Method of applying a coating composition to a substrate

A method of applying a coating composition utilizing a high transfer efficiency applicator assembly that is a unitary component and that comprises a first high transfer efficiency applicator and a second high transfer efficiency applicator, wherein the first high transfer efficiency applicator comprises a plurality of first nozzles each defining a first nozzle orifice and arranged in a linear configuration relative to one another along a first axis and the second high transfer efficiency applicator comprises a plurality of second nozzles each defining a second nozzle orifice and arranged in a linear configuration relative to one another along a second axis, wherein the first axis and the second axis are parallel to each other, the method comprising:

• providing a substrate having a first end and a second end and defining a first target area and a second target area disposed adjacent to each other between the first and second ends, wherein a path is defined extending between the first end and the second end;
• moving the first high transfer efficiency applicator and the second high transfer efficiency applicator from the first end to the second end along the path,
• expelling the coating composition through each of the plurality of first nozzle orifices independent of one another which produces droplets of the coating composition that contact the first target area in a single pass along the path from the first end to the second end during the step of moving such that at least 99.9% of the droplets contacts the first target area of the substrate and at least 80% of the droplets are monodispersed such that the droplets have a particle size distribution of less than 20%;
• and
• expelling the coating composition through each of the plurality of second nozzle orifices independent of one another which produces droplets of the coating composition that contact the second target area in the single pass along the path from the first end to the second end during the step of moving such that at least 99.9% of the droplets contacts the second target area of the substrate and at least 80% of the droplets are monodispersed such that the droplets have a particle size distribution of less than 20%,
• wherein the coating composition has a solids content of from about 15 to about 70 weight % based on a total weight of the coating composition as measured in accordance with ASTM D2369 and comprises:
• a carrier;
• a binder present in an amount of from 15 to about 25 weight percent based on a total weight of the coating composition;
• and a crosslinker present in an amount of from about 4 to about 6 weight percent based on a total weight of the coating composition,
• wherein the coating composition has a viscosity of from about 0.005 Pa*s to about 0.05 Pa*s, as measured according to ASTM 7867-13 with cone-and-plate or parallel plates at a shear rate of 1000 sec-1, a density of from about 838 kg/m3 to about 1557 kg/m3, a surface tension of from about 0.015 N/m to about 0.05 N/m, and a relaxation time (λ) of from about 0.0005 s to about 0.02 s;
• wherein the coating composition has an Ohnesorge number (Oh) of from about 0.01 to about 12.6;
• wherein the coating composition has a Reynolds number (Re) of from about 0.02 to about 6,200;
• wherein the coating composition has a Deborah number (De) of from greater than 0 to about 1730.