Sawhney, A.P.S., Singh, K.V.*, Condon, B. and Pang, S.S.** Southern Regional Research Center, Agricultural Research Service, USDA, New Orleans, LA * Mechanical and Manufacturing Engineering Department, Miami University, Oxford, OH ** Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA SIZE-FREE WEAVING OF COTTON FABRICS ON A MODERN HIGH-SPEED WEAVING MACHINE: AN UPDATED PROGRESS REPORT Beltwide Cotton Conferences New Orleans, Louisiana, USA January 9-12, 2007

Outline Motivation of this research Research Approach Materials and Methods Summary of results and discussions Concluding remarks Future research plans Acknowledgements

Textile Processes Weaving is by far the largest market for the value-added utilization of cotton (~75% market share, worldwide) Motivation of this research Raw Cotton (Combed) Spinning Finishing (Carded) Spinning Weaving Warping and Sizing Can we eliminate the costly process of warp sizing and the subsequent fabric desizing?

Motivation of this research CHALLENGE: ABRASION OF YARN DURING WEAVING

Research Approach Production of a yarn structure that has most of the most desirable attributes * for size-less weaving (* viz., low hairiness, high abrasion resistance, and excellent uniformity and consistency of other characteristics) Development of a method to set (stabilize) twist torque/liveliness of the yarn and prepare a loom beam for weaving without the traditional sizing. Modification of critical loom components, mainly the reed, to minimize abrasion of warp yarn in weaving. Manipulation of weaving parameters and conditions, including fabric construction, weaving speed, and machinery settings, to study their effects on the weaving performance and fabric quality.

Materials and Methods HVI Strength: gf/tex Elongation 11.7% UHML 1.193” Uniformity Ratio 84.3% Short Fiber Index 6.78 Micronaire Rd 80.11; +b 8.89 Leaf content 1.4 Area: 0.44 Cut 9; Grade 11-2 Maturity Ratio % Fineness mtex. Cotton (Acala)

Materials and Methods The selected cotton was opened and cleaned (using Whitin hopper-feeder, Superior inclined cleaner, and Fiber Controls Corporation Vertical Fine Opener). Chute fed to a Crosrol Mark 4 single card; carded at about 60 lb per hour. The card sliver was drawn once with auto-leveling on a Hollingsworth 990SL DF. The drawn sliver was converted into laps with a modified Whitin Super Lapper. YARN PRODUCTION

Materials and Methods The laps were combed using a Hollingsworth comber running at 200 nips per minute and removing 12% noils. The combed sliver was drawn once with autolevelling, using the same drawframe. A 30 tex (Ne 20/1) yarn was spun on a Schlafhorst Autocoro with the rotor speed of 110,000 rpm and twist multiplier of 140 ( TM 4.51 E); Corolab was set to remove major yarn imperfections. YARN PRODUCTION

Materials and Methods YARN PREPARATION: BEAMING START OF BEAMING Split zone 57 Yards Split zone Size Box ~ 20 m 57 Yards Split zone Size Box ~ 20 m First (Zero) Treatment: No application of any heat &/or fluid. 2.The yarn was sitting on the cylinders, while the latter were being heated from room temperature to F. 3.Second Treatment: cylinders at F. 4.The yarn was sitting on the cylinders at F, while the water for yarn washing was being boiled in the (size) box.

Materials and Methods END OF BEAMING Split zone Size Box ~ 20 m 57 Yards Split zone Size Box ~ 20 m Approx. 57 Yards Third Treatment: The yarn was washed in boiling water and dried on heated cylinders at F. 6.The yarn was sitting on the heated cylinders, while a typical PVA size mix/formulation (as a control) was being prepared. 7.Fourth Treatment: The warp was slashed with the traditional size. YARN PREPARATION: BEAMING

Materials and Methods Machinery: A modern high-speed, flexible-rapier weaving machine, with maximum speed of 500 picks per minute (ppm), was used. Fabric Construction: ½ -Twill with face down; ~61 ends/inch (epi); and 20 – 50+ picks/inch (ppi). Evaluation of Weaving Performance: Was done by the number of machine stoppages due to a yarn breakage and/or failure and by the fabric quality (appearance, defects, hand, and other properties) WEAVING

Summary of results and discussions The 20/1 Ne (30-tex) rotor-spun yarn had excellent metrics. Single-Strand Mean Breaking Strength: 500 cN Count-Strength Product: 128 kN/tex Uster Unevenness CV Index: 12.8% (with very low numbers of imperfections). The yarn performed very well with no major failure during warping and beaming. YARN PROPERTIES

Summary of results and discussions Very Good!! For the first time ever, ~ 100 yards of 100%- cotton twill fabrics of light construction were produced under mill-like conditions without sizing and, more importantly, with no warp yarn failure or breakage. The maximum weaving speed for a particular fabric construction (ppi) was 500 ppm and the maximum pick density attained at a certain loom speed was 50 ppi. MECHANICAL WEAVING PERFORMANCE

Summary of results and discussions Unsatisfactory (mainly due to presence of tiny, fuzzy-ball-like defects on either face of the fabric) FABRIC QUALITY Fabric Defects: Ball formation Progressive abrasion of yarn during weaving

Summary of results and discussions A preliminary inspection of the size-free woven fabrics (greige) indicates that the pick density of 40 ppi and the corresponding weaving speed of 400 ppm may be the optimum weaving conditions for obtaining a “reasonable” fabric quality with a few defects that probably can be tolerated only in certain fabric styles. FABRIC QUALITY

Summary of results and discussions MECHANICAL PROPERTIES of SIZE-FREE WOVEN FABRICS Fabric Sample*Tensile (Breaking) Strength*** (MPa) Tear Strength*** (MPa) 500 ppm/30 ppi 500 ppm/40 ppi 500 ppm/50 ppi ***The tests were conducted in accordance with the ASTM D5035 standard for “Breaking Force and Elongation of Textile Fabric” and ASTM D2261 standard for “Tearing strength of Fabrics by the Tongue (Single Rip) Procedure”. *The fabric samples were corresponding to the fifth treatment (The yarn was washed in the boiling water and dried on the cylinders at 220 F.

Summary of results and discussions The weaving speed does not seem to be as critical as the pick density and/or the weave type. (For example, the 50 ppi density at 400 ppm presented a rather difficult condition by way of producing a much higher frequency/number of fabric defects, compared to the pick density of 30 ppi at 400 and even 500 ppm). Plain weave, as expected, was very difficult even at 40 ppi and 400 ppm. The weave produced a fabric of totally unacceptable quality with numerous fuzzy-ball formations.

Summary of results and discussions The presence of fabric defects generally was random, but it appeared that the frequency of defects was particularly greater on one side of the fabric width. However, occasionally, a couple of yards of fabric showed no defects at all. This indicated a possibility of eliminating these defects with further research on the yarn structure and quality and the weaving conditions. The ceramic-coated loom reed appeared to have generated fewer fabric defects, compared to the conventional reed.

Conclusions Size-less weaving on a modern high-speed weaving machinery is feasible at least for some fabric types, where minor fabric defects may not be critical. The yarn quality must be superior and more consistent than that of a run-of-the-mill yarn. Ordinary heat setting of warp yarn may be adequate to set the yarn’s twist torque and enable size-free weaving. Further research on improvements of yarn structure and weaving parameters is essential to minimize yarn abrasion in weaving, which is critical to expand the scope and fundamental understanding of size-less weaving.

Acknowledgements The authors greatly appreciate the ARS National Program Staff and the ARS- MSA and SRRC managements for providing the necessary resources to conduct this vital research They also acknowledge the input and cooperation of the National Cotton Council of America and Cotton Incorporated for providing the industrial prospects, research materials, and overall guidance As always, the significant input and cooperation of our technicians, especially Jim Sandberg and Jerome Jeanpierre, are also recognized.