Acrylate rubber (ACM)

Acrylate rubber, often abbreviated to ACM for "Acrylic Co-Monomer Rubber", consists mainly of ethyl acrylate and other acrylates and is typically formulated as a copolymer or terpolymer. Its composition also includes a small amount of a special monomer that plays a key role in assisting the vulcanization process. This structure gives the material its characteristic properties, including its resistance to heat and chemical influences.

Chemical Properties of Acrylate Rubber

ACM is characterized by its excellent resistance to various chemical substances. Acrylate rubber is particularly resistant to:

• highly additive engine oils
• lubricating greases
• mineral oils
• ATF oils
• ozone
• weather influences
• UV light
• heat

Products made from acrylate rubber, such as O-rings , are particularly in demand for their excellent resistance to mineral oils. Unlike other sealing materials, which swell under the influence of these oils and lose elasticity as well as experience increased friction and abrasion , ACM seals and O-rings retain their elastic and mechanical properties.

However, the resistance of acrylate rubber decreases when in contact with:

• hot water and steam
• fuels
• aromatic hydrocarbons and solvents
• glycol-based brake fluids
• polar solvents such as acetone
• acids, alkalis and amines.

The cold behavior of acrylate rubber is relatively unfavorable. In addition, ACM is not very resistant to hydrolysis and can therefore lose its mechanical and chemical properties if exposed to water or steam for a long time.

Mechanical Properties of Acrylate Rubber

The strength and rebound behavior of acrylate rubber are in the medium range, while the elasticity is low. In return, ACM has good mechanical resilience. This makes the material suitable for both static and dynamic sealing, or for applications where long periods of use and constant friction conditions are required. Dry running should, however, be avoided.

Where and how is acrylate rubber used?

In over 90 percent of cases, the material ACM is used in the automotive industry for sealing applications. Here, it can fully exploit its chemical and mechanical resistance and is an economically sensible choice, especially for high volumes. Seals and O-rings made of ACM are used in, among other things:

• combustion engines
• automatic transmissions
• power steering systems

Typical uses of acrylate rubber include housing covers, shaft seals and seals in oil pans, engines and transmissions.

Acrylate rubber (ACM) compared with other materials

Ethylene acrylate rubber (EACM), known under the trade name VAMAC by DU PONT, has similar properties to acrylate rubber (ACM). Although the strength and heat resistance of seals and O-rings made of EACM is higher, their resistance to mineral oil is worse than that of ACM.

Compared to other elastomers such as NBR, HNBR, EPDM and FKM, acrylic rubber offers a specialized and cost-effective solution for applications where high resistance to specific chemicals and temperature requirements is required. Although FKM or FPM can withstand higher temperatures, ACM is often the preferred choice due to its cost and specific resistances.

List of chemical resistances

Disposal

According to the “Regulation on the European Waste Catalogue (AVV)”, the waste product from ACM can be classified according to Chapter 7 “Wastes from organic chemical processes” and the waste code 07 02 99. This waste code stands for waste classified as non-hazardous.

They can therefore be disposed of in normal household quantities with normal household waste. Please use the container provided by your public waste disposal authority for residual waste as the appropriate disposal container.