The two companies focused on such subcritical water characteristics  as its high permeability, dissolving power , and hydrolysis effect in resins in developing a technology that successfully depolymerizes nylon 6 with that water. Subcritical water is water at high temperatures and pressures. It is free of catalysts, additives do not affect it, and it can depolymerize nylon 6 in several dozen minutes to create high yields of raw monomer. Separating, refining, and repolymerizing that monomer makes it possible to regenerate nylon 6 that performs like a virgin material.

The Ministry of the Environment adopted this technology for a fiscal 2023 project to establish a decarbonized circular economy system, including to validate recycling systems for plastics and other resources. Toray and Honda look to employ that project to set up a pilot facility with a processing capacity of 500 metric tons annually of raw resin, conducting validation testing with it.

The first step with this work is to recycle used automotive plastic parts into the same automotive materials. The two companies will develop depolymerization and monomer separation and refining technologies by employing intake manifolds as raw materials for engine intake system parts. They seek to apply these technologies for recycling chemicals in automotive resin parts by around 2027.