portfolio of solutions to resolve these issues. The company, which runs the business operations for Freudenberg Sealing Technologies in the Americas, will showcase a variety of globally-certified material options at the 2018 BevTech®, the annual meeting of The International Society of Beverage Technologists (ISBT), taking place April 30-May 2 in Albuquerque, N.M.

“Flavors are almost never the same. They are a diverse mixture of ingredients with very different chemical properties.”

“Flavors are almost never the same. They are a diverse mixture of ingredients with very different chemical properties,” said Christian Geubert, Global Application Engineering Manager for Freudenberg Sealing Technologies’ Process Industries organization. “Some of these chemicals are very good solvents for rubber, which means they can destroy rubber seals and their performance. Only through extensive testing and analysis can industry challenges with flavor transfer and cleaning solutions be isolated, understood and successfully addressed with sealing materials and designs that address an entire range of conditions.”

Geubert will discuss the complex factors associated with flavor transfer and their impact on material properties and performance during a presentation at the 2018 BevTech® meeting. Following this presentation, Geubert and a team of Freudenberg experts will be on hand in booth #45 to answer questions and explain the advantages of a trio sealing materials including 70 EPDM 291, 70 FKM 727, and Fluoroprene® XP. Each of these materials is globally-certified for food contact in the United States (NSF-51) and the European Union (EC 1935/2004).

picture of flavor transfer seals

With its outstanding qualities in critical media, Freudenberg’s 70 EPDM 291 is the first choice for a wide variety of O-Rings, formed parts and diaphragm applications in the food and beverage industry. 70 EPDM 291 is compatible with bag-in-box (BIB) syrups, is suited for exposure to dispenser cleaning fluids, and is specifically formulated to resist flavor transfer.

Dynamic sealing at dispensing temperatures just above 32°F (0°C) is problematic for most Fluorocarbons (FKM) due to reduced flexibility. Freudenberg’s 70 FKM 727 is the only globally-certified, low-temperature FKM in the food and beverage industry. While maintaining compatibility with BIB syrups and cleaning agents, 70 FKM 727 adds best-in-class flexibility in this critical temperature range.

When standard EPDM and FKM materials fail to perform in particularly demanding food and beverage applications – including those found in high-ratio, multi-flavor dispensers – Freudenberg’s Fluoroprene® XP can be called into action. This unique, highly-fluorinated FKM is not only compatible with non-polar materials like oils, it also offers excellent compatibility with polar fluids like acids and bases and provides best-in-class flavor transfer resistance.


The original article can be found on Freudenberg’s website.

To learn more about Freudenberg products, speak to a Gallagher representative today by calling 1-800-822-4063

Resolving Food and Beverage Challenges

When it comes to sealing food and beverage systems against leaks, contamination and malfunctions, meeting a product specification does not guarantee that seals will function as needed, two Freudenberg-NOK Sealing Technologies experts told a webinar audience in September. Freudenberg-NOK runs the business operations for Freudenberg Sealing Technologies in the Americas.

Food and BeverageFreudenberg’s David Clark, Operations Manager, Central Laboratory and with Ryan Fleming, Analytical Laboratory Manager, provided insight about the nature of elastomers, market trends like custom flavor combinations, regulatory requirements and the importance of material compatibility and advanced analytical testing. All of these factors must come into play when choosing the right material to produce effective elastomer components for food and beverage machinery, they emphasized during their Beyond a Spec: Choosing the Right Sealing Materials for Food and Beverage Applications webinar.

“Today’s global industry means engineering for multiple markets and diverse regulatory compliance standards, which can be challenging and expensive, so it must be considered early,” said Clark. “Simply meeting a product specification does not ensure a seal will function.”

Continue reading Resolving Food and Beverage Challenges

Heat Shields Boost Battery Safety in EVs

Due to the growing energy density of battery systems, the developers of lithium ion batteries must satisfy ever higher safety requirements. It is especially crucial to keep a single damaged cell from overheating the entire battery module. Freudenberg Sealing Technologies has developed a innovative heat shields for use in prismatic and pouch cells with almost no impact on the required installation space. It combines the high heat resistance of a silicone-based elastomer with the high insulating properties of air.

FST Heat Shields For Batteries The goal is greater range without the battery growing in size and weight: High energy density, which has been battery developers’ top priority, creates a basis for the broad acceptance of electric vehicles. But the more energy is stored in a confined space, the greater the safety requirements. So precautions are essential in case a damaged cell overheats. Experts call the phenomenon “thermal runaway,” and it can cause the temperatures in a cell to rise as high as 600°C. The risk is that the battery’s cooling system would not be able to drain the heat away quickly enough under these conditions. If neighboring healthy cells also heat up due to the heat buildup, a chain reaction can result that, in the worst case, could lead the entire battery system to explode.

Continue reading Heat Shields Boost Battery Safety in EVs

Sealing Solutions for Machine Tools

Gallagher Fluid Seals is a long-time partner of Freudenberg Sealing Technologies.  From their classic Simmerring® radial shaft seal, to V-rings, to guide rings, to u-cups, Freudenberg is an innovative seal manufacturer that solves problems.  Check out the video below to see the many sealing elements developed for machine tools, specifically hammer drills and demolition hammers.

Overcoming the toughest resistance with full penetrating power, whether against concrete or stone: hammer drills and demolition hammers literally have a huge impact. Sealing solutions and rubber molded parts from Freudenberg Sealing Technologies are meanwhile essential to them. They robustly and reliably guarantee the machine’s power output and a long lifetime of drilling, chiseling, demolishing and stripping. Freudenberg Sealing Technologies is the leading global market and technology specialist in sealing technology. Seals from Freudenberg Sealing Technologies are employed in a wide range of products. Their industrial applications include machine tools and, as quintessential examples, hammer drills and demolition hammers.

FluoroXprene Reduces Emissions

One of the greatest challenges of the 21st century is the conversion to a resource-conserving, sustainable economy. With this in mind, Freudenberg Sealing Technologies is offering customers its FluoroXprene® family of materials to help contribute to this transformation. Originally developed for use in fuel lines, these materials have the potential for use in new, challenging applications thanks to their outstanding characteristics.FST FluoroXprene Automotive

FluoroXprene was developed to reduce the permeation of fuel vapors through the walls of fuel lines. This permeation makes a notable contribution to a vehicle’s hazardous emissions. But it is often overlooked when considering total emissions. FluoroXprene reduces the escape of fuel vapors through the walls of fuel hoses into the atmosphere, slashing them to a fraction of their usual amounts. And this is not just the case for standard fuels – alternative plant-based fuels such as E10 and E85 are also securely contained by FluoroXprene materials.

Continue reading FluoroXprene Reduces Emissions

140 Beats per Second…

Freudenberg Sealing Technologies has developed a new sealing system for Atlas Copco, the leading global producer of rock drills. The system has made it possible to double the maintenance intervals for a new generation of machines used in harsh underground conditions.

The drill bit strikes the surface of the stone with a force of 25 tons up to 140 times per second. Its task: to drill 80 holes where explosive charges are inserted. They blast away rock for supply tunnels for underground mining or for road construction. The drill bits are driven by rock drills. Two factors are decisive in keeping operating costs low: On one hand, the holes must be drilled very quickly, even in hard stone such as granite, which requires very powerful forces. On the other hand, despite the strong forces, maintenance intervals are supposed to increase. With the development of its new machine, the COP MD20, Atlas Copco has resolved its conflicting objectives: Without a reduction in the machinery’s rate of advance, the company was able to double its maintenance intervals.

A new sealing system from Freudenberg Sealing Technologies was the key component in accomplishing this, as the metallic components, especially the piston that drives the drill bit, had been previously optimized by using special high-strength alloys. But the forces that are produced, especially during the bit’s recoil, are so high that they severely stress the seals in this high-pressure hydraulic system. If the seals develop wear, the result can be leakage, which has a highly negative effect on the relationship between the applied energy and the boring power – in other words, the system efficiency declines.

Rock Drills - Atlas Copco Cop MD 20
©Atlas Copco Rock Drills AB

Continue reading 140 Beats per Second…

Sealing Heavy-Duty Equipment

Article first appeared in Power Transmission Engineering blog on November 14, 2017.


Freudenberg Examines Sealing Requirements for Heavy-Duty Equipment

94 AU 30000 - New Polyurethane MaterialsThe seals and the hydraulic systems of any piece of mining, construction, agricultural or other heavy industry equipment operate under extreme conditions. Variable temperatures, aggressive hydraulic oils, dust and extended periods of operation place seals and their tribological systems under continuous duress. A new generation of material, 94 AU 30000, expands the boundaries for polyurethane use. This innovative compound can be used in standard cylinder applications where higher pressures, larger extrusion gaps, reduced internal friction, improved hydrolysis resistance and compatibility with bio fluids, among other factors, are important. DMRW2 hydraulic wipers made from 94 AU 30000 and sheet metal and the availability of this polyurethane as part of Freudenberg Sealing Technologies’ Xpress rapid replacement part service are applications discussed in the following article.

Today’s extreme environmental climates place extreme demands on the material and structure of the hydraulic seals used to maintain the performance and operation of heavy-duty equipment.  The excavators, tractors, backhoes and tunnel boring machines that grind through the earth every day must work harder, longer, cleaner and more cost efficiently than ever to feed the plant, build its infrastructure and harvest its natural resources.

Sealing requirements for these machines must now include high values for tensile strength and elongation at break, resistance to oils and ozone, high elasticity and abrasion resistance. Polyurethane materials (PU) have traditionally met these industrial requirements. In comparison with elastomers, PU has a four times greater capacity for mechanical resistance, as well as outstanding resistance to ozone. At the same time, it stands up well to the stresses of mineral-based fluids.

Continue reading Sealing Heavy-Duty Equipment