will result in yarn breaks and yarn of inferior quality characterized by coalesced filaments broken filaments etc applicant has found that the point of crystallization can be determined and if the yarn is quenched in a liquid quench bath at about this point one obtains highly oriented and yet amorphous filaments the location of the liquids quench bath to achieve this result is most easily determined on a trial and error basis for example at a spinning temperature of 310 u00b0 c and a spinning speed of 6200 ypm 5669 m min for a 75 den 17 fil yarn placement of the quench bath at 38 inches 96 5 cm from the spinneret leads to an amorphous yarn with 67 bos and a density of 1 357 gm ml the x ray diffraction pattern of the yarn is characterized by a diffuse halo which indicates the absence of crystallinity placement of the quench bath at 42 inches 107 cm from the spinneret leads to a crystalline yarn with a bos of 15 and density of 1 385 gm ml an x ray diffraction test reveals a distinct pattern indicating crystallinity the amorphous material is a more texturable product a liquid quench bath is selected to achieve rapid quenching room temperature water has been found to be quite suitable for this purpose it is important that the crystallization process be arrested within a short period of time air quenching is inadequate the exact distance from the spinneret where the yarn crystallizes is a function of several variables such as spinning speed and filament size but is easily located by a simple measurement of boil off shrinkage.