Abstract: Method for producing an interlaced multifilament yarn by rubbing and scratching a material multifilament yarn with a rotary rough surface member and with such intensity that individual filaments constituting the filament yarn are not substantially broken, the rotary surface member having projections which are smaller than the cross-sectional diameter of the individual filaments of the material yarn; diffusing a jetted fluid which is jetted in the yarn running direction along a predetermined yarn passage from a jetting aperture of a supply conduit through a nozzle formed with a rectifying and diffusing portion having a substantially uniform cross-section, and impinging the diffused jetted fluid against the running material multifilament yarn so that the individual filaments of the multifilament yarn mostly vibrate in a direction substantially parallel to a plane defined by the yarn running direction and the fluid jetting direction, the vibration taking place in a section of the yarn passage facing the rectifyi

Abstract: A process for producing polyester fiber highly suitable for a raw yarn for a woven or knitted fabric, having a residual elongation of not higher than 60%, a Young's modulus of 60 to 100 g/d, a boiling water shrinkage of 4 to 10% and a dry heat shrinkage of 5 to 12%, the peak stress temperature in a dry heat shrinkage stress curve of said fiber being lower than 100.degree. C. The process comprises melt spinning a thermoplastic polyester through a spinneret into a filament and taking up the filament after solidifying the spun filamentary polymer, characterized in that the whole process from spinning through take-up is carried out without heating the filament, the filament is subjected to stretch treatment at a stretch ratio of not more than 20% after the solidification of the filament but before take-up, and take-up is carried out at a take-up speed of not less than 5,000 m/min.

Abstract: Method for producing an interlaced multifilament yarn comprising previously rubbing and scratching a material multifilament yarn with an intensity such that the individual filaments constituting the multifilament yarn are not substantially broken by a rotary rough surface member having sharp projections which are smaller than the cross-sectional diameter of the individual filament of the multifilament yarn; then diffusing at least one jetted fluid, each jetted in the yarn running direction along a predetermined yarn passage from a jetting aperture of a supply conduit through a nozzle formed with a rectifying and diffusing portion having a substantially uniform section with the supply conduit being fixed with respect to the members defining the yarn passage; and then impinging the diffused jetted fluid against the running material multifilament yarn so that the individual filaments of the multifilament yarn mostly vibrate in a direction which is substantially parallel to a plane defined by the yarn running dir

Abstract: A polyester fiber highly suitable for a raw yarn for a woven or knitted fabric, having a residual elongation of not higher than 60%, a Young's modulus of 60 to 100 g/d, a boiling water shrinkage of 4 to 10% and a dry heat shrinkage of 5 to 12%, the peak stress temperature in a dry heat shrinkage stress curve of said fiber being lower than 100.degree. C. The fiber can be produced by a process comprising melt spinning a thermoplastic polyester through a spinneret into a filament and taking up the filament after solidifying the spun filamentary polymer, characterized in that the whole process from spinning through take-up is carried out without heating the filament, the filament is subjected to stretch treatment at a stretch ratio of not more than 20% after the solidification of the filament but before take-up, and take-up is carried out at a take-up speed of not less than 5,000 m/min.

Abstract: A potentially bulky, processed yarn which is a substantially non-interlaced multifilament yarn of a thermoplastic synthetic fiber satisfying the characteristic values of R.sub.max /R.ltoreq.2.5, .DELTA.S.sub.5 .gtoreq.1.5, .DELTA.S.sub.50 .ltoreq.3.0, Y.gtoreq.1.3 and X.sub.T --X.ltoreq.1.0, where R.sub.max is maximum tension fluctuation width, R is average tension fluctuation width of a normal portion, .DELTA.S.sub.5 is difference in maximum shrinkage among each filament of a sample having a length of 5 cm, .DELTA.S.sub.50 is difference in maximum shrinkage among each filament of a sample having a length of 50 cm, X.sub.T is maximum tension, X is average tension and Y is degree of bulkiness/dry heat shrinkage.

Abstract: Method for producing an interlaced multifilament yarn comprising previously rubbing and scratching a material multifilament yarn with an intensity such that the individual filaments constituting the multifilament yarn are not substantially broken by a rotary rough surface member having sharp projections which are smaller than the cross-sectional diameter of the individual filaments of the multifilament yarn; then diffusing at least one jetted fluid, each jetted in the yarn running direction along a predetermined yarn passage from a jetting aperture of a supply conduit; and then impinging the diffused jetted fluid against the running material multifilament yarn so that the individual filaments of the multifilament yarn mostly vibrate in a direction which is substantially parallel to a plane defined by the yarn running direction and the fluid jetting direction.

Abstract: An apparatus for producing interlaced multifilament yarn having an improved configuration is disclosed. When a material yarn is treated by an interlacing apparatus provided with an interlacing nozzle wherein a hollow longitudinal space is formed therein and a jetted fluid is introduced into the hollow longitudinal space, the jet fluid is directed to an axis of the passage of a running yarn in the longitudinal space along a direction substantially perpendicular to the axis of the yarn passage in such a condition that the jet fluid is diffused to a direction along the yarn passage. Accordingly, the individual filaments of the running yarn are vibrated about the axis of the running yarn passage, mainly along a plane defined by the axis of the yarn passage and the axis of a fluid conduit for supplying the jet fluid. According to such effective vibration of the individual filaments, a very stable interlaced configuration of the individual filaments can be created.

Abstract: A process for producing a potentially bulky yarn which is a substantially non-interlaced multifilament yarn of a thermoplastic synthetic fiber satisfying the characteristic values of R.sub.max /R.ltoreq.2.5, .DELTA.S.sub.5 .gtoreq.1.5, .DELTA.S.sub.50 .ltoreq.3.0, Y.gtoreq.1.3 and X.sub.T -X.ltoreq.1.0, where R.sub.max is maximum tension fluctuation width, R is average tension fluctuation width of a normal portion, .DELTA.S.sub.5 is difference in maximum shrinkage among each filament of a sample having a length of 5 cm, .DELTA.S.sub.50 is difference in maximum shrinkage among each filament of a sample having a length of 50 cm, X.sub.T is maximum tension, X is average tension and Y is degree of bulkiness/dry heat shrinkage.

Abstract: A method and apparatus for producing interlaced multifilament yarn having an improved configuration is disclosed. When a material yarn is treated by the interlacing apparatus provided with an interlacing nozzle wherein a hollow longitudinal space is formed therein and a jetted fluid is introduced into the hollow longitudinal space, the jet fluid is directed to an axis of the passage of a running yarn in the longitudinal space along a direction substantially perpendicular to the axis of the yarn passage in such a condition that the jet fluid is diffused to a direction along the yarn passage. Accordingly, the individual filaments of the running yarn are vibrated about the axis of the running yarn passage, mainly along a plane defined by the axis of the yarn passage and the axis of a fluid conduit for supplying the jet fluid. According to such effective vibration of the individual filaments, a very stable interlaced configuration of the individual filaments can be created.

Abstract: A textured polyester yarn having improved variation in dyeability along its length is composed of a plurality of individual filaments each having thick and thin sections randomly distributed along the filament axis, said yarn having an Uster evenness value of 1.0 to 10.0%, a T index of 3 to 30 and a variation in reflected light intensity in a continuous dyeing test of .+-.0.15 to .+-.0.80 and said yarn preferably having not-untwisted portions containing genuine twists of a fixed direction intermittently retained at random along its length. The yarn is produced by false twisting a polyester yarn composed of a plurality of individual filaments each having variation in cross-sectional area along its length, in which the thick sections have a birefringence of 15 to 80.times.10.sup.-3 and the thin sections have a birefringence of 90 to 200+10.sup.-3, at a temperature of not lower than 180.degree. C and under a twisting tension of 0.05 to 0.8 g/d with a variation with respect to the average twisting tension of .+-.

Abstract: A process for producing a highly oriented polyester undrawn yarn comprising melt-spinning a polyester from a spinneret, solidifying the melt-spun yarn and taking up a solidified yarn at a take-up velocity from 2,500 to 4,500 m/min, wherein the spinning length is set within a specific range in accordance with the take-up velocity, yarn denier and maximum allowable tension of the yarn.

Abstract: Fiber- and film-forming composition comprising a linear synthetic polyester together with antimony-containing particles, present in an amount of from 0.02 to 1.0% by weight of the composition. The content of elemental antimony in the antimony-containing particles is from 15 to 70% of the weight of the particles.