When it comes to selecting a synthetic rubber for your sealing application, you really are spoilt for choice. But for general purpose ‘O’ rings, you’d be well-advised to narrow your search to EPDM and nitrile. The trouble is, which is best? TRP Polymer Solutions give us their verdict with this in-depth EPDM rubber vs nitrile rubber comparison.
Synthetic rubber comes in a huge variety of different types, each offering their own distinct advantages and disadvantages. EPDM and nitrile are two such rubber compounds that are commonly used to make cost-effective, general-purpose ‘O’ rings. So which is better for your application?
Let’s find out.
Benefits and drawbacks of EPDM rubber vs nitrile rubber
TRP Polymer Solutions is an industry-leading manufacturer of high-performance rubber sealing components. We develop a comprehensive selection of sealing products from every type of polymer material imaginable. This makes us uniquely qualified to discuss the merits of a whole range of different rubber materials.
Here, we will be exploring the advantages and disadvantages of EPDM rubber vs nitrile rubber. Both of these rubber compounds offers excellent properties for developing ‘O’ rings, delivering comparable durability. Where they differ significantly is in terms of their resistance to certain media and environmental conditions.
Benefits of EPDM rubber
EPDM, or Ethylene Propylene Diene Monomer, is widely used to make ‘O’ rings and other seals for a variety of industrial applications, such as steam lines and truck brake systems. The benefits of EPDM ‘O’ rings include their ability to handle a fairly wide operational temperature range of -50 °C to +150 °C, and their excellent resistance to ozone and sunlight. EPDM rubber also delivers good resistance to compression set, abrasion, steam, acids and tearing.
Drawbacks of EPDM rubber
The major disadvantage of EPDM rubber is its relatively poor resistance to petroleum-based fuels, oils and non-polar solvents. This is EPDM’s Achilles heel in a straight comparison with nitrile.
Benefits of nitrile rubber
Nitrile rubber, also known as Buna-N or NBR, is made by combining butadiene and acrylonitrile. Versatile and reliable, nitrile offers good resistance to gasoline, diesel fuel, motor oil, acids and non-polar solvents. For this reason, it is widely used for general-purpose nitrile ‘O’ rings in automotive, marine and aerospace applications. Nitrile rubber can be formulated for a modest temperature range of between -25 °C and +100 °C. It also offers good resistance to abrasion and compression set.
Drawbacks of nitrile rubber
Nitrile rubber’s major drawbacks are that it performs poorly when exposed to UV, general weathering and ozone. It also offers relatively poor steam resistance, especially compared to EPDM.
The choice between nitrile rubber vs EPDM rubber is relatively straightforward. For a durable ‘O’ ring that performs well in ozone, sunlight, steam and a reasonably wide temperature range, EPDM ‘O’ rings are the obvious choice. However, where UV and ozone are not a factor but fuels are, nitrile ‘O’ rings offer a reliable and cost-effective option for a wide range of general-purpose applications.
TRP Polymer Solutions can help you to narrow down your search for the perfect ‘O’ ring material. Their experts are well-placed to provide support and guidance with your material choices, from EPDM rubber to nitril rubber and beyond! For more information, contact www.trp.co.uk.