| abstract |
A method is provided to manufacture a coated substrate, such as an optical fiber, without undesirable point lumps. The method filters a coating composition while controlling the filtering temperature, pressure drop across a filtering assembly, and filter pore size to achieve a resulting filtration factor not greater than 250,000 s −1 . The filtration factor is a function of filtering temperature and pressure drop across the filtering assembly. Typically, the coating composition is filtered by passing the coating composition through one or more filters of the filtering assembly, having an absolute pore size rating in the range from approximately 0.05 to approximately 5 microns, at a temperature less than approximately 105° F. (40° C.), and at a pressure drop ΔP across the filtering assembly of at most approximately 80 psig, wherein the ratio of pressure drop (mPa) to viscosity (mPa·s), which is dependent upon filtering temperature, minimizes the filtration factor to ≦250,000 s −1 . |