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Elasto Proxy's Sealing Solutions Blog

Elasto Proxy's Sealing Solutions Blog is the place for conversation and discussion about the design and custom fabrication of rubber and plastic components. For nearly 25 years, our family-owned company has provided high-quality, low-volume seals to a variety of industries. Doug Sharpe, Elasto Proxy's co-founder, is a former president of the International Sealing Distribution Association (ISD), a not-for-profit trade association that enhances member success through information, education, and interaction. By blogging for CR4 in this same supportive and collaborative spirit, Doug and other members of the Elasto Proxy team will share our experiences with you.

Military Gaskets: Four Things Engineers Need to Know

Posted March 21, 2017 4:55 PM by Doug Sharpe

Military gaskets provide sealing and insulation in some of the world’s most demanding environments. Marine applications include amphibious landing craft, battleships and submarines, and radar and sonar systems. Aerospace applications include aircraft, unmanned systems, satellites, and radar. Military gaskets for land systems are also used in armored vehicles, tanks, tankers, trucks, and onboard electronics.

For design engineers, specifying the right rubber gaskets for military projects can be a complex task. Many defense contractors are familiar with acronyms like MRAP, but has your design team heard of MTAP? This four-letter acronym from Elasto Proxy explains how engineers need to consider media, temperature, application, and pressure during gasket design and compound selection.


The M in MTAP stands for Media. This includes fuels, chemicals, and any cleaning-type solutions that may be applied to a rubber product. For example, the rubber gasket on a tanker truck’s fuel door must provide gasoline or diesel fuel resistance, depending on the type of engine. For that matter, the window gaskets in armored personnel carriers must resist chemical warfare agents (CWA) and support decontamination procedures that remove or neutralize these hazardous substances.


The T in MTAP stands for Temperature, another factor that may limit which materials you can use. If you’re designing a door seal for an armored vehicle, will the seal need to withstand desert heat and arctic cold? What are the maximum, minimum, and typical temperatures? For custom-fabricated components such as cab and engine bay insulation, continuous operating temperature is a key technical specification.


The A in MTAP stand for Application, another term to consider carefully. If you’re designing rubber gaskets for the doors and windows on military vehicles, do you need to account for specific flange types, flange materials, or metal fasteners? If the application is bolt-grade, what do the drawings show about the bolt pattern? EMI gaskets are different than door seals, of course, and can use shielding silicones. Do you need to meet the MIL-DTL-83528 specification for elastomeric shielding gaskets?


Finally, the P in MTAP stands for Pressure. Depending on where the military gasket will be used, there may be several specifications to consider. If the gasket is designed for use with a metal tank, what is the system or internal pressure? If the rubber gasket is for a pump, what’s the operating pressure? Maximum pressure is also important to specify in order to avoid seal failure.

Military Gaskets from Elasto Proxy

Designers of military gaskets need a complete understanding of media, temperature, application, and pressure (MTAP). Elasto Proxy is ready to assist you, and can custom-fabricate the seals, gaskets, and insulation that you need to support the mission. We also offer design assistance and can help with material selection. So whether you need one-off spares, quick-turn prototypes, or low-to-medium volume quantities, Elasto Proxy is ready for any sealing challenge.

For over 25 years, Elasto Proxy has worked hard to earn the trust of the North American defense community. Our first customer, Atlantic Defense Industries, was a military contractor that built the boom hoist on a ten-ton truck. Since then, we’ve supplied the defense industry with custom-fabricated components such as spliced and molded window gaskets, acoustic and thermal insulation, and vibration mounts. Elasto Proxy custom-fabricates EMI gaskets for military electronics, too.

By working closely with our defense industry partners, Elasto Proxy has created sealing and insulation solutions that can withstand extreme conditions. In the process, we’ve invented an acronym (MTAP) that describes what design engineers need to know during compound selection and custom fabrication. What sealing and insulation solutions can we create for you? To learn more, please contact us.

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Medical Grade Gaskets and Platinum-Cured Silicones

Posted March 07, 2017 4:55 PM by Doug Sharpe

Medical grade gaskets made of platinum-cured silicones are used in medical devices and equipment. Elasto Proxy custom-fabricates these rubber gaskets from an ultra-clean line of silicones that are FDA, USP Class VI, and RoHS compliant. At our manufacturing center near Montreal, Canada, we use water jet cutting to convert elastomers with speed and precision. Because there are no tooling charges, water jet cutting is ideal for prototyping and producing low-to-medium volumes of medical grade gaskets.

Elasto Proxy’s custom fabrication expertise includes assistance with seal design and compound selection. Just send us your CAD files and our technical team will use SolidWorks to review your schematics. The medical grade silicones that we custom-fabricate come in a range of durometers, and are available in custom colors to support your product designs. Although platinum-cured silicones are normally translucent, Elasto Proxy can manufacture medical grade gaskets in white, olive drab, and other colors.

Why Platinum-Cured Medical Silicones Are Cleaner

Silicones are synthetic elastomers that require curing or cross-linking. In medical applications, the most common curing systems use either peroxide or platinum. The peroxide system is the oldest cross-linking chemistry for silicones, but requires post-baking to remove byproducts such as volatile organic acids. By contrast, platinum curing system doesn’t require post-curing because there are no by-products. Platinum curing also offers greater control over cure rates.

To provide medical device and equipment manufacturers with high-purity products, Elasto Proxy custom-fabricates medical grade gaskets from platinum-cured silicones. Compared to peroxide-cured elastomers, these silicones have lower levels of extractables – chemical compounds that migrate from a material under conditions such as elevated temperature or surface exposure. Platinum-cured silicones are also more consistent in terms of appearance, an important consideration with medical devices and equipment.

FDA, USP, and RoHS Compliant Silicones

The platinum-cured silicones that Elasto Proxy custom-fabricates comply with FDA CFR 177.2600 requirements for high-purity rubber articles intended for repeated use. This part of the U.S. Code of Federal Regulations (CFR) is reserved for rules established by the Food and Drug Administration (FDA). Section 177.2600 lists allowable materials and sets the extraction limits. If your medical application is for the North American market, using FDA-compliant materials is probably required.

The platinum-cured silicones that Elasto Proxy custom-fabricates also comply with USP Class VI requirements for material biocompatibility. As part of the U.S. Pharmacopeial Convention (USP), USP Class VI is regarded as one of the most stringent requirements in medical device manufacturing. The platinum-cured silicones that we convert also comply with the European Union’s Restriction of Hazardous Substances (RoHS) Directive 2002/95/E, which governs medical electronics and electrical equipment.

Durometers, Colors, and Medical Grade Gaskets

Elasto Proxy custom fabricates medical grade gaskets from platinum-cured silicones that come in durometers ranging from 10 to 80 (Shore A). These medical materials are normally translucent, but can be colored with FDA-compliant pigments to meet your larger product designs. In addition to white and olive drab, Elasto Proxy can manufacture gaskets made of gray, red, plumb, and salmon colored materials. When you speak with our solutions providers, just let us know which color you need.

Importantly, sheets of platinum-cured silicones support cost-effective water jet cutting for tight tolerances and quick turn-around times. As a complete custom-fabricator, Elasto Proxy also provides splicing, taping, and laminating services. For an example of our custom fabrication capabilities, read about Fluorosilicone Gaskets for Pharmaceutical Equipment. You’ll enjoy our Fluorosilicone Gaskets in Five Steps video, too.

Are you ready to learn more about platinum-cured silicones for medical grade gaskets? Elasto Proxy is ready to help, but we need to hear from you. Contact us on-line anytime.

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EMI Shielding Gaskets for Military Electronics

Posted March 01, 2017 4:55 PM by Doug Sharpe

EMI shielding gaskets for military electronics are used in everything from touchscreens to targeting systems. To prevent electromagnetic interference (EMI) from disrupting electronic equipment, Elasto Proxy custom-fabricates EMI shielding gaskets from particle-filled silicones. These specialized materials combine the materials properties of silicone rubber with the electrical properties of metal. Elasto Proxy uses waterjet cutting to convert shielding silicones, and bond cut lengths with conductive adhesives.

EMI gaskets from Elasto Proxy meet the requirements of MIL-DTL-83528, a U.S. Defense Logistics Agency (DLA) specification for electrically-conductive elastomeric shielding gaskets. MIL-DTL-83528 establishes minimum shielding effectiveness levels for various material types over a frequency range of 20 MHz to 10 GHz. MIL-DTL-83528 also specifies hardness or durometer (Shore A) measurements for shielding silicones that are categorized as low, medium, or high durometer.

Advantages of Elastomeric Shielding Gaskets

Traditionally, EMI shielding has been made of metal sheets and formed or fabricated into custom shapes. Sheets of copper, aluminum, and steel provide rigidity and strength, but can deform under the mechanical pressure that’s required for sealing. Once deformed, metal EMI shields tend to maintain their deformed shape and may admit electronic interference. Some metals are also susceptible to rust, corrosion, and oxidation.

Today, EMI shielding materials include flexible metal screens, metal wires, and metal foams. Coatings made of metallic inks are sometimes applied to the interiors of electronic enclosures. Each EMI shielding method has its advantages, but military electronics may need to meet different requirements. For military touchscreens, engineers need EMI gaskets that can resist compression, withstand water and sunlight, and survive temperatures ranging from desert heat to arctic cold.

Silicone Shielding Gaskets

Silicones are a family of synthetic rubbers that provide thermal stability over a wide temperature range. They retain their elastic properties after long periods of compressive stress and resist water, ozone, and ultraviolet light. When filled with tiny metal particles, silicone compounds can be used for environmental seals that resist EMI and also provide reliable electrical conductivity. For military applications, these metal particles are usually pure silver, silver-coated metal, or nickel-coated graphite.

Particle-filled elastomers aren’t new, but some engineers remain skeptical that shielding silicones can meet all of their application requirements. That’s because older compounds were harder, higher-durometer materials with poor compressibility and limited tear strength. Today’s newer particle-filled silicones include lower-durometer compounds that resist tearing and support reinforcements. They also offer alternatives to fills made of pure silver, a precious metal that’s subject to sharp price increases.

MIL-DTL-83528 EMI Shielding Gaskets

Elasto Proxy custom-fabricates EMI shielding gaskets from silicones as soft as 30 and 40 durometers and with tensile strengths of 90 psi and 120 psi, respectively. For additional resistance to tearing, SSP’s lower-durometer, particle-filled silicones can be reinforced with an inner layer of conductive fabric or mesh. At our manufacturing center near Montreal, Canada, we use water jet cutting to convert MIL-DTL-83528 materials and can bond cut lengths with electrically-conductive adhesives.

Whereas older, highly-filled silicone compounds had insufficient tear strength, these newer silicone compounds can support ruggedized products and thinner, smaller, lighter EMI shielding. Depending on a project’s specific requirements, these EMI shielding gaskets can be used in military touchscreens and other defense electronics. Elasto Proxy also custom-fabricates EMI shielding gaskets from medium-durometer and higher-durometer silicones that meet MIL-DTL-83528 requirements.

EMI Gaskets for Military Electronics

Would you like to learn more EMI shielding gaskets for military electronics? Then download Elasto Proxy’s new white paper. This in-depth guide compares cost, conductivity, and shielding strength for silicones with various fill materials. The white paper also describes all of the MIL-DTL-83528 EMI shielding materials that Elasto Proxy custom-fabricates, including two Qualified Product List (QPL) materials.

Download the White Paper

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Four Reasons to Meet Elasto Proxy at IDEX 2017

Posted February 19, 2017 4:55 PM by Doug Sharpe

IDEX is the world’s most strategically important tri-service defense exhibition. For OEMs, military buyers, and prime contractors, this global event is the place to find technologies for land, air, and sea. The International Defense Exhibition and Conference (IDEX) is also where defense subcontractors present key component-level solutions for military programs and projects. That’s why Elasto Proxy, a leading custom-fabricator of specialty seals and insulation, will highlight four unique solutions at IDEX 2017.

From February 19 to 22, Elasto Proxy’s Roberto Naccarato will describe thermal-acoustic insulation, environmental sealing, EMI shielding, and custom products for shock and vibration. With the Canadian Pavilion as his headquarters, Rob will meet with decision-makers and connect with companies across the Abu Dhabi National Exhibition Center in Abu Dhabi, United Arab Emirates. Click here to arrange a meeting with Rob so that you can learn more about Elasto Proxy’s sealing and insulation solutions.

Thermal Acoustic Insulation at IDEX 2017

Elasto Proxy custom-fabricates thermal-acoustic insulation that’s used in the floors, doors, side panels, and engine bays of military vehicles. The custom “insulation sandwiches” that we build include thermally insulating materials that reduce the transfer of heat between objects of different temperatures. Fiberglass is a good choice for reducing heat transfer from conduction and convection. For radiated heat, aluminum foil or Mylar is a great solution.

The “insulation sandwiches” that Elasto Proxy builds also contain acoustical materials that absorb, transmit, or redirect sound waves. In enclosed environments such as engine bays, sound absorbing and decoupling materials are typically used. Examples include open-cell elastomeric foams such as polyester and polyurethane. With our water jet cutting and laminating capabilities, Elasto Proxy can provide your company with custom thermal-acoustic insulation for land systems, naval ships, or military aircraft.

Environmental Sealing at IDEX 2017

Elasto Proxy also custom-fabricates environmental seals for doors, windows, hatches, and gensets. As this case study explains, Elasto Proxy recently solved a sealing challenge for a manufacturer of military vehicles. The problem, an over-compressed hatch seal, created a gap that allowed dirt to accumulate inside the ground vehicle. The maker of the original seal had used neoprene rubber because of its balanced material properties, but an elastomer with greater compression set resistance was required.

The silicone sponge that Elasto Proxy recommended had enough “memory” so that the replacement hatch seals could rebound to their original thickness, even at high temperatures like the ones in desert environments. Elasto Proxy’s water jet cutting machine was the perfect platform for converting 1/8”-thick strips of silicone foam into precision-cut lengths. Our production specialists joined the ends together, and then taped the gaskets for peel-and-stick products that were easy-to-install.

EMI Shielding Gaskets at IDEX 2017

Elasto Proxy also custom-fabricates EMI shielding gaskets that combine environmental sealing with electrical conductivity and protection against electromagnetic interference (EMI). The particle-filled silicones that we convert contain metal or metal-coated particles and are available in a range of durometers. Specialized compounds include EMI fluorosilicones that resist jet fuel and chemicals, and shielding silicones that are reinforced with an inner layer of conductive fabric for increased tear resistance.

With our strong supplier network, Elasto Proxy can recommend rubber filled with silver, silver-aluminum, silver-nickel, or nickel-graphite particles. Many of the EMI silicones that we convert meet the requirements of MIL-DTL-83528, a U.S. military specification for elastomeric shielding gaskets. Two of these silver-aluminum materials have a qualified product listing (QPL) from the Defense Logistics Agency (DLA). For some military applications, nickel-graphite represents a cost-effective alternative.

Shock and Vibration Solutions at IDEX 2017

As a complete provider of custom sealing and insulation solutions, Elasto Proxy manufactures vibration mounts for the sensitive electronic displays used in land systems, naval ships, and military aircraft. We also make personal protection pads for confined spaces such as tanks and armored personnel carriers. With our custom-fabrication capabilities, we specialize in low-to-medium volume quantities (including quick-turn prototypes) for component-level solutions that the defense industry needs.

For more information about us, meet Elasto Proxy at IDEX 2017 or contact us at our world headquarters.

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Gensets: Door Seals, Acoustic Insulation, and Rubber Bumpers

Posted February 15, 2017 4:55 PM by Doug Sharpe

Gensets or generating sets are designed to supply off-grid electricity. They usually consist of a diesel or gasoline-powered engine and an electrical generator (such as an alternator) that converts mechanical power into electricity. Some gensets, such as the ones that provide emergency backup power at hospitals and water treatment plants, are large and stationary. Others gensets are portable because they’re wheeled, or are mounted on wheeled trailers that are pulled by trucks or other motorized vehicles.

Rubber Parts for Gensets

Large gensets for military, industrial, and commercial applications typically feature metal enclosures that house the engine, electrical generator, and sensitive components such as electronics. Metal doors provide access to the genset, but require rubber door seals. Because big diesel engines are loud, acoustic insulation is required. Typically, elastomeric foams are used. Large, portable gensets that are trailer-mounted and truck-driven also need rubber bumpers that can protect the unit against impact.

Genset Door Seals

Sealing the doors on gensets isn’t a job for just any rubber product. Static seals are fine when there’s no relative motion between mating surfaces, but dynamic seals are recommended when there’s motion or movement between sealing interfaces such as a metal door and a door frame. Temperature changes can cause the sheet metal for a genset enclosure to expand and contract, too. That’s why Elasto Proxy custom-fabricates rubber door seals from the right elastomers and to your precise specifications.

Genset Insulation

Acoustic insulation absorbs, transmits, or redirects sound waves – vibrations in the air that pass through objects and result in audible sound. Noise, or unwanted sound, is measured in decibels and has a specific frequency distribution. By fabricating acoustic insulation that’s “tuned” to address the frequencies in your genset application, Elasto Proxy can help you to meet requirements such as workplace limits for noise exposure. In addition to sound absorbers, we custom-fabricate sound barriers and vibration dampers, too.

Genset Bumpers

Rubber bumpers absorb energy from low-speed collisions and low-force impacts while helping to keep genset trailers on the road instead of in the shop. These rubber parts cost less than truck or trailer repairs, and are easy-to-install with standard metal fasteners such as screws, bolts, and washers. All of the genset bumpers that Elasto Proxy supplies have embedded washers and attach with standard fasteners. Through proper compound selection, genset bumpers can resist the outdoor elements, too.

Genset Parts and Custom Fabrication

Elasto Proxy custom-fabricates low-to-medium volume quantities of genset parts such as door seals, rubber bumpers, and acoustic insulation. At our manufacturing center near Montreal, Canada, we use waterjet cutting, laminating, splicing, and taping to create value-added solutions:

  • Waterjet cutting converts rubber sheets and profiles cost-effectively – and without tooling costs or waiting for tooling.
  • Lamination supports the creation of multi-layer “insulation sandwiches” made of acoustical materials with exactly the right combination of properties.
  • Splicing produces strong joints, corners, and ends. In addition to film splicing and vulcanizing, Elasto Proxy offers fast, efficient infrared splicing.
  • Taping creates peel-and-stick gaskets that are easy to apply on your genset assembly line, or right in the field.

Value-Added Solutions for Gensets

In addition to custom fabrication, Elasto Proxy can store your finished genset parts in our North American warehouses and ship them to you according to your sales forecasts or on demand. So whether you’re working on a new genset design or looking for a custom fabricator who can make high-quality but cost-effective replacement parts, ask Elasto Proxy about door seals, acoustic insulation, and rubber bumpers.

Not sure if custom-fabricated parts are the right choice for your genset application? Then download our free e-book, Make It or Buy It? The Business Case for Custom Fabrication?, for more information.

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