Do you know how to select the right gasket material? If you’re still asking for “black rubber”, you could be putting your product design at risk. There are thousands of different rubber recipes, or compounds, and each has specific properties. There are also gaskets that are made from other types of materials, including metal.
This article from Elasto Proxy is designed to help you select the right gasket material. These mechanical seals are used in countless applications, but do you know why that’s the case? This article answers that as well. You’ll also learn why you probably need a gasket that’s made of rubber instead of metal.
Keep reading to learn more and contact Elasto Proxy if you’re a gasket designer or engineer who needs help with material selection.
Why Do You Need a Gasket?
A gasket is a mechanical seal that’s installed between two mating surfaces to fill the microscopic gaps between them. Why do these gaps exist? It’s because even precision-machined surfaces aren’t perfectly smooth. Instead, they contain tiny irregularities that allow fluids or gases to pass through. Gaskets that are compressed under a load (such as a closed door) fill these gaps and form a barrier.
Why Use Rubber Instead of Metal?
Metal gaskets are typically used in high-pressure, high-temperature applications like refineries or chemical plants. For most industrial and commercial applications, rubber is the preferred gasket material because it’s compressible and elastic, environmentally resistant, cost-effective, and lightweight and easy to install.
Compressibility and Elasticity
Rubber compresses easily and rebounds when pressure is released. This allows it to conform to surface irregularities and maintain a seal even when the mating surfaces shift due to vibration, thermal expansion, or mechanical load. That happens in assemblies ranging from heavy equipment cabins and nuclear gloveboxes to food processing equipment and electronic enclosures.
Environmental Resistance
Rubber can be formulated to resist different substances and conditions. Examples include:
- Oils, fuels, and solvents
- Sunlight and ozone
- Extreme temperatures
- Water and steam
- Chemicals and cleaning agents
Rubber can also be filled with metal or metal-coated particles to provide electrical conductivity and shielding against electromagnetic interference (EMI). That’s worth noting since rubber is normally an electrical insulator.
Cost
Most rubber materials cost less than metal ones. Generally, rubber gaskets are also less expensive to fabricate. At Elasto Proxy, we use water jet cutting during gasket fabrication. There’s no tooling to wait for or pay for, and we can cut rubber sheets or extrusions with speed and precision.
Lightweighting and Installation
Rubber weights less than metal. That helps to reduce overall system weight, but the advantages don’t end there. Metal gaskets typically require high bolt loads, which complicates installation. Some rubber gaskets use metal fasteners, but others are installed with adhesive tapes instead.
The Challenge of Selecting the Right Rubber
Rubber is not a single material. Rather, it’s a family of materials known as elastomers. Here are some of the most common ones.
- EPDM for outdoor weather resistance
- Silicone for high/low temperature extremes
- Nitrile (Buna‑N) for fuel and oil resistance
- Fluorosilicone for aggressive fuels and solvents
- Neoprene for general‑purpose industrial sealing
- Conductive elastomers for EMI shielding
What happens if you choose the wrong material? Swelling, cracking, compression set, or seal failure can result. That’s why gasket designers and engineers need to consider factors ranging from temperature and media exposure to environmental conditions and regulatory standards.
To simplify this process, Elasto Proxy developed a structured approach called MTAP.
Understanding Elasto Proxy’s MTAP Methodology
MTAP stands for Material, Temperature, Application, and Pressure. Elasto Proxy uses it to guide you through material selection and to ensure that the chosen elastomer will meet your requirements.
M is for Media
The M in MTAP stands for Media. Ask yourself:
- Will the gasket encounter fuels, oils, chemicals, or cleaners?
- If so, which ones – and which concentrations?
- Is contact with this media intermittent, or does it involve full immersion?
T is for Temperature
The T in MTAP stands for Temperature. Ask yourself:
- What are the maximum and minimum service temperatures?
- Is there a continuous operating temperature to consider?
- Are there rapid changes in temperature?
Different compounds have different temperature ranges, and some rubbers that are repeatedly heat and cooled can loose their flexibility.
A is for Application
The A in MTAP stands for Application. Ask yourself:
- Where will the gasket be used (i.e., indoors vs. outdoors)?
- How will the gasket be installed (i.e., fasteners vs. adhesive tape)?
- Are there standards or specifications that you need to meet?
For example, a door gasket on a dump truck must resist vibration, dust, and water. A gasket for an electronics enclosure may need UL 94 V‑0 flame resistance instead.
P is for Pressure
The P in MTAP stands for Pressure. Ask yourself:
- What is the pressure inside the system?
- What is the compressive force or load that’s applied during installation?
- How much compression is required for the gasket to provide adequate sealing?
Rubber compounds vary in terms of hardness, which is measured in durometers on the Shore A scale. Because durometer affects how rubber responds to pressure, softer materials seal with lower compression force and harder materials can resist deformation.
From MTAP to Gasket Fabrication
Elasto Proxy doesn’t design rubber gaskets, but we can help you with material selection and review your drawings, schematics, or CAD files. We can also evaluate your part tolerances: allowable part-to-part dimensional variations. As a rubber fabricator and distributor that offers these and other value-added services, we can help you achieve sealing success.
