Abstract: A base fabric for non-coated air bags, in which both the warp and the weft or either of them comprise synthetic fiber multifilaments of flattened cross-section monofilaments having a degree of flatness of from 1.5 to 8.

Abstract: A treatment for reducing friction of seat belts which is characterized by containing therein a polyether polyester having an average molecular weight of 2000-15000 which is obtained from a polyether diol and an aliphatic carboxylic acid, and preferably further containing a silicone compound. This treatment can be applied to either seat belt yarns in the yarn-making step or to seat belt webbing. The resulting seat belt is superior in slip properties and retains them even after wear. It is also superior in retractiablity and wear resistance (durability).

Abstract: To provide a polyamide fiber such as polyhexamethylene adipamide fiber having high tenacity and excellent tenacity retention after vulcanization and GY fatigue life. This fiber is a high tenacity polyamide fiber, preferably a polyhexamethylene adipamide fiber comprising at least 95% by mole of hexamethylene adipamide units and having a sulfuric acid relative viscosity of at least 3.0, said polyamide fiber satisfying the requirements: (a) differential birefringence .delta..DELTA.n.gtoreq.-5.times.10.sup.-3 to 0.times.10.sup.-3, (b) long period (Dm) in the direction of fiber axis: Dm.gtoreq.105 A, and long period (De) in the radial direction of fiber: De=90 to 130 A, (c) main dispersion peak temperature (T.alpha.) in mechanical loss tangent (tan.delta.) curve as obtained by viscoelastic measurement: T.alpha..gtoreq.125.degree. C., and preferably further satisfying the requirements: (d) birefringence .DELTA.n.gtoreq.60.times.10.sup.-3, (e) crystal orientation function fc.gtoreq.0.

Abstract: A conjugated fiber having a sheath-core conjugated structure comprising a polyester core component composed mainly of polyethylene terephthalate and a polyamide sheath component composed mainly of polyhexamethylene adipamide, is disclosed, which has excellent mechanical properties such as a high tenacity, a high modulus, and an improved dimensional stability, and an improved adhesion to a rubber, especially a high-temperature adhesion, an improved heat resistance in a rubber, and a high fatigue resistance, and thus is useful as an industrial material. By adopting a high-speed spinning procedure in the fiber preparing process, the peel resistance in the interface of the sheath-core conjugated structure is greatly improved, and the following valuable characteristics not possessed by conventional conjugated yarns can be obtained:(1) Excellent adhesion and high-temperature adhesion comparable to those of a polyamide, which cannot be obtained in a polyester.

Abstract: A thermoplastic polymer yarn is spun into a spinning tube charged with a pressurized gas of more than 1 kg/cm.sup.2 G and withdrawn through a yarn exit provided with a unique sealing device which substantially prevents the charged gas from leakage but allows passage of the yarn out from the spinning tube. The resultant yarn has a high molecular orientation due to the improved quenching effect and the increase of resistance against yarn travelling of the charged gas.

Abstract: A thermoplastic polymer yarn is spun into a spinning tube charged with a pressurized gas of more than 1 kg/cm.sup.2 G and withdrawn through a yarn exit provided with a unique sealing means which substantially prevents the charged gas from leakage but allows passage of the yarn out from the spinning tube. The resultant yarn has a high molecular orientation due to the improved quenching effect and the increase of resistance against yarn travelling of the charged gas.

Abstract: A polyester multifilament yarn which has the following properties: an initial modulus (Mi) of 90 to 130 grams per denier, a terminal modulus (Mt), a shrinkage index value (.DELTA.S/IV) of 2 to 8 percent, a birefringence (.DELTA.n) of 165.times.10.sup.-3 to 190.times.10.sup.3, a crystalline orientation function (fc) of 0.93 to 0.97, a crystal size (D) 47 to 55 angstroms, a long period (Lp) of 130 to 145 angstroms, a molecular orientation index in the amorphous region (F) of 0.80 to 0.92, and a concentration of carboxyl end groups (--COOH) of 0 to 25 equivalents per 10.sup.6 grams of the polymer is disclosed. The yarn is improved in modulus and shrinkage. A textile reinforcement for tire cord obtained from the multifilament yarn, exhibits exceedingly improved resistance to fatigue and durability to heating.

Abstract: Process for producing polyamide monofilament including partially orienting polyamide monofilament, steaming the partially oriented monofilament, heating and relaxing under low tension for disturbing the molecular orientation of the skin layer of said monofilament and drawing the relaxed monofilament to raise the molecular orientation of its core.Monofilaments of this invention are high in knot strength and are two-layer structures comprising a core and a skin layer. The monofilaments have an average index of birefringence of at least about 50.times.10.sup.-3 and a degree of molecular orientation in the amorphous region of said skin layer of not more than about 0.5.