ring spinning vs all technologies part 1

Comparative Study of Productive Potential of Ring Spinning and New Yarn

Manufacturing Technologies

Project Coordinator:

Sir Hafeez ur Rehman Sheikh

By:

Syed Sohaib Hussnain Kazmi (Textile Institute of Pakistan)

2010

Thesis Report

Objectives:The main or primary objective of this thesis report is to understand the working principals of the machines on the production floor ,the productive potential of those machinery, the flaws in the working which interfere during the production and results in loss of production, Quality, Efficiency, and material loss and in short results in the increase of yarn manufacturing cost. These faults can be of different types, It could be a manufacturing fault, or it could be because of poor handling of the material, or it could be because of the Quality of material processed, because if we are dealing with material of not a very good quality then it will no doubt effect the production, quality, efficiency of the machine.

There are different types of yarn manufacturing technologies available i.e.

o Ring Spinning

o Compact Spinning

o Rotor Spinning

o Air jet Spinning

o Vortex Spinning

o Misc

Above mentioned are the technologies that are mostly used for the manufacturing of yarn. Each of the above mentioned techniques for yarn production compromises of different working principal and work on whole different idea of yarn manufacturing. They differ in yarn quality, production speed, efficiency, and material processing method.

Production Speed/Quality:

When talking about the capacity of a machine to manufacture a good, production speed is a very important factor along with the Quality prospective. Because it is permissible to obtain a very high production speed but neglecting the Quality factor. The above mentioned technologies differ with each other very much in production speed and quality of yarn produced by these machines. e.g.

o Rotor spinning is 7 times faster than Ring Spinning

o Compact spinning is also faster than Ring spinning

o Air jet spinning is 3 times faster than Rotor spinning it means Air jet is 10 times faster

than Ring Spinning.o Similarly Vortex spinning is a technology that is the fastest technology available in the

market.o Rotor Spinning shows produced less hairy in yarn than Ring spinning

Textile Institute of Pakistan

o Compact Spinning by eliminating spinning triangle produced finer, high quality and less

hairy yarn.o Air jet produced very fine yarn with less hairiness than Ring Spinning.

But besides of so much advantages achievable with the technologies other than Ring Spinning still RING SPINNING is considered to be the most reliable technology when dealing with different types of fibers for different end uses.

o Rotor spinning is used only for manufacturing of coarser yarns because of low torque

generation for the twist insertion, therefore its usage has restricted only to coarser yarns.

o Air jet Spinning is no doubt very fast yarn manufacturing technology but still a

limitation of this machine is that it cannot be used for the production of coarser yarns. So, its usage has restricted only to finer yarns.

o Vortex spinning is a technology, which has been implemented successfully only by

Murata Tech and its usage has restricted mostly to fashion purposes.

But Ring Spinning vs. All Technologies:

o Production of high strength yarns.

o Spinning of fine count yarns.

o Proper for special yarns.

o It is universally applicable (any material can be spun).

o The know how for operation of machine is well established accessible to everyone.

o It is flexible as regards quantities (blend and lot size).

o Since the speeds in drawing section are best controlled, yarn evenness is excellent. But if short fibers are too much, yarn unevenness occurs.

o Fine yarns can be produced as compared to open-end system

But Also Disadvantages:

o Process stages are more numerous. Roving stage exists as an extra process compared to the other systems.

o Yarn breakages are more numerous as a result of ring traveler friction and yarn air friction. Interruptions, broken ends and piecing up problems exist because of the yarn breakages.

o The high speed of the traveler damages the fibers.

o The capacity of the cops is limited.


o Energy cost is very high.

o Low production rate.

Industrial Revolution

After the Industrial revolution (1764-1784) Mule Spinning gained attention throughout the world. Continuous efforts were being made to refine this system of spinning. Later, Ring Spinning was introduced after some modifications in Mule Spinning System. The basic technology of the Ring Spinning remained unchanged.

In spite of significant developments and refinements of the system, following the commercial acceptance of the Open-end spinning, many new spinning systems were developed, some of which have gained popularity.

Open-end spinning machine, specifically manufactured for short staple fibers, was considered a good rival because of much higher production and better evenness of the yarn. However, further development of this system showed that the best performance of the OE system is limited to the coarse categories of yarn.

On the other hand, Ring Spinning Systems have been refined during the last 30 years, the ultimate objectives of spinning dialectologists are focused on higher production speed, combined with adequate quality. The quest for higher yarn quality has become in line with the much more exacting requirements and the performance criteria of the knitter, weaver etc.

Structure of a Model of Yarn Formation

Qualitative assessment of model yarn can be deduced by the mechanical behavior of fibers when bundled into yarn. A textile fiber is mechanical body of extreme length and flexibility; even the cellulosic fibers with a breaking elongation lower than 10%.

The formation of yarn should fulfill following conditions:

* The fibers must overlap in staggered way so that they join as assembly.

* The fibers must stick together so that tensional force is transmitted from fiber to fiber and this way distributed within the bundle.

* The number of individual fibers in the section must be sufficient so that discontinuity in force distribution due to the fiber ends does not significantly weaken the yarn.

The figure shows self-locking arrangements of the fibers within a yarn, as the tension is imposed on the yarn and the sticking force of fibers at the periphery increases.

The self locking effect depends upon the surface properties of fibers, providing the sticking and path of the fibers within the body of yarn, to facilitate compressing force at least part of the fibers must wrap around the yarn.

A simple way to achieve this to introduce an even twist with constant pitch throughout the yarn (as in Ring frame). The same effect can be produced by a core sheath arrangement with the large section with low twist in the center, compressed by wrapper fibers to the periphery (in case of


open-end yarn). It is also possible to produce this with a mixture of fibers that are twisted in opposite direction It is called false twist spinning process i.e. Air jet Spinning.

Consider the Process of Yarn Formation

Ring spinning is a three-step process of drafting, twisting and winding. As the roving strand passes through the draft zone of the spinning frame, from the back rolls to the front roll, the roving strand is drafted into fiber stand that has the linear density of the yarn. The yarn emerging from the front roller nip is in the shape of a flat ribbon, that is twisted, forms a triangle generally expressed as 'spinning triangle'. The traveler , ring and spindle are responsible for twisting and formation of yarn.

Yarn structure which was examined microscopically revealed that all the fibers do not contribute in the formation of yarn (i.e. not bounded fully in the yarn structure) particularly longer fibers, causing hairiness, also the short fibers which are not part of the body contribute to the 'fly lint' waste.

Limitations in Present Systems of Spinning

The limitations during formation of yarn in order to get appropriate quality product at desired speed of production lead the technologist and researcher to develop the new spinning techniques and modify the present systems of spinning.

When we look at ring spinning the major limitation is metal to metal rubbing contact between ring and traveler , which restricts the spindle speed. Secondly, the necessity of bobbin rotation for twist insertion restricts the output rate. Another important limitation of the ring spinning frame is the formation of spinning triangle by the ribbon of drafted fibers emerging from the nip of the front drafting rollers as shown in the above figure. Also it is further reported that fibers, being twisted into the yarn due to formation of spinning triangle, are under unequal initial tension that may cause a break in yarn either individually or in small groups and not simultaneously.

The open-end rotor spinning system overcomes the limitations of the ring spinning system in respect of output rate. However, the open-end rotor spinning systems also subject to limitations e.g. the disorientation of the fibers, deposited in the rotor groove, the twist loss due to rotation of the free end results in development of low spinning tension which require the minimum number of fibers at the yarn formation point. This drawback limits the spinning limit in open-end rotor spinning to coarser yarn counts as compared to that in ring spinning.

New Spinning Systems

In 70's many spinning system were introduced which lead to latest technique in the formation of yarn. As a matter of fact the productive capacity of system was about 10/ 11 times higher than that of conventional machines, the quality of the product has also improved and a wide range for further developments exist.


Arrangement of fibers in the cross-section of an Open-end yarn structure shows an irregular picture irrespective that there are not much loose fibers; also wrapper fibers are twisted in wrap direction. However, these odd arrangements of fibers do not show an adverse impact on the eventless of yarn.

In the Air Vortex Spinning the fiber arrangements are much improved defining more close spinning and real twisted yarn Murata Vortex Spinner is an improved shape of Murata Air-jet spinning machine and is claimed that it is capable of spinning 100% carded cotton at high speeds. MVS frame imparts real twist in the fibers. as opposed to the 'false twist' principle, used by Murata's jet spinning. Instead of using a pair of opposing air blasts from air nozzles to impart structural integrity to the yarn mass against as previously used by MJS, a unique guide called a spindle, a needle holder and a single air nozzle is used. The MVS utilizes a four-line roller/apron drafting system similar to that used in MJS technology.

One more intriguing feature of the MVS machine is that relatively high percentage of short fibers less than 12.5mm in length is removed in the spinning zone thus a small scale of combing is achieved at this stage converting the resultant yarn into a more valuable-added product.

Compact Spinning is the modified version of ring spinning in which the process of twisting is improved by minimizing or eliminating the spinning triangle. After the draft zone the ribbon is condensed into a strand before twist insertion. Airflow is used to condense the fiber ribbon. The compacted fiber strand is twisted into yarn with little or no spinning triangle, resulting in essentially ideal yarn formation conditions.

Summary Ring Spinning System, compared to rotor and air-jet spinning, is capable of giving much stronger yarn and a fabric of much better hand but rotor and air-jet spinning because of faster way of spinning have gained increasing importance. Still rigorous research and efforts are being made and spinders are hoping to produce new systems that deliver improved quality at higher speeds.

Recently textile manufacturer has developed new technologies for the spinning of short-staple yarns of higher quality at higher speeds.

Besides, to make higher-quality products at lower cost textile technologist are putting more emphasis on value-added products and product differentiation.

Two major spinning technologies have been introduced in the recent years: Murata vortex spinning and Compact Spinning. The characteristics of the yarns spun on these two systems are much improved but still area could be broadened towards yarn compatibility to value added fabric formation.

Newly evolved systems i.e. compact yarn spinning system unlike open-end spinning is not diverted form of ring spinning system. These systems are based on ring spinning machine; improvement is made by introducing condensing zone, fitted immediately after the delivery nip of the conventional drafting unit, eliminate the spinning triangle and its adverse effects on yarn characteristics.


Development in Spinning

During the 1970s, there appeared to be a myriad of spinning systems, such as twist less spinning, self-twist spinning, fascinated yarns, composite yarns, wrap-spun yarns, pot spinning, continuously felted yarns; and the many possible variants in open-end spinning such as rotor, electrostatic, friction spinning, and vortex spinning (the original “Polish” system). At the same time, there were continued developments in ring spinning, with ventures into rotating ring and traveler systems, individual spindle drives, high draft systems, modified travelers, double roving spinning and hybrid system.

A look at today’s industry reveals that while some systems have established a successful but small niche wrap spinning for fancy yarns, and friction spinning for specialty industrial markets very few systems have survived. Indeed, this is also true of the manufacturers of these machines. Figure 1 represents the current offerings in spinning machines and their comparative spinning speeds.

Table 1 summarizes the number of spinning positions for the major technologies, together with

their share of the spun yarn market. It is evident that, when judged from the perspective of the

number of installed spindles, ring spinning is still the most dominant spinning system there are

about three times more spindles than installed rotors. If judgment is based on the quantity of yarn

produced, it is clear that even though there are only one-third as many positions of rotors

installed, rotor spinning produces three times more yarn than ring spinning.

Ring Spinning


The technology behind ring spinning has remained largely unchanged for many years, but there

have been significant refinements. Changes, which on their own offered only slight advantages,

provided the following synergies when combined. The introduction of longer frames reduced the

relative costs of automatic doffing. The combination of spinning frame and winding (link

winders) further enhanced the adoption of automation. The introduction of automatic doffing

meant that doffing time was reduced and thus package (and ring) size was less critical.

The introduction of splicing on the winder meant that yarn joins became less obtrusive again

offering the potential of smaller package. Smaller rings meant that for a limiting traveler velocity

(40 meters per second [m/s]), higher rotational speeds (and hence twisting rates) could be

achieved. These combinations meant that the potential maximum speed of ring spinning was

raised from about 15,000 to 25,000 revolutions per minute. There also have been several other

proposed developments that have met with mixed success.

Drafting systems

While double apron drafting dominates, the system can be tweaked to enable higher drafts.

Recent exhibitions have featured machines operating at potential drafts of 70 to 100. The use of

high drafts has significant impact on the economics of the total system.

Individual spindle drives

Several manufacturers demonstrated this possibility in the 1980s. While the concept offered

advantages with respect to lower energy requirements, less noise and better control of speed, it

suffered higher initial costs and bigger spindle gauge.

Ring Design

Several approaches to reducing the limitations of traditional rings and travelers have been

proposed.

Orbit ring

This development from Rieter was aimed at increasing heat dissipation from the traveler.

Ceramic rings (Ceratwine system)


The combination of a ceramic ring and ceramic-coated traveler offered the promise of

significantly better wear resistance, which translates into long traveler life. More consistent yarn

quality and shorter break-in time are other claimed benefits.

Rotating rings

This idea was tried by several ring frame manufacturers in the 1970s. Other ventures into this

area included systems such as Cerifil, Magnetic Spinning and Super Traveler Spinning. The

problem with these types of devices is, while they appear to operate at lower spinning tensions,

and thus potentially offer lower end breakage rates, they suffer the drawbacks of short duration

and high-magnitude tension peaks because of the inertia of the twisting element, which is

significantly higher than a traveler.

Spindle identification (Schlafhorst, Barco)

The tracking of spindles from the ring frame has great potential for process quality control. This

enables the identification of those spindles on the ring frame that are responsible for producing

defective yarns, as assessed on the winding frame. It is believed this type of system will result in

improvements not only in yarn quality, but also in efficiency, by more readily indicating faulty

positions on the spinning frame.

Longer machines

Improvements in the drives used on spinning frames have enabled the number of spindles per

machine to be further increased up to 1,488 (Zinser). This has a positive impact on the cost per

spindle. Additionally, as indicated above, longer machines favor the use of automation,

particularly link-winding.

Compact spinning

Systems that use additional drafting components and pneumatics to create yarns that are less

hairy and stronger are available from several machinery makers. The many claims made for

these systems are usually mutually exclusive in that one can either have a stronger yarn or spin at

higher production speeds with lower twist. Moreover, there is a significant increase in the cost of

these machines, and the yarn thereby produced, when compared to traditional spinning frames.

While the use of compact spinning machines is claimed to have made significant inroads in


Europe, the system has not been well-received in the United States. It is evident that several

other machinery makers will venture into this market, such as Marzoli and Cognetex, and this

added competition may result in reduced machinery costs.

Rotor Spinning

Rotor or open-end spinning is now a mature technology, and since the 1960s, it has seen a five-

fold increase in twisting speeds. During the early stages of development, debates concerned such

questions as Were self-pumping or evacuated systems better? Was roller drafting feed superior to

a beater opener? Was spin through better than feed and withdrawal from the same face of the

rotor? Were twin disc bearings the best solution for higher speeds? These issues were seemingly

resolved, and most modern rotor machines are very similar in layout with relatively subtle

differences between machines from the major manufacturers.

These differences are typically associated with the aerodynamics of the transfer tube, rotor

design and navel design. While it is still possible to obtain low-tech rotor spinning frames,

present state-of-the-art machines have significant integrated automation such as doffing, piecing,

cleaning and process/product monitoring. Additionally, the machine can be part of a material

handling system from sliver through to packaged yarn.

It is generally accepted that, while rotor yarns are different from ring-spun yarns, they tend to

offer advantages in processing through weaving and knitting. This difference is a result of

structural differences introduced during yarn formation. This structure which is responsible for

the lower strength of rotor yarns, but improved hairiness and yarn abrasion is an inherent feature


of the system. While it is possible to control the formation of wrapper fibers by optimizing rotor

and navel designs,

it is impossible to eliminate them. Unfortunately, while smaller rotors are required for higher

processing speeds, this also negatively impacts wrapper fibers, and thus higher speeds often

carry the penalty of a reduction in yarn quality. Developments in rotor spinning include the use

of longer machines. Additionally, there is interest in potentially using rotor technology to

produce core yarns and using additional components to create effect yarns.

Murata Vortex Spinning

Murata Vortex Spinning (MVS) is best judged as a development of jet spinning specifically

created to overcome the limitations of fiber type. The major marketing feature of MVS was that

it was capable of spinning uncombed cotton slivers into acceptable yarns at speeds that were

significantly higher than with any other system. The yarn structure is different from jet-spun yarn

with many more wrapper fibers, and in parts the vortex yarn resembles a two-fold yarn. There

were concerns that there is excessive fiber loss using this spinning machine. But, even though the

fiber loss may be about 8 percent, most of this is short fiber, which would not contribute to yarn

quality.

MVS was introduced with a remarkable potential processing speed of 350 to 400 m/min.

Successful spinning systems historically have had a significant increase in production speed

within a few years of introduction. If this trend were to be true of MVS, it is possible that the

industry could have a staple spinning frame capable of speeds in excess of 500 m/min.

Even though it is claimed that MVS is capable of processing 100-percent cotton, it is believed

that the major use of this system is in the processing of cotton-rich blends with polyester. The

machine utilizes a roller drafting system working at high drafts and high speeds. There is proof

that indicates these systems may give rise to unacceptable yarn variations, which become

apparent in terms of fabric defects or weak spots in the yarn. This is a problem that could be

addressed by using the rotor spinning beater opener.

New developments likely for MVS include modifications to enable the production of coarser

counts and a possible re-examination of the concept of spin assembly winding, where yarns from

two spinning positions are combined onto one package that is subsequently two-for-one twisted.

It is also evident, from a cursory review of patents, that other machinery makers have invested in


significant research into technology similar to vortex spinning and perhaps there soon may be

alternative machines available.

It is clear that at the present time, there is a lull in investment in new spinning machinery in the

United States. This could be explained partly by a downturn in the industry, which seems to be

supported by the reduction in positions shown in Table 1, and partly by the fact that the current

technologies are mature.

An additional factor in this consideration is that as spinning machines become more productive,

the number of machines needed to satisfy a particular market will decline. It is quite evident

from the data shown in Table 2, that among all the major spinning technologies used in the

United States, there has been a very substantial increase in productivity over the past 10 years.

The table does not include the impact of changing from jet spinning to vortex spinning, which

would show an even greater increase in productivity for this type of yarn

RING FRAME

The ring spinning will continue to be the most widely used form of spinning machine in the near

future, because it exhibits significant advantages in comparison with the new spinning processes.

Following are the advantages of ring spinning frame

o It is universally applicable, i.e. any material can be spun to any required count


http://textile-technology.blogspot.com/2007/11/ring-frame.html

o It delivers a material with optimum characteristics, especially with regard to

structure and strength.

o it is simple and easy to master

o the know-how is well established and accessible for everyone

o Functions of ring frame

o to draft the roving until the required fineness is achieved

o to impart strength to the fiber by inserting twist

o to wind up the twisted strand (yarn) in a form suitable for storage, transportation

and further processing.

DRAFTING

Drafting arrangement is the most important part of the machine. It influences mainly evenness

and strength. The following points are therefore very important

o drafting type

o design of drafting system

o drafting settings

o selection of drafting elements like cots, apron, traveler etc

o choice of appropriate draft

o service and maintenance

. The following draft limits have been established for practical operation:

o carded cotton- up to 35

o carded blends - up to 40

o combed cotton and blends(medium counts) - up to 40

o combed cotton and blends(fine counts) - up to 45

o synthetic fibers - up to 50

o The break draft must be adapted to the total draft in each case since the main draft should

not exceed 25 to 30. It should be noted that higher the break draft, more critical is the

break draft setting


o Three kinds of top roller weighting(loading) are presently in use

o spring loading

o pneumatic loading

o magnetic weighting

o With pneumatic loading system, the total pressure applied to all top rollers is obtained by

simple adjustment of the pressure in the hose using pressure reducing valve. Moreover

the rubber cots will not get deformed if the machine is stopped for a longer duration,

because the pressure on top rollers can be released to the minimum level.

RING and TRAVELLER COMBINATION

The following factors should be considered

o materials of the ring traveler

o surface characteristics

o the forms of both elements

o wear resistance

o smoothness of running

o running-in conditions

o fiber lubrication

o A good ring in operation should have the following features:

o best quality raw material

o good, but not too high, surface smoothness

o an even surface

o exact roundness

o good, even surface hardness, higher than that of the traveler


o should have been run in as per ring manufacturers requirement

o long operating life

o correct relationship between ring and bobbin tube diameters

o perfectly horizontal position

o it should be exactly centered relative to the spindle

o The position, form and structure of lubricating film depends on

o yarn fineness

o yarn structure

o fiber raw material

o traveler mass

o traveler speed

o height of traveler bow

o Modern ring and traveler combination with good fiber lubrication enable traveler

speeds up to 40m/sec.

o The spinning tension is proportional

o to the friction coefficient between ring and traveler

o to the traveler mass

o to the square of the traveler speed

o and inversely proportional

o to the ring diameter

o and the angle between the connecting line from the traveler-spindle axis to the

piece of yarn between the traveler and cop.

o The yarn strength is affected only little by the spinning tension. On the other hand

the elongation diminishes with increasing tension, for every tensile load of the


fibers lessens the residual elongation in the fibers and hence in the yarn. Increasing tension leads also to poorer Uster regularity and IPI values.

o If the spinning tension is more, the spinning triangle becomes smaller . As the spinning

triangle gets smaller, there is less hairiness.

SHAPE OF THE TRAVELLER:

The traveler must be shaped to match exactly with the ring in the contact zone, so that a single

contact surface, with the maximum surface area is created between ring and traveler. The bow of

the traveler should be as flat as possible, in order to keep the centre of gravity low and thereby

improve smoothness of running. However the flat bow must still leave adequate space for

passage of the yarn. If the yarn clearance opening is too small, rubbing of the yarn on the ring

leads to roughening of the yarn, a high level of fiber loss as fly, deterioration of yarn quality and

formation of melt spots in spinning of synthetic fiber yarns.

WIRE PROFILE OF THE TRAVELLER:

Wire profile influences both the behavior of the traveler and certain yarn characteristics, they are

o contact surface of the ring

o smooth running

o thermal transfer

o yarn clearance opening

o roughening effect

o hairiness

MATERIAL OF THE TRAVELLER

The traveler should

o generate as little heat as possible

o quickly distribute the generated heat from the area where it develops over the

whole volume of the traveler


o transfer this heat rapidly to the ring and the air

o be elastic, so that the traveler will not break as it is pushed on to the ring

o exhibit high wear resistance

o be less hard than the ring, because the traveler must wear out in use in preference

to the ring.

SPINNING GEOMETRY

From Roving bobbin to cop, the fiber strand passes through drafting arrangement, thread guide,

balloon control rings and traveler. These parts are arranged at various angles and distances

relative to each other. The distances and angles together are referred to as the spinning geometry,

has a significant influence on the spinning operation and the resulting yarn. They are

o yarn tension

o number of end breaks

o yarn irregularity

o binding-in of the fibers

o yarn hairiness

o generation of fly etc.

Spinning Triangle

Twist in a yarn is generated at the traveler and travel against the direction of yarn movement to

the front roller. Twist must run back as close as possible to the nip of the rollers, but it never

penetrates completely to the nip because, after leaving the rollers, the fibers first have to be

diverted inwards and wrapped around each other. There is always a triangular bundle of fibers

without twist at the exit of the rollers, this is called as SPINNING TRIANGLE. Most of the end

breaks originate at this point. The length of the spinning triangle depends upon the spinning

geometry and upon the twist level in the yarn.


o The top roller is always shifted 3 to 6 mm forward compared to bottom roller. This is

called top roller overhang. This gives smoother running and smaller spinning triangle.

The overhang must not be made too large, as the distance from the opening of the aprons

to the roller nip line becomes too long resulting in poorer fiber control and increased yarn

irregularity.

o Continuous variation of the operating conditions arises during winding of a cop. The

result is that the tensile force exerted on yarn must be much higher during winding on the

bare tube than during winding on the full cop, because of the difference in the angle of

attack of the yarn on the traveler. When the ring rail is at the upper end of its stroke, in

spinning onto the tube, the yarn tension is substantially higher than when the ring rail is

at its lowermost position. This can be observed easily in the balloon on any ring spinning

machine.

o The tube and ring diameters must have a minimum ratio, between approx. 1:2 and 1:2.2,

in order to ensure that the yarn tension oscillations do not become too great.

o Yarn tension in the balloon is the tension which finally penetrates almost to the spinning

triangle and which is responsible for the greater part of the thread breaks. It is reduced to

a very small degree by the deviation of the yarn at the thread guide. An equilibrium of

forces must be obtained between the yarn tension and balloon tension.

COMPACT SPINNING :

In traditional ring spinning, fibers in the selvedge of strand emerging from front roller nip do not get fully integrated into the yarn because of the restriction to twist flow by the spinning triangle. These fibers show up partly as protruding hairs or as wild fibers. The spinning triangle is because of higher width of the strand as compared to final yarn diameter. Further the fibers are tensioned to varying extent depending upon their position in the spinning triangle. As a result full realization of fiber strength is not achieved in the yarn. The hairiness gives a rough feel to the


yarn. Variation in hairiness is a source of weft bars and warp way streaks in the fabric. Long

protruding hairs from the yarn contribute to multiple breaks in weaving and fabric faults like stitches and floats.

The length of the spinning triangle depends upon the spinning geometry and upon the twist level in the yarn. If the spinning triangle is too short, then the fibers on the edge must be strongly deflected to bind them in. This is not possible with all fibers, and lost as fly. Thus with shorter triangle, smaller weak point resulting into fewer end breaks but makes the yarn hairy. On the other hand, a long spinning triangle implies a long weak point and hence more end breaks giving smoother yarn and less fly.

In Compact Spinning, incorporating a condensing zone after main drafting zone, thereby overcoming the drawbacks of conventional spinning, eliminates spinning triangle. This will be clear from a comparison of mode of yarn formation in the two systems as shown in figure.


The condensing zone has a revolving perforated apron with suction underneath. The fibers

collected on the perforated track of the apron and get condensed. A low-tension draft is kept in the condensing zone to assist in the condensation.

Compact Spinning systems are offered by: REITER [COMFOURSPIN] SUESSEN [ ELITE SPINNING SYSTEM ] LAKSHMI [ RoCos COMPACT SPINNING SYSTEM ] ITV-ZINSER [ CompACT3 ]

REITER

In Reiter Comfor spin, a perforated drum replaces front bottom roller of drafting system. A second top roller also presses on the drum. There is a suction system-generating vacuum under the drum. Condensing of strand takes place between the two top rollers under the perforated drum non-rotating insert inside the drum with specially shaped slots helps in achieving condensation.

SUESSEN


In the Elite system of Suessen, condensing zone consists of profile tube with a perforated lattice apron running over it. A delivery top roller pressed on the apron drives the apron. A suction system under the profile tube causes condensation of the strand.

ZINSER

.

In ITV-Zinser system, illustrated in figure, condensing zone consists of a revolving perforated apron. The size of perforations in the apron is varied as per the count of the yarn to get the desired condensation.


.

SALIENT FEATURES:

o Magnetic compacting is more user friendly & avoids o Air suction o Air pipes o Perforated drums or apron o Additional air conditioning requirements


ADVANTAGES OF COMPACT SPINNING TECHNOLOGY

o 15-20% reduction in hairiness of yarn, the o reduction being more pronounced in long length hairs o 10-15% improvement in yarn tenacity o Twist in yarn can be reduced by 10% while maintaining same yarn strength o Better evenness of diameter and hairiness. o Better abrasion resistance of yarn leading to fewer ends o Breaks in weaving. Loom shed droppings and linting in knitting are reduced. o Singeing can be omitted. o Lower twist can be employed in doubling. o Improved appearance and luster of fabric with a softer. o Reduced pilling and better dye uptake.

Progress to date:

Till now, in literature review the following technologies have been covered briefly

o Ring Spinning

o Compact Spinning

o Rotor Spinning/OE Spinning

The main focus was on the Production capacity along with the Quality Prospective and machine Efficiency. As discussed above it is permissible to obtain a very high production by neglecting Quality and machine efficiency. So, the process should such that it facilitates all the elements in the yarn production process either these are on the floor or after the order delivery.

Also couple of mills surveys have also been conducted to understand the process line of these technologies, surveys conducted are given below

o Sapphire Fibers Ltd unit 3 Sheikhupura

o Siara Textile Mills Sheikhpura

o Akram Textile Mills Lahore

o Gul Ahmed Textile mill unit 6 Landhi Karachi

System installed on the above mentioned industries compromised of RING SPINNING and COMPACT SPINNING. Sapphire Fibers and Gul Ahmed were operating with COMPACT SPINNING system. Whereas, Siara Textiles and Akram were operating with RING SPINNING system, talking more specifically Siara and Akram textiles were operating with Chinese made Ring Spinning frames.


System Installed:

Sapphire Fibers Ltd

o RX 240 SF-1008

Toyota made 2003-04

Gul Ahmed Textile Mills

o Sussen Compact on Sussen frame

o Zinser Compact on Zinser frame

o Sussen Compact on China BJM 168

o China Compact on China BJM 168

Future Plans:

At the moment Ring Spinning, Compact Spinning and Rotor Spinning have been discussed briefly. Production Speeds, Quality, and Efficiency and also advantages and disadvantages and limitations of these Spinning systems have been discussed briefly. Furthermore other yarn manufacturing technologies will be discussed along with Industrial surveys of the related technology. And also these all technologies will be discussed in details along with their related Industries surveys. First of all the technologies that could not been covered in this report will be discussed briefly just for the introduction. Then all the related technologies will be discussed individually chapter wise for the better understanding of these technologies. In the coming vocations of semester break surveys will be conducted in the Punjab region. These technologies will be discussed in a manner that it will cover the machine details, parts used and their functions and the importance of those parts, also the productive potential of these technologies will be calculated keeping in view the Quality prospective and machine efficiency. And this report will tells us what are the technologies that are dominating the Pakistan Textile sector and why Ring Spinning besides of so many of disadvantaged and limitations still is the dominating technology in the whole World. And also this project will be helpful in finding new ways to produce yarn other than Ring Spinning in Pakistan.


References:

1. www.compactspinning.in 2. www.textileworld.com 3. www.campuscorner.fiber2fashion.com 4. www.textile2technology.com


http://www.textile2technology.com/

http://www.campuscorner.fiber2fashion.com/

http://www.textileworld.com/

http://www.compactspinning.in/

ring spinning vs all technologies part 1

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