FIO DE POLIESTER ESTIRADO ENCRESPADO POR ENGRENAGEM COM VOFIO DE POLIESTER ESTIRADO ENCRESPADO POR ENGRENAGEM COM VOLUME LATENTE, PANO CONTENDO UM FIO ENCRESPADO, E, PROCESSOLUME LATENTE, PANO CONTENDO UM FIO ENCRESPADO, E, PROCESSO CONTINUO PARA PRODUCAO DE UM FIO SINTETICO COM VOLUME LAT CONTINUO PARA PRODUCAO DE UM FIO SINTETICO COM VOLUME LATENTE ENTE

摘要

Hitherto the commercial production of a gear crimped polyester yarn has not proved practicable due to extremely low bulk in the yarn and inadequate yarn mechanical properties. There is now provided a drawn gear-crimped polyester yarn with latent bulk the amount and nature of the bulk being such that the yarn has an initial crimp as defined of at least 1.5%, preferably of above 2%, and a mechanical crimp stability as defined of above 0%. The crimped polyester yarn may be produced by heating a drawable polyester yarn (9) having a birefringence in the range 32 x 10<-><3> to 125 x 10<-><3> inclusive, preferably 35 x 10-<3> to 125 x 10<-><3> inclusive, crimping the yarn by guiding it between the intermeshing teeth of a set of toothed wheels (11,19) such that the yarn is caused to follow a sharply zig-zag path, the toothed wheels being rotated at a sufficient speed such that the yarn is drawn by the tension so imparted to the yarn by the toothed wheels and subsequently forwarding the crimped yarn from the toothed wheels under a controlled tension within the range 0.15 to 0.50 g per decitex inclusive based on the decitex of the drawn polyester yarn.