Provided is a power transmission V-belt containing: a rubber layer; a cord buried in the rubber layer along the belt circumferential direction; and at least one reinforcing layer buried in the rubber layer, in which the reinforcing layer contains reinforcing fiber filaments having the same length as a belt width; and contains no fibers intersecting with the belt width direction, or contains the fibers intersecting with the belt width direction in a weight per unit area of 30% or less of the reinforcing fiber filaments, in which the reinforcing layer has a structure in which the reinforcing fiber filaments are in a non-twisted state, are oriented in the belt width direction, and are spread and bonded in a sheet shape, and in which the reinforcing layer has a thickness of 0.05 mm to 0.5 mm.

An object of the present invention is to provide a stitched fiber-reinforced substrate material capable of suppressing the formation of microcracks in a fiber reinforced composite material. The stitched fiber-reinforced substrate material of the present invention is a fiber-reinforced substrate material formed by stitching reinforcement fiber sheets made of reinforcement fibers using stitching yarns, and the stitching yarn has a linear expansion coefficient in the fiber axial direction of −1×10.sup.−6 to 70×10.sup.−6/K after being heated at 180° C. for 2 hours and then cooled. The stitching yarn is preferably a stitching yarn to which an organic compound having a polar group is adhered.

A device draws filaments to form a nonwoven fabric. The device has a nozzle carrier, the nozzle carrier having an elongated drawing channel, wherein the drawing channel comprises a filament inlet and a filament outlet, the drawing channel being provided on opposite sides with air nozzles generating a downward air flow, the air nozzles being connected to an air chamber on both sides of the nozzle carrier through an air channel, a rectification device being provided between the air channel and the air chamber, the rectification device having at least one rectification chamber, a rectification wall of the at least one rectification chamber being provided to be partially ventilated. The air flow is temporarily confined in a small space by the space restriction of the rectification chamber, and as air flows, the air flows out of the partially ventilated area, which acts as a “combing” of the air flow.

A device draws filaments to form a nonwoven fabric. The device has a nozzle carrier, the nozzle carrier having an elongated drawing channel, wherein the drawing channel comprises a filament inlet and a filament outlet, the drawing channel being provided on opposite sides with air nozzles generating a downward air flow, the air nozzles being connected to an air chamber on both sides of the nozzle carrier through an air channel, a rectification device being provided between the air channel and the air chamber, the rectification device having at least one rectification chamber, a rectification wall of the at least one rectification chamber being provided to be partially ventilated. The air flow is temporarily confined in a small space by the space restriction of the rectification chamber, and as air flows, the air flows out of the partially ventilated area, which acts as a “combing” of the air flow.

A composite fiber may include at least one reinforcing filament formed of a first material. A second material maybe systematically deposited in a printed onto the at least one reinforcing filament such that at least one of a length, a width, and a thickness of the second material varies across a surface of the at least one reinforcing filament. The printed pattern may alter one or more properties of a composite structure containing the composite fiber.

A composite fiber may include at least one reinforcing filament formed of a first material. A second material maybe systematically deposited in a printed onto the at least one reinforcing filament such that at least one of a length, a width, and a thickness of the second material varies across a surface of the at least one reinforcing filament. The printed pattern may alter one or more properties of a composite structure containing the composite fiber.

The invention discloses a fiber filament non-woven fabric with a small pore size and a large porosity, which adopts an island type ultra-fine fiber single filament, which is juxtaposed into an unidirectional silk layer several times, and a thin strip-shaped liquid is applied laterally on the unidirectional silk layer. The resin adhesive liquid bonds and fixes all the silk layers into a unidirectional non-woven fabric fixed in a grid segment. The unidirectional non-woven fabric is covered with meltblown non-woven fabric on one or both sides to make a filter material that can 100% filter viruses, bacteria, and micro-particles smaller than PM2.5. It can also be used for a wider range of filter materials, thermal insulation materials, oil absorption materials, battery separator materials, medical and health materials, environmental protection materials, clothing materials, wiping materials.

A method and a device for opening a fiber bundle, capable of performing a fluctuating operation, at a high speed, of pushing a part of a conveyed fiber bundle by a contact member into a stress state and then separating the contact member from the fiber bundle so as to temporarily relax the fiber bundle, and also capable of reducing damage to the fiber bundle. The device for opening a fiber bundle includes a conveying portion 5 for pulling out a fiber bundle Tm from a yarn feeding body 11 and conveying it in a fiber length direction, a fiber-opening processing portion 3 for opening the fiber bundle by moving a fiber in a width direction while bending the fiber by letting a fluid pass through the conveyed fiber bundle Tm, and a fluctuation imparting portion 4 for rotating a contact member 42 in a direction inclined with respect to a conveyance direction while bringing it into contact with the conveyed fiber bundle Tm and pushing a part of the fiber bundle Tm into a stress state, and then separating the contact member 42 from the fiber bundle Tm in the stress state so as to temporarily bring the fiber bundle Tm into a relaxed state.

A method and a device for opening a fiber bundle, capable of performing a fluctuating operation, at a high speed, of pushing a part of a conveyed fiber bundle by a contact member into a stress state and then separating the contact member from the fiber bundle so as to temporarily relax the fiber bundle, and also capable of reducing damage to the fiber bundle. The device for opening a fiber bundle includes a conveying portion 5 for pulling out a fiber bundle Tm from a yarn feeding body 11 and conveying it in a fiber length direction, a fiber-opening processing portion 3 for opening the fiber bundle by moving a fiber in a width direction while bending the fiber by letting a fluid pass through the conveyed fiber bundle Tm, and a fluctuation imparting portion 4 for rotating a contact member 42 in a direction inclined with respect to a conveyance direction while bringing it into contact with the conveyed fiber bundle Tm and pushing a part of the fiber bundle Tm into a stress state, and then separating the contact member 42 from the fiber bundle Tm in the stress state so as to temporarily bring the fiber bundle Tm into a relaxed state.

A partially separated fiber bundle includes a separated fiber section and an unseparated fiber section, being configured to give a ratio A.sub.max/A.sub.min of 1.1 or larger and 3 or smaller, when the number of fiber bundles contained in the width direction of the partially separated fiber bundle (fiber separating number: N.sub.n) measured at a freely selected point P.sub.n (where, n represents an integer of 1 to 100, and freely selected points P.sub.n and P.sub.n+1, excluding n=100, being 50 cm or more away from each other), is divided by a full width of W.sub.n of the partially separated fiber bundle, to calculate the fiber separating number per unit width A.sub.n, and assuming its maximum value as A.sub.max and its minimum value as A.sub.min.