Electrification: Hutchinson develops a new elastomer material for sealing CO2 (R744) heat pumps

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In a bid to support the switchover to electric vehicles, Hutchinson has pioneered a new elastomer compound for Volkswagen that is capable of withstanding the operating constraints of R744, a refrigerant that holds plenty of promise for the thermal management of electric and hybrid vehicles, but which requires all the circuit components to be adapted, especially the sealing parts. 

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Hutchinson has developed an elastomer compound that is specially designed to meet the sealing needs of the components used in electric vehicle heat pump applications using the R744 refrigerant (CO2).  

The development of this innovative material can be credited to the expertise of Hutchinson's teams in formulating elastomer materials and their close collaboration with the Volkswagen Group and a major OEM in thermal management systems. Hutchinson's sealing solutions made with the 8EP3411 compound are used as standard on vehicles equipped with the MEB platform, such as the ID.3.

What exactly is R744?

R744 (CO2) is a natural, non-flammable refrigerant that is attracting growing market interest as a replacement for fluorinated refrigerants, which have a high GWP (Global Warming Potential). By definition, R744 is PFAS-free and has a GWP of 1. Its thermodynamic properties enable heat pump systems to operate at temperatures below -10°C, while improving the coefficient of performance over a specific temperature range. Less energy is required to heat the battery and the passenger compartment, which helps increase the electric vehicle's range.

A new material engineered for superior resistance and performance  

The new material developed by Hutchinson has been enhanced to meet the new specifications. Its hardness rating of 80 Shore A means that it is capable of withstanding high-pressure applications up to 130 bar, thereby improving system safety. It also boasts greater thermal performance, with a temperature range from -40 to +165°C, which is optimized for heat pumps running on R744.  Finally, tests and trials have confirmed the material's resistance to rapid gas decompression (RGD) and compliance with the NORSOK M-710 standard (the material achieved a Rating of 0, which means no defects after exposure).

A wide range of potential industrial applications

R744 is already used in heat pump systems on buses and trains, and in industrial air conditioning systems, such as supermarket refrigeration systems. Environmental regulations are likely to step up the use of R744 in industrial applications, including residential heat pumps. The scheduled end to the marketing of internal combustion engine vehicles in Europe in 2035, combined with environmental issues (PFAS, GWP, etc.), means that R744 is shaping up to be the future standard refrigerant for automotive applications in Europe.  

Contact our materials and sealing experts: communication.pss@hutchinson.com 

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hutchinson bonded seal hvac