Abstract: A short fiber and continuous filament composite yarn having a high grade cotton spun yarn-like soft touch, satisfactory resilience, and uniform appearance, including a core portion formed by a plurality of cold drawn, non-crimped individual filaments substantially in the form of a bundle and a peripheral portion formed around the core portion and comprising a plurality of cold drawn-cut, non-crimped short fibers having a smaller shrinkage in boiling water, and optionally, a lower denier than those of the individual filaments, random portions of the short fibers being penetrated into the bundle of the individual filaments and intertwined with the individual filaments, and other portions of the short fibers forming a plurality of loops projecting in the form of waves having different wave heights, from the core portion toward the outside thereof to form multilayered loop structures around the core portion.

Abstract: A polyamide fiber comprised of (A) a thermoplastic aliphatic polyamide having copolymerized therein a polyalkylene oxide unit and having a melting point of at least 160.degree. C., and (B) a polyoxyalkylene glycol, wherein the ingredient (B) is finely dispersed in the ingredient (A). A polyamide fiber exhibiting a rate of moisture absorption of at least 3.5%/5 minutes at 25.degree. C. and R.H. 90% and/or a triboelectric voltage of not larger than 1.5 kV at 20.degree. C. and R.H. 40% is obtained by removing the ingredient (B) from the above-mentioned polyamide fiber by means of dissolution.

Abstract: An improved copolyester fiber capable of being dyed with cationic dyes and having an excellent brightness, heat resistance and a satisfactory mechanical strength comprises a copolyester resin comprising a polymerization product of at least one aromatic dicarboxylic acid compound, at least one alkylene diol compound and at least one quaternary phosphonium organic sulfonate of the formula (I): ##STR1## wherein A=an aromatic or aliphatic radical, X.sup.1 =H or an ester-forming organic radical, X.sup.2 =an ester-forming organic radical, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 =an alkyl or aryl radical, n=1 or more, and having an [.eta.].sub.f of 0.5 or more, the copolyester fiber having a silk factor of 25 or more and exhibiting the number of scission of backbone chains of the copolyester molecules of 140.times.10.sup.23 or less per 10.sup.6 g of fiber when wet heat-treated in a solution of 0.4 g/l of acetic acid in distilled water at 130.degree. for 60 minutes.

Abstract: A synthetic polymer multifilament yarn capable of being converted to a bulky yarn is composed of a plurality of irregular individual filaments each having at least two belt-shaped filamentary constituents, at least one core filamentary constituent located between the belt-shaped constituents and extending in a sinuous manner and having a thickness varying alternately between thick and thin, and at least two thin middle filamentary constituents located between the core constituent and the belt-shaped constituents to thereby connect those constituents to each other.

Abstract: A polyester fiber having a superior stainproof property comprises at least one fiber-forming polyester copolymer comprising a backbone polyester polymer and at least one type of terminal substituent which blocks at least some of the terminals of the molecules of the backbone polyester polymer and which substituent consists of a polyoxyalkyleneglycol monoether group of the formula (I):R.sup.1 -O--R.sup.2 -O.sub.n (I)wherein R.sup.1 is a monovalent organic radical free from active hydrogen atom, R.sup.2 is an alkylene radical, and n is an integer of 2 or more.

Abstract: A synthetic polymer hollow irregular multifilament yarn useful for producing bulky yarn products comprises a plurality of hollow irregular individual filaments each comprising a hollow filamentary constituent, a non-hollow sinuous filamentary constituent sinuously extending in a wave form along the hollow filamentary constituent, having a smaller average thickness than the hollow filamentary constituent and being connected to one side of the hollow filamentary constituent through a middle filamentary constituent distortedly extending along the hollow filamentary constituent and having a cross-sectional profile in the form of a waist, and is produced by extruding at least one polymer melt through a spinneret having a plurality of spinning orifices each consisting of a first orifice segment adequate for forming a hollow filament, a second orifice segment adequate for forming a non-hollow filament and having a smaller cross-section than that of the first orifice segment and a third orifice segment in the form of

Abstract: A fiber composed of a polyester having at least a part of terminals blocked with the residue of at least one specific metal sulfonate compound, where the amount of the blocked terminals is 1.3 to 4.0 mol % based on the dicarboxylic acid component of the polyester and the alkali dissolution speed constant is 3.3.times.10.sup.-9 to 6.5.times.10.sup.-9 cm/sec. This polyester has a good dyeability with a cationic dye and is excellent in the heat resistance and alkali resistance. The polyester fiber can be spun at a high speed or super high speed and can be false-twisted at a high temperature.

Abstract: A synthetic polymer hollow irregular multifilament yarn useful for producing bulky yarn products comprises a plurality of hollow irregular individual filaments each comprising a hollow filamentary constituent, a non-hollow sinuous filamentary constituent sinuously extending in a wave form along the hollow filamentary constituent, having a smaller average thickness than the hollow filamentary constituent and being connected to one side of the hollow filamentary constituent through a middle filamentary constituent distortedly extending along the hollow filamentary constituent and having a cross-sectional profile in the form of a waist, and is produced by extruding at least one polymer melt through a spinneret having a plurality of spinning orifices each consisting of a first orifice segment adequate for forming a hollow filament, a second orifice segment adequate for forming a non-hollow filament and having a smaller cross-section than that of the first orifice segment and a third orifice segment in the form of

Abstract: A polyester composition with an excellent high-speed melt-spinning property, comprising(A) 100 parts by weight of a matrix polyester resin comprising at least 80 molar % of an ethylene terephthalate recurring unit, and(B) 0.2 to 7 parts by weight of a dispersoid dispersed in the matrix,the dispersoid being such that, when it is contained in a predetermined amount (w) in a typical matrix polyester resin consisting of a polyethylene terephthalate having an intrinsic viscosity of 0.640, the resultant exemplary polyester composition satisfies the relationship (I): ##EQU1## wherein: .gamma..sub.1 =shearing rate of 0.01 sec.sup.-1 ; .gamma..sub.2 =shearing rate of 5.0 sec.sup.-1 ; .eta..gamma..sub.1 (w)=melt viscosity (poise=1/10 N.multidot.sec.multidot.m.sup.-2) of the exemplary polyester composition at .gamma..sub.1 ; .eta..gamma..sub.1 (0)=melt viscosity of matrix polyester resin at .gamma..sub.1 ; .eta..gamma..sub.2 (w)=melt viscosity of the exemplary polyester composition at .gamma..sub.2 ; and .eta..gamma..

Abstract: A yarn treating composition useful for application to a filamentary yarn for high-speed friction draw-false twisting. This composition comprises substantially a polyether having a molar copolymerization ratio between propylene and ethylene oxides of 35:65-90:10 and an average molecular weight of 1,000 to 15,000, and small amounts of anionic compounds. The anionic compounds are used in the form of a mixture of salts of specific dicarboxylic acid derivatives with phosphate compounds and/or sulfonate compounds. The application of said treating composition to yarns provides a reduction of fluctuation in friction between the yarns and rollers, guides, etc. and of frictional resistance at a high running speed, improvement in threading property in false twisting, and a sharp decrease in scum deposits on heaters.