Industry standards serve as valuable guideposts for the automotive industry. Some standards are only relevant to hyperspecific components, applications, and automotive rubbers, while others apply to the industry as a whole. With so many standards in circulation, it can be challenging to navigate the automotive regulatory landscape. Learning about classification and reference standards can be an excellent starting point.
Key Automotive Rubber Standards
There are countless automotive rubber standards in circulation. Some define performance criteria for specific materials and components, while others, like ASTM D2000 and SAE J200, serve as classification documents for engineers seeking to specify and qualify rubber compounds.
ASTM D2000
ASTM D2000 is an exhaustive qualification system for two dozen rubber compounds in a range of industries, including the automotive industry. ASTM D2000 classifies rubber materials based on type and class. More specifically, type refers to changes in tensile strength, elongation, and hardness. Class refers to oil resistance.
Engineers can use ASTM D2000 as a reference when determining whether a certain material may be a good match for a specific application, based on its characteristics.
SAE J200
SAE J200 is quite similar to ASTM D2000 in that it serves as a reference document, providing classifications for specific materials. However, while ASTM D2000 is broader in scope, SAE J200 is focused only on the automotive industry. SAE J200 includes information that is especially pertinent to automotive applications, such as mechanical properties, temperature stability, chemical resistance, and other characteristics that indicate whether or not a material can perform reliably in the rigorous conditions of the automotive service environment.
Essential Performance Traits for Automotive Rubber
Automotive rubber is often subjected to a wide range of rigorous conditions while in service, from the ambient environment to the friction and vibration in the engine compartment. While each automotive rubber component has a different set of requirements, there are a few characteristics that are almost universally desirable in this industry.
Heat Resistance
Internal combustion engine (ICE) vehicles and electric vehicles (EVs) alike generate significant heat in operation. While these vehicles have cooling systems in place to mitigate excess heat buildup, there are still ample components throughout the vehicle that are exposed to intense heat while in service. Choosing rubber materials that can withstand this heat is critical to ensuring reliable performance and a competitive shelf life when developing automotive components.
Oil Compatibility
Plenty of automotive components come into contact with oil while in service. If these components are manufactured from rubber compounds that cannot withstand prolonged contact with oil, the components may swell, soften, and eventually degrade. Choosing rubber compounds with excellent oil compatibility and resistance ensures reliable performance.
Weather Resistance
While some cars are parked in covered garages while not in use, virtually all cars are exposed to the elements while in use. Extreme temperatures, dust and debris, precipitation, humidity, and other factors can have an impact on the performance of rubber components over time. It is critical to choose rubber compounds with robust weather resistance properties when designing any automotive component that will be exposed to the outdoors while in service.
Flexibility
Flexibility is a crucial performance attribute for automotive rubbers. These components may endure repeated compression, pressure fluctuations, shocks, and vibration while in service, and flexibility is key to ensuring that automotive rubbers can absorb these factors and maintain their shape and performance.
Choosing the Right Rubber for Your Automotive Application
There are dozens of different rubber classes on the market and countless more unique formulations. Choosing the right automotive rubber for your application requires balancing performance characteristics, budget, and other variables.
For example, both neoprene and nitrile rubber (NBR) do well in extreme heat, but neoprene is more resistant to weathering—and usually comes with a higher price tag. Understanding all these different considerations and determining your priorities is key to choosing the right automotive rubber.
Natural Rubber
Natural rubber plays a critical role in the automotive industry. Its tremendous flexibility and durability make it especially popular for tires, but natural rubber is also used for hoses, seals, brake pads, engine mounts, bushings, and many others.
Neoprene
Neoprene boasts a number of performance attributes that are attractive to the automotive industry, including durability and excellent resistance to extreme temperatures, oils, and chemicals. Neoprene is a common choice for hoses and gaskets.
Nitrile Rubber
Nitrile rubber, often shortened to NBR, is highly resistant to oil and gasoline, along with acids and chemicals, such as aliphatic hydrocarbons. Like neoprene, nitrile rubber also performs well even when exposed to extreme temperatures, though NBR cannot compete with other automotive rubbers when it comes to weathering resistance. Other benefits of nitrile rubber are excellent resistance to abrasion and tearing. Common automotive applications for NBR include seals, oil hoses, and grommets.
EPDM
EPDM is short for ethylene propylene diene monomer, a synthetic rubber offering excellent flexibility, resilience, and resistance to weathering. EPDM also offers highly desirable elastic properties, including tensile strength, stretchability, and shock absorption, and maintains its flexibility even in extreme temperatures. EPDM is often used for seals, gaskets, and weatherstripping, along with insulation and protection for cables and wires.
Silicone Rubber
Silicone rubber is flexible and durable, with excellent vibration and wear resistance, and performs well at extreme temperatures. This combination of properties makes silicone rubber an excellent choice for automotive hoses and damping components. Additionally, silicone rubber’s strong weather resistance makes it a popular option for window seals and other weatherproofing components.
Sponge Rubber
Sponge rubber offers a few key advantages over solid rubber for certain automotive applications. Sponge rubber is compressible, which is beneficial for creating tight seals, and its closed-cell structure leads to excellent impermeability. Additionally, certain sponge rubbers are highly resistant to extreme temperatures. In the automotive industry, sponge rubber is most commonly used for insulation, sealing, and cushioning applications. Vibration dampening components, wire harnesses, and sealing components often leverage sponge rubber.
Trust UP&R for Expert Rubber Solutions
UP&R is proud to support the automotive industry with reliable molding and extrusion services for automotive rubbers. We can help you use tools like ASTM D2000 and SAE J200 to your advantage and determine which rubber compound will best meet your needs.
Leverage UP&R’s expertise in automotive rubber by choosing us to be your go-to molding and extrusion partner. To learn more about what we can do for you, get in touch.