bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship between the Structural Geometry of a Textile Fabric and Its Physical Properties
Authors: Adams Douglas P. , Schwarz Edward R. , Backer Stanley
Published: March 2008

A simplified nomograph has been designed to permit rapid solution of Peirce's geo metric relationships for plain weaves. To illustrate use of the nomograph, several practical problems in cloth structure are presented and worked out in some detail. Advantages and limitations of the nomograph are discussed.
The Effect of Yarn Twist on Fabric Crease Recovery
Authors: Steele Richard
Published: March 2008

When fabrics are bent or creased in other than the warp or fill directions, the de formation of the individual yarns has a torsional component. The interaction of this component with the twist of the yarn should result in anisotropic creasing behavior in the fabric.

Crease recovery as a function of test direction was measured for a number of fabrics. Anisotropy attributable to torsion-twist interaction was found in cellulosic fabrics when strong directional effects due to such factors as twill ribs were not introduced by the fabric construction. The effect could be qualitatively related to the yarn twists. With fibers of greater intrinsic resilience, such as wool, nylon, or acetate, the crease recovery was essentially isotropic.

When cellulosic fabrics were treated with dimethylol urea, their crease recovery not only became greater but also was more nearly isotropic.
The Reaction of Formaldehyde with Cellulosic Fibers
Authors: Woo H.K. , Dusenbury J.H. , Dillon J.H.
Published: March 2008

The acid-catalyzed reaction of formaldehyde with cellulose has been studied under conditions comparable to those of formaldehyde treatments carried out in textile finish ing plants. Cotton, Fortisan, and viscose rayon fabrics were treated at different pad- bath pH values (2.0, 2.2, and 2.4) and formaldehyde concentrations, at different tempera tures (110°, 120°, and 130° C.), and for different periods of time.

At the higher pH values of 2.2 and 2.4, the cross-linking reaction seems to take place primarily in the amorphous regions of the fibers; at the lowest pH, a very rapid reaction occurs in the amorphous regions, accompanied and followed by diffusion of formaldehyde into the crystalline regions which controls the observed reaction rate. Both the rate and extent of reaction appear to depend on the state of internal order of the cellulosic material, being least for cotton, the material of highest crystallinity. Fortisan and viscose rayon have about the same degree of crystallinity, but the reaction with Fortisan is more rapid which causes the extent of reaction at later times to be greater than that observed for viscose rayon. Two possible explanations are either that the higher orientation of Forti san facilitates the cross-linking process or that recrystallization occurs during acid hy drolysis, and viscose rayon has a relatively higher rate of recrystallization. The results of X-ray diffraction studies carried out on the variously treated cellulosic fibers are con sistent with the proposed reaction mechanisms.
Studies on Water Repellency of Organic Silicon Compounds
Authors: Nakao Kazumune , Wada Nobuaki , Nakasima Kyozo , Nozakura Shunichi
Published: March 2008

A new water-soluble linear methylpolysiloxane containing thiuronium chloride was synthesized. It was shown that this polysiloxane, which is neutral in aqueous solution, imparted durable water resistance to fabrics with alkali treatment, heat treatment, or aging. The water resistance and durability is mainly due to formation of insoluble tri functional methylpolysiloxane resin on the surface of the fabric.
Water Transport Mechanisms in Textile Materials1 Part I: The Role of Yarn Roughness in Capillary-Type Penetration
Authors: Hollies Norman R. S. , Kaessinger Martha M. , Bogaty Herman
Published: March 2008

The movement of liquid water in fiber assemblies such as yarns and fabrics is examined in terms of a theory of water transport based on a capillary penetration mechanism. Yarn construction features, such as twist, diameter, crimp, and fiber denier, are shown to be related to the rate of water transport in such fiber assemblies. From measure ments of yarn and fiber water contact angles, it is shown that water transport in yarns is only slightly influenced by the wetting properties of the individual fiber materials and depends mainly on the wetting behavior of the whole yarn. Increase in yarn roughness due to random arrangement of its fibers gives rise to a decrease in the rate of water transport, and this is seen to depend on two factors directly related to water transfer by a capillary process. (1) The effective advancing contact angle of water on the yarn is increased as yarn roughness is increased. (2) The continuity of capillaries formed by the fibers of the yarn is seen to decrease as fiber arrangement becomes more random. The measurement of water transport rates in yarns is thus seen to be a sensitive measure of the properties of fiber arrangement and yarn roughness in textile assemblies. The present studies on cotton, nylon, Dacron, wool, and wool blended yarns thus indicate that an appropriate choice in fiber crimp, fiber denier, yarn size, and blend uniformity are all important in obtaining blended fabrics of desired properties.
Static Electrification of Filaments Theoretical Aspects1
Authors: Hersh S.P. , Montgomery D.J.
Published: March 2008

A theoretical model based on the band structure of the solid state is proposed in order to describe the transfer of charge when two solids are rubbed together. Only the struc ture in the interior is considered, the interpenetration of the bodies being supposed deep enough that the effects of foreign surface layers and of surface states are slight. The theory is applied to data on static electrification of filaments rubbed together under con trolled ambient and mechanical conditions. The theory provides a semiquantitative de scription of most of the observed phenomena.
Cellulose Interactions with Certain Textile Resins
Authors: Lineken E.E. , Davis S.M. , Jorgensen C.M.
Published: March 2008

It is known that certain resins when applied to cellulosic fibers will impart wrinkle recovery improvement to the fabric. This improved property is shown to vary directly with the amount of chemical reaction between the resin and the cellulose. The evidence for this is obtained primarily from infrared spectra. These spectra were obtained from cellophane films to which resin had been applied by techniques known to give varying wrinkle recovery. The type of chemical reaction with cellulose is shown to be the same for a number of resins and for formaldehyde.
The Absorption of Dyes by Cellulose Acetate from Nonaqueous Media
Authors: Heit Calvin , Moncrieff-Yeates Mary , Palm Ann , Stevens Mildred , White Howard J.
Published: March 2008

Results are given for the absorption of three disperse dyes by secondary cellulose acetate from solutions n benzene at 25° C. and 35° C. Additional results are given on the absorption of one of the dyes from solutions in methanol, butyl acetate, and carbon tetrachloride at 25° C. Formally the isotherms can be well represented by Langmuir's equation.

The results obtained using different solvents show that, in general, the solvents do not act as inert transfer media but effect the basic absorption process for the dye. It is shown that the results can be explained if it is assumed that some solvents compete with the dye for absorption sites within the fiber.
Epoxy Resin Blended Finishes for White Cottons'
Authors: Gagliardi D.D. , Shippee F.B.
Published: March 2008

New finishes based on blends of epoxy resins with selected aldehydes, acetals, formaldehyde-amino resins, hemiacetals, and polymeric materials such as silicones, polyethylene, polyacrylates, and epoxy based plasticizers have been explored to produce new and improved effects on white cotton fabrics. With some of the formulated blends, durable wash-and-wear finishes, crease resistance, and dimensional stability are obtained which will stand repeated laundering and chlorine bleaching operations. An outstand ing finish for white cottons has been developed based on combinations of epoxy resins with dimethylol ethylene urea.

The practical conditions of cloth preparation, drying and curing cycles, choice of catalysts, washing procedures, and afterfinishing operations are described for obtaining optimum results. Also discussed are the limitations of these and other presently avail able finishes for cotton, with special emphasis on some theoretical possibilities for new cotton fiber modification.
Fiber Structure and Mechanical Properties of Untreated and Modified Cottons
Authors: Orr Rollin S. , DeLuca Lloyd B. , Burgis Albert W. , Grant James N.
Published: March 2008

A brief review of investigations relating fiber structure to mechanical properties of cotton is given. The relationship of fibril alignment, as measured by the x-ray technique, to the strength and elongation properties of cottons covering a wide range in physical properties is discussed.

Alteration of mechanical properties of cotton brought about by degradation in hydrochloric acid, mercerization, decrystallization in ethylamine, resin treatment, and acetylation are related to changes in the fiber structure. The effects of stresses imposed during some treatments are discussed.
Concerning the Mechanisms of Fiber and Yarn Lubrication
Authors: Schlatter C. , Olney R.A. , Baer B.N.
Published: March 2008

In the past, the main approach to the problems of friction and its modification, as they apply to textile structures, has been to determine the coefficient of friction and to develop a general determinant for this constant. It is suggested in this paper that a quantitative measure of the frictional relationships between fiber and fiber or between fiber and some other material, rather than being a reasonably constant quantity, is a highly unreasonable variable. This is especially true if the fiber is coated with a finish, which is usually the case; then in addition to depending on such variables as contact pressure and area, stress-strain characteristics of the fiber, etc., the coefficient of friction will depend on such factors as the physical and chemical Characteristics of the finish, the amount of finish present, the relative speeds of the surfaces in frictional contact, and so on.

The authors feel that it may be of greater practical significance to evaluate qualita tively the changes that take place in the frictional characteristics (type as well as magnitude) with given changes in the above-described variables. The observed behavior may then be related to performance in the various unit processes employed in textile manufacturing. Evidence justifying this point of view is presented in the paper, and some rather speculative explanations correlating finish properties and frictional behavior are given.
A Two-Phase Structure for Keratin Fibers
Authors: Feughelman M.
Published: March 2008

A two-phase structure is proposed for keratin fibers consisting of a water-absorbing matrix M, in which non-water-absorbing cylinders of phase C are embedded. The cylinders of phase C are parallel to the fiber direction. The main assumption made is that only the mechanical moduli of phase M are affected by moisture uptake as long as the fiber is not stretched. On this basis, using the longitudinal and radial swelling data available, quantitative relationships between the dry and wet Young's Moduli and rigidity moduli were obtained which agreed with experimental results. Further, other physical observations were shown to be compatible with this model.
A Study of the Relationship Between Breaking Time and Breaking Load for Fabrics Tested on CRE and CRT Machines
Authors: Tweedie Audrey S. , Mitton Margaret T. , Fry J. Margaret
Published: March 2008

A study has been made of the relation between breaking time and breaking load for six different fabrics, using 1-in. ravelled strips with 3-in. initial clamp separation, tested on a constant-rate-of-specimen-extension (CRE) machine operated at a number of rates of extension, i.e., cross-head speed. The fabrics used were cotton nainsook, heavy cotton duck, acetate/viscose gabardine, viscose crepe, and nylon taffeta, so as to cover a range of extensibilities and breaking loads. In general these fabrics showed a decrease in breaking load with increase in breaking time, as has also been reported in the literature for studies on fibers and yarns.

Tests were also carried out on constant-rate-of-traverse (CRT) pendulum machines at two or three different speeds for each fabric. Good agreement was obtained between the breaking loads measured on the CRE and CRT machines when compared at equal breaking times.

To put the measurement of breaking load of fabrics on a constant-breaking-time basis appears to offer the best means of obtaining comparable results with different types and capacities of testing machines. A breaking time of 20 ± 3 sec. has recently been proposed by ISO/TC 38 for single-strand testing of yarns on CRE, CRT, and CRL (constant-rate-of-loading) machines. The data obtained in this study on fabrics suggest that a breaking time of 20 ± 3 sec. will also be suitable for the measurement of the break ing load of fabrics on different types and capacities of machines. No evidence was ob tained in favor of a longer breaking time such as the 60 ± 10 sec. commonly used with CRL machines abroad.
Rheological Interpretation of the Mechanism of Crease Recovery of Fiber
Authors: Sobue Hiroshi , Murakami Kenkichi
Published: March 2008

In an attempt to interpret the mechanism of creasing and the recovery therefrom, a theoretical study of the visco-elastic behavior of fibers and or filaments has been made. The relationship between crease angle of fiber, temperature, and creasing time is discussed theoretically and experimentally.
Chemical and Physical Effects of Finishing Cotton With Methylol Derivatives of Ethyleneurea
Authors: Frick J.G. , Kottes Bethlehem A. , Reid J. David
Published: March 2008

A study has been made of the mechanism by which cotton is made wrinkle resistant by dimethylol ethyleneurea. Estimates are made of the length of cross-links and the relative effect of several factors, including processing conditions, cross-linkage, and acid damage, on the loss in strength of the fabric on treatment. '

Various methylol derivatives of ethyleneurea were used in the study of the effect on chemical and physical properties. It has been demonstrated that the methylol deriva tives of ethyleneurea react chemically with cellulose under the influence of acidic catalysts. Metallic salts are most efficient in promoting this reaction. Both mono functional and difunctional compounds react with the cellulose. The latter, however, cause cross-linkage, which effects marked changes in the physical properties of the treated cotton fabric, particularly wrinkle resistance. Dimethylol ethyleneurea forms cross-links averaging 1.4-1.5 ethyleneurea residues in length. These residues are con nected by methylene groups. The effects of variations in catalyst, composition of the finishing agent, and curing conditions are shown. Relation of the findings to practical finishing is discussed.
Some Observations on the Vibration and Whirling of Continuously Loaded Spindles
Authors: Wroe D. , Nissan A.H.
Published: March 2008

Formulas are derived for the frequency of flexural vibration of a vertical uniformly tapered circular shaft mounted at one end. The Rayleigh and Dunkerley methods are used and the results compared both with known results of exact analysis and with experi ment.

On the basis of an extension of Dunkerley's principle, a simple formula is derived for the effect of the mass of a textile package on the critical speed of a vertical shaft held at its base.
Part II: Effects of Strains During Swelling, Washing, and Drying
Authors: Orr Rollin S. , Burgis Albert W. , Creely Joseph J. , Mares Trinidad , Grant James N.
Published: March 2008

Yarns from samples of Pima S-1 and Hopi Acala varieties were merceriud and decrystallized when strain was controlled to provide unrestricted shrinkage in length, normal length, and 3% extension beyond normal length during ethylamine treatment. Comparisons of effects of sodium hydroxide and ethylamine at different strain conditions were made from measurements on the cellulose, tensile properties of fiber bundles and yarns, and elastic behavior of the yarns. Densities of the mercerized are in general below those of the decrystallized if occluded solvents are removed. The lower densities are in accord with the higher moisture regains for mercerized than decrystallized cottons.

Strains had no influence on the crystallinity ratio during decrystallization but pre vented complete conversion to cellulose type II in mercerization. The decreases in bundle tenacities with increases in gauge length were essentially equal in the decrys tallized and untreated cottons but smaller in the mercerized. Yarn tenacities of the mercerized and untreated increased as the moisture regain was increased, white those of the decrystallized were essentially equal at standard and wet conditions. Elongation at break was decreased by strain during treatment and increased with moisture in the sample when tested. The slack mercerized or decrystallized yarns when strained to less than 2% of their elongation at break have greater recovery and less permanent set than the untreated. At high strains or stresses the reverse in recovery and permanent set was found. Yarns treated at normal length have no appreciable difference in re covery and permanent set from that of the untreated.
The Crimp of Alkali Treated Jute Fibers
Authors: Lewin Menachem , Shiloh Miriam , Banbaji Joseph
Published: March 2008

An investigation of the formation of crimp on jute fibers by the action of alkali is presented. Jute fiber-like strands are treated with various concentrations of NaOH under various conditions of temperature and time. As the result of the treatment, crimp is formed on some of the samples prepared. The measurements of crimp are carried out by a method developed by this Institute for single fibers which is adapted to the jute. The crimp diameter, the crimp ratio, the extension, and the wave number are quantitatively determined for the various jute samples as a function of the load applied to the fiber. An uncrimping energy of extension which sums up the extension over the range of loads used is measured. No crimp is formed at NaOH concentrations lower than 6%. At higher concentrations the crimp parameters increase to maximum values at 9% alkali, and thereafter decrease to constant levels. The crimp is formed after 0.5 hr. of treatment. The optimum temperature for the formation of the crimp is around 2° C. With increase in temperatures the values of the crimp parameters decrease, and at 40° C. no crimp is observed.
Studies of the Movement of Wool Fibers in Fabrics During Felting, With Particular Reference to the Permanency of Pleats
Authors: Makinson K. Rachel
Published: March 2008

Pleats in a worsted fabric which were fast to relaxation in hot water were readily destroyed by light hand washing. This has been shown to be due to small movements of the fibers, of the order of 0.5-1.0 mm. These movements are the initial stage of felting. They destroy the pleats by blurring the position of the region of maximum set and by imposing temporary opposing sets on the fibers. The shape of the fibers has been studied, and their radius of curvature and two other parameters have been meas ured.

Fibers from unpleated regions of the fabric undergo similar movements and deforma tions on washing, but their overall shape is unchanged, since it is determined by the geometry of the fabric.
Frictional Measurements on Fibrous Materials
Authors: du Bois W.F.
Published: March 2008

A method for measuring the coefficient of static friction is described. Results ob tained on various materials are given. A statistical analysis of the relationship between frictional force and normal load does not confirm the empirical equations given by other workers, but leads to a quadratic formula.
Electric Network Analog Study of Viscous Flow Normal to Parallel, Evenly Spaced Cylinders
Authors: Shearer J. Lowen
Published: March 2008

In connection with the study of viscous flow of liquids and gases between textile fibers, an electric resistance network analog was employed to solve the Navier-Stokes equations for creeping flow normal to an infinite array of circular cylinders arranged in a hexagonal pattern. The results of the analog study predict flow resistances approximately four times as great as those measured with real packages of fibers. The factor of four diner ence between predicted and experimentally measured resistances is very likely due to the uneven spacing of fibers in the real case, giving some very large passages which offer relatively little resistance to a significant fraction of the flow.

However, the variation of flow resistance with porosity appears the same, on a per centage basis, for the analog prediction based on equally spaced fibers as for the experi mentally measured resistance of real fiber masses which are unequally spaced in a random fashion.

Thus neither the predicted nor measured flow resistance varies with fiber mass porosity in accordance with the Carmen-Kozeny formula which has been successfully applied to flows through granular beds; there is now little reason to believe that the large variation of the Kozeny "constant" with porosity of the fiber mass is due simply to shift of passage size distribution with degree of packing of the textile fibers.
Interpretation of Fiber Properties
Authors: Lefferdink T.B. , Briar H.P.
Published: March 2008

The resistance of fibers to fracture due to fatigue in flexure is shown to correlate with the wear life of socks and can be used to explain other fabric abrasion resistance phenomena.

When single fibers are flexed over a rounded metal bar, the log of the number of flexures to failure has been found to be approximately linearly related to the radius of curvature of the surface of the bar and to the tension on the fiber during the test. An empirical equation is presented relating these variables along with some of the deter mined values for the various proportionality constants for several common fiber types.

The relative resistances of different types of fiber to scraping and grinding actions of emery particles was measured and compared with the generally accepted abrasion resistance of fabrics of these fibers. The correlation was so poor as to indicate only a slight probability that the grinding mechanism plays an important role in normal fabric abrasion.
Adsorption of Labeled Sodium Carboxyrnethyl Cellulose by Textile Fibers
Authors: Hensley J.W. , Inks C.G.
Published: March 2008

A carbon-14-labeled sodium carboxymethyl cellulose (CMC) has been employed to measure its adsorption by textile fibers, and in the case of cotton, to investigate the relationship between adsorption and detergency action. Adsorption of CMC by cotton was found to depend on the presence of excess cations in solution, increasing with cation concentration and valence. Equilibrium adsorption of CMC in the presence of excess cations was found to have a zero temperature coefficient. Variation of pH within the alkaline range had no significant effect. Limited measurements with fibers other than cotton indicated little or no adsorption by wool, Orlon,2 or acetate (in the presence of excess cations). There was significant adsorption by nylon and rayon, but this ad sorption was greatly reduced by addition of an alkylaryl sulfonate. Detergency evalua tions with the labeled CMC and with unlabeled material indicate that CMC adsorbed on cotton has a significant action in preventing redeposition of particulate soil materials. The adsorption and detergency data indicate that the quantity of CMC required to form a monomolecular layer on cotton fibers may be on the order of 400-500 micrograms per gram of cotton.
Some Mechanical Properties of Single Wool Fibers in D2O
Authors: Feughelman M. , Haly A.R. , Mitchell T.W.
Published: March 2008

Both the load-extension and the stress—relaxation curves were compared in the yield region for single wool fibers in water and in deuterium oxide. Also a comparison was made of the rate of penetration of water and deuterium oxide fronts into a dry fiber. In all cases the deuterium oxide acts in the wool fiber the same as water with the temper ature of the fiber reduced by about 5-6° C.
Polyolefin Fibers and Polymer Structure'
Authors: Erlich Victor L.
Published: March 2008

The polyolefins (or, more restrictedly, the poly-alpha-olefins) are a growing family of polymers which comprise the straight linear polyethylene or polymethylene and its derivatives. Their fiber-forming properties are based on the paraffinic backbone com mon to all these polymers; the derivatives can have an infinite variety of structures, and this has an extremely pronounced influence upon the fiber properties. Present polymerization chemistry and technique permit close control of these structures to a high degree of purity and in turn the control of the fibers processed therefrom.

Length and distribution of the molecular chains, their stereospecific configurations, and crystallinity and its degree are shown in their effect on the polyethylenes (low to high density) and on polypropylene, and future developments are foreseen.

The case of the polyolefin fibers is not that of "one more" synthetic fiber ; the polyolefins may well become the classical, even textbook example of the intricate relationship between molecular structure and fiber properties.

As a new textile material the polypropylene fiber is of particular interest economically and in its characteristics—all the more so as problems such as ultraviolet stability and dyeability are being overcome.
Blending Cottons Differing Widely in Maturity
Authors: Fiori Louis A. , Louis Gain L. , Sands Jack E.
Published: March 2008

The blending of extremely fine and coarse cottons was investigated as a possible way of economically using these difficult-to-market cottons in the blended form. Two cottons differing appreciably in fiber fineness (approximately 3.0 and 6.0 μg./in.) but having other pertinent fiber properties about equal were blended together to produce a mixture averaging about 4.0 μg./in. in fineness. For comparative purposes a control cotton also averaging about 4.0 μg./in. in fineness was used. The blended and control cottons were spun into coarse and medium yarns of varying twists and into yarn num bers suitable for weaving Type 128 sheeting (64 X 64). The spinning efficiency of the two cottons was evaluated, on a pilot plant basis, in terms of ends down per thousand spindle hours.

Waste, nep count, yarn properties (skein and single strand strength, break elonga tion, uniformity, and grade), and end breakage rate in spinning were similar for the blended and control cottons. Microscopical examination of yarn cross sections did not reveal any migratory tendencies of either the fine or coarse fibers. For the same yarn number the blended and control cottons produced yarns of similar diameters and softness values.
Nylon 6—Current Developments
Authors: Nesty G.A.
Published: March 2008

Epsilon polycaproamide (nylon 6), with more than twenty years' effort behind it in Europe, is now established as a commercial fiber in the U.S. Historically, its de velopment goes back at least sixty years, when it narrowly missed becoming the first truly man-made fiber. Although the molecular structure of nylon 6 is almost identical to that of nylon 6,6, its melting point is lower, probably due to special entropy con siderations. Thus nylon 6 permits easier and more economical thermal processing. Thermal properties of the two nylons, even when both are modified with antioxidants, are seen to be similar in many respects, but the 6 type has more resistance to thermal creep at high loads and is more stable with respect to end-group changes. A major domestic producer has developed technology solving the old problem of excessive monomer content without resorting to washing of yarn. Properties, applications, and current developments of various forms of nylon 6 fibers are described. A large potential is shown to exist for expanded use of this versatile fiber.
Influence of Na5P2O10-CaCl2-H2O Phase Equilibrium on Laundering of Cotton Fabric
Authors: Diamond W.J. , Grove J.E.
Published: March 2008

Study of the phase equilibrium diagram for the CaCl2-Na5P2O10-H 2O system sug gested that washing phenomena would depend on the phase region as well as specific CaCl2 or Na5P2O10 concentration.

Radioactive zirconyl phosphate was used as a redeposition soil, and tagged sodium alkyl aryl sulfonate was used for determination of detergent adsorption on cotton fabric. Ca ++ concentrations from 0 to 5.5 mmoles/l. were reacted with sodium tripolyphosphate concentrations from 0 to 32 mmoles/l.

The quantity of radioactive ingredients deposited was measured after a 10-min. wash cycle in a Turg-O-Tometer. Desorption by a 5-min. rinse cycle was also evaluated. Both redeposition and rinsability depend upon the CaCl2-Na5P2O 10 phase region in which washing is performed.

Higher tripolyphosphate concentrations in the wash cycle retard redeposition and promote the rinsing of detergent from cotton fabrics. Hardness of water definitely influences both redeposition and rinsability. The influence of tripolyphosphate on re deposition is most pronounced at low soil loads.
A Rheological Interpretation of the Hottenroth Index Method for Viscose
Authors: Onogi Shigeharu , Hayashi Yoshiki
Published: March 2008

Some rheological properties of viscose during titration with various salt solutions, especially ammonium chloride, have been studied by employing a new automatic tester. The principle of the tester is to record automatically the change in viscosity of the viscose sample during titration with salt solution; the change in torque required for stirring the sample at constant velocity is converted into the change in electrical potential by means of a linear variable differential transformer device. From the experi mental results it is concluded that the conventional Hottenroth index method for de termining the degree of ripeness of viscose does not always determine a volume of 10% NH4Cl solution by which coagulation of the viscose sample just sets in. On the other hand, it has been found that viscose with ammonium chloride solution added manifests a thixotropic nature, and a new rheological interpretation has been put on the Hottenroth index method; it measures a volume of 10% NH 4Cl solution by which a viscose sample becomes notably thixotropic.
Stress Relaxation and the Transition Temperature of Wool
Authors: Rigby B.J.
Published: March 2008

The stress-relaxation behavior of a number of chemically and physically modified wool fibers has been examined and shown to correlate with the temperature of transition of the particular modified wool. The transition temperature has been discussed previ ously by Feughelman, Haly, and Rigby. Below the transition temperature the stress decays in 1 hr. by 33%, and above the transition temperature by 73%, of its initial value. These quantities are independent of the particular modification and appear to be associated with reversible and nonreversible transformations of native keratin.
Behavior of Pleated Strips of Wool Fabric in an Extensometer
Authors: Holdaway H.W.
Published: March 2008

Certain aspects of the elastico-mechanical behavior of pleated strips of worsted wool fabric have been examined using a specially constructed extensometer. On subjecting the pleat specimens to cycles of extension and retraction, the load-vs.-extension charac teristic settled down to a repeatable hysteresis loop after about eight cycles. The loop area being relatively small, a study was made of an ''ecluivalent hysteresis-free" mean characteristic. This was found to indicate behavior which to the first order was that expected of a flat strip of linear-Hookean material having a fixed "pleat angle" at the midpoint. It should be possible to develop a relatively simple apparatus to examine pleat sharpness using the technique described here of taking successive superimposed flash photographs while extending the pleat specimen.
Reaction of Wool with Oxidizing Agents in Concentrated Salt Solutions
Authors: McPhee J.R.
Published: March 2008

Concentrated salt solutions protect wool from oxidative degradation. Oxidizing agents produce a higher degree of shrink resistance in concentrated salt solutions than in the absence of salt. Many oxidations, followed by a reduction, shrinkproof wool when either treatment alone does not.

Results support the idea [20, 46] that attack on disulfide bonds is the only primary reaction during chemical shrinkproofing and that attack at some other point of the protein structure need not occur. However, breaking of disulfide bonds is not sufficient in itself to produce shrinkproofing effects, and the exact nature of chemical changes leading to shrinkproofing is unknown. No conclusive evidence has been found to decide whether or not changes in frictional properties are the general cause of shrinkproofing.

Evidence is given that, under conditions where swelling is less than in simple aqueous solutions, reaction still occurs throughout wool fibers rather than only at the surface.

The results do not agree with theories which suggest that shrinkproofing is due in some way to formation of degraded layers of protein material in wool fibers.
An Entropy Stress Study of Various Textile Fibers
Authors: Dart S. Leonard
Published: March 2008

A stress-strain study has been made of various fibers to determine their entropy force behavior at room temperature. The relative importance of the entropy and internal energy forces is shown with some illustrations of the use of these quantities in under standing the fine structure of polymers. Details are presented to show the effects of extension and godet stretch on some samples.
Correlation between Colorfastness and Structure of Anthraquinone Blue Disperse Dyes
Authors: Salvin Victor S. , Walker Ruth A.
Published: March 2008

A correlation is estahlished between the structure of blue amino anthraquinone dyes for cellulose acetate, cellulose triacetate, and the polyester fibers and the colorfastness they exhibit towards the atmospheric agents responsible for gas and ozone fading and towards the action of light. Any structural modification which reduces the electron density on the amino nitrogen attached to the anthraquinone ring, whether it is an amino, an alkylamino, or an arylamino nitrogen, will increase the resistance of the molecule to the electrophilic agents responsible for the chemical changes which occur during fading. Several anthraquinone structures with improved resistance to fading are reported. These contain, as substituents on the arylamino radical, groups which withdraw electrons from the aromatic ring, leaving the amino nitrogen with a low electron density.
Part II: The Amino-Acid Composition of Oxidized Normal and Copper-Deficient Wool Fractions and Further Attempts at Fractionation
Authors: Burley R.W. , Horden F.W.A.
Published: March 2008

The amino-acid compositions of oxidized normal and copper-deficient wool from one sheep and of two components separated from them at pH 6 have been measured by ion exchange chromatography. The differences between the "soluble" and "insoluble" components are those expected from previous work. The "insoluble" components from normal and copper-deficient wool appear to be identical, although there is a small dif ference in the "soluble" components. Attempts at fractionating the "soluble" components , by chroniatogrtphy, paper electrophoresis, and dialysis gave indications of heterogeneity but were not very successful.
The Direct Nitration of Flax and Jute
Authors: Lewin Menachem , Epstein Joseph A.
Published: March 2008

Three samples of flax and one sample of jute were nitrated with a mixture of HNO3/H 3PO4/P2O5 for several lengths of time, ranging from to 72 hr. The crude nitrate, Fraction A, was extracted with acetone and the acetone extract precipitated with water, giving three fractions: A1, the acetone-soluble fraction precipitated by water, A2, the acetone-insoluble fraction, and A3, the acetone- and water-soluble fractions. The DP's of Fraction A1 were determined. The mode of variation of the amount of Fraction A2 with time of nitration suggests the existence of intercarhohycirate links in jute but not in flax.
Kinetic Study of the Wool-Water System
Authors: Watt I.C.
Published: March 2008

The kinetics of the uptake of water vapor by wool is dependent on the initial con centration of water and the size of the concentration increment. For small concentration increments, absorption may occur in two stages, the second stage much slower than the first. For any set of conditions, the previous treatment of the wool with respect to water vapor affects the observed kinetics and the equilibrium concentration of water in the fibers. It is shown that first stage absorption to a quasi-equitibrium obeys Fick's laws of diffusion with a concentration-dependent diffusion coefficient. The apparent activation energy of diffusion varies with concentration. Second-stage absorption is accompanied by irreversible configurational changes within the fibers. Detailed data of two-stage behavior is presented in order to test the relevance to the wool-water system of the hypothesis previously proposed that in polymer-penetrant system seçond- stage absorption occurs as a result of stress relaxation within the sorbent.
Effect of Elongation and Temperature on the Recovery and Apparent Glass Transition Behavior of an Experimental Modacrylic Fiber
Authors: Bryant George M.
Published: March 2008

The shape of the stress-strain curve of the modacrylic fiber is correlated in a definite manner with the stress-relaxation and recovery behavior. At the yield point, where the stress-strain curve has minimum slope, the tensile recovery decreases most rapidly with increasing elongation, and the rate of stress relaxation passes through a maximum. Above the normal (low-strain) glass transition temperature of the fiber (90° C.), the stress-strain curve no longer has a yield point, and the recovery and stress-relaxation behavior become relatively independent of elongation.

The tensile- and work-recovery values show a definite minimum (permanent set shows a maximum), occurring at the glass transition temperature at low, 1%, strain, and shifting to lower temperatures with increasing elongation. This shifting of the minimum in the recovery-temperature curves is interpreted to indicate a lowering of the glass transition temperature with stretching. At temperatures of 25° and 60° C., the yield strain approximates that elongation required to reduce the minimum in the recovery-temperature curves to that temperature. These results lead to a fundamental definition of the yield point as the strain level at which the glass transition temperature is lowered to the experimental temperature.

A free volume increase accompanying stretching is postulated as the underlying mechanism whereby the glass transition temperature is reduced. The equations of Ferry [13, 14] indicate that a quite reasonable value of 0.35 for Poisson's ratio could lead to an increase in free volume sufficient to speed up the molecular response by a factor of 105 at the yield strain.
Contribution of Swelling to Water-Resistant Cotton Fabrics
Authors: Goldthwait Charles F. , Sloan William G.
Published: March 2008

A summary of a comprehensive study of the manufacture and finishing of swelling- type water-resistant cotton fabrics of medium weight is presented. These are fabrics which stop the passage of water by the swelling of their constituent fibers. Such stoppage depends upon a zone of very high density flatwise through the fabric. Of many fabrics produced, a few were of swelling type in the grey, but only one after finishing.

Variables which are usually given less consideration, had most attention, viz., maturity, and use of very immature cottons; effects of processing the yarn before weaving; and effects of increasing the tightness of fabrics by adding picks up to 36% more than normal. The fabrics were finished in a pilot plant, and an unusual study was made of the effects of successive steps in finishing on air and water resistance.

Unique fabrics produced showed unusual properties, especially strength and thickness.

Fabrics were evaluated for closing by methods intended to exclude water resistance from other sources than swelling. Many special tests showed that swelling capacity was reduced by finishing, to a greater extent with immature than with mature cottons. The air spaces in dense, grey fabrics of very immature cotton constitute capillary sys tems of unusually fine pores, especially resistant to the passage of air or water. This advantage over mature cotton is largely offset, however, because the immature cotton loses 4-5% more noncellulosic material when scoured, which leaves more space to fill by swelling. Cottons of average maturity, and from fine to average in fineness, are preferable.

Entrapped air in partially swollen fabrics contributed to water resistance beyond the effect of air in ordinary water-repellent goods. This was observed especially in samples swollen in water vapor and may add to the resistance of a fabric in service if exposed to a very humid atmosphere.
The Torsional Properties of Single Wool Fibers. Part II
Authors: Feughelman M. , Mitchell T.W.
Published: March 2008

Torque-twist and torsional relaxation tests on single wool fibers in water over the temperature range 7° C. to 44° C. show a rapid change with temperature. This change indicates that torsional properties are dependent upon a rate process mechanism. In a previous paper it was postulated that these properties can be explained in terms of a matrix in the wool fiber acting as a cross-linked polymer stabilized by a network of polar bonds. The drastic change in torsional properties of the wool fibers when the pH is changed from∼6.5 to 1.0 indicated that some of the bonds are salt-linkages : others will be hydrogen bonds. However, it is pointed out on the basis of the proposed model, that whereas the hydrogen bonds in the network can break and remake during mechanical deformation of the fiber, the salt-linkages on breaking apparently do not remake.
Blending Cottons Differing in Fiber Bundle Break Elongation
Authors: Louis Gain L. , Fiori Louis A. , Sands Jack E.
Published: March 2008

Two control cottons, differing in fiber bundle break elongation, but having other pertinent fiber properties essentially equal, were blended in different percentages, spun into warp and filling yarns, woven into a standard combed broadcloth, and then finished commercially. This report discusses the physical properties of these fabrics. Two cottons having significant differences in fiber break elongation at the fiber stage show very little difference in fabric break elongation after finishing, indicating that the influence of fiber elongation gradually becomes less evident during successive fabric finishing processes. In general, the high elongation fiber cotton produces grey fabric of superior qualities, viz., breaking and tearing strengths, elongation, and flex resistance, when compared with fabric made with low elongation fiber cotton. Furthermore, data also indicate that the values of fabric properties of the blended lots cannot be predicted from those of the controls when the fabrics are subjected to various chemical treat ments. This report corroborates other findings that no apparent advantage, from the standpoint of textile quality, exists in blending low and high elongation fibers— whether in blends of natural-natural or natural-synthetic fibers.
The Supercontraction of Sound and Weathered Keratin Fibers
Authors: Swanepoel O.A.
Published: March 2008

Studies on the supercontraction of sound and weathered wool and mohair fibers have thrown further light on the mechanism of this reaction. It is concluded that the second stage of supercontraction results from the exposure of sterically protected hydrogen bonds. This can occur through disulfide exchange in the highly cross-linked zones of the microfibrils. Some of the cystine cross-links are stabilized by weathering so that disulfide exchange is inhibited, and hence much less contraction occurs.
Relaxation Shrinkage of Wool Fabrics: Its Release with Regain and Time
Authors: Baird K.
Published: March 2008

Relaxation shrinkage occurs in wool fabrics when strains set into the fabric are released, usually by the effects of moisture. In this paper, the dependence of relaxation shrinkage on the amount of moisture added and on the time are examined. It is shown that, for fabrics at various stages of finishing, shrinkage is approximately a linear function of the amount of moisture added, up to the point of fiber saturation. It also appears that shrinkage takes place rapidly, being almost complete within thirty minutes of spraying with distilled water at room temperature.
Dimensional Changes in Multicomponent Systems of Fabrics: A Theoretical Study
Authors: Lindberg Joel
Published: March 2008

In a system of two fabrics attached to each other, dimensional changes may give rise to compression and extension stresses in the plane of the fabrics. High stresses may lead to buckling of the compressed fabric, which may impair the appearance of the system. The paper discusses three different types of dimensional change occurring in practice, namely changes due to external stresses, changes due to setting operations, and changes due to releasing frozen-in internal stresses or producing internal stresses by swelling.

Each of these dimensional changes is defined. Equations are derived which, for a smooth system, give the relation between the initial difference in dimension between the fabrics, dimensional changes taking place after the fabrics are attached to each other, and certain mechanical properties of the fabrics. Three fundamental cloth parameters are shown to govern the results, namely formability, settability, and dimensional stability.
Part V: The Nature of Birefringence
Authors: Haly A.R. , Swanepoel O.A.
Published: March 2008

The birefringence of Corriedale wool fibers was measured at nine different relative humidities. After being corrected for swelling the curve of birefringence against mois ture content showed a minimum at a moisture content of 19% of the dry weight of the wool. At this point the birefringence is probably completely intrinsic, but at other moisture contents there may be a component of environmental birefringence. The curve shape may also be due in part to change of intrinsic birefringence with change of moisture content. Environmental birefringence is not likely to constitute more than approximately 9% of the total birefringence at any moisture content.
A Study of the Interaction between 2-Thiobarbituric Acid and Cotton
Authors: Rebenfeld L.
Published: March 2008

Solutions of 2-thiobarbituric acid have been shown to interact with raw cotton to form colored compounds. This interaction has been previously suggested as a test for radiation-damaged cotton [7]. Experiments were conducted to determine whether this interaction could be used as a diagnostic test for cotton which had been heat-damaged, as might occur during commercial ginning. While this test was found to be sensitive to the heating history of a given cotton, it was not possible to establish suitable absolute standards because of large differences among cottons. Investigation of the differences among cottons revealed that the interaction between 2-thiobarbituric acid and cotton is related to the alkali scourit)le matter in raw cotton as well as to fiber maturity. Possible uses for this test are suggested.