A method and system for operating an air jet spinning machine, that features at least one spinning unit with one spinning nozzle for producing a yarn. During normal operation of the spinning unit, a fiber composite is fed to the spinning nozzle through an inlet and in a predefined transport direction. The fiber composite within a vortex chamber of the spinning nozzle receives a twist with the assistance of a vortex air flow, such that a yarn is formed from the fiber composite, which leaves the spinning nozzle through an outlet. After an interruption in yarn production, a piecing process is carried out, with which one yarn end on the spool side moves counter to the transport direction through the spinning nozzle, is overlaid with one end of the fiber composite after passing through the spinning nozzle and, together with this, is brought through the inlet into the spinning nozzle. After conclusion of the piecing process, the production of yarn is continued through the resumption of normal operation. During the piecing process, at least temporarily, additive is applied at the end of the fiber composite.

A distribution system of a wetting liquid for spinning nozzles of an air-jet spinning machine comprising a supply pipe (21) of the wetting liquid (1) to the spinning nozzles (3) of individual workstations, characterized by that in the supply pipe (21) of the wetting liquid (1) is arranged at least one UV light emitting diode (5) to disinfect the wetting liquid (1), whereby the UV radiation emitted by the UV light emitting diode (5) passes through the wetting liquid (1).

A method for operating an air jet spinning machine having at least one spinning unit with one spinning nozzle for producing a yarn is provided. During the operation of the spinning unit, the spinning nozzle feeds a fiber composite through an inlet in a predefined transport direction. The fiber composite within a vortex chamber of the spinning nozzle receives a twist with the assistance of a vortex air flow, such that a yarn is formed from the fiber composite. With the assistance of at least one sensor system, the yarn leaving the outlet is monitored with regard to defined yarn flaws. The production of yarn is interrupted upon the detection of a corresponding yarn flaw. Between the detection of the specified yarn flaw and the interruption of the yarn production, a cleaning process is carried out during which an additive is fed to the spinning unit and is applied to the fiber composite and/or the yarn produced from the fiber composite and/or on parts of the spinning nozzle.

A spinning unit is provided for an air jet spinning machine with a spinning nozzle used to manufacture yarn from a fiber strand. The spinning nozzle has an inlet for the fiber strand, a vortex chamber, a yarn forming element protruding into the vortex chamber, and a draw-off channel for the yarn. An additive supply is assigned to the spinning nozzle and designed so that the spinning nozzle is supplied with an additive. The yarn forming element has at least one additive duct that ends in the vortex chamber or the draw-off channel. The additive supply encompasses an additive supply line connected to the additive duct so that an additive introduced into the additive duct via the additive supply line can be introduced into the draw-off channel and/or the vortex chamber. A process for operating an air jet spinning machine with at least one spinning unit is provided. An additive is added, at least intermittently, to the spinning nozzle of the spinning unit while it is operating with the help of an additive supply. The added additive is delivered through an additive duct of the yarn forming element to the draw-off channel and/or the vortex chamber.

A method is provided to operate an air jet spinning machine, having at least one spinning unit with a spinning nozzle for manufacturing yarn, in which a fiber strand is fed to the spinning nozzle through an inlet and is imparted a twist inside a vortex chamber of the spinning nozzle by means of a swirled air current so that a yarn is formed from the fiber strand. An additive is added with an additive dispenser to the spinning unit while the air jet spinning machine is operating and applied on the fiber strand or on sections of the spinning nozzle and/or the yarn. At least one physical parameter of the yarn is monitored by a sensor system wherein, based on a measured value supplied by the sensor system correlated with the parameter, it is determined whether and/or how much additive was applied.

The invention relates to a method for operating an air spinning machine with a multiple number of spinning units (1), whereas each spinning unit (1) comprises at least one spinning nozzle (2) with an internal vortex chamber (6), whereas the spinning nozzle (2) is fed a fiber composite (4) through an inlet (5) of the spinning nozzle (2) during the operation of the spinning unit (1), whereas the spinning nozzle (2) features a multiple number of air nozzles (9) leading into the vortex chamber (6), through which, during the operating of the air spinning machine, compressed air streams into the vortex chamber (6), in order to generate a vortex air flow within the vortex chamber (6), whereas the fiber composite (4) receives a twist with the assistance of the vortex air flow within a vortex chamber (6), such that a yarn (3) is formed from the fiber composite (4), which ultimately leaves the spinning nozzle (2) through an outlet (8), and whereas the air spinning machine features an additive supply (10), with the assistance of which, during the operation of the air spinning machine, an additive (11) is at least temporarily fed to at least one part of the spinning units (1). In accordance with the invention, it is proposed that a liquid additive (11) is used, whereas the additive (11) is degassed prior to leaving the additive supply (10). In addition, an air spinning machine with a degassing device (12) is described.

A method for preparing profiled fibers with low lousiness rate by a polyester FDY process is provided, when preparing profiled fibers by the FDY process, during the operation of a yarn path, the horizontal and longitudinal positions of wire guide ceramic pieces on the pre-entangling wire guide frame are adjusted to maintain vertical alignment of the filament bundle in the pre-entangling device and achieve optimal jitter effect, to prepare profiled fibers with a low lousiness rate; when the profiled fibers are triangular profiled fibers, the lousiness rate is 0.35-0.65%; when the profiled fibers are trilobal profiled fibers, the lousiness rate is 0.85-1.25%; when the profiled fibers are flat profiled fibers, the lousiness rate is 0.5-0.85%.

The present invention provides a modified sustainable droplet-wet spinning technology aimed at enhancing hemp yarn quality. Implemented on a ring spinning machine, the technology delivers a controlled amount of water onto the top front roller which results in a more compact spinning triangle. The invention can be readily implemented on commercial ring spinning systems and improve both tenacity and hairiness of fibers comprising hemp.