Yokohama automotive A/C hoses resist new refrigerant

Tokyo – Yokohama Rubber Co. Ltd has introduced hoses offering compatibility with HFO-1234yf, which it said is now becoming established in the US as a refrigerant for automotive air-conditioning systems.

The Japanese company said its ACBR series of high- and low-pressure hoses have already been adopted in the all-new 2018 Jeep Wrangler” and the all-new 2018 Jeep Compass.

Vehicle makers are gradually shifting to the refrigerant from the current standard HFC-134a as part of efforts to supply cars that contribute less to global warming, explained Yokohama.

While HFO-1234yf has a GWP (global warming potential) rating of just 4 – compared to 1,430 for HFC-134a – it can decompose over time, releasing acids that corrode the resin inner surface-layer of the hose.

Countermeasures have included improving the resin material, such as Yokohama’s own development of a polyamide resin containing an acid-acceptor.

The company’s new hose structure, however, employs an inner rubber with improved adhesion to the resin that prevents direct contact between the refrigerant and resin layer.

Yokohama has applied patents from Japan for the compound material for the new inner rubber layer and said it plans to develop a full range of these barrier-type hoses.