Full definition
ACM rubber, or acrylic rubber, is a polyacrylate elastomer that offers exceptional performance in high-temperature environments. This material is particularly noted for its resilience against hot engine oils, automatic transmission fluids (ATF), and lubricating greases, making it a popular choice in automotive applications. ACM maintains its mechanical properties at continuous exposure temperatures ranging from 150°C to 175°C, which positions it effectively for use in components that encounter severe thermal conditions. The ASTM D2000 and SAE J200 standards classify ACM rubber under categories DF (standard) and DH (higher heat), demonstrating its effectiveness in high-performance scenarios.
One of the standout features of ACM rubber is its superior heat and oxidation resistance compared to nitrile rubber (NBR). While NBR is widely used in various sealing applications due to its good mechanical properties, it tends to degrade at higher temperatures, particularly in the presence of hot oils. In contrast, ACM rubber remains stable and functional, thus extending the lifespan of components such as automotive shaft seals, transmission seals, O-rings, gaskets, and valve cover gaskets. Additionally, ACM is more economical than fluoroelastomers (FKM), making it a cost-effective choice for manufacturers who require durable materials without compromising on performance.
With a hardness range of 40-90 Shore A, ACM rubber exhibits tensile strength values between 7-14 MPa and elongation properties of 100-350%. While it offers a moderate compression set, its temperature range of -15 to +175°C is noteworthy; however, it is important to note that its low-temperature flexibility is limited, which can restrict its usage in colder environments. Chemical resistance is another advantageous feature, as ACM rubber demonstrates excellent compatibility with mineral oils, hydraulic fluids, and ozone, although it shows poor resistance to water, glycol coolants, and steam. This specificity in chemical resistance makes ACM rubber a tailored solution for direct contact applications where other elastomers might fail, particularly in automotive systems exposed to extreme conditions.