bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellulose Studies
Authors: Mehta P.C. , Pacsu Eugene
Published: March 2008

Native cotton and commercial viscose rayon were degraded by using a saturated solution of hydrogen chloride (about 43%) in methanol at 0° C. It was found that, on the average, 8.1 bonds in native cotton suffered methanolysis during the first 6 hrs. of the reaction, whereas in the ensuing period of 666 hrs. only 1.6 bonds became cleaved. The results indicate that the initial reaction comes to a practical standstill after about the same stage of degradation has been reached as in the mild hydrolytic scission of the same materials (D.P. ∼ 250 for cotton, and D.P. ∼ 60 for viscose rayon).

In order to gain information as to the nature of the methoxyl groups in the methanolyzed products, a study of the rate of hydrolysis of the latter was made. Evidently, if the classical concept of cellulose structure is correct—that is, if only normal methyl. glucopyranoside end groups are present—then the rate of acid hydrolysis, as measured by the increase in the reducing power, should be of the order of magnitude shown by the normal methyl glucopyranosides. On the other hand, a very fast rate of hydrolysis, which is characteristic for the open-chain dimethyl acetals of the sugars, would constitute evidence for the presence of such types of residues; hence, it would favor the new concept of cellulose structure.

The results showed that more than one-half of the material in the case of viscose rayon and about one-half in that of native cotton were hydrolyzed by 0.05N HCl at 60°C in a period of 48 hrs., which is shorter beyond all comparison than the half-life (3,450 hrs.) of methyl α-gluco pyranoside under identical conditions. These results are considered to supply the chemical proof for the presence of the acid-sensitive, open-chain glucose residues which were suggested in the new formula for cellulose.
X-Ray Microradiography of Fibers and Fabrics
Authors: Lindsley Charles H. , Fischer Earl K. , Brant Joseph H.
Published: March 2008

Soft x-rays or Grenz rays can be used to form shadowgrams of single textile fibers as well as of yarns and fabrics on fine-grain photographic plates. This paper deals primarily with the microradiography of single fibers and includes a description of experimental equipment, con ditions under which necessary resolution is obtained, impregnation of fibers with substances to increase absorption of x-radiation, and examples of the utility of the method. Single cotton, rayon, wool, and other fibers are clearly resolved by x-radiation generated at 5 kv.; at higher voltages (to 17 kv.), natural fibers give faint shadowgrams. When the fibers are impregnated with 10-20% lead sulfide or other materials, single treated fibers can then be distinguished in masses of untreated fibers. This technique provides a possible means for tracing individual fibers through processing operations.
Moisture Determination in Textiles by Electrical Meters: Part III
Authors: Whitwell John C. , Toner Richard K.
Published: March 2008

This paper, the third in a series on determining moisture in textile materials by electrical meters, describes tests made on the Moisture Register. The meter tested was designed for wool and when properly used gave results with a precision of ± 0.35% moisture, which approaches closely the precision of oven measurement. When used on materials for which it was not intended—namely, cotton sliver and acetate staple—the results were appreciably less precise. In common with other meters tested, measurements are sensitive to temperature changes and the presence of impurities.
Note on the Disintegration of Wool in Abrasion Tests
Authors: Schiefer Herbert F. , Krasny John F.
Published: March 2008

The coating which formed on the abradant when a specimen of wool fabric was abraded and caused the rate of abrasion to increase approximately ten times in three successive tests was examined critically. Microchemical analyses showed that it had the same composition as the unabraded fabric. Infrared absorption curves of the coating and of the powder of the unabraded fabric, ground in a vibratory ball mill, showed the same absorption characteristics. Electron micrographs of the coating showed that it contained extremely small particles, many of which were approximately spherical in shape and about 100 to 200 A. in size. Similar particles were observed in the abraded debris when the specimen was kept wet with water during the abrasion test, and also in the powder into which the unabraded fabric was ground in the vibratory ball mill. It was concluded that the coating which formed on the abradant consisted of extremely small particles of wool which appear to correspond in shape and size to the elemental structural units (keratin molecules) proposed in recent concepts of the structure of wool.
Stabilization of Casein Fibers by Desamination
Authors: Peterson R.F. , McDowell R.L.
Published: March 2008

Casein fibers hardened with formaldehyde solutions need further processing to withstand boiling acid dye baths. Studies on desamination of casein fiber at various steps in the spinning process are reported. Desamination of casein fiber increases its resistance to dye baths. Desami nated fiber is given additional stability by treatment with acid-formaldehyde solutions followed by baking at 110°C. Dye uptake of both acidic and basic dyes is reduced by the combined treatment.
Special Dyeing of Cotton on the Seed Gives Visual Evidence of Changes During Fiber Development
Authors: Goldthwait Charles F. , Smith Herbert O. , Roberts Florence T.
Published: March 2008

A process of differential dyeing employed to distinguish between thick- and thin-walled cotton fibers has now been utilized to show visually that the drying of normal cotton fibers for the first time-as when the boll opens in the field -greatly affects their dyeing properties. The effect was observed as a pronounced color difference when one lock from a nearly mature boll, cut open in the laboratory, was dried and another lock was kept wet, and both were dyed in the same dye bath at the same time.

The dried cotton dyed mainly red and the undried dyed green. The change in the cotton cellulose which caused the difference is undoubtedly submicroscopic, and takes place in addition to the changes visible in the microscope which are familiar in fibers that have dried normally on the plant. A significant feature of the submicroscopic change can be inferred from the dyeing behavior considered in relation to current views of the mechanism of direct dyeing—that is, undried fibers from a cotton boll are shown by a new tech nique to be more porous than fibers which have dried in the boll, and the thin-walled fibers in ordinary cotton are simi larly more porous than the thick-walled fibers, at least while wet in a hot dye bath. It follows that the differential- dyeing effect with cotton fibers is determined by cellulose structure in combination with specific properties of the two dyes employed.
Perimeter Measurements of Cotton Fibers in the Primary-Wall Stage
Authors: Pearson Norma L.
Published: March 2008

A method is described for obtaining information regarding perimeter differences of mature cotton fibers by measuring the perimeters of the fibers in the primary-wall stage. Tufts of young fibers were cut from the seed, stained, fanned out on a glass slide, and dried. The width of the collapsed dried fiber is equal to half its perimeter at the point measured. Perimeters were measured for 9 types of cotton, which had been selected to represent a range in size of perimeters. The average perimeter values obtained were compared to and found to show differences that were consistent with perimeter values obtained for the mature fibers of the same types of cotton.
The Effect of Moisture on Twisted Yarns
Authors: Maginnis James B.
Published: March 2008

The effect of moisture upon certain physical properties of twisted continuous-filament rayon yarn was studied. Data are presented on the changes in stress, dimensions, and moduli for the yarn and the component filaments. An expression is presented which gives a qualitative relation ship between yarn properties and yarn construction, based on the knowledge of filament behavior.
Stabilization of Periodate-Oxidized Cotton
Authors: Reeves Richard E. , Darby Felix F.
Published: March 2008

Earlier observations regarding the stabilization of periodate-oxidized cotton fiber by treat ment with chlorous acid or ethereal diazomethane are confirmed and evaluation of the treatments has been extended to a more complex system, cotton sewing thread. At low levels of oxidation the treated samples retain considerably more strength after exposure to sodium carbonate solution than do samples oxidized but not given a stabilization treatment. At high levels of oxidation the stabilizing treatments produce good reductions in alkali-solubility.
The Impact of Raindrops on Fabrics
Authors: Kärrholm Marianne , Kärrholm Gunnar
Published: March 2008

A study has been made of the pressure-time relationships existing during the impact of water drops on fabric surfaces. The impact was recorded by a high-speed motion-picture camera. Calculations of the pressure exerted by the waterdrop, the depth of penetration, and the manner in which the waterdrop deforms during impact are given. The theory described gives important principles that could be used for the design of water-repellent fabrics. If the fabric surface is plain the pores must be small so that the pressure required to force water through them will be high. An alternative or complementary method is to make the fabric surface highly compressible (e.g., raised fabrics); the pressure exerted by the raindrops will be much smaller than in the former case. The requirements for the testing of water-repellent fabrics are examined in the light of the theo retical and experimental results reported herein.
High-Speed Motion Pictures in Textile Research
Authors: Fischer Earl K. , Burnett Jack C.
Published: March 2008

Motion pictures which depict action greatly slowed down are of unique assistance in analyzing complex machinery and processing operations. In recent years cameras for taking high-speed motion pictures have become generally available, and the technique for their use is easily acquired. Although their application in the textile industry has thus far not been extensive, it is probable that textile engineering and production departments will find high-speed motion pictures a valuable aid in analyzing defective machinery, in "trouble-shooting," and in the development of new processing methods. This article includes a description of the types of cameras used, special details on technique, a comparison with other methods for viewing action, and illustrations of some of the applications.
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.
Colloid-Chemical Basis for the Action of the Coagulating Bath upon Viscose
Authors: Horio M.
Published: March 2008

In an effort to interpret the phenomena which occur when viscose solution is extruded into the spinning bath, as in the viscose rayon process, the stability of cellulose xanthate sol in the presence of electrolytes has been studied. Coagulation values for various salts and mixtures of salts on cellulose xanthate are reported. From these values a classification of ions according to their coagulating power and mechanism of coagulation has been suggested. In similar fashion, the behavior of salt mixtures on cellulose xanthate sol has been classified as additive, sensitizing, or antagonistic in accordance with colloid-chemical theory. The rate of coagulation by different ions and the influence of the degree of sulfidity and the degree of polymerization of the cellulose xanthate on the coagulation values are discussed. These data can be corre lated with changes which take place in the course of fiber formation during viscose rayon spinning.
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.
Mechanics of Elastic Performance of Textile Materials
Authors: Platt Milton M.
Published: March 2008

The study of the influence of textile geometry upon textile structure performance is extended to staple-fiber yarns. Methods previously developed for continuous-filament yarns [6] are applied to determine the theoretical dependency of staple-yarn tensile characteristics upon the stress dis tribution, and modifications thereof introduced by yarn twist, size, staple length, and inherent fiber properties. Both one-time loading to rupture and repeated-stress properties of acetate rayon and cotton yarns of various geometries are considered, and comparisons are made between experi mental and theoretical data.
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.
Wool as an Apparel Fiber
Authors: Hopkins Giles E.
Published: March 2008

The author of this paper, admittedly interested in the utilization of wool, has made a study of present scientific and technical knowledge concerning the functional requirements of clothing and the properties of textile fibers. He discusses some of the principal factors governing fiber and fabric relationships as they relate to the requirements of apparel fabrics, such as bodily comfort and protection as well as appearance and style. The paper should be of value to all persons who are inter ested in the development of improved apparel textiles irrespective of their interest in particular types of fibers.—Editor
Specific Volume of Native Cellulose
Authors: Stamm Alfred J.
Published: March 2008

Specific-volume measurements of native cellulose determined in different media and calculated from x-ray data are compared. Data for the specific volume of cellulose containing different amounts of water measured in a benzene medium are analyzed. On the assumption that the differ ence between the specific volumes measured in benzene and the specific volume calculated from x-ray data is due to voids, and that the differences between the x-ray value and the values deter mined in water are due to the compacting of water, reasonable compression values are obtained that are in accord with the concept of hydrogen bonding of water and other findings.
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.
The Preparation of Water- and Alkali-Soluble Cotton Yarns
Authors: Reid J. David , Daul George C. , Reinhardt Robert M.
Published: March 2008

Reports in the public press have confused the two types of soluble yarns produced in the Southern Regional Research Laboratory. This letter differentiates between the alkali-soluble metal carboxymethylcellulose fibers previously described and the new water- or alkali-soluble modified cotton yarns. A typical method of preparation is described.
The Action of Alkali on the Epicuticle of Wool
Authors: Lagermalm Gösta , Philip Bo
Published: March 2008

A short-time treatment for isolating epicuticle from wool is described. Electron micro graphs showing the penetration and disintegrating of the epicuticle caused by dilute Na2S or KOH are shown. These phenomena and their connection with the increased dyeing velocity and some other phenomena after treatment with alcoholic KOH are discussed.
A New Wool-Destroying Fungus— Ctenomyces Species
Authors: Sen Gupta S.R. , Nigam S.S. , Tandan R.N.
Published: March 2008

A species of Ctenomyces has been isolated from damaged woolen material. The morphol ogy, nature of growth, and other characteristics of the species are herein described. Its capacity for deteriorating woolen material is very high and it may therefore be used as a test organism for determining the efficiency of rotproofing treatments on wool.
Limitations of the Arealometer Method for the Measurement of Fiber Diameters
Authors: Dalla Valle J.M. , Orr C. , Cornwall R.R.
Published: March 2008

The surface area and hence the diameter of a variety of fibers calculated from arealometer data using the Lea and Nurse equation decrease with decreasing sample-bed porosity, indicating that the influence of porosity should be quantitatively determined. Previously suggested correla tions for such data are found to be of little value for fibrous materials. A new correlation is offered which indicates that a definite porosity function is associated with each material.
A Foam Method for Degumming Raw Silk
Authors: Bryant F.
Published: March 2008

A foam method for degumming raw silk skeins is described. The yarn produced is free from tensile strength degradation and even after coning presents a clean cone free from hairiness or broken filaments. The winding efficiency of such yarn has been found to be quite superior to that of yarn degummed by the more usual methods. It is suggested that a large part of the variation in the published values for certain physical properties of fibroin— e.g., isoelectric-point pH—may be due to variation in the initial material which could arise from the use of different degumming procedures.
Factors Which Influence the Kinetics of Cellulose Reactions
Authors: Heuser Emil
Published: March 2008

An attempt has been made to show that the course of cellulose reactions in which the latter's hydroxyl groups are involved is governed by its physical structure (microscopical and sub- microscopical) as well as by the chemical nature of its hydroxyl groups. It would seem that for reasons not yet always clearly understood either one or the other of the two factors predomi nates— i.e., the physical accessibility of the hydroxyl groups, as dependent upon the crystalline- to-amorphous ratio, or their intrinsic chemical reactivity, as dependent upon the position of the hydroxyl groups in the anhydroglucose units. Practically all cellulose reactions may be grouped into four main "possibilities." These are discussed and illustrated by concrete examples, such as oxidation with various agents, etherification and esterification, sorption of water, exchange with heavy water, the action of sodium metal in liquid ammonia, and various other reactions.
Air Porosity of Open-Weave Fabrics* Part I: Metallic Meshes
Authors: Robertson A.F.
Published: March 2008

A method is proposed which has been experimentally verified for analyzing porosity‡ data in terms of two dimensionless parameters—the discharge coefficient and Reynolds number—char— acterizing the flow through interyarn pores of a metallic fabric. It is experimentally shown that porosity data for wire screens ranging in texture from 8 to 120 wires per in. and in porosities from 30 to 680 ft.3/ft.2, min. can be plotted within rather narrow limits as a single line relating the two dimensionless flow coefficients.
Stabilization of Zein Filaments by Baking
Authors: Croston C. Bradford , Evans Cyril D.
Published: March 2008

Stabilization of filaments spun from formaldehyde-treated alkaline dispersions of zein is ob tained by baking at 160°C. A decreased shrinkage in water at room temperature is particularly evident in the larger filaments or bristles and is adequate for many purposes. Strengths are not appreciably reduced by the treatment.
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.
Color Changes in Wool During Processing
Authors: Mersereau E.P. , Rainard L.W.
Published: March 2008

Color is an important physical property of wool fibers which can be defined with the aid of color- measuring instruments. The color of a fiber is a limiting factor in the range of shades into which the fiber can be dyed. Color changes which occur to the wool substrate itself during normal proc essing steps, such as scouring, carbonizing, bleaching, dyeing, steaming, drying, and others, are sig nificant in terms of the resulting limitations imposed on the shades obtainable. 'I'he size of the re flectance-level changes occurring in these processes is given and related to changes in utility and value of the fiber.
Interfiber Stress and Its Transmission
Authors: Finch Rogers B.
Published: March 2008

A method is described for revealing the contact area between a plane and a fiber under the action of a transverse pressure distribution. It involves pressing the fiber against a plane-glass surface which has been lightly smoked with a gas flame and measuring the resultant impression microscopically.
Stress Relaxation and Dynamic Properties of Polymers
Authors: Tobolsky A.V. , Dunell B.A. , Andrews R.D.
Published: March 2008

The mechanical behavior of an idealized linear polymer is discussed in terms of the Maxwell relaxation theory. When a simple rectangular distribution of relaxation times is assumed, it is shown that the dynamic properties can be related to those deduced from stress relaxation data by the equation: where ηdyn is the dynamically measured internal friction or viscosity, ω the radian frequency, and E° the negative slope of the relaxation curve plotted as reduced stress vs. log10 time. Appli cation of this equation to values of ωηdyn and stress relaxation data on rubbers obtained by Dillon, Prettyman, and Hall [5] and data on textile fibers by Dunell and Dillon [6] is made. Better than order-of-magnitude agreement was obtained between dynamically measured values of ωηdyn and those calculated by the above equation for the series of rubber stocks and fibers considered. The theory presented has interesting implications in regard to the structures of the various polymers studied, most of which would not a priori be considered linear in the sense of the idealized model. The relationships deduced from the "box" distribution are extended to other broad distributions of relaxation times.
An Experimental, Gas-Fired, Infrared Textile Slasher
Authors: Rusca Ralph A. , Kyame George J.
Published: March 2008

An experimental, gas-fired, infrared textile slasher designed by the textile engineers of the Southern Regional Research Laboratory is described. The slasher processes warps 21 in. wide on beams with 18-in. heads, and is used in operations of pilot-plant scale. Among the features which represent departures from conventional methods of textile slashing are: a new system for the preparation and distribution of the sizing material; a new and more flexible design of size box; an improved means for drying the size-impregnated warp, which combines the best features of radiant and convection drying methods; and a sensitive drive system capable of controlling the warp tension during processing.
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.
The Improvement of Luster of Cotton
Authors: Fourt Lyman , Sookne Arnold M.
Published: March 2008

Practical details are given for using two different instruments for measurement of the reflectance aspects of the luster of cotton yarns. Typical reflectance curves for cotton yarns differing in luster because of mercerization are discussed and compared with the reflectance and visual properties of fabrics made from these yarns. The physical measurements on yarns are much better correlated with what the eye sees in the yarns or in the fabrics than are the meas urements on these particular fabrics. This indicates that the study of yarns by these methods is useful both for yarn and fabric. In winding the yarns for examination, a cover factor of more than 40 is found to be needed to eliminate the effect of the backing. Other points of tech nique, such as tension in winding, humidity, and the size of apertures in the optical system, produce small variations which, however, need to be cared for by standardization of technique when small differences in luster are being examined.
Application of the Specific Gravity Gradient Column to the Quantitative Determination of Additives in a Base Material
Authors: Stock Charles R. , Scofield Elizabeth R.
Published: March 2008

The requirements for, and limitations of, a method of quantitative estimation of additives in a base material, measured by differences in density, are set forth. The specific gravity gradient column of Linderstrom-Lang is described and discussed in terms of its range, sensitivity, stability, and calibration. The bearing which these factors have on the method is illustrated by an example in which the concentration of a melamine resin, applied to a wool flannel for control of shrinkage, is determined.
The Copper Technique for Dyeing Acrylonitrile Fibers
Authors: Feild T.A. , Fremon G.H.
Published: March 2008

The use of small amounts of dissolved copper in the dye bath to improve the dyeing of acrylonitrile fibers is described. Cuprous copper, obtained by reducing cupric acetate or sul fate in the dye bath, is the preferred form. The technique appears to be specific to acrylonitrile fibers, and is most effective with acid, direct, and soluble acetate dyes. Data on sorption of cop per and of other metal ions by acrylonitrile fibers and various non-acrylonitrile fibers are pre sented, and possible complexes between copper ions and polymeric acrylonitrile are postulated.
Degradation of Cellulose During Mechanical Processing
Authors: Whitwell John C. , Lemiszka Theodore , Hughes Vincent L.
Published: March 2008

Previous work [9] on the degradation of cotton during mechanical processing has been extended to include a study of the action of the pickers under various operating conditions. The results indicate that blade and carding beater types cause different amounts of degradation, that the amount of degradation caused by a very close setting can be differentiated from that due to wider spacings, and that the speed of rotation of the beater has a degradation effect which is detectable only after several passes—i.e., several consecutive picker operations. The effect of consecutive picker operations under similar conditions of the other variables is readily discernible.
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.
The Molecular Size of Proteins from Several Wools Solubilized in Aqueous Urea
Authors: Ward Wilfred H.
Published: March 2008

The soluble proteins isolated from normal wools differing widely in geographical origin, fineness, and breed show the same behavior in ultracentrifugation and diffusion. The wool protein, made soluble in aqueous 10M urea by reduction, has a sedimentation constant ap proaching 1.2 S at zero protein concentration, referred to water at 20°C. In the presence of 0.2 N lithium chloride the limiting sedimentation constant is 1.6S. The sedimentation con .stant increases with decreasing concentration of either protein or urea. Similar values are found in other media. The diffusion constant of 2% to 3% solutions is 4.9 × 10-7 cm.2 sec.-1, referred to water at 20°C. Corresponding sedimentation and diffusion measurements give the average molecular weight, 14,000, and the unusually high molar frictional ratio, 2.8, suggesting high asymmetry, high solvation, or a combination of these.
Formation of Cellulose Ethers in Water-Repellency Treatment of Cotton with Stearamidomethyl pyridinium Chloride
Authors: Schuyten H.A. , Weaver J.W. , Frick J.G. , Reid J. David
Published: March 2008

Stearamidomethylpyridinium chloride reacts with cellulosic hydroxyl groups to produce a stear amidomethyl ether of cellulose. Substitutions of 1 stearamidomethyl group per 150 anhydro glucose units have been obtained. The permanent water-repellency obtained on treatment of cotton fabrics with amidomethylpyridinium salts is due to this reaction.
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.
Check Sample Testing of Physical Properties of Cotton with Instruments
Authors: Hopper Turner H.
Published: March 2008

The series of interlaboratory check tests of the physical properties of cotton fibers summarized below represents the first large-scale effort to determine the extent to which different laboratories agree or disagree in their measurements of the fiber properties of length, strength, and fineness. Insetting up these tests, the labora tories were instructed to use their regular test procedures and no effort was made to achieve uniformity of procedure. No one should, therefore, attempt to read into the report reproducibility of results in terms of equipment or methods. It is ex pected that the interlaboratory check sample tests will be continued, and that they will ultimately lead to precisely defined methods that should result in a much better agreement between laboratories. The Task Group on Inter-Laboratory Check Sample Testing of Cotton Fibers has approved the publication of a summary of the restilts of this first series of tests for the information of all laboratories interested in cotton fiber measurements.—Walter M. Scott.†