A method and associated textile machine are provided to produce a roving having a protective twist from a fiber bundle fed to a consolidating means. The produced roving is wound with a winding device onto a tube arranged at a winding position. After the wound tube has been fully or partially wound with the roving, a tube change is initiated. During the tube change, the wound tube is removed from the winding position and an empty tube is moved into the winding position. During the tube change, the roving is wound onto the wound tube at least until the roving comes into contact with the empty tube as a result of the tube change such that the production of the roving is not interrupted during the tube change. During the tube change, the roving is wound onto the wound tube in a region that lies outside a region last wound prior to the tube change.

The present disclosure provides composite yarn, apparatus and methods preparing thereof. The composite yarn of the present disclosure includes wrapping fibers and a central yarn that is formed by a first body yarn and a second body yarn, wherein a portion of the wrapping fibers are combined with the central yarn in at least one of the following states: a first state, a portion of the wrapping fibers wrap around the first body yarn or the second body yarn; a second state, a portion of the wrapping fibers wrap around the first body yarn and the second body yarn respectively at the same time; a third state, a portion of the wrapping fibers wrap around the central yarn. The composite yarn of the present disclosure has low twist factor and high strength, which solves the problem of severe strength loss associated with low twist factors existing in conventional low-twist techniques.

The device (1) comprises a first roller (3) rotatable about a first rotation axis (3A) and a second roller (5) rotatable about a second rotation axis (5A), parallel to the first rotation axis (3A). The two are in mutual contact and define between them a yarn passage (7) and at least of them is motorized. The device further comprises 5 guide members (9) defining a feed path of at least a yarn (F; F1, F2, F3, F4), associated with the yarn passage (7) between the first roller (3) and the second roller (5). The guide members (9; 13) are movable with respect to the rollers (3, 5) in a direction substantially parallel to the first rotation axis (3A) and to the second rotation axis (5A), so as to take the yarn path temporarily outside the mutual contact 10 area between the rollers.

The device (1) comprises a first roller (3) rotatable about a first rotation axis (3A) and a second roller (5) rotatable about a second rotation axis (5A), parallel to the first rotation axis (3A). The two are in mutual contact and define between them a yarn passage (7) and at least of them is motorized. The device further comprises 5 guide members (9) defining a feed path of at least a yarn (F; F1, F2, F3, F4), associated with the yarn passage (7) between the first roller (3) and the second roller (5). The guide members (9; 13) are movable with respect to the rollers (3, 5) in a direction substantially parallel to the first rotation axis (3A) and to the second rotation axis (5A), so as to take the yarn path temporarily outside the mutual contact 10 area between the rollers.

A yarn-forming element is provided for a roving machine that produces a roving from a fiber structure using compressed air. The yarn-forming element includes an intake opening for fibers of the fiber structure, an outlet for emergence of the roving produced from the fiber structure, and a draw-off channel that connects the intake opening and the outlet. A front end surrounding the intake opening is formed as a first truncated cone in at least some sections thereof. The first truncated cone includes a larger base surface and a smaller opposite cover surface that is adjacent the draw-off channel. An angle () between a lateral line of the first truncated cone and an axis of the first truncated cone is less than 90 and greater than 70.

Friction disc for a false-twist device, comprising an annular hub, on which it is possible to fix a circular race formed by a polyurethane (PU) layer and has a minimum wall thickness required for a secure interlocking fit, the hub having a circumferential support ring and a central hole, by which the friction disc is fixed on one of the shafts of the false-twist device. To ensure better dimensional and form stability over a long service life of the friction disc, the formed race fixed on the hub is ground according to a predefinable profile such that the flanks of the race have a predefinable width dimension following the grinding process, and/or in that the hub has, at a spacing from the support ring, a circumferential shoulder for abutment for the fixable PU layer, a cross-sectional width of the shoulder being smaller than a cross-sectional width of the support ring.

A method for processing a strand-type fiber bundle includes sending the fiber bundle to an air nozzle of a pre-spinning machine used to produce roving. A twist is imparted to the fiber bundle via a vortex air current within the air nozzle to form the roving, wherein the roving leaves the air nozzle through an outlet and is deposited in a receptacle. Normal operation is interrupted in a stop phases during which roving is not produced by the air nozzle. A start-up phase is commenced between the stop phase and subsequent normal operation wherein the roving produced during the stop phase is discarded after leaving the air nozzle when quality of the roving does not meet a desired specification. The roving discharge is deactivated when the quality of the roving meets the desired specification and the roving removed by the roving discharge is separated from the roving.

During normal operation of a textile machine, a fiber bundle is supplied to a consolidating means to produce a roving having a protective twist, the roving wound onto a tube with a winding device. The roving downstream of the consolidating means is monitored for whether the roving is being produced by the consolidating means or whether the roving produced by the consolidating means is being wound onto the tube. In no roving is being produced or the roving produced by the consolidating means is not being wound onto the tube, an interruption of the normal operation of the textile machine is initiated and the tube partly loaded with roving by the winding device prior to the interruption is replaced with an empty tube during a tube changing process. The consolidating means is started up and the roving produced thereby is brought into contact with the empty tube. Normal operation is resumed and the roving is wound onto the empty tube.

During normal operation of a textile machine, a fiber bundle is supplied to a consolidating means to produce a roving having a protective twist, the roving wound onto a tube with a winding device. The roving downstream of the consolidating means is monitored for whether the roving is being produced by the consolidating means or whether the roving produced by the consolidating means is being wound onto the tube. In no roving is being produced or the roving produced by the consolidating means is not being wound onto the tube, an interruption of the normal operation of the textile machine is initiated and the tube partly loaded with roving by the winding device prior to the interruption is replaced with an empty tube during a tube changing process. The consolidating means is started up and the roving produced thereby is brought into contact with the empty tube. Normal operation is resumed and the roving is wound onto the empty tube.

A method for processing a strand-type fiber bundle includes sending the fiber bundle to an air nozzle of a pre-spinning machine used to produce roving. During normal operation, a twist is imparted to the fiber bundle via a vortex air current within the air nozzle to form the roving, wherein the roving leaves the air nozzle through an outlet and is deposited in or on a receptacle. Normal operation of the pre-spinning machine is interrupted in a stop phases during which roving is not produced by the air nozzle. A start-up phase is commenced between the stop phase and subsequent normal operation wherein the roving produced during the stop phase is discarded via a roving discharge after leaving the air nozzle when quality of the roving does not meet a desired specification. The roving discharge is deactivated when the quality of the roving meets the desired specification and the roving removed by the roving discharge is separated from the roving.