Abstract: The present invention relates to polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics containing in themselves an organic pigment having heat resistance as high as a thermal decomposition temperature of 200° C. or higher, and soluble in a mineral acid and having group(s) of —N? and/or NH— in the molecule, such as any of perinones and/or perylenes, any of phthalocyanines, any of quinacridones, and any of dioxazines, wherein they have a strength retention of 50% or higher when exposed to light from a xenon lamp for 100 hours and having a tensile strength retention of 85% or higher after exposed to an atmosphere of a temperature of 80° C. and a relative humidity of 80% for 700 hours. The polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics can be used for cords for reinforcing rubber, sheets and rods for reinforcing cement/concrete, composite materials, sail clothes, ropes, knife proof vests and bullet proof vests.

Abstract: In a diaphragm for a loud-speaker of the present invention, an increase in tensile strength is averagely attained as a whole, and the over all diaphragm is uniformly colored without showing any lattice pattern. The diaphragm includes a woven fabric comprising yarns made from a blend of a plurality of fibers wherein at least one of the plurality of fibers is PBO (poly(p-phenylene benzobisoxazole)) fiber.

Abstract: A commodity inspection system attaches a ferromagnetic body to a genuine commodity in advance and detects the magnetic characteristic of the ferromagnetic body so as to judge whether the inspection object is a genuine commodity. The system includes: an magnetization coil for applying a magnetic field changing at a predetermined frequency to a inspection object; a detection coil for detecting the change of the magnetic flux density caused by the magnetic field change; an FFT unit for acquiring a frequency spectrum corresponding to magnetic flux density change; and a judgment unit for judging whether the inspection object is a genuine commodity according to the acquired frequency spectrum. The ferromagnetic body causes a steep magnetization reversal when a magnetic field exceeding its coercive force is applied.

Abstract: The present invention relates to polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics containing in themselves an organic pigment having heat resistance as high as a thermal decomposition temperature of 200° C. or higher, and soluble in a mineral acid and having group(s) of —N=and/or NH— in the molecule, such as any of perinones and/or perylenes, any of phthalocyanines, any of quinacridones, and any of dioxazines, wherein they have a strength retention of 50% or higher when exposed to light from a xenon lamp for 100 hours and having a tensile strength retention of 85% or higher after exposed to an atmosphere of a temperature of 80° C. and a relative humidity of 80% for 700 hours. The polybenzazole fibers or filaments, staple fibers, spun yarns, and woven or knitted fabrics can be used for cords for reinforcing rubber, sheets and rods for reinforcing cement/concrete, composite materials, sail clothes, ropes, knife proof vests and bullet proof vests.

Abstract: There is provided a polybenzazole fiber or film containing a basic organic compound in the form of a monomer or a condensate, selected from the group consisting of guanidines, triazoles, quinazolines, piperidines, anilines, pyridines, cyanuric acids, and p-phenylenediamine, m-phenylenediamine and a mixture thereof. This fiber has characteristics in that the X-ray meridian diffraction half-width factor is 0.3°/GPa or less, that the elasticity decrement (Er) attributed to change of molecular orientation is 30 GPa or less, and that the breaking strength is 1 GPa or more. This fiber can be used in staple fiber, a spun yarn, a woven or knit fabric, a felt material, a composite material, a cord, a rod, a fibrous sheet, a knife proof vest or a bullet proof vest.

Abstract: In a diaphragm for loud-speaker of the present invention, an increase in tensile strength is averagely attained as a whole, and the over all diaphragm is uniformly colored without showing any lattice pattern.

Abstract: Crimped polybenzazole staple fibers which satisfy the following specifications at the same time:(1) 2.ltoreq.number of crimps (number/inch).ltoreq.40(2) 2.ltoreq.crimp index (%).ltoreq.30(3) 0.3.ltoreq.crimp index/number of crimps.ltoreq.3.0; methods for manufacturing crimped polybenzazole staple fibers; and the rotary cutter therefor. The crimped polybenzazole staple fibers of the present invention are superior in crimp property and are useful for manufacturing spun yarn and unwoven fabric. According to the method of the present invention, crimped polybenzazole staple fibers superior in spinnability can be manufactured with ease. In addition, the cutting blade of the present invention stands a long time use for manufacturing staple fibers from a continuous filaments tow of high tenacity fibers.

Abstract: High temperature resistant blended yarns exhibiting an ignition loss of 70% or less when heated in air at 850.degree. C. for 30 minutes are provided. The blended yarns can attain, without using asbestos, heat resistance at 500.degree. C. or higher temperatures, satisfactory resistance to flexing abrasion, high yields in the spinning step, excellent light-weight properties and soft touch.

Abstract: The invention is a process for the preparation of polybenzazole staple fibers which includes extruding a solution of polybenzazole polymer to form a dope filament, cutting the dope filament to a desired length, and washing and drying the cut filament. It has been discovered that the process of the invention provides a suitable means to prepare staple fibers which does not require the cutting of washed, rigid polybenzazole filaments.

Abstract: Crimped polybenzazole staple fibers which satisfy the following specifications at the same time:(1) 2.ltoreq.number of crimps (number/inch).ltoreq.40(2) 2.ltoreq.crimp index (%).ltoreq.30(3) 0.3.ltoreq.crimp index/number of crimps.ltoreq.3.0; methods for manufacturing crimped polybenzazole staple fibers; and the rotary cutter therefor. The crimped polybenzazole staple fibers of the present invention are superior in crimp property and are useful for manufacturing spun yarn and unwoven fabric. According to the method of the present invention, crimped polybenzazole staple fibers superior in spinnability can be manufactured with ease. In addition, the cutting blade of the present invention stands a long time use for manufacturing staple fibers from a continuous filaments tow of high tenacity fibers.

Abstract: Polybenzazole fibers can be rapidly dried without undue fiber damage by exposing them to two or more set point temperatures with the temperatures being selected relative to the residual moisture content of the fiber. The residence time required for the fiber at each progressively higher temperature can be reduced if the fiber is always in full contact with the set point temperature of the drying equipment.

Abstract: A metal fiber having unidirectional dendritic texture which is an assembly of a group of dendrites wherein primary arms have grown at angle of within 20.degree. relative to the metal fiber axis, diameter of said fiber being not greater than 100 .mu.m. There is also disclosed a single crystalline metal fiber which is a single crystalline material throughout the entire length, diameter of said fiber being not greater than 100 .mu.m, length of said fiber being not less than 40 mm. These fibers can be produced by melt-spinning of metal.