US3772873A - Process for false-twisting a yarn - Google Patents

Process for false-twisting a yarn Download PDF

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US3772873A
US3772873A US00210816A US3772873DA US3772873A US 3772873 A US3772873 A US 3772873A US 00210816 A US00210816 A US 00210816A US 3772873D A US3772873D A US 3772873DA US 3772873 A US3772873 A US 3772873A
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yarn
frictional
rotors
speed
tension
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H Hino
N Asaka
M Tsuge
S Tsuda
N Arai
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Teijin Ltd
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Teijin Ltd
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    • D—TEXTILES; PAPER
    • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
    • D02G1/02—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist
    • D02G1/04—Devices for imparting false twist
    • D02G1/08—Rollers or other friction causing elements
    • D02G1/087—Rollers or other friction causing elements between the flanks of rotating discs

Definitions

  • ABSTRACT A process for false-twisting a yarn, which comprises passing a continuous filament yarn through the frictional engaging surface of two frictional rotors of the same diameter which face each other with the rotary shafts not being on the same axis and rotate in opposite directions to each other, wherein the yarn is fed to the frictional engaging surfaces at a speed of at least 500 meters per minute and imparted a tension defined by the following formula 0.85 F 6.35 X 10"V 0.100 wherein F is the tension of the yarn in grams per denier, and V is the speed of feeding the yarn in meters per minute, in a twisting zone, and then the yarn is withdrawn from the frictional engaging surfaces.
  • This invention relates to a process for false-twisting a yarn stably at high speed by passing a continous yarn such as multifilaments (to be referred to simply as yarn) between the frictional engaging surfaces of two frictional rotors of the same diameter opposing each other and rotating in opposite directions to each other.
  • a method has previously been known in which a yarn is introduced between contact surfaces (this will often be referred to as engaging surface hereinafter) of two frictional rotors of the same diameter rotating in opposite directions to each other (U.S. Pat. No. 3,156,084 and Japanese Patent Publication No. 1467/65).
  • the above object of the invention can be achieved by a process for false-twisting a yarn which comprises passing a yarn between the frictional engaging surfaces of two frictional rotors of the same diameter, the rotors opposing each other and rotating in opposite directions to each other, and the rotating axes of the two rotors being not on the same axis, wherein the yarn is fed to the frictional engaging surfaces at a rate of at least 500 meters per minute, exerting a tension defined by the following expression wherein F, is the tension of the yarn. (gr/dc), and
  • V is the rate of feeding the yarn, on the yarn in a false-twising zone, and withdrawing the yarn from the frictional engaging surfaces.
  • the rate of feeding the yarn as mentioned herein is the speed of a yarn to be fed to frictional rotors which advances in a helical fashion. In the case of a nonstretchable yarn, this yarn speed is almost the same as the speed of the yarn at feed rollers located upstream of the frictional rotors.
  • the rate of feeding the yarn or yarn speed can be measured at withdraw rollers where the yarn is withdrawn under a tension (usually, about 0.1 g/d) required to remove the crimping of the yarn upon withdrawing from the frictional rotors.
  • the number of rotations of the yarn per minute is at most 1,200,000 to 1,500,000 r.p.m. (300 to 400 meters per minute) in the direct twisting method (for instance, Japanese Patent Publication No. 21494/65) utilizing frictional rotors or a method (for instance, US. Pat. No. 3,156,084) in which a yarn is false-twisted by holding the yarn between two frictional rotors rotating in opposing directions to each other, and 600,000 rpm meters per minute) in the spindle method.
  • the direct twisting method for instance, Japanese Patent Publication No. 21494/65
  • a method for instance, US. Pat. No. 3,156,084
  • the yarn can be false-twisted stably with reduced yarn breakage by removing the balooning of the yarn utilizing a high stretching zone of the yarn.
  • the yarn is processed at a yarn speed of at least 500 meters per minute while maintaining a tension F in the twisting zone at a value defined by the following empirical formula wherein Y F, is the tension of the yarn (gr/dc), and
  • V is the speed of the yarn (meters/min).
  • the yarn breakage can be reduced as compared with the ordinary false-twisting operations.
  • FIG. 1 is a schematic view showing one example of the false-twisting step according to the invention
  • FIG. 2 is a graphic representation showing the relationship among the twisting tension, withdrawing tension, and the number of fuzzes formed
  • FIG. 3 is a view illustrating the components of the peripheral speed of frictional rotors used in the invention.
  • FIG. 4 is a perspective view showing one example of a liquid removing nozzle used in the invention.
  • FIG. 5 is a view showing the cooling method for frictional rotors in the present invention.
  • FIG. 6 is a sectional view of the twisting portion of a false-twisting device used in the invention.
  • FIG. 7 is a sectional view of the false-twisting device used in the invention, in particular a fixed disc using radial ball bearings;
  • FIG. 8 is a sectional view of the false-twisting device used in the invention, in particular a freely-movable disc using a pneumatic bearing.
  • yarn Y leaves a bobbin 1, and fed by a feed roller 3 pressed by a press roller 2. It is heattreated by a heater 4, and after passing guide 5, is falsetwisted by frictional rotors 6 and 7 whose surfaces are covered with rubber. The yarn is then withdrawn by a withdraw roller 10 via a guide 9, and wound up on a package 12 by means ofa winder 11.
  • the reference numeral 13 represents a wool-like cord, one end of which is connected to a tank 14 containing liquid inert to the yarn, and from the other end of which the liquid is fed to the surfaces of the frictional rotors 6 and 7.
  • a nozzle for removal of the liquid is designated at 8, and is adapted to blow off the liquid contained in the yarn by air.
  • the yarn is false-twisted while being held by the engaging surfaces of two opposing frictional rotors of the same diameter rotating in opposite directions to each other.
  • the twisting of the yarn is imparted between the frictional rotors 6 and 7 and the feed roller 3 (to be termed a twisting zone).
  • the tension of the yarn in the twisting zone is controlled mainly according to the speed of the frictional rotors, and the interaxial distance between the rotors. Delicate control can also be made by varying the contact pressure between the yarn and the heater 4, or the withdrawing speed of the withdraw roller 10.
  • Inert liquid water, 300 cc/min.
  • the tension was measured between the heater 4 and the guide 5 of FIG. 1 by means of an electron tension meter (product of Roschild Company, Switzerland).
  • the figures in the parentheses show the detwisting tension of the yarn.
  • the yarn tension for stable processing is between 35 and 64 g at a yarn speed of 1,000 meters per minute.
  • the number of rotations of the yarn reaches as much as 3,200,000 rpm.
  • a twospindle machine was operated for a total of 2,520 hours at a processing speed of 1,000 meters per minute using a tension of 45 2 g, six yarns were broken during this time, and this means that per yarn breakage, the processing was continued for 420 hours. This is comparable to the conventional false-twisting operation in which an average time needed for one yarn breakage is 400 hours.
  • the tension at the twisting zone is 7 i 1 g, and at such a tension, the processing speed is at most 400 meters per minute. According to the process of the invention, a processing speed unexpected from the conventional methods can be attained. Thus, the processing can be made at extremely high speeds.
  • A shows yarn breakage occurred in minutes to 30 hours.
  • the relation among the tension F, of yarn in the twisting zone, the tension F of yarn being withdrawn from the frictional rotors, and the number of fuzzes formed is shown in Table 4.
  • the yarn used was a polyethylene terephthalate yarn (75 denier/24 filaments), and processed under the conditions shown in Table 5.
  • the apparatus used was a l2-spindle machine, and the evaluation of the results was made with respect to 300 kg of the yarn for each set of the conditions employed.
  • Frictional rotors 90 mm in diameter, made of polyurethane rubber having a hardness of 55; interaxial distance 52 mm; contact pressure, 3.0 kg; counter angle of inclination 1 Inert liquid: 300 cc/min. of water Yarn feed rate: 1000 meters/min.
  • the tension in the twisting zone was measured at a place between the heater and the frictional rotors, and the withdraw tension, between the guide 9 and the withdraw roller 10.
  • the measurement of the tensions was performed using an electronic tension meter (product of Roschild Company, Switzerland),
  • the measurement of the number of fuzzes was made using a fuzz detector (product of Kasuga Electric Co., Ltd.), and the number of fuzzes per million meter of the yarn was counted while maximizing its sensitivity. It is seen from Table 4 that when the withdraw tension F 2 is larger than the tension F, in the twisting zone, the occurrence of fuzzes becomes remarkable abruptly, and a crimped yarn of good quality cannot be obtained. On the other hand, if the tension F is smaller than the tension F,, the occurrence of fuzzes is reduced, and a very good crimped yarn is obtained.
  • Table 6 shows the tension F, of yarn in the twisting zone, the withdraw tension F of yarn, and the number of fuzzes formed in the processing ofa nylon 6 yarn denier/34 filaments) under the conditions shown in Table 7. It is seen from the table that for good results, the tension F of yarn in the twisting zone should be Frictional rotors diameter: 82 mm material: nitrile rubber with a hardness of 52 interaxial direction: 33 mm contact pressure: 0.7 kg
  • tension F should be larger than the tension F
  • the withdraw tension F should be not more than percent of the twisting tension F, in order to reduce the number of fuzzes remarkably it is preferred that the withdraw tension F should be not more than percent of the twisting tension F, in order to reduce the number of fuzzes remarkably it is preferred that the withdraw tension F should be not more than percent of the twisting tension F, in order to reduce the number of fuzzes remarkably it is preferred that the withdraw tension F should be not more than percent of the twisting tension F,.
  • Inert liquid water 300 cc/min.
  • Yarn feed rate 800 meters/min.
  • Length of the heater 2m
  • Temperature of the heater 240C.
  • the occurrence of fuzzes can be reduced only when the withdraw tension F is lower than the tension F of the twisting zone.
  • the processing can be performed at high speed of more than 500 meters per minuteand in a stable condition
  • the tension of the twisting zone can be maintained within the range required of the present invention by mainly controlling the rotation speed of the frictional rotors and the interaxial distance between the two frictional rotors. It has been further discovered that when the rotation speed of the frictional rotors and the interaxial distance between the two frictional rotors satisfy the following relation with respect to the yarn, greater improvements can be achieved in the stability of twisting operation and the occurrence of fuzzes.
  • D is the diameter of the frictional rotors
  • e is the interaxial distance between the frictional rotors (0,0'),
  • r is the speed of rotation of the frictional rotors
  • V is the speed of the yarn.
  • the ratio of the yarn speed to the yarn twisting speed should be 07-09, and the ratio of the yarn speed to the yarn feeding speed should be 1.05-1.40.
  • the ratio of the yarn speed to the yarn twisting speed is less than 0.7, the twisted yarn assumes a state near the so-called double twist (also called kink twist) because of excessive twists.
  • double twist also called kink twist
  • the ratio ofthe yarn speed to the yarn feeding speed exceeds 0.9, the usually desired number of twists are not imparted, and the resulting yarn has a reduced value as crimped yarn.
  • the ratio of the yarn speed to the yarn feeding speed (AC) is smaller than 1.05, the tension F of the yarn in the false-twisting zone becomes higher beyond 0.85 gr/de, and there is a frequent breakage of yarn. If the ratio is larger than 1.40, the yarn tension F 1 in the false-twisting zone becomes smaller than (6.35 X 10V- 0.100). Thus, similarly to the case of excessive twist, yarn breakage at the twisting portion becomes frequent, and stable processing cannot be performed.
  • Japanese Patent Publication No. 16748 discloses that the ratio of the yarn speed to the surface speed of a twisting tube is optimum at 0.5 to 0.9. Tracing experiments show however that this relation holds true with yarn of less than denier at a speed of up to 300 meters per minute. At a higher speed above 300 meters per minute, especially more than 500 meters per minute, the number of twists becomes a maximum at the above ratio in the vicinity of 0.7. This number is less than percent of that actually required, and it has also been confirmed that fuzzes occur frequently, and good processing cannot be expected. Furthermore, with a yarn of denier, the speed ratio of 0.54 is an optimum value as shown in the above-mentioned Japanese patent.
  • the optimum value is obtained at a yarn speed- /yarn twisting speed of around 0.80.
  • the frictional surfaces of the frictional rotors 6 and 7 are preferably wetted with a liquid inert to the yarn which is fed from the tank 14 through the wool-like cord 13.
  • a liquid inert to the yarn which is fed from the tank 14 through the wool-like cord 13.
  • Such a liquid is applied to the engaging surfaces of the two frictional rotors so that at least that part where the yarn comes into contact with the rotors becomes wet.
  • the application can be effected by a method shown in FIG. 1. Also, it can be effected by a method wherein the liquid surface of a liquid reservoir tank is pressed by pressurized air, and the liquid or air containing the liquid is jetted out from a nozzle, or a method wherein a liquid level in a tank is utilized, or a method in which the liquid is sprayed by a sprayer.
  • the crimped yarn obtained from a false-twisting apparatus in such a state contains excessive amounts of the above liquid.
  • the moisture plasticizes the yarn wound up on a bobbin, and with the passage of time, the amount of crimps is reduced.
  • the liquid contained in the yarn wound up on a bobbin evaporates gradually or diffuses into other substances, and therefore, the liquid content of the yarn decreases.
  • the liquid content fluctuates. In order to maintain the liquid content of the yarn at a constant or reduce it to nearly zero, an additional moisture-controlling step or drying step becomes necessary, and the significance of reducing the cost by processing at high speed will be lost.
  • the crimped yarn tends to contain liquid more than ordinary filament yarns, and the rate of yarn travel is high. it is therefore difficult to remove the liquid within a very short time, that is, over a short distance in the machine.
  • the liquid could not be removed sufficiently by a method in which a rotary body having a diameter of not more than 20 mm is rotated at a speed of more than 5,000 rpm, and the liquid is thrown off by a centrifugal force by winding the yarn around the rotary body several tens of times, a method wherein the yarn is passed through two squeeze rolls to throw off the liquid, a method wherein the yarn is heat-treated on a heating roller, or a method wherein the liquid is removed by passing the yarn through a heater.
  • FIG. 4 shows one example of the pressurized air jetting nozzle used-in the present invention.
  • the reference numeral 1 represents a main body 1; 2 and 3, yarn-passing slits; and 4, a pressurized air pipe. By the pressurized air fed from the pipe 4, the liquid adhering to the yarn Y is thrown away.
  • pressures of at least 0.5 Kg/cm gauge can be used. if the pressure is below 0.5 Kg/cm gauge, the liquid contained in the interior of the yarn'cannot be removed.
  • a compressed air jet pipe with a diameter of at least 1.0 mm (area of at least 0.8 mm) is used for compressed air of at least 2 Kg/cm gauge.
  • the yarn path has a diameter of 0.5 to 10 mm. It is desirable that the sectional area of the air jet pipe is not more than two times the area (generally the sectional area of the yarn path) of the nozzle to discharge air. If the area of the jet pipe becomes large, the effect of blowing off the liquid is low as compared with an increased rate of flow of air.
  • the angle between the jet pipe and the yarn axis is between 20 to C. As the air stream to be jetted out against the direction of yarn travel becomes stronger, the efiect of removing the liquid becomes higher.
  • the jet nozzle for air may be merely an opening (circular or non-circular shapes) provided in .the yarn path, or provided annularly along the circumference of the yarn path.
  • Compressed air may be heated.
  • compressed air When compressed air is heated, the effect of drying by heat adds to the air jetting effect, but an additional step of heating is required.
  • the position of fitting the nozzle may be at any place between the frictional rotor and the wind-up device.
  • the position between the rotor and the delivery device is convenient for a machine having the delivery device since the delivery device is not contaminated.
  • slit-like notches may be provided in the yarn path. It is possible to swirl the air flow by providing the jet nozzle eccentrically to the axis of the yarn path, but in this case, care should be taken not to provide the slit-like notches in a position to make the yarn deviate from the yarn path.
  • the stick slipping and burning of the contact surfaces of the frictional rotors can also be prevented by positively cooling the engaging surfaces.
  • the resulting yarn has some crimp irregularities (fully allowable for limited applications), but the level of crimps and the high speed of processing are comparable to the abovementioned wet method.
  • the scattering of the liquid can be avoided, and the liquid does not adhere to the yarn. This method is a very good falsetwisting method in operability and handling from the industrial standpoint.
  • the positive cooling of the yarn holding surfaces of the frictional rotors is conveniently performed by the method shown in FIG. 5 in which compressed gases 1 and l are jetted out at high speed.
  • compressed gases 1 and l are jetted out at high speed.
  • the use of air is generally economical. Air is first compressed by a compressor, and if possible, cooled to the greatest possible extent, and then jetted out from a nozzle at a place as close as possible to the surfaces 2 and 2' of the frictional rotors. If the nozzle is of a small opening, more than one nozzle can be provided at intervals within an allowable range on the circumferential surface of the frictional rotor, which surface does not overlap the opposing frictional rotor.
  • the shapes of the jet openings of the nozzle may be made slit-like on the circumference which does not overlap the opposing frictional rotor.
  • the pressure and the amount to be jetted out of air are selected according to the material of the surfaces of the rotors, the pressure of contact between the frictional rotors (to be referred -to as contact pressure), the speed of rotation, and the shape and number of the nozzles.
  • the pressure of'the air is at least 0.5 Kg/cm gauge, and the amount of air is at least 10 Nl/min. Compressedair may be used after having been cooled.
  • the yarn is rotated while being held between the engaging surfaces of two frictional rotors.
  • the yarn holding surfaces of the rotors are desirably made of rubber having a hardness of 40 to 70.
  • the hardness of rubber is measurrd with a spring-type hardness tester, in accordance with the specifications of JlS-K-630l-l962 (Physical testing method of vulcanized rubber).
  • the surface, shape and thickness of the frictional rotors that hold the yarn affect the quality of the yarn and operability especially during high speed rotation.
  • the material of the frictional rotors at the outermost periphery is extremely deformed by a centrifugal force, and the condition of holding the yarn changes from that at the time of holding it in a stationary condition, resulting in reduced yarn holding power and yarn twisting power and accordingly an unstable operation.
  • the thickness of the rubber with a hardness of 40 to 70 should be 0.5 mm to mm. Furthermore, the rubber should be bonded firmly to a substrate second to the rotary shaft. It is also possible to increase the thickness of rubber beyond 5 mm and provide a reinforcing outer wheel on the periphery of the substrate and the rubber. In the case of providing the reinforcing outer wheel, rubber is made to extend beyond the end of the outer wheel by 0.5 to 5 mm.
  • FIG. 6 shows a frictional rotor in which an outer wheel is provided on the periphery of the substrate and rubber.
  • annular substrate 2, and 2 are fixed to the ends of rotary shafts 1 and 1 by nuts 3 and 3.
  • rubbery elastomers 4 and 4 are attached, to thereby form frictional rotors 5 and 5.
  • outer wheels 6 and 6' are secured.
  • the rubbery elastomers have a hardness of 40 to 70.
  • Yarn Y travels in the direction of the arrow, and is twisted and detwisted.
  • Letter D indicates the thickness of the rubbery elastomer from the adhering surface of the frictional rotor or from the mold surface, and d designates the projecting thickness from the outer wheel 4 to the surface of the frictional rotor material.
  • the thickness of a frictional sustance of a frictional rotor from the adhering surface differs at its outermost circumference according to the hardness of the frictional substance. It has been found that the upper limit of thickness D is determined by a space above the apparatus, and with regard to the twisting, it appears to be about 50 mm; but that the lower limit of thickness D greatly affects the twist ing and yarn stringing. If the thickness of the frictional substance is less than 0.5 mm, the adhering surface of the metal exerts a great influence, and the moldulus of elasticity of the frictional substance apparently decreases, which in turn results in a reduced holding power of the yarn.
  • the projecting thickness d As to the projecting thickness d, it has generally been thought that larger thicknesses d are preferred by reason of increased number of uses. However, it has been found that when the thickness d is increased, the projection of the outermost periphery becomes greater with high speed rotation, and yarn breakage occurs in several hours. The limit of thickness is therefore 5 mm.
  • this thickness should be 0.5 to 5 mm.
  • a ZOO-denier polyethylene terephthalate yarn is processed at a yarn speed of 450 meters per minute using frictional rotors whose diameters are mm, and whose interaxial distance is 50 mm.
  • the hardness of rubber on the rotors is 60.
  • one of the two frictional rotors may be a fixed disc capable of being rotated in the circumferential direction but completely free of gap in the axial direction by such means as double nuts; the other rotor is rendered rotatable both in the circumferential and bearing directions.
  • the movement of one disc in the bearing direction can be performed by the following mechanisms.
  • the disc is made to slide between the disc shaft and the inner lace.
  • the disc is made to silde between the outer lace and the bearing housing C.
  • the disc shaft is supported by an air bearing, and made to float completely.
  • the method shown in (C) does not require lubrication, and there is substantially no resistance with regard to the movement in the axial direction. Thus, this is the most ideal supporting method, and there is little deviation among the spindles.
  • the yarn can be maintained always at an equal contact pressure, and the deviation in the quality of yarn is reduced.
  • the reference numerals l and 2 represent discs which consist of discs of the same diameter rotating in mutually opposing directions. They contact each other and deliver the yarn 3 while nipping it therebetween, and imparting twists to the yarn at the same time.
  • the disc 1 is secured to the disc shaft 4 and supported by radial ball bearings 5 and 6, and clamped to the disc shaft in the axial direction by double nuts 7 and 3 and thus fixed without a clearance therebetween.
  • the reference numeral 9 is a disc shaft on the free-moving side, and supported by bearings 10 and 11.
  • the bearings are made of an alloy such as phosphorbronze, and 10 to 20 small holes 12 and 13 are provided in a radial fashion at a place in contact with the disc shaft 9.
  • a bearing housing 14 includes channels 15 and 16 at places corresponding to the small holes 12 and 13 provided in the bearings 10 and 11. Compressed air openings 17 and 18 are connected to these channels through the outer circumference. Compressed air provided by pipes 19 and 20 is supplied to these holes from outside.
  • a radial ball bearing 21 is secured to the end of the disc shaft 9, and supported by a bearing housing 22.
  • a piston 23 is in contact with the bearing housing 22 through a rubber cushion at the foreward end.
  • a cylinder 25 receives compressed air from the pipe 26, and urges the piston 23 against the bearing housing 22.
  • a lever 27 is integral with the bearing housing 22, and comes in contact with the cylinder 25 through a spring 28.
  • a hole 29 is provided in the cylinder housing, and when the lever 27 reaches this position, the spring acts to separate the discs from each other and fix them.
  • the outer diameter of-the disc was adjusted tov mm, the diame-,.
  • EXAMPLES l to 11 Polyethylene terephthalate yarn(PET for short) and nylon 6 yarn (N for short) were false-twisted by the false-twisting apparatus shown in FIG. 1.
  • the frictional rotors used were made of nitrile rubber with a hardness of 52 (Examples-l and 2), polyurethane rubber with a hardness of 55 (Examples 3, 4, 5 and 6).
  • the thickness of the rubber was 6 mm.
  • a reinforcing outer wheel was provided around the substrate and the rubber, and the projecting thickness of the rubber from the foreward end of the outer wheel was adjusted to 3 mm.
  • the contact pressure between the two frictional rotors was 3 kg, and the engaging surfaces between the frictional rotors were wetted with water.
  • the length of the heater was 2 m.
  • the liquid content could be reduced to less than 4 percent, and at 2 kglcm the liquid content could be reduced to 0.5 percent, and that good crimped yams same as commercially available crimped yams could be produced.
  • EXAMPLE 12 the rotors took place at a processing speed of meters A 75 denier/24 filament polyethylene terephthalate yarn was processed by the apparatus shown in FIG. 1 under the conditions shown in Table l 1.
  • the liquid content of the yarn with the pressure of the compressed air varied between 1 to 4 kg/cm is shown in Table 12. It is seen from the table that by per minute. and the surface of the rubber was fused.
  • a process for false-twisting a yarn which comprises passing a continuous filament yarn through the frictional engaging surfaces of two frictional rotors of the same diameter, said rotors facing each other with the rotary shafts not being on the same axis. said rotors rotating in opposite directions toeach other and at least the'engaging surfaces of said frictional rotors are wetted with a liquid inert to the yarn, wherein said yarn is fed to said frictional engaging surfaces at a speed of at least 500 meters per minute and imparted a tension defined by the following formula wherein F is the tension of the yarn in grams per denier,
  • V is the speed of feeding the yarn in meters per minute, in a false-twisting zone, the yarn being fed to the engaging surfaces of the frictional rotors at a feed speed which simultaneously satisfies the following two conditions:
  • the ratio of the yarn feed speed to the speed component (AD) of the peripheral speed of the frictional rotors in the yarn twisting direction is from 0.7 m 0.9, and
  • the ratio of the yarn feed speed to the speed component (AC) of theperipheral speed of the frictional rotors in the yarn delivering direction is from 1.05 to 1.40;
  • each of said frictional rotors is constructed of a substrate fixed to a rotary shaft, with a rubbery elastomer secured to said substrates, said rubbery elastomer having a hardness of 40 to and a thickness of 0.5 mm to 5 mm.
  • each of said frictional rotors is constructed of a substrate fixed to a rotary shaft, a rubbery elastomer secured to said substrate and having a hardness of 40 to 70, and a reinforcing outer wheel provided around the substrate and the rubbery elastomer, said rubbery elastomer projecting from the forward end of said outer wheel by 0.5 to 5 mm.
  • one of the frictional rotors has its rotary shaft secured to a bearing so that the bearing surface can be slided in the axial direction, and the other is supported by a bearing so that its rotary shaft does not substantially slide in the axial direction.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
US00210816A 1970-12-24 1971-12-22 Process for false-twisting a yarn Expired - Lifetime US3772873A (en)

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JP11837270A JPS5111708B1 (enrdf_load_stackoverflow) 1970-12-24 1970-12-24
JP11755270 1970-12-25

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CA (1) CA946237A (enrdf_load_stackoverflow)
CH (1) CH549108A (enrdf_load_stackoverflow)
DE (1) DE2164303A1 (enrdf_load_stackoverflow)
FR (1) FR2119748A5 (enrdf_load_stackoverflow)
GB (1) GB1375380A (enrdf_load_stackoverflow)
IT (1) IT944368B (enrdf_load_stackoverflow)
NL (1) NL7117804A (enrdf_load_stackoverflow)

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US4583355A (en) * 1983-05-18 1986-04-22 Heberlein Hispano S.A. Process for the spinning of fibers and a device for carrying out the process
CN103668592A (zh) * 2012-09-18 2014-03-26 际华三五四二纺织有限公司 带有恒温加热装置的假捻转子
US20210214891A1 (en) * 2018-02-09 2021-07-15 Larsen Strings A/S Method for fabricating a string, in particular a string for a bowed musical instrument, and an apparatus for carrying out the same

Families Citing this family (15)

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US4424664A (en) 1979-07-14 1984-01-10 Barmag Barmer Maschinenfabrik Ag Friction false twist apparatus
DE3145513A1 (de) * 1981-11-17 1983-05-26 Barmag Barmer Maschinenfabrik Ag, 5630 Remscheid "friktionsfalschdraller"
US4370853A (en) 1979-07-14 1983-02-01 Barmag Barmer Maschinenfabrik Ag Friction false twisting apparatus
US4414803A (en) 1979-07-14 1983-11-15 Barmag Barmer Maschinenfabrik Ag False twisting apparatus
CH653381A5 (de) 1980-06-14 1985-12-31 Barmag Barmer Maschf Friktionsfalschdraller.
FR2484473A1 (fr) 1980-06-14 1981-12-18 Barmag Barmer Maschf Dispositif de fausse torsion a friction pour la texturation par fausse torsion de fils synthetiques
DE3025921A1 (de) * 1980-07-09 1982-01-28 Barmag Barmer Maschinenfabrik Ag, 5630 Remscheid Friktionsfalschdraller zum falschdrahttecturieren synthetischer faeden
US4408449A (en) 1980-06-26 1983-10-11 Barmag Barmer Maschinenfabrik Ag Friction false twisting apparatus
US4370852A (en) 1980-07-09 1983-02-01 Barmag Barmer Maschinenfabrik Ag Friction false twisting apparatus
US4383405A (en) 1980-09-08 1983-05-17 Barmag Barmer Maschinenfabrik Ag Yarn false twisting apparatus and method
US4406116A (en) 1980-09-15 1983-09-27 Barmag Barmer Maschinenfabrik Ag Yarn false twisting apparatus having friction discs
US4391091A (en) 1981-03-17 1983-07-05 Barmag Barmer Maschinenfabrik Ag False twisting apparatus and method
US4387557A (en) 1981-03-21 1983-06-14 Barmag Barmer Maschinenfabrik Ag False twisting apparatus and method
US4402179A (en) 1981-04-09 1983-09-06 Barmag Barmer Maschinenfabrik Ag Yarn false twisting apparatus having improved thread-up capability
DE102019116484A1 (de) * 2019-06-18 2020-12-24 Saurer Spinning Solutions Gmbh & Co. Kg Fadenverbindungsvorrichtung zum knotenfreien Verbinden zweier Fadenenden

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US3156084A (en) * 1960-05-02 1964-11-10 Res Nv False twist device
US3373554A (en) * 1965-05-06 1968-03-19 Heberlein Patent Corp Yarn twisting apparatus
US3488941A (en) * 1966-12-05 1970-01-13 Teijin Ltd Process for splitting a narrow film or false twisting a fibrous material

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US3156084A (en) * 1960-05-02 1964-11-10 Res Nv False twist device
US3373554A (en) * 1965-05-06 1968-03-19 Heberlein Patent Corp Yarn twisting apparatus
US3488941A (en) * 1966-12-05 1970-01-13 Teijin Ltd Process for splitting a narrow film or false twisting a fibrous material

Cited By (4)

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Publication number Priority date Publication date Assignee Title
US4583355A (en) * 1983-05-18 1986-04-22 Heberlein Hispano S.A. Process for the spinning of fibers and a device for carrying out the process
CN103668592A (zh) * 2012-09-18 2014-03-26 际华三五四二纺织有限公司 带有恒温加热装置的假捻转子
US20210214891A1 (en) * 2018-02-09 2021-07-15 Larsen Strings A/S Method for fabricating a string, in particular a string for a bowed musical instrument, and an apparatus for carrying out the same
US12281437B2 (en) * 2018-02-09 2025-04-22 Larsen Strings A/S Method for fabricating a string, in particular a string for a bowed musical instrument, and an apparatus for carrying out the same

Also Published As

Publication number Publication date
IT944368B (it) 1973-04-20
DE2164303A1 (de) 1972-08-17
CA946237A (en) 1974-04-30
NL7117804A (enrdf_load_stackoverflow) 1972-06-27
GB1375380A (enrdf_load_stackoverflow) 1974-11-27
FR2119748A5 (enrdf_load_stackoverflow) 1972-08-04
CH549108A (enrdf_load_stackoverflow) 1974-05-15

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