Jack Simpson

Effect of Cotton Fiber Fineness and Strength on Mechanical Processing and Open-End Spinning and Yarn Properties

Blends of a coarse and fine and a high- and low-strength cotton were varied to determine their effect on open-end spinning and yarn properties. Fiber fineness was more important in open-end than in ring spinning, because fiber paral lelization is poor in open-end yarns. Fiber strength was more important in ring spinning. When a fine fiber was sub stituted for a coarse one, the strength of open-end yarns increased more than did ring yarns, wereas the results were reversed when a weak fiber was replaced with a strong one. The use of the fine fibers or the strong fibers improved both ring- and open-end spinning and yarn strength.

New Roving Twist Formula

The oldest roving twist formula on record, whose origin is unknown, is based on the premise that twist is proportionate to the square root of the hank (size) roving. This formula does not take staple length into account and is applicable over only a limited range of hank rovings. The formulas of Bissonnette [2], Brandt [3], Duerst [4], and Lawton [7] are based on both length and hank roving as factors influencing twist. However, twist determined by formulas based on these two factors does not give the

Relation Between "Minority" Hooks and Neps in the Card Web

Schematic diagram of cylinder and doffer explains the relationship between the minority hooks and neps. The cylinder- to-doffer fiber transfer region is divided into two zones, upper and lower.

Effects of Combing-Roll Wire Design and Rotor Speed on Open-End Spinning and Cotton Yarn Properties

The effects of combing-roll wire design, particularly the front angle, on lint and trash in the trash box, rotor trash, fiber breakage, fiber orientation in the rotor, and yarn properties, were investigated by means of various combining-roll and rotor speeds and different methods of cotton sliver preparation. Combing-roll and rotor speeds and sliver prepara tion had a significant effect on all the yarn properties investigated, while wire design had much less effect. Generally, combining-roll wire front (forward rake) angles of 0 and 30° yielded the poorest results, and the 15° angle wire yielded slightly better results than the other combiriing-roll wires studied.

Effect of Carding Rate and Cylinder Speed on Fiber Hooks and Spinning Performance for an Irrigated Acala Cotton

The effect of carding rate and cylinder speed on fiber hooks and spinning perform ance was investigated for an irrigated Acala 4-42 cotton. It was found that increased carding rate increased minority and decreased majority hooks. The rate at which the minority hooks increased was greater for the Acala 4-42 cotton than a Deltapine cotton previously investigated. Generally, second-drawing sliver uniformity and end breakage were not affected by increases in carding rates. High carding rates resulted in less noils being removed without detrimentally affecting fiber length, yarn properties, or end breakage. Yarn imperfections and minority hooks of card sliver were related, indicating that, possibly, the phenomenon which produces minority hooks also produces neps and, thereby, yarn imperfections. This limited study seems to demonstrate that each type of cotton has its own peculiar fiber-hook formation pattern as carding rate is increased. The practical application of the research is briefly discussed.

Effect of Mixing Cottons Differing in Micronaire Reading and Carding Variables on Cotton Sliver Quality, Yarn Properties, and End Breakage

Three cotton blends of average micronaire reading but composed of various percentages of high, low, and average micronaire reading cottons were carded into three sliver weights at each of three levels of card production rates. The effect of blend, sliver weight, card production rate, and Hat speed on card loading, card waste, sliver uniformity, fiber orientation, and processing performance were observed.

An Analysis of Carding Efficiency and Processing Performance of Cotton /Polyester Blends:

The effect of various levels of cotton and polyester fibers blended during opening and picking on carding efficiency and processing performance was investigated. The cotton was middling grade, 1 1/16-in. staple length, and 4.2 micronaire reading; the polyester was high modulus, 1.5 in. long, and 1.5 denier. As the percent polyester in the blend increased, compression recovery increased moderately and shear friction appreciably. The increase in friction offset the increase in compression recovery so that cylinder load, fiber hooks, and card sliver variability increased with greater polyester content. However, as the polyester content increased, the increase in fiber friction and length uniformity improved drafting efficiency so that second drawing sliver and yarn uniformity improved. Increasing the polyester content of a blend did not improve yarn grade; high cotton content blends had the same grade as high polyester content blends. At constant end breakage, production in spinning increased rapidly to a 65c/35p blend; additional increases in polyster resulted in only slight improvements in spinning efficiency. Very little polyester was lost in the carding waste even with close flat-to-cylinder settings (0.010 in.), which no doubt provided better carding action on the cotton component in the blend than do settings commonly used. However, it is possible that this close a setting for high percentage polyester blends might cause excessive cylinder loading under mill conditions.

A Method of Automating the West Point Cohesion Tester

tester. (~entry [2] has dl’scribed a semiautomatic method to obtain the average drafting force of the W est Point cohesion tester by means of a fading memory integrator. This letter describes a method by which the area under the force-time curve of the W est E’oint cohesion tester is obtained automatically with a continuous integrator. The instrument used in conjunction with the West Point cohesion tester was an Instron ’ I tensile tester, floor model Tut -8, with a Type-1 basic chart drive and Instron integrator. Figure 1 shows a hlock diagram of

The Effect of Testing Conditions on Fiber Drag: Part I: Dynamic Method

The effect of testing conditions on fiber drag when a dynamic drafting force measurement (West Point Cohesion Tester2) is used was investigated. It was demonstrated that the drag characteristic of a particular cotton can best be evaluated by measuring the drafting tenacity at several roll settings. An exponential type of curve was obtained when the reciprocal of roll setting was plotted against drafting tenacity. Based on the equation for a particular draft, the equation for any draft can be derived by multiplying the constant of the equation by the ratio of the drafts. The drafting-force wavelength increased with increases in fiber length, roll setting, and draft, and it corresponded exactly to the wavelength of the sliver thickness wave as obtained with the Saco-Lowell Sliver Tester.

Effects of Blends of Medium-Staple Low and High Micronaire Reading Cottons, Sliver Weight, and Carding Rate on Card Loading, Sliver Quality, and Processing Performance

This study determines the effect of such carding parameters as sliver weight, doffer speed, and carding rate on cylinder loading, card sliver quality, and waste removal on the processing performance of three blends composed of various per centages of low, average, and high micronaire reading cottons, blended to obtain a constant average micronaire reading of the mix. Blend composition, sliver weight, and carding rate had no significant effect on yarn skein strength, uniformity, and elongation. High carding rates decreased long-term card-sliver variability and increased card sliver short-term varia bility; increased yarn imperfections appreciably and decreased yarn grade slightly. At high carding rates, a blend con taining 30% of low and 70% of high micronaire reading cottons resulted in a greater cylinder load and lower fiber transfer than the other two blends containing various percentages of average micronaire reading cotton. This blend also had higher fiber breakage at high carding rates and slightly higher end breakages in spinning. Compared with light-weight card sliver, heavy card sliver increased cylinder load, majority hooks, yarn irregularity, and imperfections and decreased the cleaning efficiency of the card. More fibers and less actual waste were removed than when producing a light-weight card sliver.