Gain L. Louis

Comparison of Properties of Cotton Yarns Produced by the DREF-3, Ring, and Open-End Spinning Methods

The DREF-3 spinning method produces a yarn by wrapping a fibrous core with a fibrous sheath at production speeds up to 200 meters per minute. The comparative merits of this high-production spinning method to spin all-cotton yarns are inves tigated and reported. Two sets of cotton differing mainly in fiber length, strength, and Micronaire reading are used in this experiment. Yarns produced by the DREF- 3 machine are compared with yams spun by conventional ring and open-end methods. The influence of fiber properties on yarns spun by the three methods are discussed in terms of yarn strength, elongation, uniformity, and appearance. The effect of exhaust air pressure on yarns spun by the DREF-3 is also discussed.

Blending Cottons Differing in Fiber Bundle Break Elongation Part I: Effect on the Properties of Combed Single Yarns

Two long staple cottons, differing in fiber bundle break elongation but having other pertinent fiber properties substantially equal, were blended in different percentages to permit a study of the effects of break-elongation on yarn properties and spinning etbciency. Yarn strength and elongation were affected by fiber elongation, with fibers having the highest fiber elongation exerting the greatest influence. Furthermore, nep formation increased linearly as the percentage of higher elongation cotton increased in the blend, indicating that neps are directly influenced by average fiber stiffness. It was also found that yarn toughness index correlated closely with yarn impact data, thus suggesting its possible substitution for yarn impact data. The inconsistency of end breakage of the warp and hlling yarns during spinning offered no conclusive evidence as to the relative spinnability of the cottbns and cotton blends investigated.

Blending Cottons Differing Widely in Maturity Part I: Effect on Properties of Single Yarns

The blending of extremely fine and coarse cottons was investigated as a possible way of economically using these difficult-to-market cottons in the blended form. Two cottons differing appreciably in fiber fineness (approximately 3.0 and 6.0 μg./in.) but having other pertinent fiber properties about equal were blended together to produce a mixture averaging about 4.0 μg./in. in fineness. For comparative purposes a control cotton also averaging about 4.0 μg./in. in fineness was used. The blended and control cottons were spun into coarse and medium yarns of varying twists and into yarn num bers suitable for weaving Type 128 sheeting (64 X 64). The spinning efficiency of the two cottons was evaluated, on a pilot plant basis, in terms of ends down per thousand spindle hours. Waste, nep count, yarn properties (skein and single strand strength, break elonga tion, uniformity, and grade), and end breakage rate in spinning were similar for the blended and control cottons. Microscopical examination of yarn cross sections did not reveal any migratory tendencies of either the fine or coarse fibers. For the same yarn number the blended and control cottons produced yarns of similar diameters and softness values.

An Improved SRRC No-Twist Yarn System

Progress has continued on the SRRC no-twist yam system since the work was originally announced at the 1979 Natural Fibers Textile Conference. Various me chanical modifications that have allowed the production rate to reach 1.5 m/second (100 yards/minute) are discussed. Yam properties of no-twist yarns made from three different staple length cottons at varying production rates are compared to ring spun and open-end yarns from the same cottons. These results show that the no-twist yams compare favorably in uniformity and grade, but are weaker with lower elongation than the ring or open-end yams. Properties for knitted jersey fabrics from selected no-twist yarns compare favorably with ring and open-end fabrics. Work is continuing on the experimental no-twist yarn system.

Some Factors Affecting Open-End-Spun Cotton Yarns:

The spinning variables of two cottons with widely differing fiber properties (one cotton long and strong, the other short and weak) were studied. The cottons were used in their 100% forms and in 2:1- and 1:2-ratio blends. The relationships of the mechanical-spinning variables (rotor speed, rotor diameter, and feed-plate setting) to yarn strength, fiber-wrapper formation, and yarn uniformity were determined. Fiber composition in the blend affects open-end yarn strength significantly more than the change in rotor speed or yarn size. Fiber wrapper and yarn strength are inversely related for a given cotton, and rotor speed affects fiber-wrapper formation much more than it affects yarn strength. Furthermore, cotton with longer staple length tends to be more susceptible to fiber-wrapper formation.

Ring Spun All-Staple Core-Wrap Yarn—A Progress Report

common spinning equipment. In this report, we describe progress in producing allstaple core-wrap yarns by modifying a ring frame, as well as the hardware used in the simple modification. We discuss selected physical properties of the experimental (core-wrap), polyester-core, cotton-covered yarns and compare them with conventional ring spun, open-end rotor, and friction spun (DREF-3) yams. The components for producing core-wrap yarn on

Processing Mechanically Cleaned and Shortened Scoured Wool on the Cotton System

Intensive investigations with a large-scale laboratory model of the SRRC carding cleaner (CC) and two grades of wool showed that the CC sufficiently shortened and cleaned the wool so it could be processed into yarn on the cotton system. A CC with a coarse wire and a low tooth density caused less fiber breakage and produced a better grade yarn compared to a fine wire with a high tooth density. For cotton/wool blends, open-end spun yarn has better quality than ring spun yarn. The study showed that to obtain uniform drawing sliver, roving, and yarn. more emphasis should be given to short than long fibers of the fiber length distribution in determining roll settings. Additional research is needed on the CC to reduce the amount of short fibers less than 12.7 mm long.

No-Twist Cotton Yarn Made from Card Web1

A technique for producing a no-twist yarn from a card web has been developed. The fibers in a strip of web are aligned by a special drafting device. The fibers are impregnated with a binder, dried, and packaged. The binder holds the untwisted fibers together until the yarn is made into a fabric. The binder is then removed, and the fibers are held together by the fabric construction. Fabric properties including strength compare favorably with fabric properties of conventional yarns. A yarn production rate of 1 m/s has been achieved.

Linear Densities of Fibers in Selected Length Groups of 42 Domestic and Foreign Cottons

measure length groups shorter than 1:!!~H to 1%.; in. long, w hereas f~~iori et a]. in their Figure 1 showed the fineness-length distribution for all groul>s v/ ri in. and longer It will he noted that the shorter fine fihers occur below the r’-’-~,;-irl. hoint. :’~ttention was called in the paper to the curvilinear relationship which i~ often found. The linear density or weight filleness was measured in accordance with the rec-

X Direction Filament-Wrapped Yarn

A new filament wrap yarn, the X-wrap, is presented, as well as a procedure and device for producing the new yarn. The theoretical aspect of the X-wrap yarn is also presented. The strength and elongation of the new yarn, which are superior to con ventionally wrapped yarn, are discussed and compared.