prepared in accordance with the present invention fig4 a shows a false twist textured polyester yarn and fig4 c shows a flat yarn the irregularity of the crimp of the individual yarn fibrils is clearly evident from comparing fig4 b to fig4 a and 4c fig5 shows a scanning electronic microscope photograph of a yarn prepared in accordance with the present invention the magnification of the yarn in fig5 was 2100 1 the transverse surface lines which result when practicing the process of this invention are clear from this photograph the invention will be more fully explained by the following examples here a polyester poy dtex 150 f 15 was manufactured at a speed of 3100 m min the drawing took place with a ratio of 1 1 93 at 652 m min and at room temperature on a draw twist machine subsequently the bobbins were shrunk in a shocking way on a fixing machine and a poststabilizing machine respectively while in a convection heater maintained at 200 u00b0 c the heat length was 63 cm the withdrawal speed of the yarn was at 110 m min the delivery speed varied between 154 m min and 198 m min the lower limit i e 154 m min corresponds to a 40 overfeed with a 28 6 shrinkage see fig3 curve h and the upper limit i e 198 m min corresponds to an 80 overfeed with a 44 4 shrinkage see fig3 curve i the properties of the yarn prepared in.