Coating process using dispersions of tetrafluoroethylene polymers and polyethersulphones and article

A process for the production of a coated article comprising applying to the article in a single coating step an aqueous dispersion of a tetrafluoroethylene polymer and a thermoplastic aromatic polyethersulphone in which at least 20% of the end groups of the polymer chain are aromatically bound hydroxyl groups and said polyethersulphone having a reduced viscosity below 0.25, as measured at 25.degree. C. on a solution in dimethyl formamide containing 1 g of polymer in 100 cm.sup.3 of solution, drying the coating, and thereafter baking the coated article in the presence of oxygen at a temperature in the range 420 to 450.degree. C. to achieve a single coating of thickness at least 15 .mu.m.