Method and apparatus for manufacturing slalom false twisting on ring yarn

Abstract

In a process for manufacturing a singles ring yarn, a method and apparatus is invented which utilizes double belts as a false twist device and incorporates it in the conventional ring spinning machine for producing a singles ring yarn. In this invention, a double-belts is applied thus two twisting points, instead of one twisting point, are adopted for the yarn false twisting to improve the false twist efficiency. Accordingly, a ratio of the velocity of the belt to the delivery speed of the yarn is controlled and the wrapping angle of the yarn on the belts is adjusted in order to obtain the desired property of the final singles ring yarn. The said invention can enhance the strength of fiber strand at the spinning triangle and thus ensure the yarns spun in a normal condition at low twist multipliers, which is unable to be obtained by the conventional ring spinning machine. The method produces yarns with good strength, less hairiness and lower yarn residual torque at low twist level and endows the resultant fabric with softer handle, low spirality as well as clear and smooth surface appearance. The method and apparatus has the advantages of easy yarn piecing-up and doffing process, low spinning end-breakage when using ordinary raw materials and low cost of investment and maintenance, which not only is able to meet the commercial requirements of the large-scale production in the textile industry but also possesses a high false twist efficiency.

1 . A method for producing singles ring yarns, comprising:
 imparting a first high twist to a strand of traveling drafted fibers emerged from the front-drafting-roller nip with the upper belt of a false twist device for producing a preliminary singles yarn, wherein the belt travels at the velocity of the belt for twisting the fibers and thus the strength of fiber strand is enhanced at the spinning triangle when a low twist level is adopted in the final singles yarn;   immediately after the false twist step by the upper belt severed as the first twisting point, imparting a joint twist of a second twist in the same direction as the first twist and a third twist in the reversed direction to the preliminary singles yarn for the production of a final singles ring yarn, wherein the second twist is produced by a running of the lower belt on the yarn, wherein the third twist results in correspondence to the first twist by a running of the upper belt on the yarn;   immediately after the false twist step by the lower belt severed as the second twisting point, imparting a joint twist of a forth twist in the same direction as the second twist, and a fifth twist in the reversed direction to the preliminary singles yarn for the production of a final singles ring yarn, wherein the forth twist is produced by a rotatable take-up package of the ring spinning machine onto which the final singles yarn is drawn, wherein the fifth twist results in correspondence to the second twist by a running of the lower belt on the yarn; then the final singles yarn was drawn onto the take-up package;   running the upper and lower belts in the opposite directions with the same velocity; and   controlling a ratio of the velocity of the belts to the delivery speed of the yarn and the wrapping angles of the yarn on the double-belts for controlling the false twist efficiency for yarn and thus the yarn property.   
   
   
       2 . The method for producing singles ring yarns of  claim 1 , wherein the yarn interacts with the false twisting device in the form of two false twisting points and in fact the yarn is false twisted by the torque generated by running the double belts in opposite travelling directions with the same velocity. 
   
   
       3 . The method for producing singles ring yarns of  claim 1 , wherein the geometry interrelation of the yarn, the upper belt and lower belt is important in determining the optimal adaptation of the double belts false twist device to the desired impartation of false twist, and in optimizing the yarn tension conditions and false twist efficiency. 
   
   
       4 . The method for producing singles ring yarns of  claim 1 , wherein the residual torque and other yarn properties of the final singles ring yarn are controlled by controlling the friction between the yarn and the surface of the upper belt and lower belt, and the ratio of the velocity of the belts to the delivery speed of the yarn. 
   
   
       5 . The method for producing singles ring yarns of  claim 1 , wherein the high false twist efficiency that utilizes double belts as a false twist device is provided during the yarn spinning process, and wherein the ordinary raw materials can be used to produce singles ring yarn due to the improved strength of fiber strand in the spinning triangle and the improved fiber inter-friction within the yarn at a low twist level. 
   
   
       6 . An alternative method for producing singles ring yarns, comprising:
 imparting a first high twist to a strand of traveling drafted fibers emerged from the front-drafting-roller nip with a nip false twister consisting of the two belts in close position for producing a preliminary singles yarn, wherein the false twist device provides one twisting point instead of two twist points for a yarn, wherein the false twist device provides more false twist efficiency than that of one belt false twist device, and wherein the yarn is false twisted by the torque generated by running the double belts in opposite travelling directions with the same velocity.   
   
   
       7 . An another alternative method for producing singles ring yarns, comprising:
 imparting a first high twist to a strand of traveling drafted fibers emerged from the front-drafting-roller nip with double belts running in cross direction and regulation block for the friction adjusting between the yarn and belts for producing a preliminary singles yarn, wherein a yarn is advanced along the line which bisects the angle formed by the two crossing belts, i.e., the false twisting zone.   
   
   
       8 . The method for producing singles ring yarns of  claim 7 , wherein the belts are pressed against the yarn in the area of the twisting zone by the regulation block which consists of spring and shim assembly, and wherein the regulation block can adjust the friction between the yarn and belts, improve the control of fiber movement during the false twisting of the yarn as well as provide a easier yarn piecing process. 
   
   
       9 . An apparatus for producing singles ring yarns, comprising:
 the upper belt of a false twist device travelling at the velocity of the belt imparting a first high twist to a strand of travelling drafted fibers emerged from the front drafting-roller nip such that a preliminary singles yarn is produced;   the lower belt of a false twist device travelling at the same velocity as the upper belt imparting a second twist in the same direction as the first twist to a preliminary singles yarn emerged from the upper belt such that a further preliminary singles yarn is produced;   a rotatable take-up package onto which the final singles yarn is drawn imparting a fourth twist in the same direction as the first twist and second twist to a preliminary singles yarn emerged from the lower belt such that final singles yarn is produced, wherein the double belt travels at the velocity of the belt for twisting the fibers and thus the strength of fiber strand is enhanced at the spinning triangle when a low twist level is adopted in the final singles yarn, wherein a joint twist of a second twist in the same direction as the first twist and a third twist in the reversed direction are imparted to the preliminary singles yarn for the production of a final singles ring yarn, wherein the second twist is produced by a running of the lower belt on the yarn, wherein the third twist results in correspondence to the first twist by a running of the upper belt on the yarn, wherein the yarn was drawn onto the take-up package at the delivery speed of the yarn, wherein a joint twist of a forth twist in the same direction as the second twist and a fifth twist in the reversed direction are imparted to the preliminary singles yarn for the production of a final singles ring yarn, wherein the forth twist is produced by a rotatable take-up package onto which the final singles yarn is drawn, and wherein the fifth twist results in correspondence to the second twist by a running of the lower belt on the yarn, wherein the ratio of the velocity of the belts to the delivery speed of the yarn can be controllable and the wrapping angle of the yarn on the belts is adjustable such that the false twist efficiency and the yarn property can be adjusted.   
   
   
       10 . The apparatus of  claim 9 , wherein the false twisting device mainly comprise the double belts severed as two false twisting points when the double belts travel in opposite travelling directions with the same velocity. 
   
   
       11 . The apparatus of  claim 9 , wherein the belt guides and pressuring discs are used to control the belts movement, as well as adjust the geometry interrelations of the yarn and the upper belt and lower belt and the tension of the belts. 
   
   
       12 . An alternative apparatus for producing singles ring yarns, comprising:
 a nip false twister consisting of the two belts in close position imparting a first high twist to a strand of traveling drafted fibers emerged from the front-drafting-roller nip for producing a preliminary singles yarn, wherein the false twist device provides one twisting point instead of two twist points for a yarn, and wherein the yarn is false twisted by the torque generated by running the double belts in opposite travelling directions with the same velocity.   
   
   
       13 . An another alternative apparatus for producing singles ring yarn, comprising:
 a false twist device with double belts running in cross direction imparting a first high twist to a strand of traveling drafted fibers emerged from the front-drafting-roller for producing a preliminary singles yarn, wherein a yarn is advanced along the line which bisects the angle formed by the two crossing belts, i.e., the false twisting zone.   
   
   
       14 . The apparatus of  claim 13 , wherein the belts are pressed against the yarn in the area of the twisting zone by the regulation block which consists of spring and shim assembly, and wherein the regulation block can adjust the friction between the yarn and belts, improve the control of fiber movement during the false twisting of the yarn as well as provide a easier yarn piecing process. 
   
   
       15 . The apparatus of  claim 9 , wherein ten different types of belt shapes such as round shape, elliptical shape and with/without hollow inside the belt for the false twist device can be used for the yarn false twisting process and which one is to be used mainly depends on the required false twisting effects. 
   
   
       16 . The apparatus of  claim 12 , wherein ten different types of belt shapes such as round shape, elliptical shape and with/without hollow inside the belt for the false twist device can be used for the yarn false twisting process and which one is to be used mainly depends on the required false twisting effects. 
   
   
       17 . The apparatus of  claim 13 , wherein ten different types of belt shapes such as round shape, elliptical shape and with/without hollow inside the belt for the false twist device can be used for the yarn false twisting process and which one is to be used mainly depends on the required false twisting effects.