Material Selection and Chemical Resistance

Chemical Resistance
Chemical Resistance

Philippe Grenier
Production Coordinator at Elasto Proxy

Last week, we learned how a failed seal on a diesel tank’s access door traveled through a fuel line and clogged an engine. Believed to be made of Buna, a synthetic rubber known for its chemical resistance, the gasket disintegrated from the splash of diesel fuel after just a few weeks. What can technical buyers learn from this experience, and how can seal fabricators help them source the right rubber compounds?

Charts and Chemical Resistance

Rubber manufacturers publish charts that describe the suitability of various elastomers for service with specific chemicals, including diesel fuel. When evaluating rubber materials, suppliers consider factors such as service temperature, service condition, material grade, and durometer. The material properties of the rubber compound itself are also important to consider.

As a rule, higher temperatures increase the effects of chemicals on rubber compounds. Although these increases vary with both the material and the chemical, all polymers are affected by high temperatures. In the case of our failed door seal then, was the gasket exposed to unusually high heat? This is different than service condition, which refers to the gasket’s suitability for static or dynamic sealing.

Grades, Fillers, and Costs

Door seals are dynamic seals in that one surface (the door) is in motion relative to the other (the door frame). To prevent fluid leakage, a specific amount of compression is required to maintain contact with the sealing surfaces. Just as different rubber materials can withstand different amounts of compression, different grades of the same rubber may have different compression and recovery characteristics.

If material properties don’t meet all of an application’s requirements, gaskets may not seal properly. The use of fillers to reduce costs or alter material properties may also play a role. Pure Buna costs more and has different characteristics than Buna that contains fillers. Durometer (duro), a measure of hardness, may also be a factor  since harder compounds generally provide greater chemical resistance.

Lettered Rating Systems

To express chemical resistance in a standardized format, rubber manufacturers use a lettered rating system to indicate a material’s suitability for use with a specific chemical. The letter A indicates that the rubber is recommended with only minor effects from the chemical. The letter B indicates that there are minor to moderate effects, but that parts made of the material are still useful in many applications.

This lettered system also indicates if a compound is potentially problematic, unsuitable, or unknown in its chemical resistance. The letter C denotes that the chemical can have moderate to severe effects on the material, and that rubber parts are useful only in limited applications. The letter U means that the rubber is not recommended, or that the chemical’s effects on the material are still unknown.

Is there more to selecting the right rubber than reading a chart? Yes, of course! Although the reasons behind the failed fuel-tank door seal are still in doubt, I’m certain about one thing. It’s critical to work with partners that you trust, who ask questions about your application, and who analyze the answers before recommending sealing solutions.

Do you have questions about material selection and chemical resistance? Do you need help balancing application requirements against material costs? How can we help you? Please comment on this blog entry, or contact us today.

Material Selection and Supplier Relationships

Buna Profile Diesel Damage CloseUp

Philippe Grenier
Production Coordinator at Elasto Proxy

Diesel engines are big, powerful, and a lot more expensive than the rubber seals used with vehicle fuel tanks. If a gasket on an access door fails, however, a rubber part that costs just a few dollars can stop an engine that costs thousands. For the owners of diesel-powered equipment, engine failure can mean repairs and downtime. For suppliers who provide rubber compounds to seal fabricators, the cost of component failure can mean a loss of trust.

Seal Failure

Consider the case of a rubber gasket used on a 2’ x 2’ access door for a diesel fuel tank. The gasket fabricator ordered Buna N from an overseas supplier, but believes to have received low-quality material. The custom-fabricated component was delivered on-time and installed properly, but lasted just two weeks in the field.  The splashing of diesel fuel caused the rubber to disintegrate, sending small pieces of material through the fuel line and clogging the engine.

Today, a laboratory is inspecting the failed seal to determine if the rubber compound that was supplied was really Buna N, a synthetic material that offers resistance to oil, fuel, and other chemicals. The lab is also checking the rubber’s durometer or duro, a measure of hardness, to determine if the material met the fabricator’s (and the customer’s) specifications. All of the original material has been scrapped, and new Buna N obtained from a trusted, local supplier.

The Importance of Trust

Without trust, supplier relationships cannot succeed – especially in our global economy. In the case of the failed door seal, the original material came from China and was delivered to the fabricator in North America. The Chinese supplier had filled several orders before, with one other material-related problem. After just six months, a silicone gasket had dried out and cracked prematurely.

For companies that do business in China, there are many challenges to overcome. For example, by the time rubber compounds arrive in North America, it may be too late to meet customer delivery dates if inspection reveals that materials are defective. Inspecting rubber compounds before they leave China is one solution, but trust and a shared commitment to quality is preferable to the need for verification.

Customers and Compound Selection      

Now that you know the story of the failed fuel-tank seal, we’ll examine how customers can source the right rubber compounds. Next week, we’ll look at the chemical resistance of various elastomers and consider how to balance your application requirements against material costs. We’ll also consider why it’s important for supply chain partners to ask questions about your application requirements, and how a trusted custom fabricator can help your business with that process.

Rail Safety, Canada’s Energy Future, and the Lac-Mégantic Disaster

Lac megantic

Image source:

By Clyde Sharpe
President of International Sales

Lac-Mégantic is a town of 5,900 that sits on the shores of a freshwater lake near Quebec’s border with Vermont.  According to the area’s original inhabitants, the Abenaki, the word Mégantic means “place where fish gather”. What most people now know about Lac-Mégantic, however, is that it’s the site of a recent train derailment marked by fire, death, and unanswered questions.

Freight Train Derailment and Crude Oil Explosion

On the night of July 6, 2013, an unattended freight train rolled down a 1.2-degree grade and picked up speed. By the time the runaway train reached a curve in nearby Lac- Mégantic, the locomotive and all 73 cars were traveling too fast. Owned and operated by the Montreal, Maine, and Atlantic (MMA) Railway, the freight train included 72 tanker cars carrying crude oil from North Dakota to New Brunswick.

Although firefighters extinguished a blaze in the locomotive, explosions rocked Lac- Mégantic during the early hours of July 7th. While much of the downtown was immersed in oil and fire, as many 30 buildings were destroyed. Over 1,000 residents were evacuated from their homes, with some still unable to return. Today, a boil-water advisory remains in effect for the “place where fish gather”.

As a family-owned company based in Boisbriand, Quebec, Elasto Proxy is saddened by this tragedy that has now claimed 15 lives with 60 people missing.  For those of us who visited Lac-Mégantic before the train derailment, our memories of this beautiful community are fond ones. We will keep the residents of Lac-Mégantic in our thoughts and prayers, and encourage them as they rebuild the place they call home.

Energy Controversies

Yet we must also ask how similar tragedies can be prevented. Although the cause of the Lac-Mégantic train derailment is still undetermined, CTV News reports that that rail shipments of crude oil have increased 28,000% over the last five years. Billed as a cost-effective alternative to controversial pipelines such as the Keystone XL, oil trains may provide the fuel for a new political firestorm.

Then there’s hydraulic fracturing, the controversial process used to extract the North Dakota crude oil that spilled in Lac-Mégantic. Commonly known as “fracking”, this technique mixes water with sand and chemicals and then injects the mixture at high pressures into a well bore.  According to opponents, the environmental damage from fracking far outweighs its economic benefits.

Emerging oil extraction technologies may also spark debate about Canada’s energy strategy. As Reuters reports, energy companies want to remove a sludgy, tar-like substance called bitumen from porous rock in northern Alberta. Today, Canada holds the third largest oil reserves in the world. By extracting some a projected 500 billion barrel of oils from bitumen, however, Canada would claim the top spot.

Rail Containment Systems

What place will technology have in debates about Canada’s energy future – and are there ways to make rail shipments of crude oil safer today? Tank spill prevention and containment systems are available, but can they be safely, reliably, and economically modified for railcars? How about fuel bladder containment systems that could absorb impacts and provide high structural strength?

There are still many questions surrounding the Lac-Mégantic train derailment and disaster. What are your thoughts on rail shipments of crude oil? How about fracking and the extraction of bitumen from Canada’s oil sands? Can new containment systems make rail shipments safer, protecting not only lives and property, but also our natural resources? I hope you’ll join the conversation by commenting below.

Cable Cleats for Electrical Conduits and Hydraulic Hoses

Cable Cleats Elasto Proxy


Alex Bergeron
Sealing Solutions Provider at Elasto Proxy

Image source:

Did you drive to work today? Did you use mass transit instead? If you commuted by car, maybe you pressed a button to roll down the power windows and let in some fresh air. If you traveled to the office by bus, maybe you noticed that the driver braked and shifted gears.  If you took a subway or elevated train to the jobsite instead, you entered and exited a passenger car through powered doors.

Electrical Cables and Hydraulic Hoses

Automobiles, mass transit, mobile specialty vehicles, and even military transports all use electrical and hydraulic systems. Jacketed cables consisting of bonded, twisted, or braided wires carry electric current to doors, windows, and instrument panels. Sturdy but flexible hydraulic hoses carry high-pressure fluid to brakes and transmission systems. Though often unseen, cables and hoses are mission-critical.

Securing a vehicle’s electrical cables and hydraulic hoses is important, too, both for vehicle performance and passenger safety. Cable cleats, durable rubber components that retain and secure these conduits, must be properly designed and made from the right compound. Often, these rubber parts are installed on a vehicle’s undercarriage, where conditions are especially demanding.

Cable Cleat Location and Material Selection  

For example, cable cleats used on snowplows must be able to resist cold temperatures, bad weather, road salt, and aggressive chemicals that help keep roadways safe during winter driving conditions. On buses and trains that run year-round, cable cleats may need to withstand sunlight, extreme weather, and temperatures that can range from +40° C to -40° C.

Typically, rubber cable cleats are made of silicone or EPDM. A synthetic resin, silicone is a polymer that repels water and is suitable for use over a wide temperature range. EPDM rubber is also synthetic, and is a reliable elastomer that provides good resistance to ozone and UV rays.

Form and Function

Cable cleat location and compound selection are important, but they’re not the only considerations when designing and fabricating these rubber parts. Do you need to secure one or more hydraulic hoses, electrical cables, or both? What are the sizes of the conduits you need to support? Cable cleats can be molded into various shapes and sizes, and even e color-matched to your vehicle.

As a custom-fabricator of high-quality, low-volume rubber components, Elasto Proxy provides cable cleats for both mass transit and mobile specialty vehicles. Some partners need round, diaphragm-style, or multi-component cable cleats that clamp together after the conduits are installed. Others need parts that look like door hinges or are as small as 1” in diameter to as tall as 16” high. How can we help you?

Elasto Proxy Invites You to Support Centraide Laurentides

Megan Centraide Elasto Proxy Award

Doug Sharpe
President of Elasto Proxy

Are you more likely to tell your friends about a good experience or a bad one? In recent years, books like Satisfied Customers Tell Three Friends, Angry Customers Tell 3,000 have warned organizations about the power of disgruntled people in our hyper-connected age. Blogs and social media channels make it easy to complain to a large audience – and sometimes bad news travels fast.

But what about the good work that a great group is doing? Is there a way to encourage your neighbors to support a charitable organization that is meeting a diverse range of needs? Of course there is! The Elasto Proxy blog entry that you’re reading proves it. In September, our Boisbriand-based company will also visit neighbors face-to-face to encourage them to support Centraide Laurentides.

What is Centraide Laurentides?

Centraide Laurentides is a non-profit organization that helps a network of community assistance groups throughout the Laurentians, the region north of Montreal that Elasto Proxy calls home. By collecting donations from businesses and individuals, Centraide supports food banks, provides tuition assistance, buys eyeglasses, and even pays for children’s visits to museums.

Although Centraide Laurentides is part of the United Way, this organization is independent. There are 18 Centraide branches in Quebec, but all of the money that is donated is used to help our local community. Last year, nearly 9 out of 10 Elasto Proxy employees contributed to Centraide Laurentides via Direct Deposit paycheck deductions. For every dollar employees gave, the company added 2.5 dollars more.

Community Outreach and Increased Involvement

Elasto Proxy continues to support Centraide Laurentides in 2013 and is grateful for the awards the charitable organization has given us. Last year, our family-owned company received the Grand Prize of Excellence for encouraging other employers to donate. Elasto Proxy also earned awards for our rate of employee participation (86%) and for year-over-year increase (36%) between 2011 and 2012.

This year, we will expand our efforts on behalf of Centraide Laurentides by appealing to our neighbors in the industrial park where Elasto Proxy is based. First, we will mail invitations and follow-up with phone calls. In September, Elasto Proxy employees will walk throughout the industrial park, visit neighbors door-to-door, and discuss this year’s fundraising campaign face-to-face.

Help Spread the Word

Is it true that people are more likely to tell their friends about a bad experience than a good one? Perhaps. In our fast-paced, hyper-connected world, it’s now easier than ever to complain. But what about you? Will you share this blog entry via social media, or perhaps leave a comment below? And will you tell your neighbors about the good work of Centraide Laurentians?