A stainless steel rod is wound
with a tight spiral of wire, also made of stainless steel. The diameter of wire can vary from
0.18 mils to 13.5 mils for different coating thickness. The grooves between the wire coils
determine the precise amount of coating materials that will pass through as it is moved
along the web. The thickness of wet film is directly proportional to the diameter of the wire
used. After applying the metering rod, the initial shape of the coating is a series of stripes,
spaced apart according to the spacing of the wire windings. Almost immediately, surface
tension of the liquid film pulls these stripes together, forming a flat and smooth surface,
ready for the following drying and curing process through heat or UV light sources.