John J. Brown

Effects of Cotton Fiber Fineness on the Physical Properties of Single Yarns

The effects of the single fiber property fiber fineness on the physical properties of single yarns, both coarse and fine and of varying twist, were investigated. To permit the study of fiber fine ness while maintaining other important properties approximately constant, a special technique was used which controlled the length factor by reducing all the cottons to common quartile and mean lengths. The cottons selected—Seaberry Sea Island, Mesa Acala, Tanguis, and Rowden 41—B—represented extremes in fineness, ranging from 2.9 to 5.6 μg. per in., and had other impor tant fiber properties approximately equal. The study showed mainly that a relationship exists between fiber fineness and the turns per inch required in a single yarn to obtain optimum yarn- strength benefits. Low-twist yarns decreased less rapidly in strength from maximum strength when made from fine than when made from coarse fibers. In contrast, high-twist yarns de creased more rapidly in strength when made from fine rather than when made from coarse fibers. Yarns made from coarse fibers required more twist to attain maximum yarn strength than those made from fine fibers. The study also revealed that fiber fineness does not materially affect yarn elongation. In addition, it was found that fiber fineness is a critical factor of roving twist.

Effect of Cotton Fiber Strength on Single Yarn Properties and on Processing Behavior

Fiber length, fineness, and strength are the properties which contribute the most to yarn strength. Yarn strength is considered to be the principal criterion of yarn quality. Recently, breeders have developed cotton varieties having fiber strengths which average from 25 % to 50% above normal. These new cottons of average length but with a high fiber strength will find a ready market if they can be processed efficiently and satisfactorily. It is the purpose of this study to determine the effect of the strength of the fiber upon the strength of the yarn. At a previous Cotton Research Clinic we reported on the effect of fineness of cotton fibers upon yarn strength, and the findings of this study were published in the October, 1951, issue of the TEXTILE RESEARCH JOURNAL. At some later date, we hope to have an opportunity of reporting on a similar study of the effect of fiber length on yarn properties. We plan to set up tables showing the values of the various fiber properties as they influence yarn properties, and from these tables we hope to derive a formula which will form a basis for predicting yarn strength for any cotton whose fiber properties are known. Such a prediction formula would be useful to cotton breeders in guiding them in their breeding work; it would likewise be useful to manufacturers in their selection

The Effect of Fabric Structure on Fabric Properties

Research leading to the development of specialized fabrics for an agency of the Department of Defense is described. Requirements called for the fabrics to be highly resistant to the passage of water and air and to possess relatively high tensile and tear strength, yet to be light in weight. The effects of 7 types of fabric structure on the physical properties of the fabrics are discussed. Of the constructions tested, basket weaves offered an acceptable com promise among the properties desired, with a 2/2 basket being highly water resistant without any chemical treatment and a 3/3 basket being slightly less water resistant and slightly more tear resistant. Regardless of the weave, as the picks per inch were in creased, air and water resistance increased and tear strength decreased. Bleaching, mercerizing, and dyeing significantly decreased the tightness of the fabrics; however, application of a flame-retardant and water-repellent treatment almost restored the original resistance of the fabrics to the passage of water and air.

Evaluation of the Yarn Properties of a High- Strength Interspecies Cotton

The reported results compare the yarn properties of a high-strength (11.5 Pressley Index) Interspecies cotton with those of five other cottons having a comparatively wide range of fiber properties. The cottons were processed alike on conventional processing equipment into 18/1, 36/1, and 72/1 carded yarns using a range of twist multipliers from 2.75 to 5.75. The sliver and roving made from each cotton were measured for uniformity and the yarns were tested for uniformity, appearance, and strength. It was found that yarns made front the Interspecies cotton were as strong as those made from the much longer and finer Karnak cotton and stronger than those made from the other cottons. The Interspecies and Karnak yarns were about equal in uniformity with both being more uniform than the other control yarns. A limited statistical analysis of yarn breaking strength data indicated that fiber strength is more important to yarn strength than either fiber fineness or length.

Effect of Single and Ply Twists on the Properties of a 15.5/2 Carded Cotton Yarn

The effect of single and ply twists on the properties of a 31/2 cotton carded yarn was studied. A widely grown cotton variety (Deltapine) of average fiber properties was spun into a 31/1 yarn (Z twist) using a range of twist multipliers (2.9-6.9). Each single yarn twist multiplier construction was then 2-ply twisted (S twist) with a range of twist multipliers (1.9-7.9). Maximum ply strength was obtained when low-twist single yarns were 2-ply twisted with a high twist multiplier. Maximum elongation at break was obtained with a similar single-ply twist construction. For certain twist constructions single and ply twist may be varied within reasonable limits without materially decreasing strength. When the same twist multiplier was used in the single and ply yarn, maximum ply yarn strength was realized with that twist multiplier which resulted in maximum single yarn strength. Elongation is related linearly and directly to equivalent twist multiplier constructions. The ratio of ply to single yarn strength, based on maximum ply yarn strength, was highest when single yarn strength was lowest (low twist), decreased rapidly as the single yarn strength approached maximum, became approximately constant in twist combinations resulting in single yarns of maximum strength, and increased slightly as single yarn strength decreased (very high twist).

Effects of Roller Ginning and Saw Ginning on Pima S-1 Cotton

A pilot plant evaluation was made to compare the effects of roller ginning and saw ginning on the fiber, yarn, and fabric properties and processing performance of Pima S-1 cotton. Combed and carded yarns made from roller- and saw-ginned cotton and sewing thread and fabric made from combed lots of each stock were evaluated. The fabrics were compared in the grey and after finishing (singeing, mercerization, scouring, bleaching, dyeing, and Sanforize treating). It was found that, within the limits of this study, the general processing efficiency of the roller-ginned cotton was better than that of the saw-ginned cotton. The method of ginning had no appreriable effect on the strength, uniformity, or elongation at break of combed yarns, but carded yarns spun from roller-ginned cotton were significantly stronger than those spun from saw-ginned stock. Combed yarns spun from the roller- ginned cotton were better in appearance than those spun from the saw-ginned stock. There were no significant differences in the physical properties of sewing thread pro duced from combed saw- or roller-ginned cotton. Fabrics produced from combed cotton ginned by both methods were approximately equal in tearing strength, but the saw-ginned cotton produced fabric that, in some cases, had a lower elongation and breaking strength. There were no significant differences in abrasion resistance between the fabrics before finishing, but the results for abrasion resistance of the finished fabrics were inconclusive. The fabric woven from the saw-ginned cotton contained consider ably more neps than that woven from the roller-ginned cotton. Since this type of cotton is generally used for the production of fine quality yarns and fabrics, it was concluded that saw-ginned extra long staple cottons would not be suitable for these uses. Also, due to the greater amount of waste during processing and poorer spinning performance of the saw-ginned cotton, processing costs would be higher and possibly offset any savings in ginning costs.

Yarn and Fabric Properties and Processing Performance of Cotton Treated with a Cross-Linking Resin

Results are reported of an investigation to determine the general processing per formance, in the cotton processing system, of cotton containing various percentages of fibers treated with dimethylol ethyleneurea, and the properties of the resultant yarns and fabrics. The resin-treated cotton was evaluated in 100% form and in blends with scoured cotton. Fabrics woven with filling yarns spun from the 100% treated cotton and the blends, using a common untreated warp, were evaluated for warmth properties in terms of thickness, bulk density, and air permeability. Difficulties were experienced in processing cotton with large percentages of resin- treated fibers due mainly to uneven drafting and the formation of static charges during the carding and drawing operations. Yarns spun from cotton containing resin-treated fibers were progressively weaker. less uniform, and more degraded in appearance as the percentage of resin-treated fibers was increased. Yarn elongation-at-break decreased with the addition of resin-treated fibers, but elongation at loads below the breaking point increased, indicating a relationship between yarn elongation at low loads and yarn bulk. Although experimental fabrics having improved warmth properties were made from yarns composed of 50% or more resin-treated fibers, it was concluded that, with present knowledge, the lower yarn quality and the poor processing performance would make production difficult on a commercial scale.

A Comparison of Some Physical Properties of 80x80 Print Cloth Produced from Three Cottons Differing Primarily in Flat Bundle Strength

In previous reports 14, 5. 8) the authors showed that, while cotton filer strength has little or no effect on processing efficiency up to spinning, highstrength cotton produces stronger single and 2-ply yarns than low-strength cottons for any given yarn number or twist. A similar study (7 on the effect of mechanical and chemical processing on cotton fiber properties presented sound evidence for the premise that cotton hber properties influence the behavior of the resultant fabrics. Because of the need of knowing how fiber properties, particularly flat bundle strength, translate

Properties of Fabrics Produced from Three Extra Long Staple Cottons

Results are reported of a comparative evaluation of the properties of fabrics produced from the American-Egyptian Pima S-1, Egyptian Karnak, and a high strength Upland cotton, Hybrid Strain 330. Relationships of some fiber and yarn properties to fabric properties are shown. The reactions of fabrics woven from these cottons to chemical finishing treatments (mercerization, scouring, bleaching, and dyeing) are also discussed. In general, it was found that the Pima S-1 cotton produced fabrics which were ap proximately equal in breaking and tearing strength to those made from Hybrid Strain 330 cotton and which were stronger than those made from Karnak. Grey fabrics made from Pima S-1 had higher elongation, greater resistance to flex abrasion, and better draping qualities than those made from the other two cottons. The finishing treat-- ments had varied effects on the fabrics, but in most cases those made from Pima S-1 re mained equal to or better than those made from the other cottons in the properties measured. Fiber and yarn properties were closely related to fabric properties.

The Effect of Twist on the Static Modulus of Cotton Hawser-Twist Cord

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