Choosing the Right Rubber for Low Temperatures

Ice Road
Vehicles need rubber door and window seals that can withstand low temperatures.

Paulo Arruda
Purchasing and Logistics at Elasto Proxy

Cold temperatures can cause rubber parts to contract, lose their flexibility, and become brittle. These problems affect seals and gaskets, which can harden at low temperatures and resist deformation to pressure. Here in Canada, where Elasto Proxy is based, suppliers of on-road and off-road vehicles need door and window seals that won’t quit when the weather grows cold. Manufacturers in other parts of North America and all around the world also need sealing and insulation for extreme environments.

For over 25 years, Elasto Proxy has specialized in the design and custom fabrication of rubber products for a variety of industries. By analyzing your requirements and listening to your needs, we can help you select the right rubber for your low-temperature application. Material selection can be complex, and all rubber isn’t the same. If you choose a compound that contracts at cold temperatures, seal failure may occur. When the contact surface shrinks, look for leaks of liquid or air.

Fortunately, technical buyers don’t have to be material scientists to avoid seal-related problems. By understanding what to ask for – and that many different types of rubber are available – you can select a compound that’s made with just the right recipe for your application. Vulcanization, a chemical process that uses sulfur or other curatives, converts polymers into more durable materials. Vulcanized elastomers are made of natural or synthetic rubber, and meet specific low-temperature requirements.

ASTM D2000 Callouts for Low-Temperature Rubber

ASTM D2000 is a published standard that provides buyers and suppliers with a common way to describe vulcanized rubber materials. Originally designed for automotive applications, this publication from ASTM International is used also by other industries.  As How to Read ASTM D2000 Specifications explains, the ASTM D2000 description for a vulcanized rubber contains letters and numbers that designate or “call out” specific material properties and testing conditions.

In the ASTM D2000 specification, the letter F is used as a callout to indicate low temperature resistance. This letter is then followed by a number that indicates the test method and test temperature. For example, the callout F17 indicates that the material was tested under ASTM D2137 for its ability to withstand breaking when bent at a given temperature for a period of time. This three-minute test is performed at temperatures under -40° C, and the sample must be non-brittle at the end of the test.

Vulcanized rubber with the callout F19 is also tested under ASTM D2137 for brittleness point, but under even colder conditions. This three-minute test is performed at temperatures under -55° C, and the test sample must be non-brittle at the end of the test period. If your project specifications state temperature requirements in Fahrenheit, note that -55° C equals -67° F. Because of the way that degrees Celsius are converted to degrees Fahrenheit, however, -40 C° equals – 40° F. You can learn why here.

Additional Application Considerations

Many rubber products that are exposed to low temperatures are used in outdoor conditions. That’s why suppliers of mobile specialty vehicles need to select compounds that can withstand sunlight, water, and even road salt. EPDM rubber is often the right choice for these outdoor environments, with applications ranging from door seals to hoses and tubing. Indoors, EPDM seals are used with cold-room doors since this synthetic rubber is an effective insulator.

Does your project require an elastomer than can resist low temperatures along with oils and lubricants? Do you need to source cost-effective compounds that can withstand both low and high temperatures? By taking the time to understand everything that you need, Elasto Proxy can recommend the right rubber, strengthen your seal designs, and then custom fabricate high-quality rubber parts for you.

How can we help you choose the right rubber for low temperatures? Contact Elasto Proxy on-line to learn more about what we can do for you. You can also join the conversation about this topic on LinkedIn, Facebook, Google+, and Twitter. Elasto Proxy has a YouTube channel, too. There, you’ll find our Capabilities video, as well as other informative content. Finally, please subscribe to our free e-newsletters. They’re a great source of information, too.

EMI Gaskets for Military Electronics

EMI RFI Shielding Products
EMI RFI Shielding Products

Doug Sharpe
President of Elasto Proxy

Electromagnetic interference (EMI) can disrupt military electronics and endanger the lives of the war-fighters who depend on them. The causes of EMI are numerous, and include everything from electric motors and radio transmitters to computer circuits and power lines. Electronic jamming or intentional EMI (IEMI) also concerns military planners. Military radios, cameras, sensors, and telecommunications systems can experience interruptions during battlefield conditions, or suffer permanent damage.

Several global incidents underscore these concerns. In May 2012, over 500 airplanes in South Korea experienced global positioning system (GPS) failure from electromagnetic fields that were traced to the North Korean city of Kaesong. Two years earlier, North Korea reportedly purchased truck-based systems that could jam GPS signals. IEMI weapons were used in Chechnya against the Russian military, and in Moscow against a standard telephone system.

Environmental Sealing and EMI Shielding

Military environments are especially challenging, so technical buyers and electronic designers need to select materials with the right balance of properties. Particle-filled silicones are elastomeric compounds that combine the advantages of silicone with the electrical characteristics of metals. An inert, synthetic rubber, silicone offers thermal stability over a wide temperature range and resists ozone and ultraviolet (UV) light. Silicone rubber also resists water, and can be formulated to impart electrical conductivity.

When filled with metal particles, silicone compounds can be used to fabricate gaskets that provide both environmental sealing and EMI shielding. Metal fillers include particles made of pure silver, silver-plated aluminum, or silver-plated copper. Conductive silicones that are filled with silver-plated glass, nickel-plated graphite, and carbon black are also available. Before choosing a compound, however, buyers and designers need to understand application requirements and applicable military standards.

Understanding MIL-DTL-83528C

MIL-DTL-83528C is a general specification from the U.S. Department of Defense (DOD) for electrically-conductive elastomeric shielding gaskets. Released in January 2001, it supercedes the MIL-G-83528B standard that is sometimes still referenced in data sheets. MIL-DTL-83528C sets requirements for part identifying numbers (PIN) and contains a Material Type section with lettered designations for both silicone and fluorosilicone compounds.

For example, Type B materials are silver-plated, aluminum-filled silicones that are capable of 100 dB of plane wave shielding effectiveness at 10 GHz with a continuous use temperature range from -55°C to +160°C. Conductive fluorosilicone shielding materials also carry shielding effectiveness and temperature specifications, and offer resistance to solvents and jet fuels. By understanding your sealing and shielding requirements, an EMI gasket fabricator can recommend the right material.

How Can We Help You?

Does your project require a Type B silver-plated, aluminum-filled silicone with a Qualified Products List (QPL) acknowledgement from the Defense Logistics Agency (DLA)? Elasto Proxy can source cost-effective conductive compounds for you, and them custom fabricate high-quality EMI gaskets. Our solutions providers can also source EMI shielding materials that are designed to meet the requirements of other parts of the MIL-DTL-83528C specification

For over 25 years, Elasto Proxy has custom-fabricated specialty seals and custom insulation for military and defense. How can we help you with EMI gasketing? Contact us today, or join the conversation about this blog entry on LinkedIn, Facebook, Google+, and Twitter. Elasto Proxy has a YouTube channel, too. There, you’ll find our Capabilities video, as well as other informative content. Finally, please subscribe to our free e-newsletters.

EMI Shielding for Automotive Applications

EMI Shielding from Elasto Proxy
EMI Shielding from Elasto Proxy

Doug Sharpe
President of Elasto Proxy

Today’s automobiles are equipped with automotive electronics that direct drivers and manage vehicle safety and performance. Advanced cameras check for pedestrians. Adaptive cruise control automatically adjusts your speed to stay a safe distance away from vehicles ahead. An alarm beeps or the driver’s seat vibrates if your car leaves its lane. Truck headlights brighten or dim with changes in lighting conditions and oncoming traffic. Collision warning with automatic braking can slow or even stop your vehicle.

Does your car, truck, or sports utility vehicle (SUV) have these safety features? If not, your next ride probably will. Meanwhile, automakers are incorporating additional electronics for security, navigation, communications, and entertainment. After all, technologies such as global positioning systems (GPS), Bluetooth, and other radio frequency (RF) applications delight car buyers. For electronic designers and electromagnetic compatibility (EMC) consultants, however, there are other important considerations.

What Is Electromagnetic Interference (EMI)?

Installing a large number of electronics into a small interior space can cause these systems to interfere with each other. Malfunctions or failures caused by cross-talk aren’t the only risks, however. Strong electromagnetic fields (EMFs) can affect human health. That’s why the batteries in electric vehicles (EVs) are enclosed in more than just a metal box. A shielding gasket atop the box contains EMFs and prevents electromagnetic interference (EMI) from the battery from disrupting other electronics.

EMI gaskets are also used with the inverters and converters that manage the power and recharging circuits in electric cars and hybrid electric vehicles. Shielding gaskets are also needed at EV charging stations, where multiple chargers can generate strong EMFs as well as EMI. Paying for an EV charge could pose a problem, however. Electronic cash registers have drawers for dollar bills, and point of sales (POS) systems use electronics for credit card processing. Both need EMI gasketing.

EMI shielding isn’t just for electric cars and hybrid vehicles, however. Luxury automobiles powered by gasoline or diesel engines use cameras, sensors, and radar. As more mid-range models add automotive electronics, carmakers will need EMI shielding solutions that balance performance with cost. For EMC consultants and designers of automotive electronics, it’s important to know which shielding materials work best – and which gasket fabricator can meet all of your requirements. 

Particle-Filled Silicones for EMI Gaskets

EMI gaskets aren’t new, but some buyers still think that particle-filled silicones are too hard, too brittle, too expensive, and too thick for automotive electronics. Loading a high percentage of particle filler into silicones can result in tough tradeoffs, but Elasto Proxy sources innovative elastomers that address these concerns. The shielding materials we recommend balance electrical conductivity with cost-effectiveness, and provide benefits that strengthen your electronic designs.

For example, the particle-filled silicones we source can be used in shielding gaskets that are thin, flexible, and able to withstand the high temperatures associated with automotive engines. Silicone gaskets from Elasto Proxy also provide environmental sealing. Fluorosilicone gaskets are available for automotive applications that involve contact with fuels or solvents. Silicones provide many desirable properties, and compounding this rubber makes it a great choice for EMI shielding.

Today, silicone gaskets that are filled with nickel-coated graphite particles are used between metal enclosures to protect automotive fuses. Elasto Proxy can also source semi-conductive silicones filled with carbon black for static dissipation. Both conductive materials are available in continuous rolls, a form factor that promotes the cost-effective fabrication of EMI shielding. Elasto Proxy can also source particle-filled EMI shielding as uncured moldable compounds and compression molded sheet stock. 

How Can We Help You?

For over 25 years, Elasto Proxy has custom-fabricated specialty seals and custom insulation for a wide range of industries, including automotive and mobile specialty vehicles. How can we help you with EMI gasketing? Contact us today, or join the conversation about this blog entry on LinkedIn, Facebook, Google+, and Twitter. Elasto Proxy has a YouTube channel, too. There, you’ll find our Capabilities video, as well as other informative content. Finally, please subscribe to our free e-newsletters.

Is Outsourcing In Your Plans for 2015?

Outsourcing in 2015
Is Outsourcing in Your Plans for 2015?

Doug Sharpe
President of Elasto Proxy

Are you thinking about outsourcing some of your fabrication in 2015? Chris Coghlin, the CEO of Cogmedix has some good advice – and it’s not just for medical device manufacturers. “Often,” he explains in an article for Medical Device Technology (MDT) magazine, “the temptation is to choose a contract manufacturing partner based solely on the price per unit cost. Don’t be too short sighted.”

Outsourcing Costs and Challenges

Whether you make medical equipment or agricultural machinery, it’s important to consider all of your costs – and all of your potential challenges. Otherwise, your company could face problems ranging from “poor product quality” to “high field service costs”, Coghlin explains.

For example, if you’re a medical equipment manufacturer, poor-quality EMI shielding could fail to protect sensitive electronics from electromagnetic interference (EMI). If you’re a maker of tractors, the cost of replacing defective door seals could involve both labor and materials.

Before outsourcing a project, however, it’s important to determine whether a potential partner has the custom fabrication capabilities and supply chain strength to deliver. In short, you’ll need to decide whether their internal operations are strong enough to meet all of your requirements.

Offshoring and Outsouring

Chris Coglin examines this idea in a white paper called Solving the Outsourcing Equation. As the CEO explains, an electronics OEM that brought outsourced operations back home realized a significant cost savings. Offshoring was cost-effective when production volumes were high, but not when demand fell.

Cost containment is critical, of course, but it’s not the only factor to consider. Technologies and regulations evolve, and your company’s products need remain competitive – and compliant with standards and regulations. Your business is ready for the New Year, but what about beyond 2015?

Today, a potential outsourcing partner’s per-unit cost may seem paramount. But does the contract manufacturer have the technical expertise to help you address tomorrow’s challenges, too? For that matter, how well do they understand factors such as FDA regulations and vehicle safety requirements?

How Can We Help You?

For over 25 years, Elasto Proxy has custom-fabricated specialty seals and custom insulation for a wide range of industries, including makers of mobile specialty vehicles and manufacturers of medical devices and equipment.

How can we help you make 2015 your greatest year yet? Deciding whether to make it or buy it is an important business decision, and Elasto Proxy has the technical knowledge and application expertise to help you evaluate the outsourcing of high-quality rubber parts such as custom gaskets.

Are you ready to talk about outsourcing? Look for us on LinkedIn, Facebook, Google+, and Twitter. Elasto Proxy has a YouTube channel, too. There, you’ll find our Capabilities video, as well as other informative content. Finally, please subscribe to our free e-newsletters.