Abstract: A method and device for determining the orientation of a cross-wound bobbin tube (1) having a yarn draw-off end face (27) configured as a tube tip (2) with a beaded edge (4) and an opposite end face (27) configured as a tube foot (3) without a beaded edge (4). A digital image of an end face (27) of the bobbin tube (1) is detected, the digital image is subjected to an edge detection to determine the object edges (6, 7, 8, 9) of the tube (1), a recognition parameter dependent on the width (b1, b2) of the circular ring (10, 11) formed by the object edges (6, 7, 8, 9) is determined, this recognition parameter is compared with a reference value and a conclusion is drawn about the orientation of the bobbin tube (1) depending on the result of the comparison.

Abstract: A method and device for determining the orientation of a cross-wound bobbin tube (1) having a yarn draw-off end face (27) configured as a tube tip (2) with a beaded edge (4) and an opposite end face (27) configured as a tube foot (3) without a beaded edge (4). A digital image of an end face (27) of the bobbin tube (1) is detected, the digital image is subjected to an edge detection to determine the object edges (6, 7, 8, 9) of the tube (1), a recognition parameter dependent on the width (b1, b2) of the circular ring (10, 11) formed by the object edges (6, 7, 8, 9) is determined, this recognition parameter is compared with a reference value and a conclusion is drawn about the orientation of the bobbin tube (1) depending on the result of the comparison.

Abstract: A method for forming the wound package of cylindrical cheeses on rotor spinning machines, wherein a crossing angle ?M in a central zone of the bobbin traverse is less than 28° and a crossing angle ?R in the end zones located adjacent the ends of the wound package is increased in respect to the central zone. The cylindrical cheeses thereby produced are distinguished by great running lengths, solid structure, good density distribution, and excellent unwinding properties.

Abstract: A method for forming the wound package of a conical cheese on rotor spinning machines, wherein a crossing angle ?M in a central zone of the bobbin traverse is less than 28° and a crossing angle ?R in the end zones located adjacent the ends of the wound package is increased in respect to the central zone. The cylindrical cheeses thereby produced are distinguished by long running lengths, solid structure, good density distribution and excellent unwinding properties.

Abstract: A process for using low-molecular weight compounds that are water-extracted from (co)polyamides in the production of polyamide is disclosed. The process entails reacting these compounds with 10 to 15 wt. % water for a period of 3.5 to 6 hours at a temperature of 220° C. to 270° C., and polymerizing the resulting product along with caprolactam.

Abstract: A process for producing a polyamide or copolyamide freed from volatile constituents by removing the volatile constituents, in particular the monomers and dimers, in at least two stages from the polymer melt by using an, in particular, gaseous entrainer is described. The invention also relates to polyamide compositions made of polyamide 6 or a copolyamide with a reduced volatile constituent content, as well as moulding compositions made of the above-mentioned polyamides, and moulded articles and fibers which are produced from these moulding compositions.

Abstract: A process for removing low molecular weight constituents from polyamide 6 or from copolyamides based on caprolactam (herein (co)polyamide) is disclosed. The process comprise subjecting the (co)polyamide to liquid-extraction at a temperature which is above the boiling point of the liquid at atmospheric pressure said liquid containing water in an amount of at least 80 percent relative to its weight.

Abstract: A process for producing a polyamide or copolyamide freed from volatile constituents by removing the volatile constituents, in particular the monomers and dimers, in at least two stages from the polymer melt by using an, in particular, gaseous entrainer is described. The invention also relates to polyamide compositions made of polyamide 6 or a copolyamide with a reduced volatile constituent content, as well as moulding compositions made of the above-mentioned polyamides, and moulded articles and fibres which are produced from these moulding compositions.

Abstract: A method for forming the wound package of a conical cheese on rotor spinning machines, wherein a crossing angle &agr;M in a central zone of the bobbin traverse is less than 28° and a crossing angle &agr;R in the end zones located adjacent the ends of the wound package is increased in respect to the central zone. The cylindrical cheeses thereby produced are distinguished by long running lengths, solid structure, good density distribution and excellent unwinding properties.

Abstract: A method for forming the wound package of cylindrical cheeses on rotor spinning machines, wherein a crossing angle &agr;M in a central zone of the bobbin traverse is less than 28° and a crossing angle &agr;R in the end zones located adjacent the ends of the wound package is increased in respect to the central zone. The cylindrical cheeses thereby produced are distinguished by great running lengths, solid structure, good density distribution, and excellent unwinding properties.

Abstract: An open-end rotor spinning machine having a plurality of work stations, wherein each work station comprises an open-end spinning device for manufacturing a yarn, a winding device with a creel, a yarn traversing device for producing a cheese, a pivotably supported, vacuum-chargeable suction nozzle, an individual drive for pivoting the suction nozzle between a yarn take-up position in the area of the winding device and a yarn transfer position in the area of a spinning piecing member, and a device for preparing a yarn end required for restarting spinning. Each work station comprises a winding device with a drive drum driven by a reversible individual drive for driving a cheese and with a yarn traversing device driven by an individual motor for defined placement of the yarn running up onto the cheese, a yarn withdrawal device, and a work-station computer for controlling the individual drives and individual motors.

Abstract: A process for removing low molecular weight constituents from polyamide 6 or from copolyamides based on caprolactam (herein (co)polyamide) is disclosed. The process comprise subjecting the (co)polyamide to liquid-extraction at a temperature which is above the boiling point of the liquid at atmospheric pressure said liquid containing water in an amount of at least 80 percent relative to its weight .

Abstract: A service unit (16) for a cheese-producing textile machine (1), in particular an open-end spinning machine, has manipulation devices for repairing ordinary yarn breaks, an auxiliary yarn transport device (34) for piecing yarn following a cheese/empty tube exchange, and a control device (24) storing a first program with optimal operating parameters for piecing an ordinary yarn break and a second program setting differing operating parameters for producing a safety piecing following a cheese/empty tube exchange.

Abstract: A method for improving the monitoring of the fill state of a sliver can (5) at a spinning station of a textile machine processing sliver wherein a defined portion (24 or 124) of a can bottom (22) is initially kept free from sliver (6) while a predetermined amount of sliver (6) is deposited on an adjoining portion (25 or 125) of the can bottom (22) and only after the adjoining portion (25 or 125) is covered with sliver, is the defined portion (24 or 124) covered with sliver (6). The method includes monitoring the defined (24 or 124) portion while the sliver is being drawn out and detecting when the defined portion of the can bottom (22) is uncovered to trigger a signal for exchanging an empty can for a filled sliver can. In one preferred embodiment, a sensor (27) for monitoring the defined portion (24 or 124) and detecting an uncovered can bottom is mounted on a service unit (16) which passes over the spinning stations.

Abstract: A servicing apparatus for automatic repair of yarn breaks in open-end spinning machines is provided with a device for replacing finished yarn packages with empty tubes, and a multi-functional yarn manipulating element having a work head equipped with a yarn brake and a contoured yarn guide element, the manipulating element being selectively movable between a position (c) at a top end of the tube for forming a top winding at the completion of winding a full yarn package, a position (a) at a base end of the tube for forming a yarn reserve winding upon beginning the winding of an empty tube, and a position (b) moving axially along the tube to prevent the creation of parallel windings during the repair of a yarn break.

Abstract: An open-end rotor spinning machine is equipped with a service structure for the automatic correction of yarn breaks occurring in the course of the bobbin winding and for the automatic exchange of empty tubes for finished packages, wherein empty tubes are delivered to and finished packages are removed from the work stations via an endless transport device. The service structure has a package ejector for ejecting finished packages from the work stations, a tube gripper for retrieving an empty tube from the transport device, and a tube positioning device connected with the package ejector of the service structure to position an empty tube held by the tube gripper precisely into desired disposition relative to a respective work station to be supplied with an empty tube.

Abstract: An open end spinning machine with an associated service device having a supplementary yarn conveying device utilizing a delivery tube disposed on a delivery tube holder which can be pivoted into various work positions. A yarn guide plate is movably seated in the area of the delivery tube holder and has a yarn guide notch as well as a yarn placement slit and can be selectively controlled by means of a thrust cylinder. By pivoting the yarn guide plate, the yarn extending through the yarn guide notch is transferred to specially designed yarn catch devices of a tube supporting disk seated in a creel of a work station of the spinning machine. Subsequently, the grasped yarn slides automatically into the yarn placement slit which is disposed below the notch and, while being securely guided in the yarn placement slit, is wound as a reserve winding on the empty tube rotating in the creel.

Abstract: An apparatus for removing fully wound cheese-type textile yarn packages from a textile machine and replacing them with empty yarn winding tubes comprises an endless transport apparatus having a plurality of transport units connected via a traction member. Each transport unit has a freely accessible, upwardly facing transport receiver surface which is selectively used for receiving a completed cheese package as well as receiving an empty replacement tube. The exchange of a full package for an empty tube is performed by means of a traveling servicing unit on the textile machine, equipped with, among other things, a tube gripper for handling the empty replacement tubes and servicing elements for handling the completed cheese packages.

Abstract: An open-end spinning machine embodied as a yarn piecing unit for automatically repairing yarn breaks during bobbin winding and for replacing finished bobbins with empty tubes, and an auxiliary yarn transport arrangement for supplying and removing an auxiliary yarn used for the piecing operation. The auxiliary yarn transport arrangement has a yarn supply tube that can be positioned among various operating positions: (a) a first position wherein the auxiliary yarn is transferred to a yarn locating nozzle of the piecing unit; (b) a second operating position wherein the piecing cycle is initiated by spinning an end of the auxiliary yarn with individual fibers fed into the spinning rotor of the spinning machine; and (c) a third operating position wherein the auxiliary yarn and its pieced end is severed from the trailing length of newly spun yarn from the spinning rotor and the new yarn is applied to an empty tube in the winding creel of the spinning machine.

Abstract: A method for transferring a yarn after a yarn break to a normal yarn travel position at a textile machine winding station including making a yarn connection between a yarn supply point and a takeup bobbin and subsequently transferring the yarn to the normal yarn travel position at a transfer point at the reciprocating yarn guide with a tranfer motion of a yarn transfer device of a device that re-establishes yarn travel. The chronological course of the making of the yarn connection and the transverse motion of the yarn guide are monitored. The tranfer motion of the yarn transfer device and the transverse motion of the yarn guide are adapted to one another as a function of the chronological course for causing the yarn and the yarn guide to substantially simultaneously arriving at the transfer point. An apparatus for performing the method includes a first device for monitoring reciprocation of the yarn guide to a yarn tranfer point.