Abstract: The invention provides a voluminous, false twist texturized filament yarn having a great number of individual protruding filament ends; the filaments forming the filament yarn being of the same polyester raw material. The strength of such filament yarns must be of from 1.3 and 1.7 cN/dtex at a clamping length of 5 cm, and at a clamping length of 200 cm of less than 75% of the strength at 5 cm of clamping length, at least however of 0.8 cN/dtex, and the unevenness of the yarn must be less than 3 Uster %.These filament yarns can be processed to web-like structures which correspond to webs made from staple fiber yarns obtained by secondary spinning with respect to their textile properties, their handle, drape and appearance, and which furthermore are distinguished by their low pilling.

Abstract: Multifilament feed yarns in drawable state made from fiber-forming polyester are provided which in accordance with the invention can be processed in a combined draw and false twist process to voluminous filament yarns having individual protruding filament ends. The feed yarns must consist at least in part of filaments having a flex abrasion resistance of less than 1500 cycles and a crack index of more than 5. By using suitable spin finishes, the crack index can be varied and thus the hairiness of the voluminous filament yarns manufactured can be adjusted independently from the crimp values and the pilling behavior.

Abstract: For the smooth production of filaments from polyesters it is very important to use accurately cleaned polymers and also accurately cleaned spinnerets. For removing remainders of polyesters from the spinneret a mixture consisting of at least 70 percent by weight of tri-, tetra-, penta- and hexaethyleneglycol and from 2 up to 10 percent by weight mono- and/or diethyleneglycol and up to 20 percent by weight of hepta-, octa- and higher ethyleneglycols has proved to give best results. Zinc acetate may be added for the solving process.