an expert yarn engineering system

AN EXPERT YARN ENGINEERING SYSTEM

Dr. Nomusa DLODLO1,3

1National University of Science and Technology, Bulawayo, Zimbabwe

3Council for Scientific and Industrial Research, National Fibre, Textile and Clothing Centre,

Port Elizabeth, South Africa

Prof. Dr. Lawrance HUNTER2,3 2Nelson Mandela Metropolitan University

Port Elizabeth, South Africa 3Council for Scientific and Industrial Research,

National Fibre, Textile and Clothing Centre, Port Elizabeth, South Africa

Cyprian CELE3



Dr. Anton F. BOTHA3



Roger METELERKAMP3



ABSTRACTThis paper develops the concept and structure of an expert system for yarn engineering. It describes the process of yarn

engineering, in addition to the structure, components and functional features of a yarn engineering expert system. To reduce thecomplexity of the expert system it needs to be broken down into a number of sub-expert systems that enable the determination of fibrespecifications, yarn type, yarn specification, twist, draft sizing and yarn performance under various spinning systems. These sub-expertsystems interact and exchange information to produce a seemingly whole functionality.

Key Words: Expert system concept, Yarn engineering, Spinning

1. INTRODUCTION

Expert systems have been adopted toprovide substantial support in thetextile industry. These systems arecomputer models of human expertisein a specific domain of work. They arecapable of offering advice anddecision-support related to specificproblem-solving in a well-definedknowledge domain. An expert systemacts like an expert consultant, askingfor information, applying thisinformation to the rules it has learned,and drawing conclusions [3], [7].

The typical expert system receivesinputs describing a problem in its fieldof operation, and then uses itsinferencing technique to extractappropriate information from itsknowledge base to produce an answer,diagnosis or description of a solution.Such systems have been used tointerpret medical test results, diagnosecar problems and determine the causesof telephone line failures [3], [7].

This paper describes the concept andstructure of an expert system thatenables the process of engineering ayarn. The four areas where an expertsystem can provide support to thevarious experts involved in yarnengineering process are; (1) in yarndesign, where the expert system canrecommend choices of composition,structure, manufacturing parametersand manufacturing procedures for theintended yarn; (2) prediction of yarnproperties and performance; (3)interpretation of testing results wherethe performance of sample yarns canbe analysed and compared; and (4)modification of yarn design andprocessing parameters, where theexpert system can diagnose the mostlikely causes of any discrepanciesbetween the designed and the requiredyarn, and provide advice on how tomodify the design and manufacturingparameters. The architecture of theyarn engineering system takes theseinto consideration. The systemenvisaged would consist of a small

number of sub-expert systems toprovide guidelines for determining theyarn type, fibre specifications, yarn twist,etc, and enabling the yarn performancecharacteristics under various spinningmachines to be compared.

The remainder of this paper isstructured in the following manner:

Section 2 introduces a generaloverview of an expert system. Section 3looks at related work. Section 4describes the yarn engineeringprocess. Section 5 describes thecomponents of an expert systemsarchitecture for yarn engineering,looking at each of the sub-expertsystems separately. Section 6summarises the benefits of thisarchitecture.

2. COMPONENTS OF AN EXPERTSYSTEM

The components of an expert systeminclude the knowledge base, inferenceengine, knowledge acquisition

48 TEKST?L ve KONFEKS?YON 1/2008

component, and explanation system asillustrated in Figure 1.

Knowledge base. The permanentknowledge of an expert system isstored in a knowledge base. Itcontains the information that theexpert system uses to make decisions.This information presents expertisegained from top experts in the field.This knowledge comes in the form offacts and rules. Facts are minimalelements of the knowledge which mustbe identified before anything else. Forexample, “Hairiness is a characteristicof yarns” is a fact. Rules consist ofif….then statements, where a givenset of conditions will lead to aspecified set of results. If a condition istrue then an action takes place. Forexample, “if the yarn linear density is40 then the hairiness level for anUSTER specification of 95% is 9.5”[13]. A frame is another approach tocapture and store knowledge in aknowledge base. It relates an object tovarious facts or values. Expertsystems using frames to storeknowledge are also called frame-based expert systems. Semantic nets,neural networks and fuzzy logic areother methods of representingknowledge in the expert systemknowledge base.

Inferencing. The purpose of theinference engine is to seek informationand form relationships from theknowledge base and provide answers.It determines which rules will beapplied to a given question, and inwhat order, by using information in theknowledge base. The inference enginedrives the system by drawing aninference from relating user-suppliedfacts to a knowledge-base rule andthen proceeding to the next fact andrule combination [16].

Two types of inference methodstypically implemented in expertsystems are backward and forwardchaining. Backward chaining is anapproach that starts with the goal,

e.g., “What is the hairiness level of theyarn for a 5% USTER specification?”and works through a potential thesisuntil it reaches the fact that supportsthe thesis. A forward chaininginference engine is goal-oriented inthe sense that it tries to prove a goalor rule conclusion by confirming thetruth of all its premises. Thesepremises may themselves beconclusions of other rules. It is amethod that begins with a set ofknown fact or attributes values andapplies these values to rules that usethem in their premise.

Knowledge acquisition. Most expertsystems continue to evolve over time.New rules can be added to theknowledge base by using theknowledge acquisition subsystem.

Explanation subsystem. Anotherunique feature of an expert system isits ability to explain its advice orrecommendations and even to justifywhy a certain action wasrecommended. The explanation andjustification are done in a sub-systemknown as the explanation subsystem. Itenables the subsystem to examine itsown reasoning and also explain itsoperations. The ability to traceresponsibility for conclusions to theirsources is crucial both in the transfer ofexpertise and in problem solving.

3. RELATED WORK

This section discusses literature that isrelated to yarn engineering. [2]identifies four critical aspects of yarnengineering, namely yarn type, fibretype, yarn structure and the contributionof yarn structure to fabric performancecharacteristics from a broad perspective.The idea of post spinning yarn hasalso been discussed in [11]. [5 and 6]also studied the possibilities and limitsof yarn engineering for ring yarns andopen-end rotor yarns based on thesimulation of knitted fabrics and fromthe point of view of the innovativechanges for the engineering ofblended yarns. Neural networks havebeen applied in the prediction of theyarn characteristics in the false-twistprocess [14]. A computer-basedmathematical simulation model of theinteraction of yarn count, fibrefineness, fibre tenacity, fibre frictionand fibre length for engineering air-jetspun yarns was also studied in [15].

4. THE YARN ENGINEERINGPROCESS

The end use of the yarn determinesthe type of fibre and the fibrecharacteristics required and thestandard yarn performancecharacteristics, such as the twistfactor, and spinning system. The yarnperformance characteristics are in turndetermined by the spinning machinethat is used. Figure 1 shows the flowof processes in yarn engineering.

From an analysis of the end use of theproduct the engineer comes up withthe specifications of the fibre/yarn. Thefibre/yarn specification looks at thelinear density (tex) of the yarn, theblend of fibres used, the twist,hairiness, evenness and tensilestrength of the yarn, etc. Thespecification of the yarn identified isthen matched to an USTERspecification. For example, to producea yarn that falls within the 5% range ofan USTER specification means that


Knowledge base

Knowledge acquisition component

User interface

Inference engine

Explanation facility

Knowledge engineer

User

Figure 1. General structure of an expert system

only 5% of the world yarn manufacturerhave been able to produce a yarn of asimilar quality. The USTERspecification determines the fibreblend type and yarn type required fromthe selected fibres. The yarn typewhich can be ring-spun, rotor-spun,

staple, filament, single, plied, twistedor non-twisted or a combination ofsome, as required by the manufactureris identified [13].

In the case of the worsted system,from the combination of the fibre andyarn type used the linear of the top

and draft that is required for spinningare determined. When calculating thesize of the top to be processed into ayarn waste is compensated for. Forexample, if a spinning system suffersa loss of 5% of its fibres duringprocessing then this has to becompensated for within the draft or inthe linear density of the input sliver orroving.

The twist factor is normally defined bythe user or end use. If the yarn is to bebulky and/or soft it means the twistfactor is to be reduced. Generally theyarn twist related is inverselyproportional to the square root of theyarn or linear density.

Different types of spinning machinesproduce yarns of different structuralqualities. For example, for minimumhairiness, an open-end spun yarn willbe preferable to a ring spun yarn.Nevertheless, different spinning systemscannot always handle all the diversity offibres available. For example, rotorspinning machines are predominantlyused for short staple fibres such ascotton, but are rarely used for long-staple fibres, such as wool.

5. ARCHITECTURE OF THE YARNENGINEERING EXPERT SYSTEM

The architecture of the yarnengineering system is shown in Figure2. It shows the various sub expertsystems that make up the whole yarnengineering expert. This includes theyarn type advisor, the fibre selectionadvisor, the yarn twist advisor, yarnanalysis advisor, draft specificationadvisor and the spinning machineadvisor. Each of these adopts thestructure of an expert system asdescribed in section 2.

5.1 Fibre selection advisor

Fibre selection is based on therelationship between two sets of data,that is, the fibre/yarn to be usedversus the properties of the endproduct. For example, if summer

TEKST?L ve KONFEKS?YON 1/2008 50

Define twist factor

Select spinning machine

Capture end-use of product

End use / yarn or fibre properties

Select fibre to be used

Spinning machine / Yarn performance characteristics

Yarn characteristics

Define yarn type

Define top (draft) characteristics

Analysis of yarn specifications from end-user product

USTER specification

Yarn /fibre characteristics

Yarn type

Gauge yarn characteristics against USTER standard

Figure 2. System flow for yarn engineering

YARN TYPE ADVISOR

FIBRE SELECTION ADVISOR

YARN ENGINEERING

EXPERT SYSTEM

YARN TWIST FACTOR ADVISOR

SPINNING MACHINE ADVISOR

YARN ANALYSIS ADVISOR

DRAFT SPECIFICATION ADVISOR

Figure 2. Architecture of yarn engineering expert system

apparel is needed to retain coolness,be strong and have dimensionalstability, a blend of cotton andpolyester would suffice. Polyesterwould bring coolness and dimensionalstability, while cotton retains warmthand moisture. The required quality andprocesses of the yarn are also critical.For example, if a high quality fibreweaving yarn is required the fabricwould out of necessity have to be longand fine.

Fibres can be broadly classified intofour groups, namely, animal, vegetable,mineral and synthetic fibres. Examplesof animal fibres are wool, mohair, silkand angora hair. Vegetable fibresinclude cotton, linen, hemp, jute andsisal. Mineral fibres on the other handinclude asbestos, carbon, glassfilament and ceramic. Synthetic fibrescover nylon, polyester, acrylic andpolypropylene.

The end uses of fibres are varied.These can be classified as apparel,domestic, industrial and technical. Inapparel fibres are used in underwear(vests, underpants, etc), outwear(shirts, suits, socks, dresses,cardigans) and the like. Domestic enduses fibres include bedding, kitchentowels and cloths, drapes such ascurtaining and linings, floor coveringsuch as carpets and mats, andupholstery and cushions.

5.2 Yarn specifications advisor

This component determines the yarnspecifications given the end use of theproduct. The USTER standards defineyarn specifications. USTER statistics[13] represent a comprehensive surveyof the quality of textile materialsproduced in major textile regionsaround the world, and they constitutethe mainstay of global marketintelligence related to textile quality.USTER statistics are there for qualitybenchmarking. The statistics coversyarn quality for carded and combedfibres. The fibres can be fibre blends orpure fibres such as 100% cotton, 100%

polyester, 100% rayon, 65% polyester/35% cotton, 65% polyester/35% rayon,50% polyester/50% cotton, 100% wool,etc. The yarns can be ring spun, rotorspun, airjet spun, etc.

Table 1. USTER yarn specifications forhairiness in 100% combedcotton on ring spinning

95% 75% 50% 25%40 9.5 9 8 7.5 730 8.5 8 7.5 7 6.525 7.5 7 6.5 6 5.520 7.25 6.5 6 5.5 515 6.5 6 5.5 5 4.510 4.75 4.25 4 3.75 3.55 3.5 3.25 3 2.75 2.7

An example of the USTER standardvalues for yarn hairiness on 100%combed cotton on ring spinning is asshown in Table 1. The percentagesindicate the numbers of textilemanufacturers that produce yarns withthe particular characteristics, e.g., inthis case, the particular hairinesscharacteristics. The same approach isapplied for yarn neps, breakingtenacity, elongation, coefficient ofvariation, thin and thick places, and allrelated yarn characteristics.

5.3 Yarn type advisor

This component assists in theidentification of the yarn type duringyarn engineering. A yarn is aconstructed assembly of textile fibres

to produce a coherent entity or yarntype. A range of yarns can beproduced in terms of staple, filament,single, plied, twisted, and cabled asshown in Figure 2.

However, to be more general, yarnscan either be spun staple yarns orcontinuous filament yarns. Staplefibres are twisted together. Filamentyarns fibres are laid side by side andvirtually running straight the wholelength of the yarn. Yarns spun fromfilaments are generally smooth andshiny. This is because filaments arecontinuous strands of fibre that can bemany kilometres long. The only naturalfilament is silk. Shorter lengths arereferred to as staple. Staple lengthsvary in length from fibres which are acentimetre long such as rabbit fibres tofibres that are several centimetreslong as in merino wool. Longer staplewill spin into smooth lustrous yarn.Longer staple also lends strength andresilience to a yarn. Yarns made of ashort staple will tend to have a fuzzyappearance.

There is a vast range of staple fibreyarns. Ring spun yarns remain themost popular and are produced on thering and traveller system from a widerange of fibres of different types,fineness and length. Rotor spun yarnsare produced mainly from short staplefibres on rotor spinning machines.Twistless yarns are produced fromstaple fibres where the consolidationof fibres is by means of some form ofadhesive.

Wrap spun yarns consist of a parallel

bundle of staple fibres bound into acompact structure by another yarn,usually continuous filament. Core spunyarns are characterised by having acentral core wrapped with staplefibres. Self twist yarns are two ply


Yarn type

Staple

Filament

Single cabled Single Plied Plied cabled

Figure 2. Classification of yarn types

yarns produced in a single operation.During manufacture, each componentis twisted in alternating directions inshort segments. The two componentsare subsequently put together in sucha way that they twist together to formthe final yarn. Friction spun yarns areproduced on spinning systems whichuse two rotating rollers to collect andtwist individual fibres into a staple yarnstructure. Air-jet yarns are producedby air-jet (vortex) where fibres in theyarn are intermingled and wrappedaround.

In most cases, except for self-twist, forexample, the yarn is first spun into asingle yarn. These single yarns areoften “plied” together to form 2-ply, 3-ply and 4-ply yarns. Plying makes theyarns stronger, more uniform andmore abrasion resistant. Each ply is asingle yarn which is generally pliedtogether using a twist that is oppositeto the one that is used in the initialspinning of the yarns. That is, a pliedyarn having a Z-twist comprises singleyarns that were spun with an S twist.The linear density of the resulting yarndepends not only on the number ofplies in the yarn but also on the lineardensity of the single yarn. A yarn inwhich two or more folded (plied) yarnsare twisted together in one or moreoperations is called a cabled yarn.

Continuous filament yarns may beproduced in either monofilament ormultifilament form. Standard filamentyarns are known as “flat” filamentyarns in contrast to textured yarns.Textured filament yarns are man-madecontinuous filament yarns that havebeen modified by subsequentprocessing to introduce durablecrimps, coils, loops or other distortionsinto the filaments, so as to improve itsbulk and related properties.

In terms of wool, depending on thelength of the fibres and the way theyare handled before spinning we have“worsted” and “woollen” yarn. Worstedyarns are spun from longer combed

fibres, so resulting in yarn that issmooth and firm. Woollen yarns arespun from uncombed wool and arefuzzier and not as strong, muchshorter fibres being used for woollenspinning.

5.4 Draft specification advisor

Different end-uses require yarns ofdifferent thicknesses. The acceptedway to indicate the thickness of yarnor material from other stages ofprocessing is to state its linear density.The linear density can be expressedeither directly as mass/unit length, orindirectly as length/unit mass. Themain direct system in use is the Texsystem. Tex is the weight in grams of1000 metres. The coarser the yarn thehigher the linear density.

Drafting is the processing of fibresprior to spinning. By passing fibresbetween relatively slow rotating backrollers and a pair of front rollersrunning at a higher surface speed in aspinning machine, the fibres arecaused to slide over each other so thatthe fibre assembly becomes longerand thinner (i.e. fewer fibres in thecross-section) and fibre parallelisationis improved. The draft imposed isusually expressed as the ratio of theinput mass per unit length to theoutput mass per unit length. Draftingcan take place in two stages, viz. initialor break draft and final draft. Thereforeto produce a yarn of a specific lineardensity, the total draft, from the aboveratio is equal to the Initial Draftmultiplied by the Actual Draft.

In drafting and spinning, a factor ofgreat importance in determiningprocessing performance is the numberof fibres required in the yarn crosssection. In terms of fibre diameter theformula relating the number (n) offibres in the yarn cross-section to fibrediametre and other variables for fibresof reasonably circular cross-section is:

)1(4

000,122 vd

texn

Where,

n=number of fibres in the cross-section

tex = yarn count (linear density ofyarn)

d = average fibre diametre (microns)

v = coefficient of variation of fibrediametre expressed as a fraction

p = density of fibre

5.5 Yarn twist advisor

Yarn twist is the spiral disposition ofthe components of a yarn, which isusually the result of the relativerotation of the extremities of the yarn[10]. The twist lends strength to theyarn. A twist advisory componentrecommends a suitable range of yarntwist by taking into account the enduse requirements, yarn count (lineardensity of yarn) and tarn type.

A recommended range of yarn twist iscalculated using the equation

Mtex

T 1000

T is turns per metre

Tex is the single yarn linear density intex

M is the metric twisting factor as shownin Table 2

In filament yarns either Z or S twist isused. However, the twist direction ofthe majority of spun yarns is Z twistand the twist direction of their foldingor final twist is S twist. Twist can beclassified from several view points [9]:

Table 2. Yarn twist factor ranges

Yarn Twist Factor Ranges


Wool Blend TwistFactor(MetricCount)Ranges

Pure new wool – 2 fold yarn

for flannel (semi-melton)70-80

Pure new wool – normal 2

fold yarns80-85

Pure new wool – single

weft yarns65-70

55/45 polyester/wool

(normal polyester)100-110

55/45 polyester/wool (anti-

pilling)85-95

70/30 wool/regenerated

cellulosic fibres75-85

Twist direction. The twist can be“Z twist”, which runs upwards andto the right, formed by spinningthe yarn in a clockwise direction.“S twist” is formed by twisting theyarn counterclockwise, theresulting twist runs upwards andto the left. The twist in the yarn forS and Z runs in the samedirection as the diagonal used toform these letters.

The amount of twist, e.g., <300t.p.m. for a low twist, <1000 t.p.mfor an ordinary twist, and <3000 tp m for a hard twist (dependingupon the yarn linear density)

Single or ply twist. Twisted singleor multiple yarns into onedirection, i.e., S or Z twist….singletwisted, Twisted two or severalsingle twist yarns, first twist intothe opposite direction….ply twist

5.6 Spinning machine advisor

Yarn performance characteristics arelargely determined by the spinningmachine used. Once the fibre hasbeen selected according to theultimate output, the question is, “is theequipment to process these fibresavailable. Ring-, rotor-, air-jet-, friction-,composite-, self-twist, vortex-, andcentrifugal-spinning machines willeach produce a yarn of different

characteristics from the same set offibres. Ring spinning, for example willproduce more hairiness than open-endspinning. The yarn characteristicsinclude the linear density (yarn count),yarn twist, yarn breaking strength(tenacity), extension at break,irregularity (CV%), thick and thinplaces / 1000m, neps, hairiness andend breaks. Please note that open-end spinning variants include rotor,friction and vortex (air-jet) systems(Nissan, 1959) and [4].

Through the spinning machine advisorit is made possible to compare theresultant yarn characteristics from thevarious spinning machines. Thefollowing section looks at thecharacteristics of ring and open-endspinning to show how each would affectthe quality of the yarn.

Ring spinning. Spinning iscontinuous in its action and uses rollercombined with apron drafting entirely.The purpose of drafting is to reducethe sliver or roving to yarn proportions.The resulting attenuation by fibreslippage causes an improvement inthe alignment of the fibres which isnecessary for spinning. The simplestmethod of drafting is by passing thesliver through two successive pairs ofrollers, the second pair rotating at afaster speed than the first pair. Theratio of their peripheral speeds isknown as the draft.

The bottom rollers are eachmechanically driven. Each top roller ispressed down upon its lower roller,using either dead-weighted or springpressure, so that the fibre strand issandwiched between them at what iscalled the nip. In a system such asthis there is always a possibility ofroller slippage taking place, thus thispossibility is reduced by using flutedbottom rollers working in conjunctionwith top rollers covered with resilientmaterial such as synthetic rubber,cork, or leather on cloth, and byweighting these sufficiently to give and

adequate pressure at the roller nip. Tobetter control the fibres within thedrafting zone aprons, from leather orother material, are used betweenwhich the fibres are sandwiched andtransported or carried.

The roller setting, i.e. the distancebetween the nips of the 2 pairs ofrollers, is of importance – if too narrowa setting is used the long fibres will begripped by both pairs of rollers andmay be broken, whilst too wide asetting would afford very little controlto the fibres, particularly the shorterfibres. The actual setting used dependsupon the staple length of the fibresample, although other factors whichcan affect it are the draft applied, theinter-fibre friction and the extent of theroller nip, which itself depends uponthe diameters and degrees ofhardness of the rollers.

Twist is inserted into yarns to increaseinter-fibre friction to the extent ofpreventing slipping. Twisting isperformed by one of two methods –spindle or flyer. Spindle twisting isbasically only used on hand spinningwheels. In flyer twisting the flyer frame(which, in the processing sequence,precedes the spinning frame) formaking of rovings, twisting andwinding are performed at the sametime. Twist is inserted by the constantrotation of the flyer and winding isperformed by the rotation of thespindle relative to the flyer.

Ring spinning is an extreme exampleof flyer spinning, in which the flyer, inorder to enable it to be pulled round athigh speed by the yarn process, isreduced in size to the dimensions of asmall wire clip, viz. the traveller, givingbobbin-lead winding.

Open-end spinning. While in ringspinning a drafting action is applied tothe sliver or roving to create a yarn, inopen-end spinning the sliver isdismantled at a point and the fibresare transferred to a collecting point atwhich they are assembled in


sequence to form a yarn. As the fibresarrive at the point of break, they arewithdrawn at the rate necessary toform a yarn of the required count, thusfor example, a finer yarn would requirea faster rate of withdrawal. The yarn isthen wound onto a take-up package.Thus, unlike the conventional draftingsystem, there is a break in thecontinuity of the sliver and an openend of yarn appears. This open-endmust be rotated to impart thenecessary twist on the yarn formed.This is achieved by means of a rotorwhich rotates at a very high speed ofup to 180 000 r/min

Fibres in an open-end spinning yarnhave a more open structure and arenot as well orientated as in ring-spunyarns. However, open-end yarns aremore uniform than ring-spun yarnsmade of the same material; they alsocontain fewer thin places, thick placesand neps and are less hairy, but aremuch weaker and needs a highertwist.

The yarns produced by such a systemare defined having so-called fascinatedyarns, having outside binding fibreswrapped around a core of parallelfibres.

Because of the striking increase inspeeds of preparatory processes forspinning and consequently the actualspinning process became abottleneck, which impeded automatingbeyond the drawn sliver stage. Rotorspinning was one of the firstimprovements and then came air-jetspinning, especially in the short staplespinning side. The major differencebetween air-jet spinning and rotorspinning is that the former method is afalse twist process and does notinvolve open-end technology.

Air-jet spinning. Air-jet spinning usesa high-speed spinning frame, with nohigh-speed rotating mechanism, whichtwists and spins yarn by means ofcompressed-air jet [1]. This systemconsists of a stretch breaking unit to

break the filament supplied, an air-operated collecting aspirator, an air-jetfalse twister and a cheese type windingunit. The process involves draftingstrands of fibres which are forwardedby an aspirating jet to a torque jet,whereby the fibres are consolidatedinto a fascinated yarn assembly by fluidtwisting. The drafting fibres arepresented in a flat, ribbon-shapedbundle to the aspirating jet, andadvanced to the torque jet whichintroduces true twist or wrappings tothe surface by a phenomenon referredto as “twist transference”.

After drafting, the supplier sliveremerges from the front roller as auniform, ribbon-shaped fleece. Thedrafting fibre band is separated by afleece separator and, as a result, onepart becomes free fibres. These fibreshaving one end in the open-end stateare twisted around the remainingassembly of fibres. The twisted fibrestrand and the untwisted free fibres aresubsequently consolidated and afterthey pass through the nozzle, the freefibres wrap around the non-twistedcore. The Toray is composed of a 4 linedrafting system, a yarn-forming sectionthat includes a single air-jet nozzle anda fleece separator, and a windingsection that includes a delivery roller, aslub catcher and a cheese winder.Many man-made fibres, cotton andblends can be spun by this system,compared to the first one.

In air-jet spinning there are severalparameters that can affect the yarnproperties, such as air-pressure in thenozzles – influences tenacity, evenness,thin and thick places and neps. Draft-influences breaking load, elongationand hairiness. Delivery speed andtake-up ratio influences tenacity,evenness, hairiness, fibre extend, twistand thin and thick places and neps.The condenser width influences yarnstrength due to fibres wrapped aroundthe parallel core fibres

6. CONTRIBUTION ANDCONCLUSION

In the textile industry there is a need tomaintain adequate skills levels amongworkers. But the problem is a shortageof experts to impart such skills to thepopulace. Expert systems aretherefore an appropriate solution tosubstitute the expert. The advantagesof expert systems are:

They act as consultants once theknowledge of experts has beencaptured.

Since human experts are in shortsupply, expert systems providethe means to use knowledge in awide number of locations withoutactually having the human experton site.

They provide advice that is moreconsistent

They can be put to work in ahostile environment

In this paper an architecture of anexpert system for automating theprocess of yarn engineering has beenlooked at. The architecture is madeup of component expert systems tooffer advice on the selection of fibre,yarn type, yarn specification, draftsizing, yarn twist and spinningmachine. The advantage of thisarchitecture is that it reduces thecomplexity of the yarn engineeringprocess by breaking down theprocesses into modules of smaller,less complex expert systems. Each ofthese is autonomous and specialised,but they all interact to create a wholefunctionality.

The added advantage is that this is aninterdisciplinary architecture. It marriestextile technology and InformationTechnology (IT).



REFERENCES

1. Basu A., 1999, “Progress in Air-jet Spinning”, Textile Progress, Vol: 29(3).

2. Elmogahzy Y., 2006, “Yarn Engineering”, Indian Journal of Fibre and Textile Research, Vol: 31(1), pp.160-169.

3. Giarratano J., Riley G.D., 2004, “Expert Systems: Principles and Programming”, Course Technology, ISBN-13: 978-0-534-38447.

4. Goswami B.C., Martindale J.G. and Scardino F.L., 1977, “Textile Yarns: Technology, Structure and Applications”, John Wiley andSons Publishers, London.

5. Greig M., Wulfhorst B., 1999, “Yarn engineering based on the simulation of knitted fabrics – possibilities and limits for ring-yarns andopen-end-rotor-yarns”, Proceedings of the 1998 Beltwide Cotton Conference, Vol: 2, pp. 1628-1631, Sandiego.

6. Greig M., Wulfhorst B., 1999, “Yarn engineering based on the simulation of knitted fabrics – innovative chances for the engineering ofblended yarns”, Proceedings of the 1998 Beltwide Cotton Conference, Vol: 2, pp. 805-808, Sandiego.

7. Ignizio J.P., 1991, "Introduction to expert systems: the development and implementation of rule-based expert systems", McGraw-Hill,ISBN 0-07-909785-5.

8. Ishtiaque S.M., Salhotra K.R., Gowda R.V.M, 2003, “Friction Spinning”, Textile Progress, Vol: 33(2).

9. Ishida, T., 1977, Japanese Textile News (JTN), pp. 109-111.

10. Johnson N., 1981, “The Role of Twist in the Modern Yarn Technology”, Textile Journal, pp. 8-12.

11. Khan Z., Wang X., 2003, “Post-spinning Yarn Engineering”, Textile Magazine, Vol: 30(3), pp. 8-11.

12. Nissan A.H., 1959, Textile Engineering Progress, Butterworth Scientific Publishers, London.

13. USTER STATISTICS, 1997, Uster News Bulletin, Vol: 40, Zellweger Uster Publishers, CH-8610 Uster, Switzerland.

14. Veit D., Bauer-Kurz I., Wulfhorst B., Prediction of Yarn Characteristics in the False-twist Process with Neural Networks, ChemicalYENİ KİTAPLAR

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Cilt1: A-E1. Baskı; 551 Sahife; Ciltli; Çok sayıda Şekil ve Resimli31.03.08’e kadar indirimli fiyatı 100,00 €;01.04.08’den itibaren kitapçıda satış fiyatı 125,00 €ISBN 978-3-86641-128-9

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Bu yenilikçi eser, tekstil terbiyecileri ve terbiye makinesi imalatçılarının yanında; öğrenciler, eğitim-öğretim ve Ar-Geçalışanları; iplikçi, dokumacı ve örmeciler; kimyasal madde üretici ve satıcıları; tüketiciyi koruma organizasyonları veözellikle de konfeksiyoncular, tekstil ticaretiyle uğraşanlar ve küresel satın almacılar için tekstil ürünlerinin terbiyesihakkında vazgeçilmez bir başvuru kaynağı oluşturmaktadır. Bu insanlar için küreselleşen pazarda daha geniş bir bakışaçısına sahip olmak önemlidir.

Prof. Dr. Hans-Karl Rouette, Hochschule Niederrhein’in Tekstil ve Konfeksiyon Tekniği Bölümü’nde tekstil terbiyesi veekoloji dersleri vermektedir. Rouette, tekstil terbiyesi ve terbiye makineleri konularında uluslararası görev yapan yeminlihakem olup, tekstil terbiyesi, ekoloji ve tekstil tarihi hakkında çok sayıda kitabın yazarıdır.

an expert yarn engineering system

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