Abstract: A yarn false twist texturing apparatus having a plurality of side by side processing stations for texturing a plurality of thermoplastic yarns, wherein at each station a first feed system withdraws the yarn from a feed yarn package, and advances the yarn to a false twist zone composed of a heater and a cooling device, as well as a twisting unit. A second feed system withdraws the yarn from the false twist zone and advances it to a takeup device. The cooling device includes a cooling tube, with the yarn spiraling in contact with its outer surface. For an intensive cooling of the yarn according to the invention, the cooling tube is cooled from the inside with a coolant flow, which flows in a direction opposite to the direction of the advancing yarn.

Abstract: A false twist texturing machine for the texturing of synthetic threads in one handling position at a time, in which a heating device and a false twist unit are disposed within a false twist zone. In an after-treatment zone are disposed a second heating device and a counter-twist apparatus. In this case a residual twist left in the thread from the false twist unit is removed by the counter-twist apparatus. The counter-twist apparatus is for this disposed in one plane with the second heating device, so that the thread is run substantially in a straight thread path.

Abstract: A yarn false twist texturing apparatus having a plurality of side by side processing stations for texturing a plurality of thermoplastic yarns, wherein at each station a first feed system withdraws the yarn from a feed yarn package, and advances the yarn to a false twist zone composed of a heater and a cooling device, as well as a twisting unit. A second feed system withdraws the yarn from the false twist zone and advances it to a takeup device. The cooling device includes a cooling tube, with the yarn spiraling in contact with its outer surface. For an intensive cooling of the yarn according to the invention, the cooling tube is cooled from the inside with a coolant flow, which flows in a direction opposite to the direction of the advancing yarn.

Abstract: The invention relates to a false twist device for a synthetic multifilament yarn for use in false twist texturing machines. The false twist device comprises at least three sets of disks that are each arranged on an axle for rotation in the same direction. The axles are arranged to form an equilateral polygon such that the disks overlap in the center of the polygon. To keep a yarn tension as low as possible at a high yarn speed, the circumferential surface of the disks is the zone of a sphere or a torus with a circumferential surface radius that has a magnitude of at least 35 times the diameter of the twisted yarn.

Abstract: The invention relates to a false twist texturing machine and to a method of texturing synthetic yarns in, in each case, one processing point, in which a twist-stopping device, a heating device, a cooling device and a false twisting unit are disposed inside a false twisting zone. The yarn is withdrawn from the false twisting zone by means of a delivery mechanism. According to the invention, the twist-stopping device takes the form of a rotatable transport roller, around which the yarn is at least partially wrapped in a peripheral direction and which is drivable by a drive in such a way that the yarn is braked or delivered, so that the yarn tensile force is adjustable inside the false twisting zone.

Abstract: A yarn false twist texturing apparatus which includes a serially arranged heater, cooling device, and twisting unit. In order to collect and remove the oil vapors arising within the false twist zone, the cooling device is configured as an elongate hollow body, and the yarn is conveyed for cooling in contact with the inside wall of the hollow body. A vapor extraction system is provided which communicates with the interior of the body. In another embodiment, a tubular protective body is arranged between the heater and the cooling device, and the interior chamber of the tubular protective body encloses the yarn and is connected to an extraction device. The advancing yarn may be wetted with a cooling fluid at a location between the heater and the cooling device, to facilitate the volatilization of the oil constituents in the yarn as well as cool the yarn.

Abstract: A yarn false twisting apparatus which comprises a drive motor and a yarn false twist assembly, both mounted on a base frame. The yarn false twist assembly comprises a plurality of spindles mounting friction disks which are rotated in the same direction by the motor, and the assembly is releasably mounted to the base frame so it can be separated from the base frame by withdrawing the assembly in an axial direction. The drive motor has a drive pulley, and at least one of the spindles has a belt pulley, which can be interconnected via a drive belt. The drive belt is arranged in a drawer-like housing, which is displaceable in the operating plane of the drive belt. At its free end, the belt pulley mounts a cone, which ensures that the drive belt slides onto the belt pulley when mounting the false twist assembly to the base frame.

Abstract: A method is described for controlling the tension of an advancing yarn, which is crimped in a friction false twist unit of a false twist crimping machine. In accordance with the method, the tension of the advancing yarn is measured downstream of the friction false twist unit and the yarn tension is converted via a time filter and by comparison with a predetermined desired value into an adjustment signal for correcting the friction false twist unit, the control range being determined by defined limit values of the adjustment signal. The adjustment signal is a current value and is corrected adaptively via a PI controller, the control behavior of which takes into account the quotient from the change of the yarn tension and the change of the current value of the adjustment signal.

Abstract: The invention relates to a friction false twist unit for crimping synthetic filament yarns, the friction element shafts of which are movable with a radial play, and which are influenced in their movement by friction dampers.

Abstract: A method and apparatus for controlling a false twist texturing machine, which extends the previously known process for controlling operation during the normal operation of the machine, to exceptional operating conditions, such as during yarn thread-up and/or restarting after a temporary stoppage of operation by reason of a power failure. In accordance with the invention, the known method which includes control of the frictional force imparted to the yarn as a function of the yarn tension, is modified in such a manner that during periods other than normal operation, the control of the frictional force as a function of the yarn tension is terminated, and a predetermined frictional force is imparted to the yarn.

Abstract: A rotary yarn twisting disc which is adapted for imparting twist to an advancing yarn as part of a false twisting process. The disc has an annular yarn contacting peripheral surface which includes a first segment having a relatively high coefficient of friction and a relatively large radius of curvature, and a second segment having a relatively low coefficient of friction and a relatively small radius of curvature.

Abstract: A yarn false twist texturing process and apparatus wherein the tension of the advancing yarn is monitored. The resulting signal is processed through a time filter to produce a time averaged signal, and the time averaged signal is compared with a set point signal to produce an adjusting signal which acts to control the false twisting unit so as to provide a substantially constant tension. The adjusting signal is also used to detect deficiencies of the false twisting process which disturb the uniformity of the texturing process.

Abstract: A false twisting roll for imparting false twist to an advancing yarn of manmade fibers is disclosed. The roll has a generally conical and somewhat concave surface configuration, and the angle of inclination of the roll axis is adjustable with respect to the yarn path leading into contact with the roll. To insure optimal twisting conditions at all adjustable inclinations of the roll, the position of the pivotal axis of the roll, and the shape of the surface of the roll are adapted to each other so that the yarn path leading into contact with the roll is predetermined and remains constant. This in turn assures that the upstream twisting conditions of the yarn are unchanged.

Abstract: A yarn false twisting apparatus is disclosed which comprises a flexible disc mounted for rotation with a cooperating rigid disc to define a twisting zone therebetween. A pressure applying member is positioned adjacent the back face of the flexible disc for biasing the disc toward the rigid disc locally at the twisting zone so as to firmly engage the yarn passing through the twisting zone. The flexible disc comprises a hub portion disposed adjacent the center of the disc, an annular ring disposed concentrically about the hub portion and including a yarn engaging friction surface on one face thereof, and a distinct and highly flexible junction portion joining the hub portion and annular ring. The highly flexible junction portion permits the annular ring to readily flex in the lateral direction, to thereby permit the deflecting force to be minimized, while still permitting the rotating torque to be transmitted to the annular ring without significant circumferential deformation.

Abstract: A method and apparatus of false twisting a yarn is disclosed which utilizes a pair of endless belts mounted in crossing relation to define a twisting zone therebetween, and a pressure applying member for locally biasing at least one of the belts toward the other at the twisting zone. The yarn is advanced along a path of travel through the twisting zone, and the acute angle formed between each belt and the yarn path of travel is adjusted so as to generally correspond to the desired twist angle of the yarn in its twisted condition. Further, the speed of each belt is adjusted so as to optimize the yarn tension conditions both preceding and following the belts. To achieve an essentially slipless operation, the pressure exerted by the biasing means is adjustably controlled so that the torque exerted by the belts exceeds the natural restoring torque of the yarn.

Abstract: A yarn false twisting apparatus and method is provided which permits ready conversation from S to Z twist, or vice versa. The apparatus comprises a pair of friction discs which are rotatably mounted on a common carrier plate, and the discs are rotated in opposite directions by a drive system which includes a whorl mounted to each supporting shaft, and an endless drive belt having a run which engages opposite sides of the two whorls. The carrier plate is designed to permit the respective positions of the two discs to be reversed, and the direction of rotation of each disc to be reversed, to thereby convert from S to Z twist, or vice versa. In other embodiments, conversion between S and Z twist may be effected by the axial displacement of the two discs, or by the use of the two pressure applying members which define two separate twisting zones and which are alternately actuated.

Abstract: A yarn false twisting apparatus and method is provided which permits ready conversion from S to Z twist, or vice versa. The apparatus comprises a pair of friction discs which are rotatably mounted on a common carrier plate, and the carrier plate is pivotally mounted to the frame of the apparatus such that the discs may be selectively rotated between first and second operative positions disposed 180 degrees from each other. The discs are rotated in a common rotational direction in each operative position, and the yarn is advanced through a twisting zone between the discs in a direction parallel to a line extending perpendicularly between the axes of rotation of the discs. Thus conversion from S to Z twist, or vice versa, may be effected by pivoting the carrier plate between the two operative positions, without changing the direction of rotation of the discs or the yarn path of travel.

Abstract: A yarn false twisting apparatus and method is disclosed which comprises a pair of friction discs, with one of the discs being thin and flexible, and a pressure applying member for biasing the flexible disc toward the other disc locally at the twisting zone. The discs and pressure applying member are mounted to permit selective movement whereby the ratio of twist to yarn speed may be varied, and to achieve a desired twist in the advancing yarn. The biasing force of the pressure applying member is also adjustable, to achieve an essentially slipless operation by assuring that the torque exerted by the discs exceeds the natural restoring torque of the yarn.

Abstract: A false twister for S or Z false twisting in which the false twist-imparting members, e.g., disks, and their shafts are rotatably driven about a fixed axis of rotation by alternately selectable drives in turn driven by tangential contact between an endless drive belt and a pair of whorls, the whorl assembly being swingably mounted on the twister assembly to provide drive contact and counterpressure contact by respective whorls.

Abstract: In combination with a friction false twist assembly including yarn supply means to feed a synthetic filamentary polymer yarn to a friction false twisting device and yarn take-up means to collect a false twist texturized yarn from the twisting device, preferably with means to heat-set the false twisted yarn being fed to the twisting device, this invention provides an improved friction false twist element comprising an axially elongated rotational body having a sleeve hub with a plurality of disc-shaped flanges formed integrally thereon at axially spaced positions, the integral hub and flanges being made of a molded, durable and rigid plastics material, e.g. a thermosetting resin, each flange carrying a circular yarn contacting ring as a rim fastened thereto and providing a wear-resistant, roughened outer circumferential surface ideally suited to the friction twisting of the yarn. In a preferred form, the twist element is made up of a thin metallic layer onto which a wear-resistant surface layer is applied.