bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallinity of Cellulose and Its Significance for the Fiber Properties
Authors: Ward Kyle 
Published: March 2008

The subject of this paper is treated mainly from the standpoint of cotton cellulose. The concept of crystallinity is discussed not simply in the narrow sense of degree of crystallinity but in the broader sense, which involves the whole fine structure of cellulose. With respect to crystallinity in the latter sense, there are four main factors, each involving a mean value and a distribution of values, both mathematical and spatial. These parameters, independent within certain limits, are (1) the nature of the crystal lattice, (2) the percentage of crystalline ma terial, (3) the size of the crystallites, and (4) the orientation of the crystallites. A well- planned analysis of covariance between these factors and the important physical properties of cotton would be desirable. This would be a task of considerable magnitude even if other variables not directly related to crystallinity, such as molecular size and morphology, were not active. In the absence of such an analysis it is still possible to show the marked influence of some of these parameters on certain of the important physical properties of cotton. The relation of physical properties to the crystalline modification has been pointed out frequently by a com parison of the properties of the native fibers with those of regenerated fibers or with those of mercerized fibers. However, the changes in the percentage of crystalline material which usually occur in these transformations have not been evaluated exactly, and the conclusions drawn from previous studies should probably be checked. Decreased crystallinity and higher content of amorphous cellulose is symbatic with in creased elongation, increased moisture regain, and increased chemical reactivity. Of particular interest in the last category is the special case of hydrolysis, a reaction in which it is possible that crystallization may occur. Data on the third parameter, the size of the crystallite, are too scanty to permit any con clusions to be drawn. A study of this factor will have to wait on improved methods for meas uring the size and size-distribution of the crystalline areas. The increase of fiber strength and of refractive index with improved orientation has been well established. A decrease in elongation usually accompanies this.
Measurement of Fineness of Cotton by Air-Flow Methods
Authors: Brown Hugh M. , Graham John S. 
Published: March 2008

Using 7 varieties of cotton harvested at different times to give an extremely wide range in fiber development, a study was made of the air-flow method of measuring fineness and maturity of the lint. The data show that when porosity meters are calibrated in units of weight per unit length of fiber (i.e., fineness) the curves for different varieties of cotton are quite different. This is due to the fact that resistance to air-flow through a fiber plug correlates more closely with the surface area of the fibers composing the plug than with their fineness. This surface area varies with variety and maturity, independently of the fineness of the cotton. Using a plug of constant weight and volume made of fibers having a constant density enables the use of a simple theory which predicts essentially the actual variation of air-flow with both variety and maturity of the cottons tested. Two quite different types of air-flow apparatus are shown to give similar results that are more consistent with the specific surface † of the several cottons than with the fineness of the fibers. For several cottons, the air-flow data published by the U. S. Department of Agriculture for the 1948 crop are compared with the previous 10-year averages for fineness which had been measured by counting and weighing the fibers.
Studies on the Microbiological Degradation of Wool
Authors: Stahl William H. , McQue Bernard , Mandels Gabriel R. , Siu R.G.H. 
Published: March 2008

Measurements of the susceptibility of various keratins and fibrillar proteins to digestion by a keratinolytic fungus were made. Both normal and modified proteins were used. Digestion of the following fibrillar proteins by Microsporum gypseum over a 21-day period was, from the highest percentage digestion to the lowest: collagen, feather, hoof, wool, horn, horsehair, mohair, and silk. The primary factors which determine the rate of digestion of fibrillar proteins were found to be the chemical composition and the molecular architecture. In keratins, the degree of poly merization assumes the greatest importance. The higher the degree of polymerization, pri marily attributed to the disulfide cross-linkages, the more resistant the keratin is to enzymic digestion. Histological complexity of keratinaceous tissues and geometrical structure of the keratin molecule do not influence the rate significantly.
Influence of Fiber Ends on the Adhesion of Bare Tire Cords
Authors: Lyons W. James 
Published: March 2008

1. Comparison of results on 100% cotton and 100% rayon-staple cords, neither being coated with an adhesive dip, indicates that the former have about 25% better adhesion. Since the advantage cannot be due to the presence of fiber ends protruding from the cord in one case and not the other, it is concluded that the superior adhesion of the bare cotton cord is in part due to a surface chemical or geometric property of the cotton fiber. 2. Comparison of results on 100% rayon-staple and continuous-filament cords, obtained from the same supplier, show that the staple-fiber product has about 60% better adhesion than the continuous-filament cord. This result indicates that, as has been frequently claimed in the litera ture, the presence of fiber ends in a tire cord does contribute toward improving adhesion. A 100% improvement in adhesion would be required, however, to show that only the lack of fiber ends curtails the adhesion of bare, conventional rayon cords.
Stabilization of Neutral Hypochlorite-Oxidized Cotton Fiber
Authors: Reeves Richard E. , Jung Julius R. 
Published: March 2008

Cotton fiber oxidized by neutral hypochlorite solution, like cotton fiber oxidized by periodate, suffers two types of damage: one type is immediately evident; the other is latent damage, which becomes evident after exposure of the oxidized fiber to aqueous alkali. But when fiber oxidized by neutral hypochlorite is treated with ethereal diazomethane before exposure to alkali, a portion of the latent damage does not develop. The oxidized and treated fiber displays lower alkali solubility, lower cuprammonium fluidity, and greater strength after exposure to alkali than does the fiber that is oxidized but not treated. , Chlorous acid, found to be effective against the latent damage in periodate-oxidized cotton, is not effective against the latent damage in hypochlorite-oxidized cotton.
The Relationship Between the Structural Geometry of a Textile Fabric and Its Physical Properties
Authors: Backert Stanley 
Published: March 2008

This paper is primarily concerned with the mechanics of textile fabric abrasion. However, considerable attention is devoted to the theory of friction and the theory of cutting of crystalline solids. This is intended as a framework for the study of visco-elastic fibrous materials. Such an approach seems logical in view of the significant part which both the elastic and plastic properties of metals play in the phenomena of rubbing and cutting. It is particularly significant that these studies on metals often report the use of solid high polymers as models and experimental materials. It has taken over 100 years of research on the part of physicists and engineers to determine the nature and causes of friction in crystalline solids, and only in the last 15 years have they made progress in the study of surface cutting. Within the last few years several workers in the field of fibrous high polymers have recognized the applicability of the findings of crystalline-solid research as related to the study of friction, but no one in the fiber field appears to have profited from available infor mation dealing with surface cutting. It would seem that more use should be made in textile research of the experimental techniques and the analytical conclusions of previous investigators in the more general field of solid bodies.—Editor.
Flow Through Fabric-like Structures
Authors: Penner S.E. , Robertson A.F. 
Published: March 2008

A method is presented for the visual investigation of flow through fabrics. The fabric pores are considered as orifices, and the effect of weave structure on the fluid flow is investigated in the range of Reynold's numbers 10 to 400.For this investigation, a liquid is forced past models representing the four possible combina tions of yarns in a woven fabric interstice, and the fluid motion is visualized by using air bubbles, which are detected by means of a suitable light source, as the distinguishing medium. Since both the fluid and the construction material for the models and viewing chamber are translucent and possess the same refractive indices, it is possible to obtain uninterrupted, undistorted visualization of the fluid flow through and past the fabric-like structures. Visual and photographic investi gations of the flow are made in various significant planes normal to the fabric-like structures, or parallel to the direction of flow. The resulting photographs are analyzed and interpreted to provide information concerning the effect of fabric construction and variation of Reynold's num ber on the area available for the passage of fluids through each pore type, or the so-called "effective pore area."It is shown that the four pore types do not behave like geometrically similar orifices, so that for a given diameter/pitch ratio the effective pore area is not the same in all cases. This area decreases with increasing Reynold's number. Except at very low Reynold's numbers, the effec tive pore area proves to be less than the actual minimum pore area, but greater than the pro jected area, with the exception of the plain-weave pore type. Assuming a minimum cross- sectional pore area, as determined by graphical analysis, it is shown that the effective pore area/minimum pore area ratio is almost a constant for all four pore types of the models tested at a Reynold's number of 400.
Quantitative X-Ray Studies of Order in Amorphous and Crystalline Polymers
Authors: Krimm Samuel , Tobolsky Arthur V. 
Published: March 2008

The application of a Geiger counter spectrometer to the quantitative study of the scattering from amorphous and crystalline polymers has been investigated, and this technique has been shown to be very well suited to this purpose. The experimental technique used is described. The following polymers have been studied, in order to gain some insight into the structure and order characterizing the amorphous and crystalline regions : hexadecane, polyisobutylene, natural rubber, polystyrene (oriented and unoriented), polymethyl methacrylate, polytrifluorochloro ethylene, octacosane, polyethylene, polytetrafluoroethylene, and various natural keratins. The scattering patterns are analyzed for their structural implications. It has been found that the x-ray diffraction patterns of polystyrene and polymethyl methacrylate change as these materials are heated through and above the region of their second-order transi tion. It is shown that these changes are interpretable in terms of definite changes in structure of the polymeric chains. The bearing of these results on the nature of the glass transition in these materials is discussed.
Chemical Substitution in Fibrous Cotton and Resistance of Substituted Cotton to Microbiological Deterioration
Authors: Goldthwait Charles F. , Buras Edmund M. , Cooper Albert S. 
Published: March 2008

The resistance for months to deterioration by microorganisms (in soil burial) of suitably acetylated fibrous cottons, some with only one-third of the hydroxyl groups substituted, depends upon the distribution of the acetyl groups as well as upon the total number of such groups present.Under usual conditions of acetylation, according to the literature, reaction takes place first in the amorphous cellulose, starting at the most accessible places. According to the present ex perimental acetylations and special dyeing tests, the reaction, which is probably confined at first to the amorphous cellulose, takes place along fibers in various segments and throughout cross sections rather than as a layer increasing in thickness from the surface inward. At one-third substitution the amorphous cellulose is converted to triacetate; the cotton fiber still contains about two-thirds of the original cellulose, which is present as crystalline material surrounded by acetylated cellulose. The swelling capacity of the cotton in water is greatly reduced.While the mode of attack by microorganisms is not completely understood, they apparently begin at the most readily accessible amorphous cellulose. From the literature and from the present experiments, protection by partial acetylation is believed to be due to the blocking of hydroxyl groups, the filling of spaces between chains in the amorphous cellulose, and the sup pression of swelling. It represents a general method of rendering cellulose unsuitable, or at least inaccessible, as a food for microorganisms.A relatively low degree of partial saponification may detract greatly from the rot-resistance of a well-protected acetylated cotton owing to the restoration of amorphous cellulose, with loss of blocking groups and a restoration of swelling capacity.Partial methylenation by treatment with formaldehyde may impart a moderate degree of rot-resistance, which seems best explained as being due to the suppression of swelling by cross linking. Formaldehyde-containing resins which impart rot-resistance apparently act similarly.The evidence obtained indicates that the amorphous cellulose is the part which is normally attacked, and that its ability to swell in water may be a more important factor in microbiological attack than is commonly recognized.The use of dyeing has been exemplified for qualitative tests to supplement other evidence regarding substitution and the composition and properties of substituted cottons.
Some Observations on the Constitution of the Primary Wall of the Cotton Fiber
Authors: Tripp Verne W. , Moore Anna T. , Rollins Mary L. 
Published: March 2008

The primary wall of fully matured cotton fibers has been isolated and its morphology and composition studied by electron microscopic examination and by chemical analyses. The pri mary wall appears to contain about 50% cellulose; protein, wax, and pectic substances occur in lesser amounts; cutin or suberin and mineral matter are also present. The concentration of noncellulosic substances in the primary wall is much greater than in the whole fiber.Electron microscopic examination of the primary wall indicates that it consists of a network of cellulose fibrils, having diameters of 100-400 Å, surrounded by the noncellulosic constituents. The oriented fibrillar systems observed with the polarizing microscope have not been seen in the electron micrographs of the specimens studied. There is an apparent increase in the diameter of the fibrils of the primary wall and in the denseness of the network as the fiber matures. The existence of layers in the cellulose network has been observed.
Effects of Tension on the Swelling of Cotton Fibers
Authors: Giuffria Ruth , Tripp Verne W. 
Published: March 2008

Changes in the cross-sectional area and circularity of cotton fibers tensioned in water and other media have been measured microscopically. It was found that the area increased significantly over that brought about by water-swelling alone. Fibers tensioned in bundle form at 0.45 g./grex for 1 hr. in water showed an average increase of 98% in area compared to dry untensioned fibers, and an increase in circularity (axis ratio) of 57%. These increases were not retained on drying, even when tension on the fibers was maintained. Immersion without tension in urea solution, ethylamine, or sodium hydroxide of mercerizing strength, followed by removal of the reagent and drying, in each case produced increases in area and circularity over those of the untreated fibers. Tensioning at 0.45 g./grex during im mersion in these reagents increased the circularity, but decreased the area with respect to the untensioned fibers. The elongation of fiber bundles tensioned in the various media was measured. The sodium hydroxide solution produced the greatest elongation.
An Evaluation of Long- and Short-Term Variation in Sliver and Roving
Authors: Simpson J. , Landstreet C.B. , Corley J.R. 
Published: March 2008

To study the effects of processing variables on product uniformity, a procedure for evaluating uniformity has been developed. Two types of variation, long- and short-term, are common in slivers, rovings, and yarns. It is shown here that short-term variation is a better indicator of the effects of processing variables than is either long-term variation or a composite of long- and short-term variation. By measuring only short-term variation it was possible to: study the effects of doubling and drafting on product uniformity; develop drafting curves for the various drafting systems by which product variability may be predicted; and develop a formula for the comparison of the variation in unequal counts of roving and yarn.
The Geometry of Plain and Rib Knit Cotton Fabrics and Its Relation to Shrinkage in Laundering
Authors: Fletcher Hazel M. , Roberts S. Helen 
Published: March 2008

The geometry of six plain and six rib circular-knit cotton fabrics with three different finishes was studied. Data on both gray and finished fabrics for stitch length, diameter of yarn, and wale and course spacings were used in evaluating the equations derived by Peirce for length of yarn in one stitch and for weight per unit area. Measured stitch length agreed with that calculated from Peirce's formula, l = 2p + w + 5.94d, when a specific volume of 1.1 was as sumed for the yarn. When the measured value for the yarn diameter was used, the stitch length was given by l = 2p + w + 4.56d. Weight of the fabrics calculated by Peirce's formula showed good agreement with that obtained by weighing a known area. In laundering tests, it was found that the shrinkage of the yarn was negligible, usually less than 1% in the finished fabrics. Curves relating the wale and course spacings of the unlaundered gray fabrics conformed to no orderly pattern. The gray material shrank in length and stretched excessively in width. Wale spacings plotted vs. course spacings in the laundered gray and finished fabrics followed parabolic curves. The finished fabrics in which wale and course spac ings approximated the parabolic relationship of the laundered fabrics changed the least in the length and width dimensions. These were the tighter-knit fabrics of two of the finishes. On the other hand, the fabrics having the greatest knitting stiffness shrank the most in area.
Properties of Apparel Wools
Authors: O'Reilly D.F. , Whitwell J.C. , Steele R.O. , Wakelin J.H. 
Published: March 2008

Modification of the fiber surface during processing has been studied on three wools of Aus tralian fine, domestic fine, and domestic medium grades. Samples were taken from each wool at each stage of their manufacture into a worsted fabric by the Forstmann Woolen Company. Groups of fibers, selected randomly from each sample, were treated with Pauly reagent and ex amined microscopically. The amount of color on the fiber was estimated visually, and the amount of scale disturbance was assessed. The rate of exhaustion of Anthraquinone Blue SKY was also measured on samples from each processing stage. A consistently increasing amount of surface modification was observed with all three wools as the manufacturing process advanced. The susceptibility of the wools to staining with Pauly reagent and their rate of taking up Blue SKY from a dye bath also increased. However, all of these changes were reversed by a steaming process such as is frequently used in normal worsted processing. It was concluded that the dye susceptibility of processed wool is related to the amount of scale disturbance of the fibers and that the epicuticle does not seem to constitute the only major resistance to dye penetration.
Observations of the Birefringence and Refractive Index of Synthetic Fibers with Special Reference to Their Identification
Authors: Heyn A.N.J. 
Published: March 2008

Birefringence and refractive indices of synthetic fibers are measured by the polarization color and immersion methods. These properties prove to be much more consistent and characteristic for synthetic fibers than for natural fibers and rayons, to which previous studies had mainly been confined. These fea tures can therefore be used in the identification of synthetic fibers. A simple polarizing device for making these measurments using an ordinary microscope is described.
Mercerization of Yarn—Experimental Apparatus and Techniques
Authors: Goldthwait Charles F. , Murphy Alton L. , Lohmann Idas W. , Smith Herbert O. 
Published: March 2008

Apparatus is described and general methods are indicated for the study of the process of mercerization of cotton yarn in skeins and for the experimental mercerization of lots weighing up to about 3/4 1b. Special techniques, including the use of a strain gage, are given for measuring the tension developed in yarn during mercerizing. This indication of the swelling behavior of cotton is expected to supplement the usual observations of mercerized yarn properties—luster, dyeing capacity, and strength—to help breeders and prospective users of new cottons in their selections. Observations of developed tension can also be employed to indicate the rate of mercerizing as the caustic penetrates and swelling causes tension to build up in the yarn, and to show differ ences between yarns and processes even more readily than between cottons. The equipment is now being used to test yarn made from breeders' samples to help predict the response to commercial mercerizing of newly developed cottons, although results for this work are not included herein.
The α-β Transformation in Stretched Hair
Authors: Elliott A. 
Published: March 2008

The interpretation of the x-ray diffraction diagram of hair, both natural and stretched, is considered, and attention is drawn to the importance of considering the amorphous as well as the crystalline parts of hair. Infrared spectra show that there is a mixture of a and β structures (folded and extended polypeptide chains, respectively) both in natural hair and in hair which has been extended 100%, and that the orientation of the β material, at least, is very imperfect. It is concluded that in such a system no simple relationship exists between the extension of the molecular chains on unfolding and the extension of the whole fiber.
Silicon-Containing Azo Dyes
Authors: Sunthankar S.V. , Gilman Henry 
Published: March 2008

The dyeing properties and the lightfastness on cellulose acetate rayon of several azo dyes prepared from m-trimethylsilyl- and m-triphenylsilyl- N,N]- bis- (β-hydroxyethyl)-aniline have been examined. The dyes derived from m-triphenylsilyl- N,N- bis-(β-hydroxyethyl)-aniline have been found to lack substantivity for cellulose acetate and to have inferior lightfastness, whereas the dyes obtained from the trimethylsilyl analogue showed fairly good substantivity and very good light fastness. A comparison of the dyeings and the lightfastness of some of the dyes synthesized from m-trimethylsilyl- N, N- bis-(β-hydroxyethyl)-aniline with those of the corresponding dyes obtained from the methyl analogue, which are commercial dyes, has revealed that the substan tivity of the silicon-containing azo dyes is less, but the lightfastness is more, than those of the commercial azo dyes. The reflectance spectra of the 1% shades of some of the azo dyes have been recorded, and the Munsell renotations for hue, lightness, and chroma of the color of the dyes have been determined.