Category Archives: Freudenberg Sealing

Diaphragms Designed to Precisely Fit Different Gas Meter Designs

In the safety-driven natural gas industry, system leaks are a dangerous and costly issue. Residential gas meters and regulators, in particular, are at risk when crucial components such as diaphragms are not optimally designed and manufactured for the environment in which they will work.

An advanced polymer technology, trademarked by Freudenberg Sealing Technologies’ Metflex Precision Moulding organization, addresses these challenges with fiber-reinforced materials that improve the reliability, functionality and longevity of critical gas system components. Diaphragms made using Metflex Dispersed Fibre Technology (DFT)™ offer better sealing performance, longer flex life, improved low temperature resilience and enhanced design capabilities than standard diaphragms made from fabric coated polymers. To date, more than 40 million DFT diaphragms have been used in medium and low-pressure application, primarily in North America but also in other regions of the world.

Safety concerns and costs associated with gas leaks and equipment failures

Continue reading Diaphragms Designed to Precisely Fit Different Gas Meter Designs

The New Hygienic Forseal and Hygienic Pressure Seal From Freudenberg

Strict hygiene regulations in the food industry present major challenges for sealing technology. Freudenberg Sealing Technologies is enhancing its proven portfolio of hygienic sealing solutions with two products that are also designed for high-pressure applications. This was made possible thanks to special design solutions and the premium elastomer and PTFE materials developed in-house.

Food processing demands strict hygiene and cleanliness standards. It’s also important to ensure that no substances can migrate from the materials coming in contact with food, which could lead to contamination of the product. With its hygienic product line, Freudenberg Sealing Technologies has developed sealing solutions that fulfill food industry standards and are also resistant to CIP/SIP media. The Hygienic Forseal and Hygienic Pressure Seal are the newest members of this innovative product family.

Lena Eberspach, Rainer Kreiselmaier and Sina Etter (f.l.t.r.) from Freudenberg Sealing Technologies discuss the new products of the company’s hygienic sealing solutions portfolio. Copyright: Freudenberg Sealing Technologies

One of the basic requirements for sealing solutions in accordance with the hygienic design standards is a dead-space-free construction. It prevents the collection and settling of product residues and micro-organisms in undercuts, for example. The selection of applied materials and their resistance to hot water, steam, acids, alkalis and high pressures are also relevant. Observing the deformation at the relevant temperature plays a particularly important role in detecting distortions and the associated formation of dead spaces at an early stage in the product development. Continue reading The New Hygienic Forseal and Hygienic Pressure Seal From Freudenberg

Case Study: 3-A® Compliant Rod Seal Capable of Handling High-Pressure

Valves are indispensable components in the hygienically sensitive systems used in the food, beverage and pharmaceutical industries. Until now, there were no high-pressure valves available for food-product contact applications that conformed to 3-A® standards. These global hygiene standards address the design and manufacturing of components that come into contact with food.

Bardiani Valvole approached Gallagher’s partner, Freudenberg Sealing Technologies, for help in developing a solution to tap into its material expertise. As a result of joint cooperation, Freudenberg engineers developed a main rod seal that was both 3-A® compliant and capable of handling high-pressure of up to 2175 psi (150 bar) that the customer’s valve required. The main rod seal incorporates proven Freudenberg technology with advanced component design in an entirely new combination that is also compatible with other industrial high-pressure valves.

picture of valve example
Copyright: Bardiani Valvole Spa

Prototypes produced without any tools

The 3-A® compliant main rod seal combines a sealing lip, manufactured from EPDM 302 or Fluoroprene® XP 43, with a backup ring made of PTFE. Freudenberg’s product engineers were inspired by the design of a proven shaft seal and an O-ring with a backup ring. In order to meet development and cost deadlines, the team initially produced one-off prototypes to share with Bardiani Valvole using the unique capabilities of Freudenberg Xpress®, a fast turnaround, high-quality manufacturing service that can generate custom seals in as little as a day. It offers machined seals made of original materials and original profiles for prototypes, spare parts or economical small series.

By eliminating the need to set up manufacturing tooling to produce sample parts, this results in considerable cost and time advantages for the customer. Thanks to special turning and milling techniques, individual designs can be tuned to exact specifications. The tailor-made sealing solution for the new high-pressure valve could also be produced economically in an extremely short time. The Freudenberg Xpress® Service is represented at numerous Freudenberg sites worldwide, enabling rapid delivery of spare parts, for example.

The seal’s design is free of dead space and prevents residue infiltration from process and cleaning media. It is hygienic, easier to clean, and compliant with all relevant material specifications for food, beverage, and pharmaceutical industry applications. Both materials used have very good thermal resistance and excellent mechanical properties. They also meet the demanding requirements for use in Cleaning in Place and Sterilization in Place (CIP/SIP) processes. Continue reading Case Study: 3-A® Compliant Rod Seal Capable of Handling High-Pressure

Freudenberg Sealing Technologies Launches Modular Sealing Unit

Freudenberg Sealing Technologies has developed a new, innovative sealing concept for small, electric household appliances. // Copyright: Freudenberg Sealing Technologies 2020

Freudenberg Sealing Technologies has launched series production of a modular sealing unit that combines a classic radial shaft seal with a plastic outer case. The design promotes better long-term seal performance and longevity, is easier to assemble, and significantly lowers manufacturing costs in comparison with traditional metal-encased radial shaft seal units. Freudenberg has developed the innovative sealing concept for use in general industry applications that are especially focused on small, electric household appliances.

Whether it’s to knead bread dough, mix a cake batter, puree soup ingredients or blend a smoothie, most people reach for an electric kitchen appliance to get the job done. The durability of the appliance depends largely on how well the seal at the outlet point of the drive shaft protects the interior from ingress of food residue or liquids. Seals made of high-quality elastomers or the polymer polytetrafluoroethylene (PTFE) combine low wear with excellent long-term resistance against leakage. In the past, a metal case was the best option available to maintain the integrity of the seal’s performance over a long period of time. Freudenberg Sealing Technologies has now succeeded in developing a modular sealing concept with a plastic case that meets the specific requirements for long-term performance as well as those made of metal. There are three major advantages to the new design: Significantly, in the price-sensitive, small appliance industry, the lower production costs associated with forming enclosures from plastic is an important consideration. In addition, Freudenberg’s modular sealing unit concept accommodates the integration of additional components, such as shaft bearings. Finally, because small appliance housings are typically made from plastic, fastening the seal case to the appliance housing is easier to achieve. Continue reading Freudenberg Sealing Technologies Launches Modular Sealing Unit

Freudenberg’s New Plastic Rotating Bearing

In an innovative first, Freudenberg Sealing Technologies has introduced a machine component that combines a plastic rotating bearing with a seal in a single, precisely matched unit.

The design offers significant weight, cost and friction advantages over separate bearings and seals and also improves the properties of the mated bearings and seals. Freudenberg has validated the advantages of this new component through extensive testing performed in a sensor housing unit including the seal-bearing component.

While mostly hidden from view, seals and bearings are nonetheless important components in automotive and industrial applications. They are key elements in operational safety and performance and their durability must be optimized to prevent system failure. At the same time, these bearings and seals must be small, lightweight and cost efficient in keeping with manufacturers’ efforts to remove cost and weight from vehicles without sacrificing performance.

Freudenberg has resolved this challenge with the introduction of its seal with integrated bearing (SWIB). The company spent two years developing this engineered solution and has successfully tested it in a sensor housing of a an electric power steering (EPS) system installed in an electric powered vehicle.

The sensor records data, like steering angle, which is critical to advanced driver assistance programs like electronic stability control (ESC). The seal inside the housing is responsible for protecting the sensor from the penetration of dust, splash water and other media over the entire service life of the vehicle. Bearings used in the assembly are also important; they must withstand significant mechanical loads – sometimes as much as 3,000 Newton (675 lbs) of radial force when a car drives over a curb with its wheels at an extreme angle.

Integrated system can reduce loads and vibration

picture of FST seal with integrated bearing

Freudenberg Sealing Technologies’ integrated solution offers significant improvements compared with separate bearings and seals. The rigidity of the integrated plastic bearing is higher so that its deflection is reduced by nearly 50 percent when lateral forces are exerted. This reduces the induced vibrations to increase the steering comfort for the driver. The seal, on the other hand, has 35 percent less friction, which reduces resistance during steering – especially important for highly automated driving. The weight of the overall solution is reduced by as much as 80 percent through integration. Freudenberg’s patented plastic bearing plays a major role in achieving these component breakthroughs.

Automotive safety applications are subject to many requirements which individual manufacturers define according to their own specifications. Freudenberg Sealing Technologies used common specifications – a temperature resistance of -40°C to 125 °C (-40°F to 257°F) under mechanical stress, for example – to test its integrated component during the past year. Extreme cases, such as direct exposure to high water pressure, which can occur in practice during engine washing, were also tested. The seal that includes an integrated bearing proved itself in all tests. “We can now commence with customer-specific series development at any time,” says Freudenberg expert Frank Schönberg.

The design offers significant weight, cost and friction advantages

Product experts at Freudenberg Sealing Technologies are already researching additional industrial applications for the new component. In addition to automotive applications, seals with integrated plastic bearings can likely bring benefits to many industrial operations. Freudenberg is also looking to the manufacturing process for further innovation: If the seal/bearing unit is currently still being assembled, it could be produced using new materials in an integrated two-component injection molding process in the future.


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

 Gallagher Fluid Seals is an authorized distributor of Freudenberg Sealing Technologies. To see if this seal is a right fit for your application, contact our engineering team today.

Accurate Long-Term Predictions for Seals

The static seals used in large energy and industrial facilities can be challenging to install and difficult to replace. They must, therefore, function flawlessly for periods longer than 20 years. Up until now, the existing tools used to calculate the long-term performance of sealing materials for these kinds of applications have often led to the components being larger than actually necessary.

Freudenberg Sealing Technologies has now developed a method that takes into account the material changes at the molecular level when predicting the long-term durability of seals. The new methodology is more reliable than previous models and ensure fewer materials to be used.

picture of wind turbinesThe seals used in plant engineering must have a very long service life. Once they are installed – to protect offshore wind turbine towers from salt corrosion, for example – customers typically require that they perfectly fit for more than 20 years. The service life of a seal is limited based on two things: First, by setting or stretching (physical relaxation). And second, chemical changes cause the material loses its elasticity over time.

Under the influence of atmospheric oxygen or ozone, two basic effects that influence the aging of seals can be observed: First, the polymer chains and networks can fracture under mechanical stress, and second, additional oxygen bridges can develop in the network as a result of oxidation processes. Both effects influence important properties of relevance for seals such as stiffness, contact pressures or the ability to regain their original shape after deformation, also referred to as resistance to deformation.

Extrapolation with the Arrhenius Equation

To determine whether a material actually meets the requirements for a specific application, engineers usually conduct so-called “storage tests” in which the test specimen is exposed to temperatures well over 100° C for a longer period of time – usually 1,000 hours – to predict temperature-dependent aging. Engineers typically extrapolate the measured values using the Arrhenius Equation, a method named after the Swedish chemist and Nobel Prize winner Svante August Arrhenius. Continue reading Accurate Long-Term Predictions for Seals

Freudenberg Develops Next-Generation Low Friction Bearing for Improved Lubrication

Freudenberg Sealing Technologies has developed an optimized design for its proven Levitorq axial thrust washers.

Through a new “scoop” feature, the enhanced Levitorq design is able to collect and push lubrication under the washer to enable higher critical speeds and enhanced performance. Levitorq is part of the company’s Low Emission Sealing Solutions (LESS) product portfolio.

The original Levitorq design was created to reduce weight, decrease friction, improve thickness/flatness control and often provide a cost benefit to the customer. It relies on the principles of hydrodynamic oil film technology and is designed to create a surface on which a bearing can roll, or a load can be applied. Traditionally, thrust washers are made from metals, but Freudenberg has used its material expertise and design knowledge, along with proprietary software and testing capabilities, to develop design alternatives in thermoplastic or thermoset materials that allow engineers to replace heavy metal thrust washers.

In pushing thrust washer technology further, Freudenberg engineers and material scientists looked at a variety of application parameters to optimize design performance, including thrust load, rotation speed, temperature, counter surface characteristics, lubricant type, and availability of the lubricant. A team of experts developed several scoop designs based on the types and availability of lubricants used in powertrain applications. These designs help optimize the availability of lubrication at the inner diameter, thus improving lubrication across the washer.

Nine Times the Pumping Ability, Three Times the Critical Speed

picture of levitorqPressurized or splash lubrication from the outer diameter is challenging to address because of limited fluid availability to remove heat. Recent design and material innovations from Freudenberg have enabled the use of polymeric thrust washers for such applications. The new Levitorq scoop feature significantly affects performance as it enables the application to use available fluid more effectively. Also, polymeric materials are designed to have low friction coefficients even in dry running conditions. These materials have dry friction coefficient one tenth of metal thrust washers.

Critical speed is when loss of pumping ability occurs due to centrifugal force. In a comparison between Freudenberg’s patent-pending D11 polymer thrust washer and its traditional thrust washer, the effectiveness of the new scoop design becomes obvious. The new polymeric thrust washers have nine times the pumping ability and three times the critical speed.

These designs are ideal for applications with limited or splash lubrication. The scoop feature is able to successfully move fluid under the washer to enable the application to run at higher critical speeds – up to 10,000 rpm – and pressures without failure.

An Exciting New Industrial Solution

“This patent-pending design is ideal for transmissions and driveline components, as well as a number of industrial applications,” says Ray L. Szparagowski, Technical Director Automotive and High Performance Plastics at Freudenberg-NOK Sealing Technologies.

“Our new Levitorq thrust bearings have the potential to optimize lubrication in most applications, so the possibilities are very broad and exciting.”

Freudenberg’s LESS portfolio of engine, transmission and E-Mobility products includes a variety of seals, gaskets, encoders, accumulators, sealing modules and lightweight housings. These products have been uniquely engineered to reduce friction and weight, cut fuel consumption, ease installation challenges and lower emissions. First developed and benchmarked for automotive applications, Freudenberg has been able to leverage its LESS technology for other industrial applications resulting in a significantly shortened development cycle.


The original article was featured on Fruedenberg’s website and can be found here.

Gallagher is an authorized distributor of Freudenberg products. For more information about this low friction bearing, LESS technology, or other Freudenberg products, contact our engineering department.

Friction Reduction in the Seal

Wettablility of the Sealing Lip

The optimum function of rotary shaft seals depends on many factors. One of them is the “wettability” of the sealing lip. This parameter plays a particularly important role with synthetic lubricants such as polyglycol. If wetting is too low, not only does wear on the sealing lip increase, but the contact with the rotating shaft can also damage the shaft itself. The engineers at Freudenberg Sealing Technologies (FST) and Freudenberg Technology Innovation (FTI) have developed a new coating that forms a flexible bond with the elastomer of the seal and significantly improves wetting with synthetic lubricants.

Thanks to different materials and shapes, radial shaft seals for sealing rotating shafts can be used in a wide variety of industrial applications. What they all have in common is the demand for the lowest possible friction, low wear, and reliable sealing effect. Optimum lubrication of the entire tribological system depends on permanent wetting of the sealing lip.

This poses a particular challenge for poorly wetting lubricants based on polyglycol, which are used in drive technology, for example in worm gears. Too little wetting increases wear on the sealing lip and can also lead to increased shaft runout due to contact with the shaft, which ultimately necessitates replacement of the machine parts.

A flexible bond over a long service life

picture of friction reductionFST has developed the new 75 FKM 585 plus coating to achieve optimum lubrication in gears and pumps with synthetic lubricants. “We have succeeded in coating the sealing lip in such a way that polar oils distribute much better,” explains Dr. Matthias Adler from FST’s global materials development department in the Simmerring Industry division. “The mechanics of the layer have been modified so that it forms a flexible bond with the elastic material of the elastomer over a long service life – even under dynamic load. In addition, the coating is applied where no wear occurs.” The current development was specially designed for customers who already use the standard Simmerring 75 FKM 585 in drives for which the use of polyglycol oils is recommended by the manufacturers.

The elastomer is coated using plasma-assisted chemical vapor deposition (PE-CVD). In this process, the elements in the process gas form a chemical bond with the surface of the base body. The decisive criterion for the optimization of the wetting behavior is the targeted modification of the interaction between the coating and the synthetic lubricant. The measurements show that by using special components in the new surface coating such as carbon, oxygen and silicon in a certain molar ratio, optimal wetting can be achieved compared to the standard material 75 FKM 585.

New technology can be transferred to other materials

The layer thickness of 75 FKM 585 plus is a few hundred nanometers and its properties meet the standards of the manufacturers of industrial gear units with regard to oil/elastomer requirements. Although it is designed for particularly low wear at high revolutions, it has been shown that the coefficient of friction is significantly lower than that of the standard material, even at low speeds such as in the breakaway forces and mixed friction ranges. The newly developed technology is not limited to applications with FKM, adds Dr. Adler, “but can also be transferred to other materials. Initial tests on NBR and EPDM have also shown positive results in optimizing the interaction between coating and poorly wetting oils.”


The original article was published by Ulrike Reich, head of media relations & internal communications at FST.

Gallagher Fluid Seals is an authorized distributor of Freudenberg Sealing Technologies. For more information about how we can help with your specific application, please contact our engineering department.

How to Properly Measure an O-Ring

Measuring an O-Ring is quite simple when you have the right tools at your disposal. All that is required is a clean, level surface; an o-ring; and a measuring device such as a caliper or other measuring tools such as cones, gauges, and size charts.

Directions to Measure an O-Ring

To measure an O-Ring, following the directions below:

  1. Place your o-ring on a flat surface clean of debris.
  2. Determine the inside diameter (ID) and outside diameter (OD) of the o-ring. The o-ring dimensions chart below illustrates where on the o-ring each dimension is measured.
  3. Measuring the width, or cross-section (CS), can be tricky and is measured by lightly pressing the caliper ends onto O-ring as shown in section A-A.

For more information on O-ring sizes click to see the JIS B 2401 Standard O-Ring Size Tables.

Dimensionally specifying an o-ring can typically be done with just two dimensions, the inner diameter (ID) and the cross-section (CS). Occasionally, an O-ring may be specified with an outer diameter (OD) and cross-section or an inner diameter and outer diameter. If two of the three dimensions are known, the third can be calculated using the formulas shown below.

O-Ring Dimensions

O-Ring Dimensions

 

O-Ring Dimension Calculations

o-ring dimension calculations


The original article can be found on Dichtomatik’s website. Gallagher Fluid Seals is a distributor of Dichtomatik, a brand of Freudenberg.

For more information about measuring o-rings or determining the best o-ring to use, please contact Gallagher’s engineering department.

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.