Innovations in Spun Yam Technologies-Present and Future

Indian Journalof Fibre & Textile Research Vol. 31, March 2006. pp. 1 16-124

Innovations in spun yam technologies-Present and future

W Oxenham" College of Textiles, North Carolina State University, Raleigh, NC 27695-R30 1, USA

Globalization has profound effects on the textile industry, including yarn production. These effects are not only evident in shifts in the geographical bases of production but also in the 'drivers' for manufacturing. This means that yarnproducers are expected not only to produce higher quality yarns on much shorter lead times, but must also be competitive on prices in order survive. A modernyarn producer must therefore be technologically aware. efficient, flexible. and cost conscious. The matojority of recent developments in yarn production have been refinements of existing techniques plus improvements in process and product quality. While there are potentially many techniques that .could be used to produce yarns, many have met with limited commercial success. Automation is.an obvious way to reduce labor costs and improve quality; however, this often carries the penalty of reduced flexibility. Competing on pricing is prerequisite to survival and the major component of yarn price in a modern spinning mill is the cost of the fiber. Thus,a any saving made in raw material directly impacts possible profits. This paper reports the above aspects and their possible interactions. Keywords: Compact spinning, Open-end spinning. Ring spinning, Spun yarn technologies. Twistless spinning, Wrap spinning IPC Code: Int. CI.8 DOIH, D02G3/00

Background and Spinning Demographics It is also interesting to note that there has been a 1 During the 60s and 70s there was a tremendous significant shift in the manufacturing base which is amount of research on 'new spinning technologies', primarily associated with manufacturing costs, as is This resulted in a few successful, commercially evident from Fig. 3 (ref. 3). Thus, while it is clear adopted systems and many more failures. Since that from Table I (ref. 4) that there have been shipments time, there has been a dramatic reduction in research to Europe, North America and Asia, these have activity in this area but there have been continued essentially been to three counties, namely Turkey, 2 refinements in existing technologies. Throughout this Mexico and China. It is, however, clai med that even time the developments in spinning machinery have in these countries of recent growth, there appears to been less prolific and this is no doubt associated with be slowing down in investment. the changing markets for machinery. Additionally, there is a much lower market share occupied by long 2 Possible Spinning Technologies staple spinning and thus machine makers have focused There have been many potential innovations In on the dominant (representing over 90% of installed spinning which have met with limited success for spindles) short staple spinning machines. An additional ______25 ...... consideration with respect to the developments in � otton Wool spinning equipment is the fact that while the _ _ _ ' "'"' -'Synthetic Staple production of cotton has increased and the production Synthetic Filam nt � I Cellulosic Staple (and consumption) of wool has remained fairly _ _ Cellulosic Filament� _ constant (Fig. I), the natural fibers share of the fiber --.--+.-�-.. --.-- market has continued to diminish (Fig. 2).1 A further factor for the reduced research and development in staple spinning technology is that there has been a downturn in sales of spinning machines (about a 30% reduction between 2002 and 2003)2 which obviously impacts possible research budgets.

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2002 .. E-mail: [email protected] Fig. I-World fiber production OXENHAM: INNOV ATIONS IN SPUN YARN TECHNOLOGIES 117

various reasons but, in general, the primary limitation 3.1 Wrap (Hollow Spindle) Spinning has been associated with an inability to match the While this system was capable of producing 'high quality of yams and ultimate fabrics produced by ring quality' yarns at relatively high speeds, it was not spinning. Figure 4 illustrates the various spinning widely accepted for 'normal' yam processing. Yarns systems available and their potential processing speeds; strength and uniformity were as good, if not better, as the shading represents their present and potential conventional yarns and the fabric abrasion and pilling 5 acceptance as a commercial technique. Solid shading is were superior. Problematic was the presence of used for those systems which have met with significant wrapping filament which could impact handle (in success, horizontal shading for those systems with particular stiffness) and potentially limit the wider small niche areas but no likely major acceptance, and acceptance of this type of yarn. It has found use in the remainder is for systems which have found some some coarse yam applications (such as upholstery usage or may have potential. Within each technique, yarns), fancy yarn production and technical yarns. All there may be variants and specific components which of these are, however, best considered as small differentiate the various machinery makers and may markets which are susceptible to variable demand make a technology more applicable to a certain fiber induced by fashion changes. type. 3.2 Twistless Spinning While this system was heavily studied for use on Spinning Technologies of Limited Success 3 cellulosic fibers, the promise of softer fabrics with Briefly, this group of possible spinning technologies good abrasion and pilling properties was never includes:

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Jet • I

Friction I

Self Twist I I I I I I I Rotor • I

Centrifugal ""'-'-'-Ii

Ring • -··· · ..IIP" ;;;;:;....--/ }. ---J../ --- . -" " '-, _'_'/ ...... - f .-.-�.- ..... o 50 100 150 200 250 300 350 400 Spe ed (m/min) Fig. 4-Potential spinning systems 118 INDIAN J. FIBRE TEXT. RES., MARCH 2006

6 commercially realized. The major problem was 4 Ring Spinning and its Variants finding temporary adhesive which could easily be There is absolutely no doubt that ring spinning is applied and removed, produced acceptable bonding, the most successful spinning system for all types of and was inexpensive, The use of soluble binders in staple fiber and there are presently in excess of 170 wrap spinning offered an alternative route to twistless million spindles installed, with about 10% of these fo r fabrics, However, while experimental trials showed long staple fibers. While the yarns and subsequent that fabric aesthetics were outstanding and fabrics produced by this system may not excel in all performance attributes were reasonable, the high cost respect (for example it is possible to produce stronger of soluble binders precluded wide acceptance of this or more uniform yarns), they represent an ideal blend technique.5 of attributes which make them outstanding for many apparel and technical applications. The major 3,3 Felted Yarns drawbacks of the system are: Low production speeds, The technology of continuous yarn felting arose • Limited package size, out of a need to find an alternative to the batch • Need to utilize rovings, and process of felting skeins (or hanks) of carpet yarns, • which was being adopted as an approach for Yarn hairiness, necessitating additional • improving the appearance retention of certain carpet twisting (folding). ? styles. Several techniques were available and it The technology behind ring spinning has remained became apparent that the continuous felting process largely unchanged for many years but there have could in fact be a 'spinning system' when fed with obviously been significant refinements, taking a suitable slubbings (ropings), rovings or slivers. While system that was considered to be old and ready for potential uses were explored for these novel yarns, it replacement in the 60s, through to a 'high tech' was clear that their market was primarily for carpets machine which occupies a dominant position in the and then only for specific styles, which unfortunately industry, that no one can foresee being usurped. These were subject to fashion cycles. More recently, the changes consisted of several improvements, which on introduction of the Fehrer Yarn Puncher offered an their own offered only slight advantages. Fortunately, alternative approach to consolidate yarns, which is these developments combined synergistically and 8 purely mechanical and thus can be applied to fibers thus, other than wool. the introduction of longer frames reduced the • relative costs of automatic doffing, 3.4 Self Twist Spinning the combination of spinning frame and winding Self-twist spinning was developed for the • (link winders) further enhanced the adoption of processing of wool fibers for knitting (ST) and automation, weaving (SIT) yarns. While it met with some initial the introduction of automatic doffing meant success, particularly in processing polyester wool • that doffing time was reduced and thus package blends, and research was carried out into the (and ring) size was less critical, possibilities of this systein for short staple fibers, the the introduction of splicing on the winder main commercial usage was for high bulk acrylic • knitting yarns. The problems with the system were meant that yarn joins became les<; obtrusive - primarily associated with unwanted patterning again offering the potential of smaller package, smaller rings meant that for a limiting traveler produced by the cyclic change in the twist There has • been a re-emergence in interest in this system with the . velocity (40m/s) higher rotational speeds (and recent introduction of the Macart Spinning System hence twisting rates) could be achieved, and in-line setting of twist and automatic transport S300 which essentially is a modified Repco system • but processes sliver through to fully relaxed yarn in of packages to twisting frame significantly one integrated machine.s There has also been interest reduce labor and could improve the economics in the use of alternative twisting units with particular of the total system. attention given to air twisters since it may be possible These combinations meant that the potential to randomize twist and twisting cycles and thus maximum speed of ring spinning could be enable more acceptable fabrics to be produced.9•10 significantly raised. OXENHAM: INNOVATIONS IN SPUN YARN TECHNOLOGIES 119

In addition to the above improvements, there have and traveler. The ring thus guides the yarnonto been several other proposed developments which the package and creates drag to provide have met with mixed success. Specific examples of winding tension. The super traveler system these proposals are described below. replaces the traveler with an annular guide, 4;1 Drafting Systems which slides in a track around the package. Visually, the system resembles traditional cap While double apron drafting dominates, it has been " demonstrated that the system can be tweaked to spinning or the more recent Cerifil. The enable higher drafts and the recent exhibitions have problem with these types of devices is that featured short staple machines operating at potential while they appear to operate at lower spinning drafts of 70-1 00. High drafts have been shown to be tensions, and thus potentially offer lower end possible for long staple processing using multizone breakage rates, they suffer a major drawback. drafting systems, and while these developments This is that they usually create very short primarily focused on unconventional systems, it duration (high frequency) and high magnitude seems reasonable to assume that they could be tension peaks, because of the inertia of the twisting element (which is significantly higher adapted to ring spinning. The use of high drafts had 12 significant impact on the economics of the total than a traveler). system and the current debate is whether to feed light 4.4 Spindle ID weight slivers (like Suessen RingCan) or heavy The tracking of spindles from the ring frame has weight roving (being promoted by Zinser). great potential for process quality control and systems

4.2 Individual Spindle Drives are available from several manufacturers. 13 This Several manufacturers demonstrated this possibility enables the identification of those spindles on the ring in the 80s and more recently a system has been frame that are responsible for producing defective exhibited by Howa (DDS system). While the concept yarns (as assessed on the winding frame). It is offered advantage with respect to lower energy believed that the use of this type of system will result requirements, less noise and better control of speed, it in improvements not only in yarn quality but also in suffered the major disadvantage of higher initial costs efficiency by more readily indicating faulty positions and bigger spindle gauge. on the spinning frame.

4.3 Ring Design 4.5 Longer Machines Several approaches for reducing the limitation Improvements in the drives used on spinning imposed by traditional rings and travelers have been frames have enabled the number of spindles per proposed and these include: machine to be further increased up to 1488 (Zinser). This has a positive impact on the cost per spindle. Orbit rings-A development from Rieter that • Additionally, as indicated above, the longer machines was aimed at increasing the dissipation of heat favor the use of automation, particularly link-winding. from the traveler. Ceramic rings (Ceratwine system)-The 4.6 Compact Spinning • combination of a ceramic ring and ceramic­ Systems, that use additional drafting components coated traveler offers the promise of and pneumatics to create yarns that are less hairy and significantly better wear resistance, which stronger, are available from several machinery makers translates into long traveler life. Additional (Fig. 5). The many claims made for these systems are claimed benefits are more consistent yarn usually mutually exclusive (i.e. you can either have a quality and shorter break in time. stronger yam or spin at higher production speeds with Rotating rings -This idea was tried by several lower twist), and there is a significant increase in the • ring frame manufacturers in the 70s and cost of these machines and the yarn thereby produced recently exhibited again by Howa. Other when compared to traditional spinning frames. Much ventures into this area included systems, such of the advantages made for the system center around as Cerifil, magnetic spinning system, and super the lower hairiness of compact yarns, which are traveler spinning system. The 'magnetic claimed to improve subsequent processing costS.14.16 spinning system' utilizes a magnetically While the initial development was centered on supported ring to replace the conventional ring cotton processing and the long staple systems were 120 INDIAN J. FIBRE TEXT. RES .. MARCH 2006

Fig. 5-Compacl yarn (Sussen) simply adaptations, there are several newer systems which are specifically designed for worsted processing. These include units from Gaudino, Zinser and Cognetex (Fig.6).'7 While it could be argued that this added competition may result in reduced Fig. 6---COM4WOOL machinery costs and potentially benefit spinners, this is unlikely since with the present downturn in spinning machinery sales, the development costs must be amortized over fewer machines. The entry of these newer players into the compact spinning arena is intriguing since it is assumed that a market has been identified, despite the difficulties encountered by other machinery makers. While the system is being promoted because of its lower hairiness and improved physical characteristics, this comes at the penalty of increased initial investment (up to 100% over the cost of a traditional machine), and increased maintenance which ultimately result in higher yarn prices (typically +20%) (ref. 18). It is intriguing that the recent developments are aimed at narrowing the width of the drafted strand so that a more compact (less hairy) structure is created. This was of course available many years ago when Ambler Superdraft spinning was (unsuccessfully ?) introduced. This system Fig. 7-Sirospun utilized a modified drafting system incorporating a flume which condensed the fibers entering the front drafted strands and some of this twist is 'locked' into roller of the drafting zone and the net effect was very the structure when the strands converge (Fig. 7). This similar to the current claims for compact spinning.'9 yields a yarn with lower hairiness and has been utilized commercially since 1980s, and despite 4.7 Sirospun and Variants drawbacks (such as twist liveliness, higher two-fold Sirospun was an earlier attempt for creating a knots and knot slippage) it is claimed to have been 20 weavable worsted yarn directly from the spinning well adopted in China. machine. The system is a double roving spinning A recent 'development' in this technology is the system with a specific, optimum, separation of the recently introduced EliTwist (Fig. 8) which roving so that the twist travels up the individual essentially combines the technologies of double OXENHAM: INNOVATIONS IN SPUN YARN TECHNOLOGIES 121

Fig. 9-Solospun

Table I-Cumulative shipments (1994 -2003) Rin s indle Fig. 8-EliTwist two ply yarn Region g � Short Long O-E roving spinning with compact spinning. The claims staple staple rotors made for the system are that it affords significant Africa 53 1,268 105,202 40,834 advantages in yarn properties when compared to siro­ North America 1,639,472 150, 108 489, 114 spun and conventional two-fold yarns?' South America 801 ,704 77,164 195,849 Asia 28,05 1,757 1,710,098 1,136,157 4.8 Solospun Euro�e 5,056,386 1,045,804 753,874 It is interesting to note that while most machinery makers are promoting the concept of reducing the are that the rotor diameter should be greater than the width of the fiber strand emerging from the drafting fiber length; there is a minimum number of fibers system in order to produce more compact and less (typically about 100) required in the yarn section for hairy yarn, solospun adopts exactly the opposite stable spinning. The system is sensitive to impurities philosophy. By taking the sirospun yarn formation and trash. A further problem is that the aesthetics of process to extremes, the issuing drafted strand is open-end yarn are not as good as ring-spun yarn and it divided into many discrete strands, into which twist is often classified as having a harsh handle. can run by an additional clip-on separator roll (Fig. 9). Modifications to various machinery components have This is claimed to yield yarns with higher tenacity, resulted in improvements in handle but there is still lower hairiness and better fabric abrasion than somewhat a stigma attached to the yarn. An additional . problem is that open-end yarns and subsequent fabrics SIfo. spun.20. 22 Th e system IS reI' atlve I y to apply to existing spinning frames and should represent a lower tend to be slightly weaker than their ring-spun cost alternative to some other offerings. The system counterparts and this can be critical if fabrics are to has found some applications in woolen and worsted undergo severe finishing treatment. An example of processing and there is active research to explore the this is the use of 'stone-washing' of denim where it is possible use of this system for cotton fibers. found preferable to use ring-spun yarns since the higher initial strength of the fabric yields a final fabric Open-end Spinning 5 which is still acceptable after treatment. It is clear from Table 1 that open-end spinning is The trends in machinery design are towards longer now a mature technology with wide acceptance for automated machines with up to 320 positions and to certain types of yarns and markets. It is also apparent use smaller rotors running at high speeds (28mm that open-end yarn processes really well through diameter @ ISO,OOOrpm). These are however aimed weaving and knitting with fiber shedding and yarn at finer yarn counts and one of the challenges of rotor breaks significantly less than ring-spun yarn. The spinning is to fully utilize the machines potential immediate problems identified with this technology across a wide range of counts and fiber types. Indeed 122 INDIAN J. FIBRE TEXT. RES., MARCH 2006

there have been attempts to utilize other fibers such as wool on this system23 but these are only likely to meet with limited success because of radically different aesthetics produced by the coarser fibers.

6 Fasciated Yarns Jet Sp innillg and Vortex Sp illning-The concept of fasciated yarns was first proposed by DuPont but only becall1e a commercial success for short staple fibers with the introduction of Murata Jet Spinning. Much research was carried out and the major advantages of this system were best realized while processing fi ne to medium count short staple polyester and polyester­ rich blends.24 The reasons for this are well understood25 and attempts to process different types of fiber proved unsuccessful. An adaptation of the Fig. 10-Coll1plex yarn structure; ulltwisting yarnsclearly show system utilizing two pairs of jets to create two-strand two parts structure yarns2Cl, which were subsequently twisted together, yarn, and can provide a useful prediction of met with very limited success, typically in the subsequent performance. Similarly, the latest processing of mid-staple polyester blends. The more regularity testers not only provide information on recent introduction of MVS (Murata Vortex Spinning) defects and with appropriate software the likely was intended to overcome some of the limitations of origins of the defects, but can additionally be linked jet spinning and enable the satisfactory processing of to software and hardware which can give renditions of fibers other than polyester at much higher speeds. The likely fabric appearance. major difference between jet- and vortex-spun yarns Improvements in the level of sophistication of low is in the greater number of wrapper fibers present in cost optical sensing devices has enabled greater the latter, which in parts has the appearance that is 17 27 applications of on-line sensing and while this can be quite similar to a two-fold yarn (Fig. 10). . While used to detect, and if necessary respond to, major there are still refi nements needed for this system changes in yarn thickness, perhaps the most particularly with respect to fiber preparation, significant application of these devices is for the minimization of fiber loss and yarn processing, there detection of foreign fibers. Several manufacturers is great potential for this system because it was now offer systems which can be incorporated into introduced commercially with a speed of 400mlmin winding machines or, in some circumstances, and history has shown that successful machine tends spinning machines. In the former case, when coupled to double in running speed during the first eight years to spindle ID systems (see above), this provides a following its introduction. The addi tional major useful approach to potentially sourcing major defects. benefit of this system is that it produces yarns with There have al so been many improvements in the inherently low hairiness and this would be' beneficial tools available to spinning technologists and to the processing of fibers which usually result in researchers and these largely center on sophisticated fabrics that are prone to pilling. image processing systems. These enable much more rapid and dependable analysis of changes in Additional Technology processmg parameters on yarn structure and 7 There has been a significant increase in on-line and properties. These are immensely useful while off-line measunng, monitoring and testing studying the mechanics of structures, or indeed equipments which can be utilized for quality proposing changes in existing or new technologies to monitoring, troubleshootin g or research purposes. effect improvements in particular properties. Of note There is no doubt that yarn evaluation equipment has is the recent availability of commercial DVI (Digital become more sophisticated and the use of apparatus Volumetric Imaging) equipment which is being used such as Uster Tensojet28 enables very rapid evaluation to study fibrous structure from the automatic of the tensile characteristics of large quantities of computer restructuring of data generated from OXENHAM: INNOV AnONS IN SPUN YARN TECHNOLOGIES 123

several technologies. There is no doubt, however, that any new system must offer significant benefits over existing technologies and the goal of 'ring-spun yarn properties' at very high production speeds is still the ultimate (but perhaps unrealistic?) goal of machinery makers and their potential customers. A further aspect which must be considered is that while it may be more economic to spin very large lot sizes in semi-automated high speed spinning plants, this is only true if the yarn meets the demands of the customer (i.e. there is a ready market for the yarn!). ]n the US and Europe, there is a lot of interest in the development of niche markets, as a way of opting out of competing in the commodity market, which can be better served by less well developed countries. The Fig.I I-DVI image problem this raises is that niche markets usually are transient and require rapid response (and change) and multiple sections taken of the product. Figure II typically involve smaller lot sizes. Thus, the shows an image of a yarn generated from this traditional philosophy of 'make it fast and make it technique (obtained from images of a series of cross cheap' becomes problematic since niche market sections) plus a single fiber 'electronically extracted' products would not typically be fo und in this t·rom t h e yarn. 29 environment. There is thus a need for smaller efficient manufacturing machines capable of meeting the needs Future Developments 8 of this new climate. The idea of utilizing a centrifugal chamber to twist and collect the yarn is not new and indeed the References Topham Box was a feature of early Rayon filament I Juvet J L, Looking back to the future. Internatirmal Textile spinning lines. Other incursions into this type of Malluj(lcturers Federatioll Annual COI!lerence Report. spinning included the Greenbank Axispinner, which Lucerne. Switzerland. 26-28 September 2004. was designed for producing two-fold worsted yarns. 2 Australian Wool IlIIlOvation. 2004. http://www.woo\'­ com.aulLi vePage.aspx ?pageId= 1218. Recently, there has been renewed interest in this 3 ITMF Imernatiollal Production Cost Comparisons (ITMF. technology and such a system. was shown as a Zurich, Switzerland), 2003. prototype at ITMA '99 by the Russian Company 4 ITMF Intenwtional Textile MachinelY Shipments (lTMF, Techmaschexport. The advantage of such a system is Zurich, Switzerland), 2003. S Oxenham W. Mahgoub A & Leaf G A V, Th e properties of that it would produce yarnof the same quality as ring­ 0 yal1ls alld fa brics produced using the hal/ow spindle (wrap spun yarn but potentially at much higher speeds. spinning) technique, paper presented at the METLAN-Sth There have been several patents awarded to other International Wool Conference, Gdynia, Poland. 22-27 May companies and no doubt that the major machinery 1991. 6 East G C. Oxenham W & Scatchard T J, Th e twistless ,Ipinlling makers have carried out studies on this technology. f of wool and its efect on knitted fa bric properties, paper However, despite the potential advantages of such presented at the Sixth International Wool Textile Research systems, which mainly center on the ability to Conference, Pretoria, South Africa, 26 August-3 September produce a yarn with ring-spun quality at much higher 1980 . speeds, it is unlikely that a commercial machine will 7 Kankesan S, Collfinllous yam fe lting. Ph D thesis. University be launched in the immediate future. of Leeds, 1984. 8 Oxenham W, Spinning-Innovative developments in the There are rumors of other systems being spinning sector, Text World, January (2004) 32-39. reinvestigated, including both friction spinning and http://www.textileworld.comiNews.hun?lD=6482. electrostatic spinning but these systems have inherent 9 Mahmoudi M R & Lawrence C A, The lise of aIr Jet problems that would make the production of yarn technology to produce self-twist yam, J Text Inst. 94 (3/4) with acceptable quality at high speeds a non-starter. (2003) 141. 10 Meadwell E, All exploration of fa llcy yam creation. M S Additionally, it is not unrealistic to predict that some thesis, N C State University, USA, 2004. hybrid system may emerge, which will combine II Sutradhar N C. A study of rill[?-Jpilllling with particular INDIAN FIBRE TEXT. RES., MARCH 2006 124 1.

refe rence to rotating rings, Text Inst, Ph 0 thesis, University of Leeds, spinning J 60 (1969) 558. 1986. 20 Xing M & Chong wen Y, Spinning methods coming up, Text 12 Huang X C, Oxen ham W & Grosberg P, A comparison of the Asia, January (2003) 33. Cerifil system and ring spinning with particular reference to 21 Brunk N, Spinnovation (Suessen), Spindelfabrik Suessen, No. elld-breaks, paper presented at the Eighth International Wool 20, 2004, 10. Relationship between the Textile Research Conference. Christchurch, New Zealand, 7- 22 Fuh P H, Cheng L D & Yu X y, 14 February 1990. hairiness and twisting principles of soiospull and ring spun 13 Oxenham W, ITMA review -Staple spinning, Text Prog, 30 yams. paper presented at the Annual Conference of the (1/2) (2000) 1-12. Textile Institute, Shanghai, China, 23-27 May 2003. 14 Am P, Betz D & Joas W, COlllpact spinning - chance fo r 23 Krohe U & Schmidt R, Sp inning pure virgin wool on Alllocoro wool processillg - with /lew yam structure to inllovative rotor spinning lIIachilles - an opportunity fo r the classic products, paper presented at the Tenth International Wool woollen yam spinning mil/, paper presented at the Tenth Textile Research Conference. Aachen, Germany, Y A-5, 26 International Wool Textile Research Conference, Aachen. November-I December 2000. Germany. YA-8, 26 November-I December 2000. 15 Hountondji A, COlllpact spinning systelll EliTe® Fir worsted 24 Puttachaiyong S & Oxenham W, Properties of jet-spun poly­ rillg yams frolll wool and other lOllg staple ibresf paper cotton yarns,Text Asia, 23 (10) (1992) 52-55. presented at the Tenth International Wool Textile Research 25 Miao M, Oxenham W & Grosberg p, The insertion of twist Conference. Aachen, Germany, Y A-6, 26 November-I into yarnsby means of air-jets, J Text IlIst, 78 (3) (1987) 189- December 2000. 204. 16 Oxen ham W, Machine Italia: Spinning, Text World, June 26 Lamb P R & Junghani L, J Text IIISt, 82 (199 1). (2003)34-38. http://www.textileworld.comlNews.htm?CD- 27 Basal G, Oxen ham W, Vortex spun yarns air-jet spun yarn, V.I'. = I 875&ID=5204. AUTEX Res J. 3 (3) (2003) 96-101. http://www.autexrj. 17 Oxen ham W, Fasciated yarns- A revolutionary development. J org/No3-2003/0066.PDF. Text Apparel Te cl1ll01 Mallagelllellt, 1 (2) (200 I) 1-7. 28 Lee E.K, Bauer-Kurz I. & Oxen ham W . Yam tellsile le.wing. paper presented at the 10th EFS System Research Forum, http://www.tx.ncsu.edu:8190/j tatm/volume 1 issue2/articles/oxe nhamloxenham_full.pdf. Raleigh, North Carolina, 6-7 November 1997 . 18 Salholra K R, Ishitaque S M & Kumar A, Compact spinning­ 29 Basal G, Th e slrUClUre alld properlies of vortex alld cOlnpaC! A comprehensive survey Text Asia, November (2003) 34-41. .Ipun yams, Ph D Dissertation, N C State University, USA, 19 Taylor D S & Hayes R L, Reduction in tly during Ambler 2004.