RECENT DEVELOPMENTS IN RING SPINNING.pptx

ring frame

1. RECENT DEVELOPMENTS IN RING SPINNING

2. The quality of a yarn is judged by many parameters, like evenness, count CV%, strength, imperfections, yarn appearance, etc. Thus, in short staple spinning system, to produce yarn of acceptable quality, the raw material has to be processed through a sequence of machine.

3. Categories of developments The developments or innovations can be divided in different categories: 1. Minor modifications. 2. Modification related to quality/production monitoring or enhancement in production/speed. 3. Major modifications.

4. LIMITATIONS OF RING SPINNING

5. DEVELOPMENTS IN CREEL Suspended Creels:

6. The bobbin creel is simple in design, but it can nevertheless have an influence on the occurrence of faults.  If take-off from the bobbin is not trouble-free, incorrect drafts or even thread breaks occur. This is why bobbin suspension pivots are used nowadays rather than bobbin holders. Nowadays bobbin creels occupy lots space in terms of width, as very large roving bobbins are usually used.

7. ROVING GUIDE DRIVE Zinser OptiMove :

8. Marzoli twin traverse method: A double traverse motion for the roving guide used by Marzoli covers the wider area over the cots and consequently increases the cots and apron life .

9. Section through the drafting system

10. The INA drafting system

11. MODIFICATION IN DRAFTING ARRANGEMENT Ri -Q bridge and Arco Bridge: Conventional bridge-shaped cradles are flat with a step guide. New bridge cradles are designed with a convex shape (arc). Rieter’s Ri -Q bridge and Marzoli’s Arco bridge are arc-type cradles.

12. With the new design, the top and bottom aprons assume concave and convex shapes respectively in the working region and are kept at a higher tension compared to that when running on flat cradles. This type of arrangement extends the pressure fields on the fibres held by the middle rollers close to the front rollers, improving the guidance of short fibres.

13. When spinning finer yarns, fewer fibres are drafted and arc-shaped cradles might be useful. Arco bridge cradles are recommended for compact and finer yarns. It has been shown that Rieter’s bridge reduces yarn CV% and imperfections and improves yarn strength by 18%.

14. Suessen ACP cradle: Suessen Active Cradle with special Pinspacer (ACP) is able to improve the yarn quality. The sector length of 15-30 mm, in the drafting system, where the inter-fibre friction is minimum, do not able to guide short fibres. The pinspacer of ACP deflects the fibre in this zone thereby increases the friction field of the front roller nipping line towards the cradle. The tendency of the fibre spread is suppressed along with improvement in fibre orientation and extension consequently improves overall regularity and strength of the yarn.

15. Technological advantages of the Active Cradle over a conventional rigid cradle Lower cradle spacers for perfect operating stability Less imperfections Less variations in yarn strength and elongation Better tenacity Less yarn irregularity (USTER CV)

16. Saddle spring loading : The top rollers are also loaded directly by plate springs as shown in figure. The force of the springs is carried over to the top rollers without the use of any moving part and therefore involves no friction. The pre-tension of the spring can be changed by a cam at the front weighting unit to adjust the load.

17. The critical feature is that the top rollers are loaded directly by heavy-duty plate springs without clearance or friction. Furthermore , the plate spring is supported free from play in the top arm body. At the same time, the plate spring serves as a guiding element and prevents the possibility of lateral forces from acting on the top roller position. In addition, the mechanical treatment of the wider top roller supports will guarantee the precise parallelism of the top and bottom roller axles.

18. Delayed start-up of drafting rollers: The drive for the drafting rollers is a rigid one (by gears) and the spindle is driven by a flexible drive (belt). The initial belt tensions on both sides of the spindle are the same while the machine is at rest. When the ring spinning machine is started, the belt tension in the forward direction increases, and at the back it decreases enough to build up the required torque on the spindle.

19. Additional slackness present on the spindle belt compounds the problem . The acceleration of the spindle lags behind that of the drafting rollers and the yarn slackens; if it slackens much, this might lead to balloon instability and the end breaks. Delaying the starting of the drafting rollers by a few seconds would solve this problem. In the Marzoli ring spinning machine, at the beginning of cop build-up, the starting of the drafting rollers is delayed so that the spindle starts to rotate first, which tightens the initial yarn ends.

20. CONDENSED SPINNING SYSTEM All the optimizations and improvements of the ring spinning frame have not enabled the reduction of the spinning triangle, which can be defined as the most problematic and weakest spot in the yarn formation process using the ring-traveller system.

21. The spinning triangle that occurs while the yarn is formed is the cause of many fibres leaving the drafted roving, or being partly spun into the yarn with one end only. This causes greater waste of fibres, lower exploitation of fibre tenacity in yarn, poorer appearance and greater hairiness of the spun yarn. The newest research in the field of ring spinning has minimized spinning triangle, or even without it at all. This modified process is called compact or condensed spinning.

22. Conventional Vs Compact Spinning

23. If the twists are imparted, the fibres at the edges are either loosely bound or lost as a fly and produce hairy yarn. The main purpose of the compact spinning is to eliminate spinning triangle at front roller, technically speaking the ‘weakest point ’ of the ring spinning. The elimination of the spinning triangle results in permanent change of yarn structure, which distinguishes the compact spinning from conventional ring spinning.

24. Methods of compacting fibre strand Aerodynamically compacting system: a) Suction by drum and b ) Suction through perforated apron. Mechanical compact system. Magnetic compacting system.

25. Aerodynamically compacting system Com4Spin® of Rieter:

26. this compacting process is supported by a specially designed and patented air guide element (6). the special feature of "air guide element" is to enhance the compacting efficiency in the compacting zone

27. Suessen Elite® Compact Spinning

28. The profile tube (S) has a small slot in the area (S1-S4) and is closely embraced by a lattice apron. The porosity of the apron and the negative pressure in the slot area result in a condensed fibre bundle that is transported up to the zone (4-S4). The oriented fibres remain completely condensed and closed up to the delivery clamping and twist insertion line (4-S4) because of the slot length. Therefore , no spinning triangle is formed, which enables literally all the fibres to be wound into the yarn and optimal yarn structure.

29. Zinser Air-Com Tex 700

30. Com4®wool by Cognetex Com4®wool is the trademark of the compact spinning for long staple fibres that Cognetex (an Italian based company) has developed for 'IDEA' make ring spinning machine in cooperation with Rieter. Here front drafting roller is replaced by a perforated drum. This enables the airflow to compact the fibres directly on the drafting cylinder. It is claimed by the manufacturer that for the wool sector, a patented elastic control roller with a slant axis prevents fibres that are being pinched at the same time by the drafting system and the front roller, from being tensioned.

31. Olfil system by Marzoli Olfil is the compact spinning system designed and developed by Marzoli. The condensing system is positioned at the delivery of the drafting unit. The bottom section of the condensing system has one stainless steel pipe for every 8 spindles with a perforated apron at each spindle.

32. The top section of the condensing system is composed of two pressure rollers driven by the toothed belt. For each 48 spindles section, there is one motorized inverter driven fan that provides suction for the condensing system. A wide area air distribution and compensation allows for the correct balancing of the suction.

33. Toyota's compacting method RX240NEW-EST-make Toyota's ring spinning frame is equipped with compact spinning system. The condensing device consists of suction slit and perforated apron and works on aerodynamic compacting principle.

34. The special features of the machine, as claimed by the manufacturer are : 1. Smooth collection of fleece fibres by suction slit and perforated apron. 2. Precise slip-free rotation of the perforated apron because of positive drive of the top and bottom delivery rollers. 3. Inverter-controlled adjustable suction pressure. 4. Easily detachable condensing unit.

35. 5. Perforated apron, driven by a bottom roller, is not affected by top roller diameter. 6. For easier handling, each 4-spindle condensing unit can be conveniently detached and disassembled without using special tools. 7. The rollers are driven by a geared front-bottom roller and maintenance-free carrier gear, resulting in a simpler structure.

36. Mechanical Compact System Mechanical Compacting Spinning (MCS) is given by Officine Gaudino for long staple. This compact system makes the compact yarn without the use of air. The compacting of the fibre strand is carried out with smooth bottom front roller and an angled top roller. Officine Gaudino offers long staple spinning machine (Model FP 03) with mechanical compacting system.

37. This compacting system does not require the additional suction system. The MCS consists of an additional smooth bottom front roller and an angled top roller. These rollers run at a slightly slower speed than the front drafting rollers and this 'negative draft', coupled with offset top roller, creates false twist which compacts the drafting strand as it comes out from the compacting zone. This system can be incorporated into the new machines and is claimed to be easily added or taken off the spinning frame.

38. Magnetic Compacting System Magnetic Compact Spinning, as the name implies, is a compacting system that makes the compact yarn with the use of magnetic compactor. The RoCoS compact spinning system, developed by Hans Stahlecker of Rotorcraft Maschinenfabrik , Switzerland is incorporated into LMW's Ring Spinning Frame. RoCoS stands for ' RotorCraft Compact Spinning' system and it works without air suction and uses magnetic mechanical principle only

39. The bottom rollers (1), support the front roller (2) and delivery roller (3). The condensing zone extends from clamping line A to B. The very precise magnetic compactor (4) is pressed by permanent magnets without clearance against cylinder (1). It forms, together with the bottom roller, an overall enclosed compression chamber whose bottom contour, the generated roller surface of the cylinder, moves synchronously with the strand of fibres and transports this safely through the compactor.

40. Advantages of Condensed Yarn Spinning Considerably reduced yarn hairiness Highly increased yarn strength and breaking extension Sizing and Singeing can be completely or partially dispensed with. Conventional two-fold yarns can be replaces with compact spun yarns. Classical combed yarns can be partly replaced by EliTe compact spun yarns Consistently reduced fly generation/liberation, i.e better fibre utilization and cleaner spinning conditions.

41. Noil percentage at the comber can be reduced, because short fibres, in particular, are better integrated in the yarn during spinning Significantly reduced imperfections, resulting in better yarn quality. Appreciably reduced ends-down, leading to higher machine efficiency. Softer fabric handle Increased pilling resistance, luster and fabric strength and Higher yarn sales price due to better yarn quality.

42. Disadvantages of Condensed Yarn Spinning The various methods of condensed yarn spinning described here no doubt promise ideal yarn characteristics, but their commercial popularity is still under test due to: Higher capital cost of the machinery Increased maintenance of suction / perforated devices Fibre loss due to suction into the perforated drum in Rieter’s Comfor process and chocking of suction holes in the perforated apron in Suessen’s EliTe proess .

43. SIRO SPINNING

44. SOLO SPINNING

45. DEVELOPMENTS IN RING & TRAVELLER The ring is the race track over which the traveller has to revolve to impart twist to the yarn balloon. Running at a speed of 110-170 km/hr, the traveller generates heat at its interface with the inner edge of the ring. As the traveller is very light, its temperature can reach as high as 300 C in spite of heat losses due to conduction and convection, leading to localized melting and it quickly wearing out.

46. Considerable research work has been done by the ring and traveller manufacturers, aimed at reducing the frictional wear resistance of the ring and travellers and increasing heat conduction at the traveller-ring interface. This has resulted in the use of carbon-rich steel, lubricated rings, ceramic rings, special finishes (diffusion treatment, nickel plating) and new designs of ring and traveller combinations with an increased area of contact.

47. The travellers used for short staple spinning are C-Type on a low crown ring/ T-Ring, Orbit and SU.

48. The area of contact between the ring and traveller is greater in the case of SU and Orbit types, providing better heat dissipation. The traveller describes an up-and –down motion and tilts in the radial and tangential planes continuously due to the variation in the balloon size and its tension and also the change in the lead angle with the ring rail movement. In SU and Orbit rings, the design of the ring itself provides a certain balancing effect on the traveller while it is tilting / oscillating.

49. Traveller wire-profile

50. The fibres protruding from the yarn body are crushed between the ring and traveller and form a steady lubricating film. The fibre lubrication prevents metal-to-metal contact and reduces the friction coefficient considerably, in cases from 0.12 to 0.08, depending on the fibre. With new rings, metal-to-metal contact occurs at the ring-traveller interface and gives rise to a high friction coefficient that results in increased yarn tension and breaks. When rings are changed for new ones, it is usual practice to run the spindle at lower speeds then progressively increase the speed over a period of a few days, called ‘running-in’, to generate fibre lubricants and deposit them on the ring.

51. DEVELOPMENTS IN DRIVE SYSTEM A unique trend has been observed for changing the yarn count and twist by pushing a button, i.e. without any mechanical intervention. Another trend is the division of drafting systems on long ring spinning machines into two halves, each driven independently.

52. Rieter FLEXIdraft : The FLEXIdraft flexible drive, equipped on Rieter G33 ring spinning machine, features separate drives for the drafting system and the spindles. Synchronous motors controlled by frequency converters drive the drafting system cylinders individually. The cylinders are split in the center of the machine to ensure very smooth running and drafting operation.

53. The multi-motor drafting system drive (2 motors on each side at the head and foot of the machine, i.e. a total of 8* motors) offers maximum user friendliness when adjusting the spinning parameters to new conditions. This system enables change in the yarn count, twist and twist direction (S/Z) via, the control panel of the machine. The drafting rollers are split in the centre of the machine to ensure smooth running of drafting operation.

54. Advantages yarn count and twist change at the push of a button high-precision settings considerably fewer ends down at start-up no mechanical work significantly reduced noise levels start-up and spin-out in quarters maintenance-free S/Z twist can be set at the control panel

55. FLEXIStart : On the basis of FLEXIdraft , each drafting system drive can be started or stopped individually via, FLEXIstart system. Thus depending on machine length, 1-sided or 2-sided drafting system drives are used .

56. Zinser SynchroDrive , SyncroDraft and ServoDraft Zinser SyncroDrive is a multi-motor tangential belt drive system . The system employed several motors arranged at defined positions to drive spindles through tangential belt. The consistency in spindles speed relative to each other minimizes the twist variation apart from reduction in noise level and minimum power requirement.

57. SynchroDraft transmission is for long machines to drive the middle bottom rollers from both ends, consequently minimizes twist variation between gear end and off end of the machine. Zinser ServoDraft system employs individual motors for driving bottom rollers of the drafting system. Hence yarn count and twist change can be done by simply feeding required parameters at the control panel of the machine that adjust the motors speed accordingly.

58. Toyota ElectroDraft System The Toyota ElectroDraft System features independent servo motors drive for front and back rollers. The spindles are also driven by separate tangential drive system where one motor drives 96 spindles . Thus the required draft and yarn twist can be set via, control panel.

59. Marzoli multi-motor drive system The main motor with a relative inverter drives only the spindles. An asynchronous motor drives the ring rail. The drafting rollers have two separate drives, one on each side of the spinning machine, through asynchronous motors. On each side, one motor drives the front drafting rollers and the other one drives the middle and back drafting rollers.

60. The production parameters, namely main draft, twist and shape of the bobbin, must be entered at the control panel, making any gear changing redundant; this ensures fast and precise control of important parameters, thereby increasing the flexibility of the ring spinning machine.

61. SPINDLE DRIVES Two types of system are employed t drive the spindles, namely 4-spindle group drive with tapes and tangential belt drive.

62. Tangential Spindle Drive

63. In the tangential belt drive, a belt extends from the motor past the inner side of each spindle. A number of tension rollers are placed along the belt to press against it and ensure a constant tension on the belt for all the spindles. However, there is a possibility of non-uniform tension on the belt due to variations at the locations of the tension rollers. This might lead to a variation in yarn twist on each spindle. Tangential belt drives are available in three forms: single, double and grouped. If a belt breaks, production is affected on a large number of spindles.

64. 4-Spindle Tape Drive

65. In this arrangement, a jockey pulley mounted on the main shaft of the spinning machine drives two spindles on one side of the machine and a further two spindles on the other side of the machine by means of a flexible tape. Two tension rollers on either side of the pulley ensure an even, firm tension on the belt. The 4-spindle drive offers a greater angle of wrap around the spindle wharves by manipulating the position of the tension pulleys.

66. This ensures less slippage on the belt, and provides constant rotation speeds to the spindles over the total length of the machine, regardless of the number of spindles on the machine. Furthermore, it leads to less tension on the belt and hence a lower consumption. In the event of a belt breaking, only the 4 spindles are affected, and it is also a quick job to replace.

67. Zinser OptiStep and Optistart :

68. OptiStep is a system of adjusting spindle speed in 10 different ranges through-out the cop builds on Zinser ring spinning machines. The start-up, tip and main spinning speeds can be defined with a 10 point speed curve. Similarly OptiStart is a running-in programme for ring travelers to perform the running-in phases of the ring travellers with precise accuracy up to production speed. Hence the traveller service life is substantially extended.

69. Marzoli variable spinning speed:

70. Marzoli’s variable spinning speed ensures high productivity and reduced breakages during bobbin build up. The speed increases as yarn tension decreases, in order to maintain high quality minimizing irregularities. The software program also balances energy supply with spinning speed. In case of power fault the computerized system is able to control the stop of the machine without yarn breakages.

71. Zero Under-winding concept Servo Grip from RIETER The yarn has to wind several times around the lower end of the spindle to hold it in the spinning position at the time of doffing. These under-windings often cause multiples end down and lead to fibre fly when machine is restarted after doffing. SERVOGRIP is a system of doffing ring cop without the under-winding threads. The main elements of the SERVOgrip is a patented clamping crown.

72. At the time of doffing the ring rail moved downward and the clamping crown gets open while the spindle is still revolving slowly. The yarn gets inserted in the open crown and the crown gets closed afterward. When the cop is replaced, the length of the yarn remains firmly clamped; enabling piecing after machine is started.

73. Marzoli Wondercleaner

74. The Marzoli rather uses a wonder cleaner to remove the underwind. Wondercleaner is an overhead cleaner with suction unit. This removes underwind only when the ring rail has reached certain minimum height. To cut the under coil binding on the spindle, it is used a simple metallic cutter which cut the yarn when the blower pushes it against the spindle. The yarn is reduced in small pieces and then scattered on the floor. This solution is good enough for medium and fine yarn.

75. The Wondercleaner is an overhead cleaner with a positive suction unit which perfectly removes the winding of the binding coils for coarse yarn.

76. The spindle cleaner is used with the blower only between doffing cycles, when the ring rail has reached a minimum height. It cuts and collect the underwind yarn coils from every spindle instead of just cut and scatter them in the room. After the cleaning is performed, the suction activity remains idle (Wondercleaner works as a conventional overhead cleaner).

77. Marzoli different winding geometry

78. The production of high quality yarn is strictly related with the geometry of spinning. Marzoli offers three geometries (180-200 mm, 210-230 mm, 240-260 mm) which keep the spinning angle variation inside the best theoretic range. The ideal distance between anti-balloon, delivery angle (front roller), guide thread and ring rail has been optimized.

79. Reduction of heat in spinning room Rieter INTERcool :

80. INTERcool is a closed-circuit, in the machine integrated cooling system. INTERcool feeds the heat from all the motors and frequency converters directly to the air conditioning system via an internal heat exchanger. This considerably reduces the load on the air conditioning system. The integrated system prevents the heat from the machines from being released into the spinning mill. The air sucked in via the extraction system flows through the heat exchanger and feeds the heated air directly to the exhaust air duct of the air conditioning system.

81. Advantages: closed-circuit cooling system efficiently reduces the load on the air conditioning system constant spinning climate along the entire length of the machine positive influence on running properties and yarn quality no fly formation no filter no filter cleaning necessary

82. Marzoli:

83. The drives have been installed in an electric box with forced ventilation in order to allow a proper operation. The pneumafil suction air is discharged separately into a centralized fibre compactor, and the main motor releases hot air into the underground duct which transports the air to the air conditioning system.

84. AUTOMATION IN RING-SPINNING MACHINE Automation in ring spinning consists of Transferring the roving bobbin into creel of the ring spinning machine Stopping the roving feed when it breaks Machine and production monitoring Doffing Transporting cops to the winder

85. Roving bobbin transfer: On the creel of the ring spinning machine, optical sensors are placed near each of the roving bobbins. Full roving bobbins move in the area near the ring spinning machine. If a bobbin is exhausted, the movement of roving bobbins is stopped and a T-shaped lever with pegs at each end for holding the roving bobbin comes into action.

86. One side of that takes the new bobbin and the other end takes the empty roving bobbin from the ring spinning machine creel. The lever then rotates through to 180 and transfers the fully wound bobbin to the ring spinning machine’s creel and the empty bobbin to a creel nearby. The operator only joins the roving ends, which saves them time and reduce roving bobbin run out time caused by their negligence.

87. 2. Transfer of roving bobbin from roving machine to creel of the ring frame machine Most machine manufacturers offer the automatic transport of roving bobbins to the creel of the ring frame machine. A design offered by Oerlikon schlafhrost on the Zinser 351 ring spinning machine has four rows of creels, which are designed as transports rails driven by trolley trains. Three rows of creels are in working positions and the fourth one serves as a reserve. If one of the rows of working creels runs out of roving bobbins, the next one automatically takes over as the supply creel. The operator of the ring-spinning machine to join up roving ends to the waiting full bobbins.

88. By simply pressing a button on the ring-spinning machine, the trolley with empty tubes is sent back and a new full trolley train requested. The empty trolley train now enters the cleaning station then waits in the storage section to be filled again. The control centre sends a new full trolley train to the ring-spinning machine. There are two modules offered: a stand- alone module integrated into the transport system or a tube cleaner integrated into the roving machine.

89. How bobbin transport to the ring frame? CIM TRACK3 – Fix flow CIM TRACK4 – Flex Flow The word CIM means Computer Integrated Manufacturing. Apart from optimal yarn quality, high productivity, reliability and flexibility are demanded of modern ring spinning systems. For these requirements, offers ring spinning systems with modular design with roving frames, ring spinning machines and the optimal connection of these by roving bobbin transport systems for any material flow requirement.

90. Creel Automation CIM Track 3: Fix Flow Principle With the so-called AutoFlow systems, the roving bobbin transport systems, it provides automation for roving bobbin transportation to the ring frame. FixFlow is a fixed linkage, i.e. a circular conveyor system, which is ideally used in spinning mills with a constant production and spinning programme.

91. With CimTrack 3, there are 3 TRACK of roving bobbins are directly transported into the ring spinning machine creel using trolley trains (one per creel row).

92. Bobbin exchange is dropped. The operator has only to piece up the roving. A row change is performed. The creel rows are initially fed with bobbins that have stepped fill levels. There is also a changing spare row on each machine side. Following this, the resulting change cycle means that full roving bobbins are transported in whichever creel row becomes vacant.

93. Automation CIM track 4: It is based on the principle of FlexFlow . Flex Flow is a flexible linkage. That means the material flow system is ideally used in spinning mills With frequently changing production and spinning programmes. As a specialist for roving frames and ring spinning machines, is capable of offering – apart from standardized solutions – the suitable individual transport system for any material flow requirement.

94. With CIM Track 4, there are 4 track of roving bobbins are directly transported into the ring spinning machine creel using trolley trains (one per creel row).

95. Bobbin exchange is dropped. The operator has only to piece up the roving. A row change is performed. The creel rows are initially fed with bobbins that have stepped fill levels. There is also a changing spare row on each machine side. Following this, the resulting change cycle means that full roving bobbins are transported in whichever creel row becomes vacant.

96. 3. Roving Stop Motion: When a yarn breaks during spinning, the drafting rollers continue to process the fibre strand, and fibres are sucked into an aspirator and go as waste. In poor spinning conditions (high relative humidity) the drafted fibres lick on to the drafting rollers and form a lap. This can damage the top rollers and aprons and causes ends down on the neighbouring spindles. The removal of roller lap also causes additional problems.

97. All the costs ( labour , power and indirect costs) incurred in converting the fibres into the roving become unproductive. It would be desirable to have a roving stop motion that interrupts the flow of fibres from the time an end breaks until joining is carried out. Roving stop motions can be provided as part of the travelling device or as assemblies at each individual position. The former is more economical but the roving stop would not be immediate as it in the case of integrated equipment.

98. Marzoli has brought out a roving stop motion in which the roving is locked at the back of the drafting system as soon as a yarn break is detected by a sensor. The sensor, which is placed below the lappet, senses the presence of yarn at each spindle position. Additionally, the sensors at each position are used as data collections units for the status of each spinning position. This has potential applications for machine monitoring and production data acquisition.

99. 4. Monitoring systems: Ring-spinning monitoring system are available for obtaining data about individual machines, individual blends or the complete ring-spinning installation from printed reports or from screen displays, including: spindle rpm, mean yarn twist, production data(machine and spindle), machine efficiency and downtime, doff time, number of doffs, ends down and mean period for each end down. Many sensors are used to monitor different of the machine to acquire different data.

100. A travelling sensor based on the principle of magnetic induction moves continually back and forth at about ring rail level on each side of the ring-spinning machine. If a yarn breaks, the sensor emits a pulse indicating an end down, while simultaneously identifying the spindle by its code number. This sensor registers the yarn break at one spindle several times before the positions is returned to production. The time that an end remains down is computed.

101. Another sensor, fitted to a roller corresponding to the front roller, detects delivery machine and machine downtime; a further sensor detects the number of doffs and the time taken for each doff. All this information is passed on to a computer for displaying, printing and evaluating over a given period.

102. Rieter Individual Spindle Monitoring (ISM) Individual Spindle Monitoring (ISM) is a quality monitoring system. ISM is based on optical scanning of the traveler. If the traveler is no longer rotating on the ring, the control system detects an end down and indicates this by illuminating the spindle LED directly at the spinning position. Since the traveler speed is continuously monitored, slipper spindles (spindles running at less than their rated speed for a defined period of time) can also be precisely identified and indicated.

103. 1st level: machine Two signal lamps on the headstock and tailstock of the ring spinning machine indicate the side of the machine on which the ends down threshold has been exceeded. 2nd level: section A high-intensity LED (Light Emitting Diode) on each section (24 spindles) indicates that an end down or a slipper spindle has been detected in this section. 3rd level: spindle This level indicates which spindle is operating outside the defined tolerances. Here the malfunction can be identified precisely on the basis of the light signal shown by the spindle

104. ISM – the Rieter individual spindle sensor – helps to optimize the speed curve on the ring spinning machine and displays the influence exerted by various factors, such as raw material blend, on the number of ends down. Distance covered by the operator during will be reduced by about 40% with the installation of ISM as shown in figure.

105. Advantages of the 3-level light guidance system: • Easily detect ends down • Immediately identify slipper spindles • Deal with problems selectively through personnel guidance • Optimize operations by reducing routine tours of inspection

106. Zinser GUARD system:

107. The individual yarn monitor FilaGuard monitors the rotation of the steel ring travellers on each spindle and detects any yarn break immediately. Optical signals indicate the specific yarn break, directing the operating personnel to the spindle of yarn break to rectify the problem. The automatic roving stop RovingGuard , which responses within milliseconds, interrupts the roving feed in case of yarn break thereby prevents material loss and minimize lapping tendency.

108. 5. Centralized Control of Spinning Parameters and Retrievable Rieter’s MEMO set product stores spinning parameters for up to 18 different yarns. The data are available at all times and can be retrieved and processed. The parameters are downloading directly from a laptop, and transferred between several spinning machines. Machine functions, spindle drive, drafting arrangements, auto drafting, and traveller cleaner’s details are all centrally controlled and always available on the display unit.

109. Real-time information is made available regarding output and machine status. Adjustments to production parameters, e.g. for yarn twist, are possible via a keyboard. When changing the blend, modifications to machine data can be made quickly. The time remaining to the next doffing process is available on a display, which can facilitate the allocation of personnel.

110. 6. Automatic Doffing: There are two types of automatic doffing for ring-spinning machines: stationary and travelling devices; the former is mostly used in new machines. After completion of doff, the doffer, which contains empty ring bobbins and also the provision for holding the fully wound bobbins, rises from below. Fully wound cops are then gripped by the doffer and transferred to it, and then empty bobbins are transferred from the doffer to the spindle of the ring-spinning machine. Subsequently the doffer comes back to its original position and transfers all the full cops to a conveyor belt, which might be used to transfer them to the winding machine.

111. Auto Doffing Cycle in Ring Frame: (Model Rieter G35)

112. A uto Doffing Cycle in Ring Frame: (Model Marzoli MPN) The automatic doffing has an intermediate parking rail for the empty tubes. The bottom conveyor holds only full bobbins and therefore their size (diameter) could reach bigger diameter without the limitation created by the presence of another empty tube. The doffing cycle is very reliable and simple. The individual peg is always aligned with the spindle thanks to a mechanical lever which aligns 24 pegs at a time.

113. A pneumatic piston moves the pegs without the need of any metallic band or chain which can eventually over-stretch creating misalignment with the spindles.

114. 7. Automatic cop transport to winding: Automatic cop transport to winding can be classified into: a) intermediate transport between spinning and winding sections/departments and b) direct link to a specific winding machine.

115. Intermediate cop transport

116. In an intermediate transport system, the transport devices take up the boxes of full cops coded according to their contents, and deliver them to a distribution station. This station directs the boxes to the cop preparing unit of the corresponding winding machine. The empty tubes are deposited in other boxes and returned via a second conveyor system to the ring-spinning room. Intermediate transport systems are very flexible, rapidly adaptable and less dependent on the layout of the building that houses them. However, they can be rather complex, costly and liable to faults.

117. Direct link system

118. With the direct link system, the ring-spinning machine and the winding machine can be coupled to form a production unit. The cops doffed at the ring spinning machine are passed to the winding machine. The transfer speed must correspond to the production rate of the winding machine; hence it is slow.

119. Empty bobbins are returned to the loading station of the auto doffer at the ring spinning machine. The number of winding units chosen should be such that the cops delivered after one doff have just been rewound when the cops from the next doff become available. The requirement for synchronizing each machine is difficult to achieve when products are changed frequently.

120. FANCY YARN AND CORE SPUN YARN SPINNING Technologies to produce core yarns For processing both elastic and hard filaments, attachments to feed the filaments into the front roller nip are available that can be retrofitted on existing ring spinning machines. In the case of manufacturing elastic filament core spun yarn, the control of stretch or pre draft on the filaments has to be carried out precisely using positively driven rollers that support the filament package.

121. Selection of the appropriate roughness and finish for the rollers surface is critical to avoid stick-slip of filaments. Servo motors are also used to drive guide rollers. For processing hard core filaments, a special creel for supporting and unwinding filament cop is installed. With very fine yarn, precise centering of the filament in the resultant composite yarn is difficult. A floating filament guide system with an intermediate roving guide bar is used to ensure the relative positions of filament and roving.

122. One of the main defects of core spinning is the production of yarn without any filaments when the filaments break. Different systems are available to avoid this. Mobile filament detectors can be used, one on each side of the machine. An individual filament detector, together with a roving stop mechanism, would be ideal and could be adapted to stop the production of a particular spindle when the filament broke.

123. Rieter VARIOspin for fancy yarns: Rieter VARIOspin (optional) is a fancy yarn production system incorporated on ring frame (Rieter G33) and compact ring frame (Rieter K44). Windows-based VARIOspinData PC software is used to transfer fancy yarn data to the machine control system via, the RS 232 interface. The change between fancy yarn and standard yarn is effected via, the machine control system thus no need of complicated retrofitting is required.

124. Yarn Effects achieved with VARIOspin

125. Suessen two ply and core spun yarn: Suessen incorporates devices under different trade names to spin two ply and core-spun yarn on compact ring frame. The EliTwist ® spinning method combines compact spinning and twisting of a yarn to get two-ply compact ring spun yarn.

126. The EliCore ® is the trade name given to spin core-spun on compact ring frame. EliCore ®-rigid is for corespun yarn with low elastic elongation but high strength filament in core whereas EliCore ®-elastic is for high elongation and stand strength filament in core. EliCoreTwist ® is trade name given to spin two-ply (SIRO) compact ring spun yarn. This attachment works irrespective of the type of top weighting arm used and gives jerk- free movement to the traverse motion of fibre strand and filament. The filament feed roller is independently adjustable in two planes without touching the front top roller. Setting of tension draft and traverse motion is made at a central control panel.

127. NOZZLE RING SPINNING Nozzle-Ring or Jet spinning is a recent innovation, which has until now been in the research stage. An air nozzle is placed below the front roller and the issuing fibre strand passes through it before reaching the yarn guide eye. The nozzle has to be placed such that the front roller nip, the axis of the nozzle and the yarn lie in a straight line. Compressed air is supplied to the nozzle through pipes with a pressure regulator and an air filter. Since the nozzle is the heart of the process of reducing yarn hairiness, its design plays a vital role.

128. It is an air-vortex type of nozzle which creates a swirling airflow as shown in figure. A Z-nozzle should be used for Z-twisted yarn and vice versa. The Air flow issues from the nozzle in an upward direction, i.e. against the direction of yarn movement. The yarn coming from the front roller is partially untwisted on the upstream and then re-twisted on the downstream, i.e. the yarn undergoes a false twisting action.

129. The air-drag forces acting on the protruding hairs fold and wrap them around the yarn surface. The distance between the nozzle and front roller, the angle of air inlets and the yarn channel diameter play decisive roles in the efficiency of hairiness reduction. An operating pressure around 0.5 bar is found to be sufficient to reduce it.

130. Placing the nozzle too close to the front roller would disturb the spinning triangle and affect the yarn formation process itself . Generally, the distance between the nozzle and the front roller is around 10 cm for the best results. The air nozzle preferentially reduces longer hairs. The hairiness reduction may reach 50%.

131. Nozzle-ring spinning is in its nascent stage. Many issues have to be addressed such as Joining yarns during spinning by a suitable means . Its precise positioning in the spinning region Making the cost of the nozzle affordable and Reducing air consumption below 0.5 bar, before this technology can be commercialized.

132. MAGNETIC SPINNING SYSTEM The approach adopted by the inventors replaces the traveller with a magnetically suspended light weight annular disc that rotates in a carefully pre-defined magnetic field. It is claimed that this will result in super high rotation of the disc that is robust against all the traditional limitations of the rotating element of spinning system.

133. In the magnetic ring spinning system a bias flux is generated from both permanent magnets across the air gap, supporting the weight of the rotating disk in the axial direction. In case the floating ring is displaced from its central position, the permanent magnets will create a destabilizing force that attracts the ring even further away from the center. The control system allows the current in the system to be controlled by feeding back information on the position of the rotor (obtained using four displacement sensors mounted radially to the floating ring) and adjusting the control currents based on this information.

134. Advantages: Magnetic spinning works without a traveller sliding over the ring, so there is no mechanical wear or heat generation . High speeds of the rotating magnetically suspended disk are attainable (depends on spindle rotational speed ). Friction losses are many times less than in conventional ring traveller system and result in lower operating cost . Maintenance costs are low due to the absence of mechanical wear.

135. Control system can be programmed for obtaining constant tension during spinning (yarn tension could be measured by measuring the magnetic field strength required to maintain the disk centered). Eddy current produced within the system is used to control the resisting torque of the disk in order to produce different yarn count (conventionally, the traveller mass is charged in order to obtain the same effect).

136. Disadvantages The rotating ring based on magnetic field are unlikely to be commercialized owing to their high cost, requirement of large spindle gauge, high noise level, the need for regulating the start up and shut down speeds, and the requirement of a special roving brake to prevent material waste during yarn breaks and piecing up.

137. CONCLUSIONS The ring spinning system with all the developments as described above is undoubtedly capable of producing broad count range of yarns having unique characteristics, at about 50 m/min. However, any further increase in spinning speed is a question again and the ring spinning system still exhibits the following limitations: Unable to increase the production speed beyond 50 m/min Unable to improve yarn regularity beyond certain range Relatively longer process sequence Process cannot be automated completely Small package size and High spinning tension at higher spindle speeds.

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