Tag Archives: elastomers

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

Is an ASTM Callout the Best Way to Specify Your Elastomer Needs?

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Fred Fisher, Technical Sales Manager for Parker O-Ring & Engineered Seals Division.


ASTM Elastomer Compounds

elastomer materials pictureWhen looking at drawings to define a specific application or elastomer requirement: Is there value in using an ASTM elastomer compound description versus listing an approved Parker compound number?

Specifying a compound using the ASTM callout is a good start – it clearly defines what is wanted and it sets a minimum benchmark, which makes it easy for competitive vendors to understand what the need is. The ASTM standards also set specific test parameters which makes it much more simple to do an “apples to apples” comparison between two compounds. However, over time, here is what customers have learned:

Know Your Operating Requirements

1. The ASTM standards are very general; so when a customer defines a specific FKM they need using an ASTM callout, they might receive a compliant material that just barely meets the ASTM specifications, but did not meet the actual operating requirements. Because of that, a supplier may provide a customer with the lowest cost material. Let’s say the quality of the material is on the lower-end, but it meets the ASTM criteria requested. Because of that, the customer could see a 15% increase in assemblies requiring rework, plus a rising number of warranty claims due to seal failures. The twenty cents per seal that the customer saved for their $50 application would be offset by the cost of the increased product failures. And ultimately, this would result in an unhappy customer.

Know the Fluids Your Seals Will be Exposed to

fluid exposure2.  The ASTM standard does not specifically list what actual chemicals the seal has to be compatible with as well as the operating conditions. ASTM tests compatibility based on Standardized Testing Fluids, which are: Oils, Fuels, and Service Liquids. ASTM uses standard oils, which are defined by IRM 901 and 903. Again, the ASTM standards are excellent for comparing compounds, but most people do not have their seals operating in the ASTM reference oils and many sealing applications are exposed to multiple fluids.

Know What Your ASTM is Calling Out

3.  Most engineers or folks in purchasing who review or utilize older drawings have no idea why the original engineer chose the specific compound or why they used an ASTM callout.

So what is the best way to define and specify an elastomer? Most companies go through a technical process to specify, test. and confirm that an elastomer is the correct choice for their application. All elastomers tested and approved for the application should be clearly listed on the drawing. In addition, the drawing should clearly state that  the approved materials listed were tested to confirm their suitability for the application. All substitutes or new elastomers must be tested and approved by engineering prior to use.


Gallagher Fluid Seals is an authorized distributor for Parker. For more information about their products, including o-rings or their various compounds, contact Gallagher Fluid Seals today.

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

Elastomer Seals for Instrumentation: Seal/Groove Design

Seal Design: Instrumentation IndustryGallagher recently released our High Performance Elastomer Seals for the Instrumentation Industry White Paper.  This was written by Russ Schnell, an Elastomer Consultant contracted by Gallagher Fluid Seals, and a former Senior Application Engineer with the Kalrez® perfluoroelastomer parts business at DuPont.  This white paper is now available for download on our Resources page.

Below is the third and final section of the white paper, which will discuss the importance of proper seal and groove design.


Proper Seal & Groove Design

Elastomer Seal: Perfluoroelastomer PartsProper seal design is a necessity for elastomer seals to perform reliably over the long term. Many of the instrument applications mentioned above use o-ring seals. The suggested compression for an elastomer o-ring seal to perform properly is typically a minimum of 16%, and a maximum of 30%. However, this range must also take into account the thermal expansion of an elastomer at elevated temperatures as well as any swell due to chemical exposure. Many of the elastomer seals used in instruments are small o-rings, which can create design issues. This is especially true for perfluoroelastomer parts which have a relatively high coefficient of thermal expansion (CTE). Fluoroelastomers have a lower CTE, making seal design easier at elevated temperatures.

Continue reading Elastomer Seals for Instrumentation: Seal/Groove Design

[VIDEO] How to Choose a Fluoroelastomer

Fluoroelastomer Basics - Consideration When Choosing a FluoroelastomerGallagher Fluid Seals recently posted our new Fluoroelastomer Basics webinar on gallagherseals.com.  This is the third and final section of our webinar, focusing on Considerations When Choosing a Fluoroelastomer. The full video is now available on our Resources page.

This video discusses considerations when choosing a fluoroelastomer, including temperature performance range, performance in harsh chemical exposure, and the need to take caution when using fluoroelastomer blends.

[VIDEO] Fluoroelastomer Materials

Gallagher Fluid Seals recently posted our new Fluoroelastomer Basics webinar on gallagherseals.com.  This is the second section of our webinar, focusing on Fluoroelastomer Materials. The full video is now available on our Resources page.

This section of the video discusses different fluoroelastomer materials, along with their mechanical and physical properties, and in which applications they’re normally found.

[VIDEO] Basic Understanding of Fluoroelastomers

Fluoroelastomer Basics - DOWNLOAD VIDEOGallagher Fluid Seals recently posted our new Fluoroelastomer Basics webinar on gallagherseals.com.  This is the first section of our webinar, focusing on the Basic Understanding of Fluoroelastomers. The full video is now available on our Resources page.

In this snippet, learn the differences between elastomers and fluoroelastomers, and how the amount of fluorine in an elastomer affects it’s chemical resistance and properties.

 

NEW! Elastomer Failure Modes – Part 4

Failure ModesGallagher recently published its Failure Modes of Elastomers in the Semiconductor Industry White Paper, now available for download on our site.  This white paper discusses common issues that occur with elastomer seals in the semiconductor industry. The excerpt below is the fourth and final section of our new white paper, discussing Volatiles (offgassing) and Particle Generation.  To download the white paper in its entirety, visit our Resources Page, or click on the image to the right.


Failure Modes of Elastomers in the Semiconductor Industry

Failure ModesHigh performance elastomers are found in many applications in the semiconductor industry (see paper titled Perfluoroelastomers in the Semiconductor Industry). Though perfluoroelastomer (FFKM) seals are formulated to meet the highest performance requirements of integrated circuit (chip) manufacturers, even these elastomers can’t solve every sealing application nor will they last forever in service. Additionally, end users need to understand subtle performance differences between perfluoroelastomers in the same product line. For example, one product may be better at minimizing particle generation while another may be better for high temperature services.

Continue reading NEW! Elastomer Failure Modes – Part 4

NEW! Elastomer Failure Modes – Part 3

Failure ModesGallagher recently published its Failure Modes of Elastomers in the Semiconductor Industry White Paper, now available for download on our site.  This white paper discusses common issues that occur with elastomer seals in the semiconductor industry. The excerpt below is the third section of our new white paper, discussing O-Ring Stretch, Chemical Attack, Plasma Cracking, and Permeation.  To download the entire white paper, visit our Resources Page, or click on the image to the right.


Failure Modes of Elastomers in the Semiconductor Industry

Failure ModesHigh performance elastomers are found in many applications in the semiconductor industry (see paper titled Perfluoroelastomers in the Semiconductor Industry). Though perfluoroelastomer (FFKM) seals are formulated to meet the highest performance requirements of integrated circuit (chip) manufacturers, even these elastomers can’t solve every sealing application nor will they last forever in service. Additionally, end users need to understand subtle performance differences between perfluoroelastomers in the same product line. For example, one product may be better at minimizing particle generation while another may be better for high temperature services.

Continue reading NEW! Elastomer Failure Modes – Part 3

NEW! Elastomer Failure Modes White Paper

Failure ModesGallagher recently published its Failure Modes of Elastomers in the Semiconductor Industry White Paper, now available for download on our site.  This white paper discusses common issues that occur with elastomer seals in the semiconductor industry. The excerpt below is the first section of our new white paper, discussing groove design and seal leakage.  To download the entire white paper, visit our Resources Page, or click on the image to the right.


Failure Modes for Elastomers in the Semiconductor Industry

Failure ModesHigh performance elastomers are found in many applications in the semiconductor industry (see paper titled Perfluoroelastomers in the Semiconductor Industry). Though perfluoroelastomer (FFKM) seals are formulated to meet the highest performance requirements of integrated circuit (chip) manufacturers, even these elastomers can’t solve every sealing application nor will they last forever in service. Additionally, end users need to understand subtle performance differences between perfluoroelastomers in the same product line. For example, one product may be better at minimizing particle generation while another may be better for high temperature services.

Continue reading NEW! Elastomer Failure Modes White Paper