A system and method for providing a plurality of fibers from a spinneret; subjecting the fibers to quench air; attenuating the fibers through a closed stretching unit; reducing a velocity of the plurality of fibers in a diffuser that is spaced apart from an exit of the closed stretching unit in a direction of travel of the fibers, the diffuser having opposed diverging sidewalls; and subjecting the fibers to an applied electrostatic charge before the fibers enter the diffuser, wherein the electrostatic charge is applied by one or more electrostatic charging units.

An apparatus for making spunbond from continuous thermoplastic filaments has a spinneret for spinning the continuous filaments and advancing them in a filament-travel direction, a cooler for cooling the filaments, a stretcher for stretching the filaments, a depositing device including a foraminous belt extending in a machine direction transverse to the filament-travel direction for deposition of the filaments as a nonwoven web and conveyance away from the stretcher, a diffusor between the stretcher and the foraminous belt so that filaments and primary air from the stretcher enter into the diffusor, and a suction device for extracting air through the foraminous belt at an unobstructed extraction region underneath the diffusor outlet and having a width b in a machine direction that is greater than a width B of the diffusor outlet. The diffusor forms upstream and downstream secondary air-inlet gaps at opposite ends through which secondary air is aspirated into the diffusor.

Disclosed herein are methods for producing core-sheath structures by shaping at least one filament bundle containing a plurality of filaments to form at least one shaped strand of filaments, and braiding a plurality of strands, including the at least one shaped strand of filaments, over a core to form the core-sheath structure containing a braided sheath of the strands surrounding the core, wherein the shaped strand of filaments is an untwisted strand having a twist level of less than 1 turn per meter, a cross-sectional aspect ratio of the shaped strand of filaments is at least 3:1, as measured in the braided sheath, a thickness of at least a portion of the braided sheath ranges from about 10 to about 200 μm, and the braided sheath comprises a synthetic fiber having a tensile strength of greater than 12 cN/dtex. Also disclosed herein are core-sheath structures formed by such methods.

Spunbonded nonwoven is made from continuous thermoplastic filaments emitted downwardly by a spinneret in a filament direction. A cooling chamber directly beneath the spinneret receives the filaments from the spinneret and cools the spun filaments with cooling air and has relative to a longitudinally extending machine direction a pair of longitudinal sides extending parallel to the machine direction and a pair of transverse sides extending substantially perpendicular to the machine direction between the longitudinal sides. Respective air-supply manifolds on the transverse sides feed cooling air therefrom into the cooling chamber. The cooling air is extracted from the cooling chamber at the longitudinal sides. A stretcher directly beneath the cooling chamber receives and elongates the cooled filaments, and a device deposits the stretched filaments as a band and conveys the band off in the machine direction.

An apparatus for making spunbonded nonwovens has a spinneret for emitting continuous thermoplastic filaments in a filament-travel direction, a cooling chamber downstream in the direction from the spinneret for cooling the spun filaments with cooling air, two manifolds on opposite sides of the cooling chamber opening transversely of the direction into the cooling chamber, and a respective conduit having a conduit cross-sectional area and connected to each manifold for feeding cooling air thereto. The conduit cross-sectional area increases toward the manifold to a manifold cross-sectional area, and manifold cross-sectional area is at least twice as large as the conduit cross-sectional area. At least one flow straightener is provided upstream from the cooling chamber in each manifold for orienting air flow in an air-flow direction, and at least one perforated planar homogenizing element is provided in each manifold for homogenizing the cooling air flow.

An apparatus for making a nonwoven spunbond web has a spinneret for making endless filaments moving in a predetermined direction. A monomer extractor downstream from the spinneret has an upstream extractor end face directed upstream and forming a gap with a downstream spinneret end face. A cooler downstream of the extractor for the filaments has an upstream cooler end face forming with a downstream extractor end face a second gap. A stretcher downstream of the cooler for the cooled filaments has an upstream stretcher end face forming a third gap with the downstream cooler end face. The filaments are deposited on a web former by the stretcher to form the nonwoven spunbond web. A deformable seal for seals one of the gaps, and means connected to the deformable seal press the seal against the end faces forming the one gap with a variable pressure or contact face.

An apparatus for making a nonwoven spunbond web has a spinneret for making endless filaments moving in a predetermined direction. A monomer extractor downstream from the spinneret has an upstream extractor end face directed upstream and forming a gap with a downstream spinneret end face. A cooler downstream of the extractor for the filaments has an upstream cooler end face forming with a downstream extractor end face a second gap. A stretcher downstream of the cooler for the cooled filaments has an upstream stretcher end face forming a third gap with the downstream cooler end face. The filaments are deposited on a web former by the stretcher to form the nonwoven spunbond web. A deformable seal for seals one of the gaps, and means connected to the deformable seal press the seal against the end faces forming the one gap with a variable pressure or contact face.

Disclosed herein are methods for producing core-sheath structures by shaping at least one filament bundle containing a plurality of filaments to form at least one shaped strand of filaments, and braiding a plurality of strands, including the at least one shaped strand of filaments, over a core to form the core-sheath structure containing a braided sheath of the strands surrounding the core, wherein the shaped strand of filaments is an untwisted strand having a twist level of less than 1 turn per meter, a cross-sectional aspect ratio of the shaped strand of filaments is at least 3:1, as measured in the braided sheath, a thickness of at least a portion of the braided sheath ranges from about 10 to about 200 μm, and the braided sheath comprises a synthetic fiber having a tensile strength of greater than 12 cN/dtex. Also disclosed herein are core-sheath structures formed by such methods.

A polyamide multifilament includes a polyamide resin and has a total fineness of 30.0 to 150.0 dtex, a tenacity of 7.5 to 10.0 cN/dtex, and an elongation at break of 15.0 to 35.0%. A method of producing the polyamide multifilament includes the steps of: providing polyamide chips; and making yarn using a method of direct spinning and drawing, wherein |ηa−ηb|<0.3 is satisfied, assuming that sulfuric acid relative viscosity of said polyamide chips is ηa, and that sulfuric acid relative viscosity of said polyamide multifilament made into yarn is ηb.

A polyamide multifilament includes a polyamide resin and has a total fineness of 30.0 to 150.0 dtex, a tenacity of 7.5 to 10.0 cN/dtex, and an elongation at break of 15.0 to 35.0%. A method of producing the polyamide multifilament includes the steps of: providing polyamide chips; and making yarn using a method of direct spinning and drawing, wherein |ηa−ηb|<0.3 is satisfied, assuming that sulfuric acid relative viscosity of said polyamide chips is ηa, and that sulfuric acid relative viscosity of said polyamide multifilament made into yarn is ηb.