Silicone Seals for Medical Devices and Medical Equipment

Silicone Seals for Medical ApplicationsElasto Proxy custom-fabricates silicone seals for medical devices and equipment. The high-purity elastomers that we use are platinum-cured and FDA, USP Class VI, and RoHS compliant.

Medical device makers and medical equipment manufacturers need silicone seals that are made from FDA, USP Class VI, and RoHS compliant materials. Elasto Proxy custom-fabricates medical grade seals from high-purity silicones that meet these requirements. Using water jet cutting, we convert sheets of medical silicones without expensive dies or tooling. We can also apply special pressure-sensitive adhesives (PSAs) such as cold seal formulations that form strong bonds at room temperature.

The high-purity silicones that Elasto Proxy custom-fabricates are available in durometers ranging from 10 to 80 (Shore A). These heat-cured elastomers are cost-effective, and come in continuous rolls and molded sheets that can be cut-to-size for maximum material yield. Importantly, Elasto Proxy custom-fabricates medical grade seals from platinum-cured silicones instead of from peroxide-cured ones. As a supplier to the medical equipment industry, compound selection is part of our application expertise.

Platinum Cured Silicones vs. Peroxide Cured Silicones

Curing or cross-linking forms silicone elastomers into solid materials. With medical silicones, the most common curing systems use either peroxide or platinum. The peroxide system is the oldest method, but it requires post-baking to remove volatile organic acids. By contrast, platinum curing doesn’t require post-curing since there are no by-products. Consequently, platinum-cured silicones have lower levels of extractables, chemical compounds that can migrate with elevated temperatures or surface exposure.

Platinum curing also offers greater control over cure rates and crosslinking. This means that platinum-cured silicones are more consistent in terms of appearance, an important consideration for silicone parts that are visible to buyers of medical devices and equipment. Although platinum-cured silicones are normally translucent, Elasto Proxy can source materials that are colored with FDA compliant pigments. Examples of these custom colors include gray, white, red, plumb, olive drab, and salmon.

FDA, USP Class VI, and RoHS Compliant Silicones

Medical grade silicones are available from numerous suppliers, but the term “medical grade” doesn’t necessarily mean “FDA compliant”. As an experienced provider of sealing solutions, Elasto Proxy understands that in order for a medical silicone to be FDA compliant, all of the ingredients within that silicone must comply with U.S. Food and Drug Agency (FDA) standards. FDA CFR 177.2600, part of the U.S. Code of Federal Regulations (FDA) covers allowable materials, including base elastomers and additives.

The medical silicones that Elasto Proxy converts aren’t just FDA compliant, however. They also meet USP Class VI requirements for the biocompatibility of materials used in medical devices and equipment. Part of the U.S. Pharmacopeial Convention (USP), USP Class VI is one of the most stringent requirements in medical device manufacturing. The FDA and USP Class VI compliant silicones that we custom-fabricate also comply with the European Union’s Restriction of Hazardous Substances (RoHS) Directive 2002/95/E.

From Compound Selection to Custom Fabrication

Elasto Proxy supports your medical device and medical equipment projects from compound selection to custom fabrication. This table describes the platinum-cured, high-purity silicones that we custom-fabricate.

High-Purity Silicone Shore A Tensile (psi) Elongation % Tear B (ppi) Specific Gravity
ElastoPure-10D 10 870 1200 135 1.07
ElastoPure-20D 20 1300 920 150 1.11
ElastoPure-30D 30 1400 720 125 1.09
ElastoPure-40D 40 1400 850 250 1.11
ElastoPure-50D 50 1350 675 150 1.13
ElastoPure-60D 60 1350 700 225 1.17
ElastoPure-70D 70 1400 700 225 1.18
ElastoPure-80D 80 1475 700 225 1.20

For over 25 years, Elasto Proxy has supplied low-to-medium volume quantities of rubber and plastic parts that meet demanding requirements. Examples include silicone seals for walk-in bathtubs, foam handles for patient lifts, and molded plastic parts for hospital beds. How can we help you? To learn more about high-purity silicone seals for medical devices and medical equipment, please contact us.

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Silicone Seals for Food Service Equipment

Silicone Seals for Food Service Equipment
Silicone Seals for Food Service Equipment

Learn how Elasto Proxy helped a manufacturer of food service equipment solve a sealing and insulation challenge with food prep tables.

Food prep tables and other food service equipment generally features stainless steel construction. Strong, durable, and corrosion-resistant, stainless steel is easy-to-clean and ideal as a food contact surface. Surface finishing treatments such electropolishing inhibit bacterial attachment and biofilm formation, which helps to prevent foodborne illness. Food prep tables with refrigeration systems also help keep ingredients at the proper temperatures for freshness and taste.

By following proper procedures, stainless steel surfaces can be kept shiny and clean. That includes metal surfaces where items like sandwiches and salads are assembled, as well as the pans and shelves that hold the ingredients. Yet food prep tables are built with non-metallic materials, too. Silicone seals fill slots and surround metal edges in food storage areas. They cover sharp surfaces, seal gaps, and support refrigeration. All silicone rubber is not the same, however, so it’s important to choose the right compound. Continue reading Silicone Seals for Food Service Equipment

M83528 Connector Gaskets for EMI Shielding in Military Electronics

M83528 Connector Gaskets
M83528 connector gaskets are used in military electronics. They combine EMI shielding with environmental sealing.

M83528 Connector Gaskets for EMI Shielding is the first in a series of technical articles about why defense contractors are sourcing EMI connector gaskets made of particle-filled silicones. For over 25 years, Elasto Proxy has custom-fabricated seals, gaskets, and insulation for the North American defense industry.

Defense contractors need conductive elastomeric gaskets that resist electromagnetic interference (EMI), provide environmental sealing, meet military specifications, and help contain project costs. Elasto Proxy custom-fabricates EMI shielding, including M83528 connector gaskets, that meet all of these requirements. Using water jet cutting, we convert particle-filled silicones, specialized elastomers that combine the electrical properties of metals with the environmental resistance of silicone rubber. We also offer various splicing and taping methods for M83528 connector gaskets.

M83528 Connector Gaskets and Particle-Filled Silicones

The shielding elastomers that Elasto Proxy custom-fabricates for M83528 connector gaskets use silicone or fluorosilicone as the base material. Silicone offers thermal stability over a wide temperature range and resists water, ozone, and ultraviolet light. With its fluorine additions, fluorosilicone adds resistance to solvents and jet fuels. Shielding elastomers are available in a range of durometers, including ultra-soft silicones. For added strength, particle-filled elastomers can be reinforced with an inner layer of conductive fabric.

Fill materials for shielding silicones and fluorosilicones include metal or metal-coated particles that provide electrical conductivity and EMI shielding. Some older part drawings still specify silver-filled products, but silver-aluminum silicones offer excellent conductivity and strong volume resistivity, an indirect measure of shielding effectiveness. Importantly, shielding elastomers with silver-coated fills cost significantly less than pure-silver products. The following table explains.

Filler Type Cost Electrical
Typical VR


Silver $$$$$ Extremely Conductive .0009
Silver-Aluminum $$$$ Super Conductive .003
Silver-Copper $$$$ Super Conductive .003
Silver-Glass $$$ Very Conductive .006
Nickel-Graphite $$ Conductive .01
Carbon Black $ Semi-Conductive 8.0


M83528 Connector Gaskets and QPL Materials

MIL-DTL-83528 (M83528) is a U.S. military specification (MIL-SPEC) for electrically-conductive, elastomeric shielding gaskets that suppress EMI and radio frequency interference (RFI). This MIL-SPEC consists of lettered sections (Types A through M) that establish minimum levels of plane wave shielding effectiveness at 10 GHz over a continuous-use temperature range. MIL-DTL-83528 also defines the base material and the fill material for each Type. As noted above, fill material is an important driver of EMI gasket costs.

Elasto Proxy custom-fabricates EMI gaskets from shielding elastomers that meet the requirements of MIL-DTL-83538 Types A, B, D, E, L, K, and M. Two of the compounds that we convert have a Qualified Project Listing (QPL) from the Defense Logistics Agency (DLA), part of the U.S. Department of Defense. These QPL listed materials have been independently tested for best attenuation level, as reported below.

The following table describes the M83528 connector gaskets that Elasto Proxy custom-fabricates.

EMI Gasket Material Fill
Base Elastomer Durometer (Shore A) VR (Ohms/Cm) QPL? Shielding Data?
A EMI-83528-A-65 Silver-Copper Silicone 65 .0009
B EMI-83528-B-65 Silver-Aluminum Silicone 65 .001 Yes Yes

139.1 dB @
200 MHz

D EMI-83528-D-70 Silver-Aluminum Fluorosilicone 70 .005 Yes Yes
137.4 dB @
80 MHz
D EMI-83528-D-45 Silver-Aluminum Fluorosilicone 45 .002
D EMI-83528-D-70P* Silver-Aluminum Fluorosilicone 70 N/A
E EMI-83528-E-65 Silver Silicone 65 .001
L EMI-83528-L-75 Silver-Nickel Silicone 75 .001
K EMI-83528-K-80 Silver-Copper Silicone 80 .0009
M EMI-83528-M-65 Silver-
Silicone 65 .006


* EMI-83528-D-70P* is passivated for increased corrosion resistance.

Supporting Military Electronics and Your Informational Needs

Thank you for reading this technical article about M83528 connector gaskets. Future articles will explain how Elasto Proxy also fabricates military EMI gaskets that do not need to meet MIL-DTL-83528 requirements. We’ll also describe the cost-saving benefits of water jet cutting, splicing, and taping. Finally, other articles in this series will take a closer look at the advantages of EMI connector gaskets made from specific materials, such as ultra-soft silicones, conductive-fabric reinforced silicones, and QPL listed products.

Contact Us and Then Visit Us at CANSEC 2016 (Booth #935)

Do you have questions about EMI connector gaskets? Please contact us, and then visit us at CANSEC 2016 in Booth #935 from May 25 – 26, 2016 at the EY Centre in Ottawa.

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How Elasto Proxy Supports the Mobile Equipment Industry

Mobile Equipment
Elasto Proxy Supports Mobile Equipment

Elasto Proxy creates specialty seals and custom insulation for manufacturers of mobile equipment. Learn about our custom fabrication capabilities, and how we can help you.

Manufacturers of mobile equipment need custom seals and specialty insulation that can withstand demanding environments. On-road vehicles such as graders, pavers, cranes, and excavators are subject to hot and cold temperatures, driving rain, and blinding snowstorms. Off-road vehicles such as tractors, combines, fellers, and skidders also face wind, water, mud, and snow. Steep grades and rocky terrain can challenge other types of agricultural and forestry equipment, too. Continue reading How Elasto Proxy Supports the Mobile Equipment Industry