surface area and thus enhance the repellent effect relative to blends using fewer fibers of greater coarseness ______________________________________ coarse fiber less coarse fiber______________________________________total weight a ano of m lt nfluoroplasticfiberscoarseness of u03b1 gt u03b2fluoroplasticfiberssurface area b cfor repellent u03c0 u03b1 u00d7 m u03c0 u03b2 u00d7 n effect______________________________________ from the above when m lt n and u03b1 gt u03b2 then b u03c0 u03b1x m lt c u03c0 u03b2x n see fig5 a and 5b in other words if the total weight of the less coarse fibers is equal in weight to fibers having a greater coarseness the less coarse fibers will achieve a greater repellency than the fibers having a greater coarseness it follows that one can use a reduced weight amount of less course fibers to achieve a repellency rate achieved by the fibers having a greater coarseness the economics are thus improved the invention is further illustrated with reference to the following non limiting examples tetrafluoroethylene hexafluoropropylene fep resin fibers of 1 denier 5 denier 10 denier 20 denier and 30 denier were blended with 100 wt of wool fibers to obtain a twist yarn the twist yarns were woven to obtain a woven cloth repellent degree tests were conducted before and after multiple washing cycles of the cloth the repellent degree tests were conducted in accordance with jis l1092 34 5 2 repellent degree test spray test 34 according to this test it is determined that if the repellency exceeds 80 the repellent effect is satisfactory for practical use after taking an initial repellant measurement the woven cloth was washed by a home electric washing machine using 1 7 g l of detergent 34.