In 1960, DuPont completed construction of a plant to produce its own version of acetal resin, named "Delrin", at Parkersburg, West Virginia. Also in 1960, Celanese completed its own research. Shortly thereafter, in a limited partnership with the Frankfurt firm Hoechst AG, a factory was built in Kelsterbach, Hessen; from there, "Celcon" was produced starting in 1962, with "Hostaform" joining it a year later. Both remain in production under the auspices of Celanese and are sold as parts of a product group now called 'Hostaform/Celcon POM".