hereinbelow as u201c ts 610 u201d the powder has excellent flowability time lt 10 s 0 taps for a 17 mm funnel but the coalescence estimated as described above is very poor the steel plate still being clearly visible the silica may thus be an anti coalescer at a high content a kepstan u00ae 6003 pl powder from the company arkema containing 60 of terephthalic units relative to the sum of the terephthalic and isophthalic units whose particle size has a dv50 of 50 u03bcm plus or minus 5 u03bcm was supplemented with cab o sil u00ae ts 610 silica in a magimix kitchen blender at high speed for 100 seconds a second sample of the same kepstan powder is supplemented with cab o sil u00ae m 5 silica according to the same protocol the silica cab o sil u00ae m 5 is a hydrophilic fumed silica that has not undergone any specific treatment it will be referred to hereinbelow as u201c m 5 u201d the flowability results for the two supplemented powders are given in table 1 in comparison with the silica free powder these powders are on the one hand stored at 23 u00b0 c and 50 relative humidity up to moisture saturation in the case for example of storage of the powder before machine use the moisture content is measured by the karl fischer method desorption of water from the kepstan u00ae powder by treatment for 20 minutes at 250 u00b0 c on the other hand the powders are dried overnight at 140 u00b0 c the moisture content.