a coating apparatus for applying plastic coatings onto a planar substrate includes an elongate coating head defining therein an elongate distribution channel having a length corresponding to a width of a substrate to be coated , the coating head also defining a coating gap for discharging a coating material from the distribution channel . first and second supply channels are respectively connected between respective pumps and different portions of the distribution channel for respectively supplying first and second coating materials to the distribution channel . a mixing zone is formed in the distribution channel by a partition or a hollow conical body , each of which forms a mixing gradient extending along the length of the mixing zone . ideally , the pumps for the first and second coating materials provide these materials with the same pressure within the mixing zone .