bluuebunny/crossref_metadata_2025 huggingface dataset:
Free Radical Cross-Linking of Synthetic Polymers on Cotton Textiles
Authors: Gonzales Elwood J. , Bullock Joel B. , Welch Clark M.
Published: March 2007

A variety of saturated thermoplastic polymers have been cross-linked as interfiber coatings on cotton fabric, without the cotton cellulose. the polymer with catalytic amounts of benzoyl peroxide or 2,4-dichlorobenzoyl peroxide on fabric at 100-165° C caused fixation of the coatings within a few minutes. Polyvinyl esters, acetals and ethers, and linear aliphatic polyesters were used. Copolymers of vinyl chloride with vinyl esters and with alkyl acrylates were also found applicable.

The efficiency of polymer insolubility was 60-80% and was independent of the fabric used. whether cotton, glass, paper. Orlon,2 nylon, Dacron,3 or acetate rayon, Grafting of polymer to substrate apparently did not occur. Multiple layers of cross-linked coatings were readily formed. Application of poly(vinyl stearate) at add-ons of 4-30% imparted considerable water repellency to cotton and moderately increased the flex abrasion re sistance, while leaving air permeability, breaking strength, and tearing strength essen tially unchanged, Most of the polymer was located in interfiber spaces within individual yarns. Protection of interfiber bonding in cellulose from disruption by water occurred when cross-linked vinyl chloride-alkyl acrylate coatings were used.
Thermal Transitions in Keratin
Authors: Mason P.
Published: March 2007

Wool fibers in water at room temperature were extended by constant loads chosen to produce extensions in the range 0% to 25%. After relaxation for 1 hr, the tempera ture was increased to 100° C at a constant rate of approximately 1° C/min. The length of the specimens increased progressively with the temperature; the increase was taken as a measure of a transformation in the fibers, which embodies both the normal α β phase transition of α-helical proteins as well as other structural changes which may contribute to the free energy of the transition in keratin. On reduction of the temperature from a higher to lower value, there was generally no recovery of length, although in comparable experiments at constant extension there was a considerable recovery of the force.

Under the present conditions, it was not possible to observe the length changes cor responding to the complete transformation. However, families of curves for arbitrary small extensions were obtained for different stresses and used to calculate "effective" thermodynamic parameters appropriate to the time scale of the experiments. The entropy of transition was found to be 6 cal/deg mole of residues, and the heat of transi tion was 3 kcal/mole of residues.

Treatment by formaldehyde or by an anionic detergent appeared to elevate the tem perature range of the transition region, whereas permanently setting the fiber or testing at pH 1 depressed it. Measurements on unmodified wool fibers in water at different temperatures indicated the existence of a viscous flow mechanism with an apparent activation energy of 28 kcal/mole.
Measurement of Opacity in Fibers
Authors: Brody H. , Quynn R.G.
Published: March 2007

A light-transmission measurement was developed to compare opacities of experimental nylon 6-T fibers. A fixed concentration of chopped-up fibers was suspended in a mixture of organic liquids, which matched the average refractive index and density of the fibers, to suppress surface scattering and to prevent settling.

The transmission of any given sample showed a spectral dependence, i.e., decrease of transmission with decreasing wavelength, indicating that the size of the scattering unit was of the order of magnitude of the wavelength of visible liglit. This dependence, as measured with a Beckman spectrophotometer, was analyzed by a semi-theoretical ap proach to yield values of n, the wavelength exponent appearing in the scattering law. The values of n obtained lay between about 0.9 and 2.3 and decreased on boiling, which was to be expected theoretically if the size of the scatterer was increasing. There was a rough correlation, with all the samples, between the n values and the percent transmission at a fixed wavelength, indicating that the differences in "voidiness" among the different fibers were a function of the size of the light scattering unit.

The transmission showed a good inverse correlation with V, the void volume, as calculated from density measurements, assuming a melt-spun sample to be void-free. This suggested that the opacity was indeed caused by voids and not by other kinds of light scatterers—spherulites, gels, etc. There was an excellent correlation between transmission and the quantity V/n, which emphasized the dual dependence of opacity on total void volume and void size.
Studies on Cotton Crimp
Authors: Hecht Artur , Shiloh Miriam
Published: March 2007

The crimp parameters of twelve varieties of cotton, representing a wide range of grades, were measured. It was found that these cottons can be characterized by their crimp parameters. Relationships between crimp diameters and loads were found to show some typical behavior of cotton. Curves of crimp diameters against stresses, drawn from the results of these measurements, may be used for predicting crimp diameters of other cottons with known fiber diameters. It was found that the finer cotton grades are associated with lower crimp parameters and vice versa. The same was also found for the cottons with lower staple fibers. Also, the higher the tenacity, the lower the mean crimp diameter of the cotton.
Relationships Between Structural Parameters and Tenacity of Polypropylene Monofilaments
Authors: Sheehan W.C. , Wellman R.E. , Cole T.B.
Published: March 2007

Quantitative relationships have been established between the tensile strength of polypropylene fibers and their molecular weight, molecular-weight distribution, crystal linity, and orientation. An equation describing the combined effects of the structural parameters on the strength of the fibers has been derived. The correlation shows that, with polypropylene fibers of 94% to 98% isotacticity, the strength of the fibers is primarily a function of the orientation and that the contribution of the other parameters is small in comparison.
Calculation of Finishing Effects on Cotton on the Basis of a Padding, Weave, and Cross-Linking Function1
Authors: Ruttiger W.A.
Published: March 2007

Up to now, there has been a lack of a physical-chemical function which would establish a link between the formulation of a procedure for a conventional wash-and-wear finish and the properties of the finished fabric after it has been given a household laundering. It appeared reasonably possible to work out a general function, provided excessive ac curacy was not called for. This function was arrived at by coordinating both precisely defined and approximate expressions. Details are given.

The amount of cross-linking agent taken up can be calculated from the given formula tion and padding data by means of the "impregnation function." The diffusion proc esses which occur during contact with the liquor and which can be ascertained theo retically only with great difficulty can be represented by an experimentally determinable integrated factor, the "exchange coefficient."

The attainable degree of finish for cotton, i.e., the crease recovery angle,' can be determined by means of the "cross-linking function," taking into account the yield of the condensation reaction and the loss in strength. The experimental basis and the range of validity of this function and its dependence on the nature of the fabric ("weave function") are dealt with in detail.

Finally, the self-smoothing effect (Monsanto rating) can be given in relation to house hold laundering methods (from drip to tumble drying) by employing empirical conver sion curves.

The functions are, at present, being applied to selected practical cases by means of an analog computer in order to test the utilizability of this new system of functions for re search and development purposes.
The Determination of the Volumes of Felted Wool Balls
Authors: Faure P.K.
Published: March 2007

Two methods of determination of the volumes of felted wool balls with considerable accuracy are described. The first is an indirect method by computation from the directly determined average diameter of a ball, and a measuring procedure is given whereby this average diameter can be obtained accurately even when the shape of the ball is not per fectly spherical. However, the method involves subjective personal judgment and hence suffers from some lack of precision due to operator errors which may be introduced. In the second method, the volume is determined directly by saturating the ball with water and weighing it in this condition; theory and practice are fully described. The method is simple, very accurate (± 0.01 cm3), free from operator bias, and requires only normal laboratory equipment.
Simulation Study of a Worsted Spinning Set
Authors: Liddy D.T.
Published: March 2007

This paper examines the influence of two factors on the operation of a worsted spin ning set on the same input of work. The factors are the number of spinning frames in the set and the way in which the frames will be allotted to big lots. It uses the method of simulation on a simplified model of the set. Measures of the effect of changes in the factors are made in terms of delivery frequency and duration of delays and the in-process inventory. The effect of the fluctuating demand for frame time on the number of frames necessary to meet performance criteria is indicated.
Thermal Transitions in Keratin
Authors: Mason P.
Published: March 2007

A method is described for measuring lateral load-deformation relations of fibers. The results of tests on Lincoln wool fibers are given, for aqueous test liquids at pH 2.1, 6, and 9.1, and for fibers treated with formaldehyde, with an anionic detergent, and with mercuric acetate.

In water at 20° C the shear modulus (for loading times of several seconds) is near to 2 X 108 dynes/cm2 and does not vary greatly with the chemical treatment or the acidity of the test liquid.

As the temperature increases, the shear modulus slowly decreases. At a certain temperature, approximately 80° C for this Lincoln wool in water, the modulus starts to decrease much more rapidly with temperature. This transition is accentuated and dis placed to lower temperatures at pH 9.1 or by the treatment with mercuric acetate.

Measurements of viscous flow under constant load were also obtained. Between 70° and 100° C the native wool fibers show a viscosity of the order of 1011-1012 poise, with an activation energy of about 26 kcl/mole. Some structural implications of these phenomena are discussed.
Comparison of Young's Modulus for Bending and Extension of Single Mohair and Kemp Fibers
Authors: King N.E.
Published: March 2007

The bending and extension moduli of single mohair and kemp fibers have been deter mined and compared. Previous results are not consistent—bending moduli values rang ing from larger-than to smaller-than the values obtained by stretching.

Moduli for bending and stretching of mohair were found not to differ significantly, while kemp fibers can be divided into two distinct bending moduli groups, depending, ap parently, on the structure of the medulla. The medulla of these kemp fibers may be solid or hollow (semi-solid), yielding two different results for bending. Stretching moduli for all kemp fibers do not differ significantly and are comparable with the bend ing moduli of hollow fibers only.
Some Physical Properties of Weathered Wool1
Authors: Lee Julia S. , Finkner Morris D.
Published: March 2007

The deterioration from outdoor weathering of experimental wool fabrics differing in fiber fineness was measured by breaking strength, elongation at break, and crease recovery. With the amount of solar energy held approximately constant for each sampling period of each of the three consecutive sets of exposures, ambient temperature seemed to control the rate of deterioration.

Differences in strength and elongation among the fabrics were non-significant. The fine wools recovered from creasing significantly more than the medium wool.
APO—Copolymer Systems for Cotton1
Authors: Tolgyesi W.S. , Krasny J.F.
Published: March 2007

A study of the treatment of cotton fabric with APO-thiourea and urea copolymers followed by cross-linking with dihydroxydimethylolethyleneurea (DHDMEU) has been undertaken. The two-step treatment, simulating a durable-press process, effected a desirable balance between appearance and service properties of the fabric. Dry and wet wrinkle recovery values of 300° and 260°, respectively, and vash-wear ratings of 5 (tumble dry) and 4 (line-dry) were obtained on printcloth at 60% to 70% strength retention.

Repeated laundering and tumble-drying of simulated garments indicated relatively little abrasive wear with little or no reduction in crease retention, compared to garments made from fabric treated in the regular manner with DHDMEU.

The following mechanism is suggested. The APO and urea or thiourea form copolymers in the fiber. Urea and thiourea, apart from acting as swelling agents, compete with cellulose hydroxyls for the aziridinyl rings and, thereby, repress premature cross-linking. During the subsequent DHDMEU treatment, cross links are formed, presumably between cellulose and polymer deposit as well as between cellulose chains, resulting in a greater mobility of the chains within the fiber than obtained in standard cellulose-cellulose cross-linking.
Thermoplasticity and Resilience Through Benzoylation and Cross-Linking
Authors: Willard John J. , Schwenker Robert F.
Published: March 2007

Basic studies have been carried out to define the interrelation between thermoplasticity and resilience in cotton obtained through chemical modifications. Diester cross links, introduced in combination with benzoate ester groups, provided neither satisfactory resilience nor thermoplastic character. When benzoylated cotton, prepared by partial saponification from higher DS values or by the Schotten-Baumann esterification condi tions, was dry-cured with trirnethylolmelamine, the products showed high levels of wet and dry wrinkle recovery, high resistance to abrasion, and displayed thermoplastic char acter as reflected by the fact that heat-set creases could be imparted to them.
A Study of the Shrinkage of Plain Knitted Cotton Fabric, Based on the Structural Changes of the Loop Geometry Due to Yarn Swelling and Deswelling
Authors: Moon Won Suh
Published: March 2007

The structural change of the jersey loop upon yarn swelling is related to the amount of expected laundering shrinkage in cotton jersey fabric by introducing a three-dimen sional loop model. The lengthwise shrinking is explained by the geometry of loop migration and curvature changes upon wetting and drying of the fabric. Also, width wise shrinking is explained by the relationship between wale spacing and yarn diameter. The proposed jersey model explains shrinkage phenomena and also provides a means of estimating stitch length of jersey fabric on the basis of courses per inch, wales per inch, and yarn diameter.
Effect of Carding Rate and Cylinder Speed on Fiber Hooks and Spinning Performance for an Irrigated Acala Cotton
Authors: Simpson J. , DeLuca L.B. , Fiori L.A.
Published: March 2007

The effect of carding rate and cylinder speed on fiber hooks and spinning perform ance was investigated for an irrigated Acala 4-42 cotton. It was found that increased carding rate increased minority and decreased majority hooks. The rate at which the minority hooks increased was greater for the Acala 4-42 cotton than a Deltapine cotton previously investigated. Generally, second-drawing sliver uniformity and end breakage were not affected by increases in carding rates. High carding rates resulted in less noils being removed without detrimentally affecting fiber length, yarn properties, or end breakage. Yarn imperfections and minority hooks of card sliver were related, indicating that, possibly, the phenomenon which produces minority hooks also produces neps and, thereby, yarn imperfections. This limited study seems to demonstrate that each type of cotton has its own peculiar fiber-hook formation pattern as carding rate is increased. The practical application of the research is briefly discussed.
The Variability of Wool Tops in Treatments with .Oxidative Shrink-Resist Reagents
Authors: Anderson C.A. , McPhee J.R.
Published: March 2007

A wide variation in absolute shrinkage characteristics of wool tops is found after treatment with oxidative shrink-resist reagents under given sets of conditions. This is not related to the quality of the wool, and the response of any one batch of tops to shrink-resist treatment is unpredictable.

At least two factors can cause these variations, one being the felting property of the original top and the other being the quantity of contaminant on the surface of the wool fibers. If the surface contamination is always reduced to 0.2% to 0.3% by prescouring the tops, then the same degree of shrink resistance, relative to the corresponding untreated top, is usually obtained for the given shrink-resist conditions. However, the absolute shrinkages, although often considerably better than those obtained on unscoured tops, can still vary over wide limits.
Studies on Magra (Indian) Wool
Authors: Blakey P.R. , Earland C. , Jalihal M.R.
Published: March 2007

A detailed physicochemical examination has been made of Magra wool, which is obtained from one of the principal sheep breeds found in the dry, northern region of India. In order to obtain more uniform materials to study, the wool was divided into fine fibers devoid of medulla, averaging about 56s quality (MGAF), and heterotypic fibers of about 44s quality containing fragmental medullae (MGAH). The hairs and kemp present in this breed were not examined. For comparative purposes, parallel studies were made also on 64s Merino wool.

There are three major structural differences between MGAF fibers and Merino wool. The former possesses a much lower cystine content, contains more amorphous material, and has a different ortho- and para-cortical cell distribution. Although physical mea surements indicate that MGAF fibers may constitute a good-quality wool, these differ ences must be borne in mind, and it would be essential to ensure that improved breeding methods, which would diminish the heterotypic fibers and result in the loss of the valuable "carpet wool" qualities, will in fact be followed by the development of a high- quality apparel wool.
Multiple Points of Rupture in Textile Fibers1
Authors: Warburton C.E. , Whitwell John C.
Published: March 2007

The reason for the occurrence of multiple breaks in some materials and not in others is discussed in terms of internal fiber structure. Basic postulates relating multiple breaks to molecular and supramolecular structure are advanced. The degree of, hindered structural mobility in the relaxation processes following an initial break determines whether multiple breaks will occur in a given material. A minimum distortion of the internal structure before failure must occur for hindered mobility to develop. Conclu sions are based on tensile tests conducted on a wide variety of natural and man-made fibers. The effects of chemical, thermal, and mechanical pretreatments are discussed.
Physicochemical Study of the Cotton Cellulose— Dimethylolpropyleneurea Reaction1
Authors: Gonzales E.J. , Ziifle Hilda M. , Berni R.J. , Benerito Ruth R.
Published: March 2007

Physical and chemical properties of cotton print cloth treated with 0.55 M solutions of 1,3-bis(hydroxymethyl)-2(1H)-tetrahydropyrimidinone (dimethylolpropyleneurea or DMPU) in the presence of 0.03 and 0.1 M inorganic salt catalysts have been determined. The kinetics of the reaction in the presence of 0.03 M catalysts have been investigated. Specific reaction-rate constants at 45, 55, and 65°C in the presence of ZnCl2, Zn(NO 3)2, MgCl2, and Mg(NO3)2 have been calculated by following the changes in nitrogen and formaldehyde contents. Changes in crease recovery properties of finished fabrics with changes in nitrogen and formaldehyde contents were also followed. Enthalpies, entropies, and free energies of activation at 45°C for the reaction have been calculated. Specific reaction-rate constants and activation parameters were compared with those values reported previously for the reactions of cotton with derivatives of ethyleneurea. Infrared spectral data of fabrics finished with DMPU were analyzed.
The Formation of Various Cross Linkages in Wool and Their Effect on the Supercontraction Properties of the Fibers
Authors: Crewther W.G. , Dowling L.M. , Inglis A.S. , Maclaren J.A.
Published: March 2007

Various solvent systems have been investigated for obtaining maximum alkylation of cysteine residues in reduced wool to dimethylene-S,S'-dicysteine residue. These and related amino acid residues were determined in wool hydrolyzates by means of an automatic amino acid analyzer. Cystine residues in wool were converted to both lanthionine and lysinoalanine residues by treating the wool with potassium carbonate solutions, whereas treatment with potassium cyanide solutions produced lanthionine resi dues without forming significant amounts of lysinoalanine residues in the wool. On a molar basis, lanthionine and dimethylene-S,S'-dicysteine residues had similar restrictive effects on the extent of total supercontraction in 8M LiBr, whereas one lysinoalanine residue was equivalent to about five lanthionine residues in its effect on the extent of supercontraction. The conversion of cystine to lanthionine or dimethylene-S-S'-dicysteine residues retarded the first stage of supercontraction in 4 M LiBr at pH 8.3, whereas in 6 M LiBr, only the second stage of supercontraction was retarded. Similarly, the addition of free bromine to the lithium bromide solutions retarded the first stage of supercontraction of unmodified wool fibers in 4 M LiBr but did not affect the initial rate of contraction in 6 M LiBr. It is suggested that the matrix protein molecules are unfolded in 6M LiBr, thereby obviating the need for thiol-disulfide interchange reactions in the deformation of the matrix which must accompany the contraction of the micro- fibrils. The presence of lanthionine or dimethylene-S,S'-dicysteine residues in the wool did not decrease the rate or extent of supercontraction in 4 M LiBr-N HCl at 98.5°C.
The Hydrothermal Degrádation of Wool Keratin
Authors: Sweetman B.J.
Published: March 2007

The nature of degradation of cystyl residues in wool by purified water at ca. pH 6 and at temperatures of 50-100° is studied. Cystyl residues in wool are slowly converted by water to lanthionyl residues, even at 60°, and the rate of this conversion increases with increasing temperature. At 100°, lanthionyl residues cannot form in solutions having pH values below ca. 4.5-5.0. Evidence suggests that, under these conditions, certain reactive sulfur-containing residues are also formed from cystyl residues.

The other major action of water on wool at 100° appears to be in the hydrolysis of certain peptide bonds. Limited modification of residues in wool, such as the lysyl and tyrosyl, also apparently occurs during treatment of wool with water at 100°. Comparison of the amino-acid contents of the water extracts obtained at 100° and those of the treated wool samples reveals that some residues are either more or less easily extracted from wool than others.
The Hydrothermal Degradation of Wool Keratin
Authors: Sweetman B.J.
Published: March 2007

The most marked chemical reaction occurring during the treatment of wool keratin with water or steam at high temperatures is the conversion of cystyl residues to lan thionyl residues and also, apparently, to alanyl residues. The degradation of some lysyl and aspartyl residues also occurs during treatments at 150°, together with probable losses of prolyl, threonyl, seryl, isoleucyl, phenylalanyl, and asparaginyl or glutaminyl residues. The formation of some glycyl residues was also detected.

It is postulated that, as a result of the treatments of wool with water, some peptide bonds are slowly hydrolyzed, enabling comparatively high molecular-weight peptides together with lower molecular-weight material to be dissolved from the wool. After treatments of long duration or at high temperatures, these peptides are progressively hydrolyzed to lower molecular-weight peptides, free amino acids and other degradation products.

Heat setting of wool initially containing 25% moisture results in only slight changes in the chemical and physical properties at 120° during 30 min or shorter times.
Fatigue in Textile Fibers
Authors: Lyons W. James , Ribnick Arthur S.
Published: March 2007

Samples of polyester and nylon 66 fibers have been fatigued by cyclic longitudinal tension, each sample at two strokes, at various temperatures from 21° to 90°C. In the polyester, it was found that, in general, at both 4.5 and 5.9% stroke, average logarithmic lifetimes increase with temperature. Straight lines, fitted to the experimental points by the method of least squares and representing logarithmic lifetime as a function of reciprocal temperature, were observed to have negative slopes, the slope at the 5.9% stroke having the larger (absolute) negative value. In the nylon, it was found that, with a 7.2% stroke, logarithmic lifetimes tend to decrease with increasing temperatures, i.e., the slope of the least-squares line for logarithmic lifetime vs 1/ T has a positive value. At a higher stroke (8.1%), for the nylon fibers, the converse is true. Thus —generalizing—in both samples the slope of the curve for logarithmic lifetime vs 1/T decreases with increasing stroke. Correspondingly, energies for the fatigue rupture process, calculated according to the Prevorsek-Lyons theory, were found to be negative for both tests on the polyester and for one on the nylon sample, with the 8.1% stroke. A small positive energy was calculated for the nylon at the 7.2% stroke. These results were, confirmed by the energies calculated from terminal growth rates measured on the polyester at the 5.9% stroke and on the nylon sample at the 7.2% stroke. It is concluded that the energy involved in fatigue rupture is identical with that related to growth during cyclic loading.
Some Chemical Reactions Involved in the Alkaline Yellowing of Wool
Authors: Norton G.P. , Nicholls C.H.
Published: March 2007

An investigation of the products formed during the treatment of a number of amino acids and proteins with alkali has provided evidence for the similarity of some reactions between free and protein-bound amino acids. Based on this similarity, the behavior of free amino acids and other model compounds has been interpreted to account for the yellowing of proteins. Yellowing in both cases has been attributed to an initial β-elimination reaction involving the amino acids cystine, cysteine, serine or threonine to form dehydro-alanyl residues, which then either rearrange or react further to form colored compounds.
Effects of Combined Gamma Radiation and Thermal Exposure on Some Mechanical Properties of Three Polyaromatic Yarns
Authors: Opt Preston C. , Ross Jack H.
Published: March 2007

Three experimental polymeric yarns, a polyimide, an aromatic polyamide, and a polybenzimidazole, were exposed to various gamma dosages up to 1.4 × 109 ergs/g carbon and exposure times up to 18.2 hr. Specimens ere exposed to the gamma radiation alone and also in combination with elevated temperatures. Temperatures of 400°, 600°, and 800°F were used in conjunction with the gamma radiation. All speci mens were evaluated for mechanical properties, i.e., tenacity, elongation, and work-to- rupture.

Each polymeric yarn had higher strength, greater elongation, and better energy absorbing capability after thermal-gamma exposure. Exposure at 600°F and all radia tion dosages gave the best results for the polybenzimidazole (PBI) yarn, while exposure at 400°F and radiation dosages of 1.9 × 108 and 7.3 × 108 ergs/g carbon gave the best results for the polyimide and aromatic polyamide yarns.

It can be concluded that the thermal stability of these yarns can be improved by thermal gamma treatment.
Moisture Transfer Through Impermeable Foam Insulations
Authors: Fonseca George F.
Published: March 2007

The biophysical characteristics of perforated foam systems are presented in terms of experimentally determined values of insulation and moisture vapor permeance (MVP). The effect of windbreak motion on the moisture vapor transfer through such systems is discussed. A theoretical comparison among systems is given in terms of environmental range using the concept of moisture permeability index.
Thermoanalytical Studies on the Durable-Press Curing of Cellulose
Authors: Miller Bernard
Published: March 2007

Thermoanalytical scanning has been carried out on a cross-linking agent, trimeth ylolmelamine, which is typical of the reactants used for imparting durable-press charac teristics to cotton. This compound was investigated by itself and in various combinations with glucose and cellobiose. Catalyzed and noncatalyzed conditions were compared. A variety of thermally induced processes were revealed as occurring in the temperature range 100-200°C, and it was shown that zinc nitrate catalyst can radically change the course of the reactions. By means of differential thermal analysis, it was found possible to distinguish between trimethylolmelamine homopolymerization and the reaction between this compound and carbohydrate hydroxyl groups.
A Method for the Measurement of the Rigidity of Fibers Immersed in Liquids
Authors: Goodings A.C.
Published: March 2007

A method for measurement of the torsional rigidity of fibers immersed in liquids is described. The procedure employs a torsion double pendulum which permits measure ments to be made dynamically without interfering with the condition of the fiber for successive tests. The theory of the double pendulum is discussed.
The Effect of Temperature on the Photochemical Degradation of Textile Materials
Authors: Egerton G.S. , Shah K.M.
Published: March 2007

The degradation of undyed yarns of viscose rayon, cellulose (secondary) acetate rayon, and nylon 6.6, both free from and containing titanium dioxide (anatase), has been studied at different temperatures. The degradation in moist air is particularly marked at high temperatures. A possible reaction mechanism for the sensitizing effect of titanium dioxide is discussed.
A Method for Determining Activation Energies of Microcreep in Filaments From Force-Elongation Data
Authors: Williamson Pierce M.
Published: March 2007

A new method is demonstrated for determining activation energies of microcreep in polymeric filaments. The total activation energy is presented by the generalized form of the Arrhenius rate equation k = A exp (- ΔH RT - Δ F w ). Force-elongation data, which are used to evaluate ΔH and ΔF, are obtained with a constant elongation-rate machine capable of elongating a filament as slowly as 0.1 micron/min and of mea suring force on the filament from 1 to 980 dynes.

Using a filament of 0.018-cm diam, formed by melt extrusion without drawing or thermal decomposition of polystyrene of 45 X 103 molecular weight, ΔH is 60 X 102 cal/g. molecule and ΔF 1.65 X 10-3 ergs/mole.
Glass Transition Temperature of Nylon 6
Authors: Forster Michael J.
Published: March 2007

Studies of nylon 6 of various relative lengths have been made by measuring the sonic modulus and length as functions of temperature from -50°C to 180°C. Conclusions based on these data indicate that the transition of dry nylon 6 yarn from a glass to rubberlike material takes place in two discrete steps, one centering about -50°C and the other starting at 70°C. Between these two steps, nylon 6 behaves like a ductile material, neither glassy nor rubberlike. The lower step in this transition is a result of attainment of sufficient thermal kinetic energy to permit rotational and translational motion of short-chain segments between completed hydrogen bonds in the amorphous regions. The upper step at 70°C is postulated to be the temperature at which the completed hydrogen bonds become sufficiently weak to allow motion of greater segmental lengths.

Moisture in nylon 6 yarn is an effective plasticizer between 25°C and 100°C. However, it raises the temperature of the first step in the glass transition by interfering with segmental motion.
Some Aspects of the Geometry of Simple Rib-Tuck Weft-Knitted Wool Fabrics
Authors: Song J.-H. , Turner J.D.
Published: March 2007

The problems involved in extending the well-established geometries of plain and 1×1 rib weft-knitted wool fabrics to include the half-cardigan and full-cardigan structures are discussed. The terms "tightness factor" and, "relaxation value" are introduced. It is shown that the simple fabric geometry formulas can be applied to rib-based tuck structures of mean tightness factor, and that the relaxation value of any fabric depends upon the tightness factor and the relaxation temperature and conditions. Comparisons are drawn between the geometrical properties of plain-knit, 1 × 1 rib, half-cardigan and full-cardigan fabrics knitted from the same batch of worsted yarn.
Studies in Wool Yellowing
Authors: Gruen L.C. , Inglis A.S.
Published: March 2007

Fluorescence measurements have been made on wool samples which have been treated with the fluorescent brightening agent Leucophor PAF. Several parameters have been varied, such as the effect of prebleaching the wool and of treatments with aluminum sul fate and/or thiourea-formaldehyde.

Aluminum sulfate pretreatment of wool led to increased fluorescence. Thiourea- formaldehyde aftertreatment resulted in quenching of the fluorescence for bleached samples containing low concentrations of brightener but enhancement of fluorescence for samples treated with high concentrations of fluorescent brightening agent.

Decreases in fluorescence occurred on both wet and dry irradiation, the decrease being more pronounced on wet irradiation. The correlation with previous work based on yellowness index and visual assessments are discussed, as are the implications for the production of white fabric stable to sunlight exposure.
Interpretation of the Results of the Digital Fibrograph in its Application to Worsted Tops
Authors: Barella A.
Published: March 2007

The theory of fibrograms and of the physical principle of the measurement of the Digital Fibrograph, (DF) is considered and the results obtained by means of the WIRA Fibre Diagram Machine (WFDM) are compared with those of the DF for combed tops. The conclusion is that, for the whole set of combed tops examined, there is a correlation between the 20.1% span length found on the DF and the height determined by means of the WFDM. Likewise, there is a correlation between the 12.1% span length and the beard found on the WFDM. Other correlations were found for the percent short fiber (shorter than 30 mm or 40 mm) and the 50% and 66.7% span length. Finally, techniques are described which permit conversion from the first to the second kind of fibrogram and vice-versa; these are illustrated with examples.
Encapsulation of Pulp Fibers by Vanadium Trichloride-Catalyzed Polymerization of Ethylene
Authors: Chanzy H. , Côté W.A. , Marchessault R.H.
Published: March 2007

A rapid process of encapsulating wood pulp is described. It involves first a reflux ing of cellulose with a solution of VCl4 in heptane to thermally generate VCl3 which forms crystals on the surface of cellulose fibers. These vanadium-covered fibers are suspended in a dilute triethylaluminum solution in heptane. Subsequent ethylene bubbling results in rapid encapsulation of individual fibers with high molecular-weight polyethylene. The process is rapid (100% weight increase in 5 min) and polyethylene is found only at fiber surfaces. Fiber cementation does occur, and it is relatively simple to control the thickness of the polymer sheath. Because of the relative uniformity of the polymer layer, significant surface property changes for the pulp fibers may be expected at relatively low add-ons. Polarized-light microscopy has shown that the added polymer layer around the fibers is birefringent due to a preferred tangential orientation of the growing chains.
Cam Forces in Weft Knitting
Authors: Henshaw D.E.
Published: March 2007

A technique is described for assessing tension in the yarn during knitting by measuring the needle-butt reaction forces on the cam. Results are given which illus trate the first-order effects of the major knitting variables.

Two extremes of cam shape were investigated and it was found that a flat-bottom stitch cam gave rise to a remarkably constant stitch length. Cam force measurements suggested that the flat-bottom cam gave lower knitting tensions than the. pointed cam. There appears to be a good case for investigating the practicality of flat-bottom cams in flat-bed knitting machines.

It is also found that, when knitting a very tight stitch, the peak yarn tension can occur in the loop being cast off before it reaches the widest part of the needle. An explanation is given for this effect.
Formation and Structure of Sodium Cellulosates in Relation to Physical Properties of Cellulosic Fibers
Authors: Avny Yair , Rebenfeld Ludwig
Published: March 2007

The exchange reaction between sodium methoxide and cellulose, leading to the forma tion of sodium cellulosate, has been studied with respect to the effects of reagent concen tration, temperature, time, nature of the cellulosic substrate, and mechanical constraint. Cellulosate degree-of-substitution values up to 0.6 can be achieved readily in the case of preswollen cotton and rayon yarns. The reaction is complete within a few minutes and no significant effect of temperature above 21°C was observed. The degree of substitu tion increases with increasing sodium methoxide concentration.

The distribution of the cellulosate groups was found to be close to a theoretical one, which might be expected upon random substitution. Although highly ionized anhydro glucose units were formed, no redistribution of the cellulosate groups by inter- or intra molecular exchange reactions was observed. Mechanical properties of cotton and rayon yarns which were regenerated from their sodium cellulosate derivatives by hydrolysis were determined, revealing that the formation of a sodium cellulosate derivative did not alter these properties. It was also shown that no chemical degradation of the cellulose occurred during sodium cellulosate formation.
The Impact of Needles on a Knitting Cam
Authors: Leaf G.A.V. , Blackman F.
Published: March 2007

High-speed film of the motion of knitting needles in a conventional cam system showed that most needles changed direction smoothly, without bouncing, on impact with the cam track. However, an occasional needle did appear to bounce. This be havior is investigated.

It is shown that there is a maximum cam angle; making the cam steeper than this maximum would cause the needle to jam in the angle between the cam face and the trick wall. Just below the maximum is a range of cam angles for which the needles would change direction smoothly, without bouncing. For still shallower cam angles, the needles would always bounce in the track. The various critical angles mentioned above depend on the elastic and frictional properties of the needle and trick and cam track surfaces. Some numerical estimates of the critical angles are given.
Anionic Graft Polymerization of Acrylonitrile on Cellulose
Authors: Avny Yair , Rebenfeld Ludwig
Published: March 2007

The anionic graft polymerization of acrylonitrile on cellulose was studied with sodium cellulosate as initiator and rayon yarns as substrate. Products containing up to 22% grafted polyacrylonitrile were obtained. The graft polymerization reaction was always accompanied by homopotymer formation. Graft polymers with low molecular-weight side chains (up to 15,000) and relatively high degrees of substitution were achieved. The reaction was studied as a function of the ratio of monomer/initiator concentration, and it was observed that graft polymerization yield decreased, molecular weight in creased, and the polyacrylonitrile content in the products increased with increase in this ratio. The mechanical properties of the rayon yarns under standard conditions were not adversely affected by the grafting, but strength and extensibility were decreased under wet conditions.
The Influence of Different Electrolytes on the Interaction of Chlorazol Sky Blue FF with the Cotton Fiber Surface in Aqueous Solutions
Authors: Sivaraja Iyer S.R. , Srinivasan G. , Baddi N.T.
Published: March 2007

Investigations were carried out to study the adsorption of Chlorazol Sky Blue FF on cotton fiber from aqueous solutions of 0.1 N LiCl, NaCl, KCl, RbCl, and CsCl. The dye uptake both at 50° and 60° increased markedly with increasing size of the alkali metal cation. The equilibrium dye adsorption could be described by a Langmuir-type equation. The calculated standard affinity of dye adsorption showed a fairly constant value, but the exothermic heat of dyeing and the entropy of dyeing, calculated from the individual isotherms, increased as the dye adsorption increased in the presence of either higher electrolyte concentrations or equivalent concentrations of alkali metal cations of larger size. Possible changes in the orientation of adsorbed dye ions on the cellulose surface can account for the increased -Δ H° and - ΔS° values. It is pointed out that, apart from the usual well known effects of electrolyte cations, an ,important contributory factor to the adsorption process arises from the disturbance caused by the cations to the structure of water hydrogen-bonded to the cellulose surface and "iceberg" water around the hydrophobic parts of dye molecules. This effect, which will increase with the size of the alkali metal cation, explains the results adequately.
Studies in Wool Yellowing
Authors: Leaver I.H.
Published: March 2007

A study has been made of the photo-induced free radicals in thiourea/formaldehyde- treated wool and fluorescent-brightened wool after exposure to near uv radiation in the wavelength region 2900-4000 A, and the results are compared with the observed changes in the electronic absorption spectra.

Thiourea/formaldehyde treatment of wool significantly protects cystyl residues from disulfide bond rupture which otherwise occurs on irradiation with uv light of wavelength 2900-3200 A, and there are characteristic changes in the reflectance spectra of treated wools, associated with the reduced concentration of R.CH2S. radicals.

Fluorescent-brightened wool exhibits an almost identical electron spin resonance (ESR) spectrum to that of untreated wool, when irradiated in the region 2900-3200 A, but, when exposed to 3650 A radiation, a greatly increased yield of free radicals is ob served in the brightened wool. Photosensitization of the protein by the fluorescent brightener is suggested as the most likely mechanism.
Felting Shrinkage of Plain-Knitted Wool Fabrics
Authors: Baird K. , Foulds R.A.
Published: March 2007

The dependence of felting shrinkage rate upon yarn count, cover factor, shrink proofing level, and severity of washing action has been examined, using plain-knitted wool fabrics. The investigation was a factorial arrangement with 54 combinations of factors for each of two shrink-proofing treatments. The results were subjected to analyses of variance. The felting shrinkage rate was lowered by increasing the cover factor, by increasing the level of shrinkproofing treatment, and by decreasing the severity of washing. Samples made from fine yarn shrank at a lower rate than those of heavier count. There were two significant interactions between the factors for each set of data. These showed that (i) the shrinkage rates of the fabrics made from the fine yarns were more sensitive to change of cover factor than were those of the coarser yams, and (ii) an increased level of shrinkproofing treatment increased the sensitivity of the samples to the severity of the mechanical agitation during washing. The results may be used for predicting shrinkage rates in knitted fabrics. An example is given.
Formation of Free Radicals in Chemically Modified Wools by Persulfate Treatment
Authors: Burke M. , Nicholls C.H.
Published: March 2007

The ESR spectra produced by persulfate treatment of chemically modified wools have been examined in order to ascertain the location of the oxidative attack. It has been shown that some of the free radicals produced are located at the cystyl and tyrosyl residues, while other evidence suggests that tryptophan is also a most probable site for free-radical formation.
A Comparison of Net and Continuum Theory as Applied to Cord-Reinforced Laminates
Authors: Clark Samuel K. , Dodge Richard N.
Published: March 2007

The basic formulation of plane stress-analysis techniques for textiles imbedded in rubber is given both from the viewpoint of a load-carrying net and of a continuous elastic material with orthotropic properties. The developments are basically dissimilar, and yet it is shown that, for material properties commonly encountered in rubber-coated textiles, both theories predict essentially the same textile loads, although the stresses carried by the rubber matrix differ in the two theories. This shows that the network approach, which is by far the simpler of the two, is perfectly valid for purposes of estimat ing cord load in cord-rubber structural members.

A method is presented through the use of either theory to compute the fraction of load carried by the cord network and the fraction carried by the rubber matrix.
The Influence of Alkali Treatment on Native and Denatured Proteins
Authors: Mellet P.
Published: March 2007

The influence of alkali treatment on wool keratin and on silk fibroin was investigated in a medium of K2CO3 at 50° C. It was found that the denaturing action of LiBr affects the reactivity and reactions of the disulfides differently from stretching of the fibers does.

Since the sum total of the sulfur-containing amino acids remains constant during alkali treatment of both native and denatured wool, the participation of cystine in the formation of lysinoalanine is excluded. It is suggested that seryl residues are responsible for the formation of α-amino acrylic acid residues which combine with the lysine present in wool or in silk to form lysinoalanine. The sulfur content in wool, as obtained by direct determination, was higher than the expected values, and this indicates the presence of sulfur compounds formed during the alkali treatment, which are not analyzed as any of the known sulfur-containing amino acids. No evidence was found that peptide-bound lanthionine is unstable towards 0.7 M K2CO3 solution at 50°C.

A significant increase in N-terminal seryl residues was observed for alkali-treated wool. Various possible explanations of this phenomenon were investigated.
Effect of Fiber and Dyebath Variables on the Rate of Acid Dyeing of Nylon 6, 6
Authors: Bell James P.
Published: March 2007

The results of an experimental study of the effects of several variables on the acid dyeing of nylon are presented. The dyeing rate was directly proportional to the number of amino-end groups (dye sites) in the fiber for the two dyes tested; the dyeing rate approached zero as the number of dye sites approached zero. The dyeing rate was the same for samples with viscosity average molecular weights of ∼25,000 and 30,000, but was somewhat higher for a ∼22,000 Mv sample, as might be expected from the dependence of other properties on molecular weight. The dyeing rate is shown to be linearly related to 1/√ d, where d is the denier per filament. The molecular size of the acid molecule used in the acid dyebath was investigated, and no effect was found for formic, acetic, propionic, and hexanoic acids. An effect is found on both rate and saturation, however, if the larger and more polarizable napthoic acid is used. Sodium chloride and sodium sulfate, when added to the dyebath, decrease both the dye absorbed at saturation and the rate of dye diffusion, although they offer benefits as leveling agents. The effect of sodium chloride is considerably greater than for sodium sulfate.