Noor Ahmed Raaz
Faculty Member, Dept. of Textile Engineering,
Atish Dipankar University of Science & Technology
Email: raju.uttara105@gmail.com
Introduction:
In any manufacturing industries, final goal that everyone strives for is to make completely automatic machinery that takes in raw material on its one end and delivers finished product from the other end. Increase the productivity and maintain the supreme quality is only possible when are used automation properly. Automation is widely used in different branches of textile manufacturing process. Among the different branches of textile automation is hugely used in yarn manufacturing technology.
Fig: Automation in ring spinning
In yarn manufacturing technology in textile industries, ring frame is one of the most important components. During the last two decades components of ring spinning machines have been greatly improved, changes in drafting system, drive systems and robotics have enabled large gains in productivity, flexibility and quality. Most of the technical advances in ring spinning were aimed at improving the performances on the existing technology. These are all achieved by the automation. In this article I will discuss application of automation in different stages of yarn manufacturing.
Automation in Yarn Spinning Technology:
A yarn test that used to take hours to perform 20 years ago can now be done in a matter of seconds using the HVI system. This process has been achieved through constant innovation and updated automation in the plant capacities. Automation in yarn manufacturing are pointed out below:
1. Yarn forming process has seen advancements and automation by introduction of newer methods of spinning apart from ring spinning like open-end spinning, airjet spinning and Murata Vortex System (MVS)
2. Cotton mixing in blow room has been automated so that cotton from several bales can be drawn and mixed together, forming a more homogeneous mixing of cotton, thus reducing batch to batch variation in cotton spun yarn lots.
3. Carding machines using chute feed systems, auto levelers for improvement in quality or productivity and reduced handling have helped in increasing evenness in the yarn.
4. The ring spindle speeds have gone up to 20,000 and high-speed rotors up to 1,00,000 rpm are available. Today, spinning machines can produce yarns up to 20 times faster than what they used to produce 20years ago.
5. Autoconers with splicing and yarn fault detection have been devised to obtain yarns with lower unevenness and better quality.
Automation in Yarn Manufacturing are described comprehensively in the following sections: Now automation is used in fiber manufacturing from bale management to cone winding. The cotton fiber is an industrial raw material that is utilized primarily by the textile manufacturing industry. An automatic bale opener is a must if more than two cottons are used in the mixing to avoid barre or shade variation problems.
Automation in blowroom:
High in performance, yet compact in design, a complete blow room line is composed of only four multi-function machines. A lower current consumption and lower exhaust air volumes improve the economic efficiency. Nevertheless, there are no compromises regarding cleaning, opening, and blending quality, even at a production rate of 800 kg/h.
The compact blowroom consists of the following four machines:
Automatic bale opener
Multi-function separator
Mixer–cleaner combination with high production cleaner
Foreign part separator
Automation in carding: The proverbs, “The card is the heart of the spinning mill” and “Well carded is half spun,” demonstrate the immense significance of carding for the final result of the spinning operation. A relatively high degree of evenness is required in the sliver. For various reasons, the card cannot always operate absolutely even. So, spinning mills are accordingly forced to use autoleveling equipment under highly varying circumstances. For export quality yarn, count variation is expected to meet 1.0%–2.5%. An extremely good count consistency is the most important condition for an excellent appearance of the woven or knitted end product. In order to achieve this, it is a must to control the evenness and coefficient of variation of count both at sliver as well as at yarn stage. Control of these cumulative factors can be taken care only by autolevellers. Autoleveling is usually performed by adjusting the feed rollers’ speed.
Automation in drawframe: With today’s handling equipment, robots and transport devices designed with microprocessor controlled noncontacting sensors and detection systems are used. Material transport between two machines has become fully mechanized. In the drawing section, breaker and finisher draw frames are connected by CAN link or a can-connect system.
Automation in comber: Within the overall spinning process, the comber serves to improve the raw material. It is mainly used to get fine yarns. The functions of the comber are to:
Elimination of the short fibers
Elimination of remaining impurities
Elimination of a large proportion of neps
Formations of sliver having maximum possible evenness
The ribbon breakage photo cell is used to stop the machine whenever there is a break of lap on the feed end or breakage of fleece on the table end. It consists of one control unit and two sensor units: one for the feed end and other for the lap end and empty beam stop motion.
Comber photo control for entry lamp unit consists of one control unit and eight sensors for sensing the empty lap. By fixing this unit, the continuity of the lap is maintained. One of the advantages is that the lap is stopped well before the contact rollers, so piecing is easier. Computer aided top performance is an important step in the direction of the total fiber control in the combing process has been taken with CAPD.
Automatic Lap Transport:
Automated processes call for gentle but reliable lap transport. Manual lap transport is not feasible for the comber. The automatic lap transport system SERVOlap meets the requirements of lap positioning best.
Automation in roving frame: The sliver from the draw frame or from the comber is present to the roving frame. Thus winding of roving on the bobbin occurs, which is the end product of roving frame after that the process will be moved on to the ring frame. The process for the ring frame is:
Multimotor Drive System, Automatic Winding Tension Compensating Device, Roving Stop Motion, Automatic Doffing are used in roving frame.
Automation in ring frame: Ring spinning is the process of converting roving into yarn. It is a long, rectangular, double-sided frame in which the upper part is designed to hold the bobbins, the middle part for drafting, and the lower part gives the necessary amount of twist and winds yarn on the cops.
The objectives of the Ring spinning process are:
To attenuate the roving until the required fineness is achieved
To add strength to the fiber strand by twisting it
To wind up the resulting yarn in a form suitable for storage, transportation, and further processing
The Possibilities for Automation in Ring Frame:
Transporting roving bobbins to the ring frame. This would be a very useful step of installations enabling the usage of area economically available.
Exchanging roving bobbins in the creel of the ring spinning machine. This would also be as useful step but raises difficult problems; the first installation for this purpose is also now becoming available.
Threading rovings and piecing roving breaks
Taking up and removing waste
Piecing end breaks
Stopping roving when an end breaks
Doffing
Cleaning
Transporting cops to the winder
Monitoring the machine
Monitoring production
Monitoring quality
Other Automations
High performance pneumatic guide arm with automatic, centralized pressure regulation and release assures top yarn quality.
The programmable delayed drafting in the system accomplishes the end breaks to very minimum during starting of the spinning (Spg) frame.
Besides, Individual Spindle Monitoring, Three-Level Operator Guiding System, Auto Doffing system, SERVOtrail, Ringdata are used in ring frame.
Automation in rotor spinning:
The demand on quality and productivity in processing a wide variety of raw materials in rotor Spg has long driven the development toward automation of m/c processes.
The sequence of innovations on BT903 are modern to match the yarn quality of automated m/cs.
AMISPIN
QTOP
IQCLEAN
Automatic Piecing Devices, Automatic Suction Devices, Foreign Fiber Detection System are used in rotor spinning.
Automation in cone winding: Modern cone winding machines are designed to produce consistent quality of yarn at higher productivity levels. Cones with perfect winding-off qualities and long knot free yarn length are required for producing good quality fabrics. The yarn must be free from imperfections like slubs, neps, thick and thin places, and knots. The cone should be wound with uniform tension and homogeneous in density.
Fig: Autoconer machine
The machines are essentially equipped with a precision control system, which is electronically operated to achieve required quality with higher speeds. The features are auto tense yarn tension control, upper yarn sensor, direct drive with ATT, vacuum controlled suction facility with AVC system, informatory with touch screen and integration of clearer operation, caddy system, sensor control, and monitoring of the material flow.
Advantages of Automation in Yarn Manufacturing:
Very reliable system.
Controlled by servomotor and servo drive.
Setting alteration by key pad data entry.
No special skill needed for setting
This system is still little expensive to implement
Assembly time reduces enhancing manufacturing capacities.
Setting done at the press of a button.
No special skill needed for setting
Combines the advantages of the servo drive system and at the same time is cost effective.
All rollers driven by individual motors, controlled by individual drives.
Possible to alter draft and twist from the key pad. Fine tuning of twist and draft adjustments possible.
Possible to manufacture fashion yarn like multi twist, multi count, slub yarn.
Interfacing and drive communication through Profibus and other types of protocols makes controls simple and very accurate.
Automatic doffer system is now gaining customer acceptance.
Reduced manpower requirement.
Increase machine productivity.
Reduce need for supervision.
Increase life of components and accessories like spindle and bobbins.
References:
Automation in Textile Machinery: Instrumentation and Control System Design Principles By L. Ashok Kumar, M Senthil kumar
Automation in Garment Manufacturing by by Rajkishore Nayak Rajiv Padhye
Process Management in Spinning by R. Senthil Kumar
Garment Manufacturing Technology by Rajkishore Nayak Rajiv Padhye
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
