bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue of Prenotched Graphite Fiber Composites in Compression
Authors: Berg C.A. , Salama M.
Published: March 2008

Direct observation of compressive fatigue of prenotched unidirectional graphite fiber composites reveals that fatigue cracking extends transverse to the fiber direction, via microbuckling. An elasto-plastic-strain hardening model of the material behavior, based upon experimental measurements of material properties, is used together with a finite element computation to obtain the stress and strain distribution near the notch tip. The calculated radius Rp of the plastic zone at the notch tip is shown to correlate with the observed fatigue crack propagation rates via

Fatigue cracking is seen to decelerate with crack extension, indicating a residual bearing strength of newly generated compressive fracture surfaces of approximately 10 4 Ib/in.2

The implications of compressive fatigue in composites design are discussed. It is pointed out that prevention of axial cracking in the composite is a key element in preventing compressive fatigue.
Dyeing from Aqueous Suspension in Organic Solvents
Authors: Rosenbaum Shlomo
Published: March 2008

It is suggested that water pollution and consumption in dyeing can be reduced greatly by suspending conventional aqueous dyebaths in an inert organic phase of similar density. The feasibility of the method has been verified on a number of important dye-fiber systems. The organic solvents could be reused immediately without an intermediate distillation or other purification step. In a comparison with other processes, emphasis is placed on the possibility of alleviating water problems now, without the need for lengthy development work.
Reactions of Wool with Cyanuric Chloride
Authors: Meier P.E. , Weigmann H.-D.
Published: March 2008

The reaction of wool with cyanuric chloride from an acetone-water mixture results in crosslinking only if the wool has previously been reduced. Introduction of cyanuric chloride from acetone solution and subsequent aqueous aftertreat ment causes complete reaction of all three chlorine sites in cyanuric chloride, while under comparable conditions in solution only one site is reactive. Esterification of the carboxyl groups in the wool results in a stabilization of two thirds of the chlorine sites suggesting that carboxyl groups are involved in the hydrolysis of at least two of the three chlorine sites. The intermediate formation of activated esters and their subsequent rapid hydrolysis is discussed as a possible mechanism. A 1:1 1 correspondence between the number of carboxyl groups in wool and the number of chlorine atoms in the 3- and 5-positions of cyanuric chloride indicates a stoichiometric reaction rather than a catalytic participation of the carboxyl groups. The immobilization of cyanuric chloride molecules within the wool either through direct co valent bond formation or through electrostatic interactions with amino groups is postulated.
The Dielectric Properties of Various Cotton Varieties
Authors: Lyons Donald W. , Seabolt Jarvis A. , Graham John
Published: March 2008

The use of dielectric measurements of cotton fibers as a method of measuring the mass of a fiber bundle would eliminate the tedious and time-consuming manual operation of weighing the fiber bundle. The dielectric properties of various cotton varieties were measured using several measuring frequencies for ranges of fiber moisture content and sample pack ing density. For a fiber moisture content greater than the equilibrium moisture content at 10% RH, it was found that there is a significant variation in the dielectric properties between varieties of cotton. As the fiber moisture content approaches zero, the variation between varieties diminishes. At zero fiber moisture content, the variation between varie ties becomes insignificant. At zero moisture content, it was found that it is possible to use dielectric measurements as a reliable measure of the mass of a fiber bundle.
A Fundamental Study of the Sorption from Trichloroethylene of Three Disperse Dyes on Polyester
Authors: Pkmkins Warren S. , Hall David M.
Published: March 2008

Dyeing of polyester film from trichloroethylene with three highly purified diperse dyes is reported.

Rate of sorption of each dye by polyester increases greatly with increasing temperature. Equilibrium sorption mea surements indicate that two of the dyes, C. I. Disperse Red 15 und C. I. Disperse Orange 3, give constant partition coefficients. C. I. Disperse Orange 3 gives Freundlich type isotherms, possibly due to aggregation of dye in solution which increases with increasing concentration of dye in solution and with decreasing temperature.

The tendency of dye to transfer from solution to fiher as expressed by the free energy of sorption increases with increas ing polarity of the dye molecules.

The enthalpy of dyeing is used to quantitatively express the effect of temperature on equilibrium sorption of dye by the substrate.
Grafting to Fibers to Impact High Elasticity
Authors: Williams J.L. , Woods D.K. , Stannett V. , Roldan L.G. , Sello S.B. , Stevens C.V.
Published: March 2008

Details of a preirradiation grafting technique to render cellulosic fibers highly elastic have heen examined. Special emphasis has been given to the grafting of ethylacrylate to continuous filament rayon from an aqueous emulsion. In addition comparative studies using selected chemically initiated systems have been carried out. Preirradiation grafting rates were found to increase substantially with temperature, reducing the grafting times necessary to achieve highly elastic rayon to the order of minutes at 50°C compared to 20 hr at ambient temperatures. The onset of high "rubber like" elasticity occurs around 1000%, accompanied by a large drop in tenacity. By adding a small quantity of a bi functional monomer to the grafting solution, this strength loss can be reduced without any loss in elongation. Elastomeric properties have been attained even at grafting levels below 100% by subjecting the grafted fihers to a treatment capable of decrystallizing the cellulose. The morphology and structural modifications observed by electron microscopy and x-ray diffraction are discussed for rayon fibers grafted to various levels by both preirradiation and chemical initiation, with and without sulsequent postdecrystallization. These studies indicate that in order to achieve elastomeric properties, grafting must take place throughout the fiber, expanding the fiber and disrupting its crystalline regions.
Effect of Sulfur Dioxide on the Chemical and Physical Properties of Nylon 661
Authors: Zeronian S.H. , Alger K.W. , Omaye S.T.
Published: March 2008

The degradation of nylon 66 fabric by exposure to light and air is increased if the air is contaminated with sulfur dioxide. The additional degradation becomes evident when the chemical properties of fabrics exposed to light and air are compared with those of fabrics exposed to light and air containing 0.2 ppm sulfur dioxide. The increased degradation is also in dicated by the differences in tensile properties of yarn taken from fabrics. The chemical properties and yarn tensile properties of nylon fabric hydrolyzed with sulfuric acid or hydrochloric acid and of nylon fabric irradiated with light in the presence of sufuric acid also were measured to provide comparisons with the degradation of nylon by exposure to sulfur dioxide. The effect of degradation by light and air contaminated with sulfur dioxide, by hydrolysis with sulfuric acid or by irradiation with light in the presence of sulfuric acid on the surface of nylon fibers and on the thermal behavior of nylon are discussed. The mode of degradation of the nylon exposed to light and to sulfur dioxide is considered.
Effect of Light Source on the Photodegradation of Certain Disperse Dyes
Authors: Irick Gether , Boyd Edie G.
Published: March 2008

Since outdoor weather conditions are highly variable, lightfastness determinations for dyed fabrics are generally made in controlled artificial environments. To determine how the light sources employed in such environments influenced the fading of the fabrics, certain disperse dyes in solution and on commercial synthetic fibers were photodegraded with light from monochromatic and polychromatic sources. Dyes were not degraded in liquid or polymeric media by light of wavelengths above 400 nm. Quantum yields for photodegradation of dyes by monochromatic light of wavelengths below 400 nm generally increased with decreasing wavelength; an apparent anomaly—the absence of dye photodegrada tion on polyester fabric with 254-nm radiation—was due to the screening effect of the polymer. Polychromatic irradiation of azo, anthraquinone, and methine dyes on commercial synthetic fibers resulted in dye degradation rates which were generally consistent with the fraction of short-wavelength emission of the light sources employed. Results from this work show almost any 280- to 700-nm light source is suitable for the division of dyes into 3 or 4 stability groups; however, since light absorption by dye, polymer and delusterant affects degradation rates, only a light source whose spectral energy distribution closely approximates that of sunlight can accurately simulate the dye degradation by outdoor exposure.
Enzymatic Hydrolysis as a Source of Structural Information on Cellulose
Authors: Rowland Stanley P. , Wade Clinton P. , Roberts Earl J.
Published: March 2008

An apparatus and a procedure are descrihed to facilitate saturation of accessible surfaces of solid cellulose with cellulase and to facilitate removal of inhibiting byproducts from the sphere of reaction. Fibrous cotton cellulose (lattice I) was observed to undergo enzymatic hydrolysis (cluture filtrate from T. Viride, 50°C) in a rate curve similar to that resulting from mineral acid hydrolysis (2.5 N HCl, reflux) but with a time scale greater by a factor of 24. Other similarities be tween enzymatic and mineral acid hydrolyses of this fibrous cellulose are brought out.
Below-Break Tensile Behavior of Irradiated Nylon
Authors: Morton Margaret I.
Published: March 2008

The air-dry and wet below-break tensile properties (tensile modulus, stress decay, and residual extension) of nylon 66 and nylon 6 were assessed at extensions of 2 and 5% after gamma radiation dosages ranging from 0 to 15 Mrad. Modulus increases were found for fibers extended in air subsequent to the irradiation; whereas in water, little change was evident. Slight improvements in stress decay and residual extension properties were noted from some of the irradiated fibers at ex tensions of 2% in air. Extension of the irradiated fibers to 5% in air and to 2 or 5% in water resulted in impairment of both properties. The property changes were considered to reflect internal structure modifications resulting from inter action with the radiation. Comparison of the results for the gamma-irradiated fibers with those obtained previously for ultraviolet-irradiated fibers suggested a greater influence of the crosslinking reaction on property changes of the ultra violet-irradiated fibers.
The Dimensional Properties of Woven Fabrics Made from Elastomeric Yarns
Authors: Grosberg P. , Ibrahim S.M.
Published: March 2008

Changes in dimensions which occur when fabric is released from loom are predicted. Analysis was not extended to finished fabrics, which is difficult. It is possible to predict the gray fabric dimensions of elastomeric fabrics, using relatively simple analytic methods.
The Effects of a Formaldehyde Pad-Bake-Cure Process on Cellulose Molecular Chain Length and Physical Properties of Cotton Fabrics1
Authors: Segal Leon , Timpa J.D.
Published: March 2008

Fabrics treated to several levels of combined formaldehyde by a pad-bake-cure (Form C) process were studied to in vestigate the effects of molecular degradation and crosslink formation on fabric textile properties. Breaking and tearing strengths decreased with increasing severity of treatment. Percentage of strength loss from crosslink embrittlement was initially considerably greater than that from molecular degradation; the former decreased with increasing wrinkle- recovery angle and increasing combined-formaldehyde content while percentage of strength loss from molecular degrada tion increased. A low degree of crosslinking or molecular-chain extension was induced by curing water-wet fabric.
Structural Peculiarities of G. Herbaceum Cottons
Authors: Datar K.L. , Betrabet S.M. , Sundaram V.
Published: March 2008

Structural features, viz, the fihrillar orientation, void space, micropores and ordered-disordered regions of Indian G. herbaceum cottons have been compared with those of American G. hirsutum cottons of comparable maturity range. Convolution angle and birefringence were determined and correlated with fiber bundle strength. The likely reasons for the lack of correlation between convolution angle and strength in the case of herbaceum cottons are given.

The total void space determined from propanol-2 retention and alkali centrifuge value was of the same order in both the groups of cotton for a given maturity. However, the micropores of hirsutum cotton cell wall are of larger size as compared to the herbaceum cotton as indicated by high absorption of Carbolan Violet 2 RS, a large size molecule dye. Moisture regain values of cottons before and after acid hydrolysis showed that herbaceum cotton absorbed more moisture indicating it has more disordered region and smaller crystallites as compared to hirsutum cotton.
Knitting with Cotton and Cotton Blend Open-End Spun Yarns
Authors: Black David H.
Published: March 2008

Yam data, knitting performance, and fabric properties are examined when using open-end (OE) and ring yarns. A relationship between yarn problems in warp knitting and OE yarn characteristics is given. Results from warp knitting trials show that coarser OE yarns give significant improvements in knitting performance compared to ring yams, and ring yarns with a high twist multiple give better knitting performance than ring yarn with normal knitting twist. Single-knit and double-knit fabric properties of shrinkage, burst strength, abrasion, etc. are examined. Weaker OE yams do result in lower burst strength values, but the values from most knitted fabrics will meet existing standards for performance. An assessment is given on fabric characteristics such as appearance, spirality, and pilling.
Snag- and Fuzz-Resistant Double Knits via Fabric Construction
Authors: Leung P.S.K. , Shkowitz R.L. He
Published: March 2008

Studies on the relationship of yam and fabric parameters to finished fabric performance have led to the development of an empirical expression of stitch tightness, a dimensionless quantity which includes such variables as stitch loop dimen sions and yam diameter. Rapid laboratory testing methods were developed to determine the value of this proposed constructional density factor concept. These two tests were shown to have good correlation with actual wear perform ance. Laboratory and confirmatory wear testing have determined the minimum constructional density factor for various knitted fabrics. These factors can be used to calculate the greige yarn run-in required in knitting to engineer fabrics that will have acceptable performance in wear.
Synergism and Swelling in Morpholine Ethylenediamine-Treated Cotton Cellulose
Authors: Kulkarni M.P. , Lokhande H.T.
Published: March 2008

Studies made on the swelling effects of ethylenediamine and morpholine on cotton in both aqueous and nonaqueous media indicate that the mixture of the two is a more powerful swelling reagent than either substance used separately.
Determination of the Rheological Parameters of Fabrics in Bending
Authors: Chapman B.M.
Published: March 2008

A simple method which utilizes stress-relaxation data to estimate the single-fiber, (linear) viscoelastic contribution to the total width of a fabric bending hysteresis diagram has been outlined. The method involves an auxiliary stress- relaxation experiment on single fibers, yarns, or fabric. From this stress-relaxation curve the span-to-depth ratio r of the single-fiber bending hysteresis curve is calculated. The product of r and the depth of the fabric hysteresis curve gives the span of the fabric hysteresis curve due to single-fiber, viscoelastic effects. The validity of the method has been demonstrated on single fibers of wool and nylon in bending where no frictional effects occur. In two fabrics investigated it has been shown that by ignoring viscoelastic effects, values of the frictional moment obtained from fabric hysteresis curves may be considerably in error.
Interactions of Nonaqueous Solvents with Textile Fibers
Authors: Knox B.H. , Weigmann H.-D. , Scott M.G.
Published: March 2008

Measurements of longitudinal shrinkage and volume swelling of polyester (PET) fibers in a wide variety of solvents were made at room temperature for time periods sufficient to establish quasiequilibrium conditions. Evaluated in terms of the solubility parameters (δ) concept, these results, together with iodine displacement studies, indicate that: (1) PET may be treated as an ( AB)x alternating copolymer, where A is a semirigid aromatic residue —CO-C 6H4— with a δ-value of 9.8, and B is a flexible aliphatic ester residue —O-CH2-CH2-O-CO— with a δ-value of 12.1 ; and (2) the preferential interaction of a solvent with either of the two PET residues provides the necessary chemical energy to disrupt intermo lecular cohesive forces between the polymer chains, permitting relaxation of internal orientation forces and shrinkage of the fiber. It is shown by successively treating PET in solvents of increasing plasticizing strength that solvent-induced crys tallization, a secondary process involving chain folding of the newly relaxed chains, does not inhibit shrinkage at lower temperatures. Therefore, room temperature chemical annealing is viewed as being similar to low-temperature (<175°C) thermal annealing, where small crystallites are formed which confer negligible dimensional stability on the fiber under going shrinkage.
The Limitations of Woodcock's "Moisture Permeability Index"
Authors: Spencer-Smith J.L.
Published: March 2008

The limitations of Woodcock's "Moisture Permeability Index, im," are discussed together with his suggested method of measuring im. The general expression is derived for im. from which it is clear that the Moisture Permeability Index is not a dimensionless index but depends upon the values of the convective and radiative heat losses from the outer surface of the clothing assembly. It is pointed out that Woodcock's test method using an unheated sweating cylinder is liable to give an underestimate of the heat loss from a clothed, perspiring body, first because in actual wear the clothing may become wetted in which "liquid assisted heat and vapor transfer" will take place, and second, because evaporation tends to increase the convective heat transfer from the outer surface of the clothing.
The Reactions of Cellulose with Amic Acids and Anhydride/Aminonia
Authors: Johnson Phillip R. , Bowman B. Gray , Cuculo John A.
Published: March 2008

Formulas have been developed for the calculation of free, total, and crosslink degree of substitution in Cellulose Ester Derivatives. Free and total carboxylic acid group content from established analytical methods is required.
A Theory of Self-Crimping Bicomponent Filaments
Authors: Gupta Bhupender S. , George Waller
Published: March 2008

An elementary theory of the bending of two, coupled, thin elastic elements is presented as a model for computing the curvature of bicomponent filaments. The curvature is expressed in terms of a differential extension between the two elements at the moment of "activation." The model requires expressions for the deformational energy of the interacting elements, and an explicit "material" relation expressing the details of the interactions between the "driving" and "driven" elements of the filament structure. It is closed by minimizing this energy with respect to a parameter measuring the inefficiency ΔL/L2 of the activation strain ε. Curvatures computed for near-unity ratios of rectangular cross sections and elastic moduli yield results comparable to previously published work for both ratio values near unity (the Timo shenko limit). At larger and smaller values of these ratios the curvatures obtained by the new model are lower than those obtained previously and in limited cases appear to approximate experimental experience. A discussion of the general problem of computing and understanding practical crimp situations is given.
Influence of Fiber Properties on Wrinkling Behavior of Fabrics
Authors: Butler R.H. , Lams G.E.R. , Prevorsek D.C.
Published: March 2008

Experimental evidence is presented showing that hysteresis losses in planar shear in fabrics have a high degree of correlation with crease-recovery angles. Analysis of the mechanism of hysteresis loss results in the equation ΔβF=Cμ E (1— s), relating the modulus E, the interfiber coefficient of friction μ, the settability s, and the component Δβ F of the recovery angle due only to the interactions in the fabric. The validity of the equation is supported by experimental results.
Relaxation Shrinkage of Worsted Yarns
Authors: Baird K.
Published: March 2008

This account provides information about the cause of relaxation shrinkage in worsted yams, and in particular it examines the contribution which cohesive set in single fibers makes to yarn shrinkage.

It is shown that yam shrinkage can be a significant factor in the relaxation shrinkage exhibited by both woven and knitted fabrics. It can give rise to such problems as "bubbling" in checks and variability of dimensions of knitteds. There is also good evidence to show that yam shrinkage can be the cause of fabric expansion during washing.

The conditions which should be used for measurement of yam shrinkage are discussed, and it appears that a tension of 0.2 gf/tex is appropriate in many cases.
Quantitative Determination of Dyes in Teatile Fibers
Authors: Kissa Erik
Published: March 2008

Cationic dyes in polyester fiber are determined spectro-photometrically after extracting the dye from the fiber with N,N-dimethyl formamide (DMF) or N,N-dimethylacetamide (DMAC) containing a strong acid, a salt of a strong acid, and a free-radical inhibitor. The extraction involves ion exchange between the dye cation at the negatively charged dye-site and a proton or a metal ion in the solvent. The cationic dye is extracted rapidly and quantitatively from polyester fiber at 140°C with DMF containing 0.4M (54.5 g) ZnCl2, 0.8% (by vol) conc hydrochloric acid, and 20 g/l. 2,6-di- t- butyl-4-methyl-phenol (DBMP). The precision and accuracy of the method are very good. Satisfactory results can be obtained also with DMF containing LiCl, a sulfonic acid, and DBMP, although extracted dyes are less stable in this extractant than in DMF containing ZnCl2, HCl, and DBMP.

The ZnCl3/HCl reagent is useful also for the determination of cationic dyes in acrylic fiber by the dissolution method. The reagent can be used to extract mono-cationic dyes from polyamide fiber. Most bis-cationic dyes are extracted in completely from polyamide fiber, although their extraction from polyester fiber is quantitative.
Stress-Strain Properties of Mercerized, Stretched, and Durable-Press Treated Cotton Fibers
Authors: Lawson Reba , Ramey H.H. , Elliott P.W.
Published: March 2008

Six cotton samples were slack-mercerized and stretched to 0.94, 1.0, and 1.036 of the original length. All treatments were given an overtreatment of durable-press resin. The effect on 3.2-mm-gauge bundle tenacity and elongation depended on the amount of stretching. Samples slack-mercerized and stretched to original length increased in tenacity an average of 50%, and with an overtreatment of resin, 89% of the tenacity was retained. Samples differed in their reactions to the treatments. The percent retention of tenacity after treatment varied inversely with the ratio of the 3.2-mm-gauge length tenacity to the zero-gauge length tenacity of the untreated fibers. Clamps and stretchers developed to stretch the mercerized cotton fiber bundles are described.
Capillary Sorption Hysteresis Losses in Fibrous Assemblies
Authors: Skelton John
Published: March 2008

The energy loss associated with the reorganization of the elements of a fibrous assembly by the absorption of liquids , has been calculated using a simplified model of the assembly, and has been shown to be in reasonable agreement with previously reported experimental values of this parameter.
Isolation and Qualitative Characterization of Some of the Water-Soluble By-Products of THPOH-Ammonia Polymer Synthesis
Authors: Cashen Norton A.
Published: March 2008

The side reactions of the polymerization of tetrakis(hydroxymethyl)phosphonium hydroxide-ammonia (THPOH-NH 3) for flame-retardant treatment of cotton textiles yield water-soluble products. This report attempts to answer some of the questions which relate to the kinetics and thermodynamics of these side reactions and to characterize some of the products. Hexamethylenetetramine was established by adsorption chromatography and by internal reflection infrared spectroscopy as a competing side-reaction product. Also, aminomethanol and hexahydro-1,3-5-triazine are strongly suggested as associated intermediate compounds.
Lightfastness of Reactive Dyes
Authors: Krichevsk G.E. , Vachobov B. , Ershov Yu. A. , Dovb E.B.
Published: March 2008

Reactive dyes are strongly covalently bonded with fibers, which ensures an exceptionally high dyefastness with regard to many physico-chemical factors, but with the exception of lightfastness. This article deals with the specific features of reactive dye fading on textile materials, depending on the nature of the bond between the dye and fiber, the dye concen tration in the fiber, and the spectral characteristics of the dyes exposed to mono- and polychromatic light.
Water Vapor Sorption by Resin-Treated Annealed Wool
Authors: Watt I.C. , Leeder J.D. , De Boos A.G.
Published: March 2008

The nature of the changes in the sorption capacity of wool that has been annealed and resin-treated has been de scribed. Except under conditions. known to lead to degradation, the major effect is a reduction in water content over the entire range of humidity. The changes are in the same direction and generally greater than those obtained by simply annealing the wool under similar conditions in the absence of the resin-forming reagents. The presence of resorcinol-formaldehyde resin, or treatment with either resorcinol or formaldehyde individually, does not account for- the observed changes, and there appears to be a synergistic effect on changes of water content by deposition of resin under annealing conditions.
Liquid Ammonia vs. NaOH Mercerization as Pretreatment for the Cotton- Butadienediepoxide Reaction. Spectral and Microscopical Studies
Authors: Jung Hilda Z. , Berni Ralph J. , Benerito Ruth R. , Carra Jarrell H.
Published: March 2008

Native, mercerized, and ammonia-treated cottons were reacted with butadienediepoxide (BDO), and their fine struc tural changes were followed by x-ray diffractograms, infrared absorption spectra, refractive indices, and in micro scopical cross sections. Conventional mercerization and liquid NH3 pretreatment of native cotton generally produced a more isotropic fiber. But the nature and mode of decomposition of cellulose swelling complexes formed with either NaOH or liquid NH3 differed, as evidenced by differences in crystalline lattices and the optical properties of reaction products. Optical density increased only in the direction of the fiber axis with NH3 but also perpendicularly to the fiber axis with NaOH. Subsequent treatment of NH3-cellulose controls with mercerizing strength NaOH converted their crystalline lattices to Cellulose II. BDO reaction and postmercerization affected the refractive index only in the direction of the fiber axis (η||). Generally, BDO reaction reduced η|| of all but the NH3-cellulose I control; and postmercerization further reduced η|| of only BDO-reaction products that retained the cellulose I lattice. Birefringence of postmercerized BDO-reaction products derived from NH3-cellulose I was lower than that of comparable BDO-reaction products from conventionally mercerized cotton. Before and after BDO reaction, cross sections of most fibers in reaction products from native and NH3-treated cottons with the cellulose I lattice were elliptical, while comparable cross sec tions from conventionally mercerized cotton were round. Changing the catalyst from 2% to 15% NaOH generally increased the number of circular fibers in BDO-treated cottons having the cellulose I structure. All control cottons dissolved in cupriethylenediamine, but BDO-reaction products were insoluble and cross sections appeared solid. Gen erally, reaction products from cottons pretreated with liquid NH3 had a softer hand and dyed more uniformly than did comparable products from conventionally mercerized cotton.
The Wrinkling Behavior of Wool Fabrics—Conditions of Testing
Authors: Hayes R.L. , Leeder J.D. , Taylor D.S.
Published: March 2008

The effects of time, temperature, and humidity on wrinkle formation and recovery have been studied during the five distinct phases considered to control wrinkling behavior. Quantitative test data are readily influenced by the history of the fabric, by preconditioning, and by conditioning; the environmental conditions prevailing during all phases must be carefully controlled. Conversely, application of the empirical data now available allows considerable latitude in the choice of conditions of temperature, humidity, and time. Conclusions from earlier work indicating that it is advisable to change the temperature and/or humidity immediately before wrinkle insertion are reinforced by the present results.
Some Effects of Chemical Treatments on Cotton Sliver and Roving Properties
Authors: Rhodes P.L. , Graham C.O. , Harper R.J.
Published: March 2008

The effects of chemical treatments. on the fiber and roving properties that influence the efficient processing of cotton were evaluated. Drafting tenacity, roving twist, and static electricity generation were tested. Certain chemical treatments of card sliver reduced drafting tenacity but required increases in roving twist. Less roving twist was required with several treatments, and one treatment substantially increased drafting tenacity. Practical aspects of chemical treatments are discussed.
Effect of the Afterglow on the Felting Shrinkage of Wool
Authors: Pavlath Attila E. , Kay Sue Lee
Published: March 2008

The so-called afterglow area of electric glow discharges, even if it does not emit visible radiation, still contains active particles capable of initiating a multitude of chemical reactions. When wool was exposed to the afterglow of various gases, a considerable amount of shrinkproofing effect (SPE) was observed. Quantitatively the effect was lower than that obtained in the actual glow. However, depending on the reaction variables (power, gaseous media, and reactor design), active particles were found as far as 300 mm downstream of the glow. The effect increases with the power, almost linearly, without an increase in the temperature. Therefore, in contrast to the glow, the afterglow does not singe the yarn at higher power values. These findings supplement our present theory on the species in glow discharges responsible for shrinkproofing wool. Since the electron density of the afterglow is zero, for practical purposes, free radicals and/or activated molecular species must play an important part in this type of shrinkproofing process. The effect caused by the actual glow is the combination of the high-energy electrons, ions, and other nonionic active species. The quantitative contribution of these various particles to the final SPE is still uncertain.
The Wear-Comfort Prediction of Specified Knit Garments
Authors: Paek Soae L. , Davis Sandra G.
Published: March 2008

The relationship between the comfort rating of men's knit slacks and the amount of garment ease, available fabric stretch, wearer's weight/height ratio, and activity level was investigated. The comfort rating during fifteen wear periods was significantly correlated to knee ease and attivity level. Other variables which contributed to the prediction of comfort rating were leg ease and weight/height ratio. These variables accounted for 54% of comfort score variability. The comfort rating was found to be correlated with garment wear performance properties such as clinginess, waist roll-up, and pilling and snagging. As a whole, the majority of wearers reported over-all satisfaction with the double-knit slacks tested in the study.
Creation of Reactive Centers on Cotton Part VII : Mechanism of Reaction of Cotton with Hezahydro-1,3,5-Triacryloyl-s-Triazine
Authors: Kamel M. , Abou-Zeid N.Y. , Anan S.A. , Hashem M.S.
Published: March 2008

Treatment of cotton fabrics with alkaline aqueous solutions of hexahydro-1,3,5-triacryloyl-s-triazine (I) under different reaction conditions leads to fabrics containing varying numbers of double bonds as reactive centers. A similar result is also obtained when the fabrics are treated with a mixture of acrylamide (II), N-hydroxymethylacrylamide (III), and N,N'-methylene-bis-acrylamide (IV). Experiments indicate that in all cases the presence of the double bonds in the fabrics can be attributed to the deposition of insoluble polymeric products. However, when the fabrics were treated with I in a mixture of alcohol and chloroform in presence of triethylamine, a true chemical reaction between I and cellulose could be effected to give cotton with reactive double bonds. The reaction of cotton with II, III, and IV in alkaline medium is also investigated in detail.
The Effect of Aluminum on the Load-Extension Characteristics of Some Wool Yarns
Authors: Edgar J.S. , Simpson W.S.
Published: March 2008

Aluminum ions absorbed by wool yarns from water/alcohol mixtures alter the load-extension behavior of the yams. The magnitude of the effect is related to the yarn geometry and the concentration of the various alcohols, but it is not always directly proportional to the quantity of Al absorbed. I
The Importance of Interfiber Friction in Wrinkling
Authors: Chapman B.M.
Published: March 2008

Some of the more important consequences of interfiber friction in fabric wrinkling are discussed. A simple approxi mate relation for a linear viscoelastic fabric is obtained which relates the residual set at which the fabric ceases recovering to the length of time it was held bent before release. It is also shown how the presence of friction can allow quite high residual deformations to build up following series of short wrinkle-and-recovery cycles.

For a typical single wrinkle-and-recovery cycle the frictional moment interacts with the viscoelastic behavior of the single fibers to impose a limit on the final recovery that a fabric may eventually attain. This concept is interpreted in terms of previously defined parameters V and F obtained from a standard test procedure. The importance of evressing the wrinkling behavior of a fabric in terms of its viscoelastic and frictional components is emphasized.
Geometry of Bent Continuous-Filament Yarns1
Authors: Freeston W. Denney , Schoppee Meredith M.
Published: March 2008

Expressions are derived for determining theoretically the number of filaments accommodatable in successive con centric rings in a multifilament yarn cross section as a function of yam twist and filament diameter. Increasing filament ellipticity with increasing twist is considered. Numerical values are tabulated for several typical filament diameters and a range of yam twists. The yarn packing factor is also given. Photomicrographs of model yarns illustrate that migra tion of filaments occurs with increasing twist; filaments are forced outward from one ring to the next as their ellipticity is increased.

Photographs of bent, multifilament model yams show evidence of an increase in helix angle of the filaments on the inside of the bend and a decrease of those on the outside of the bend. A change of filament packing density upon bending is also evident. An increase in packing density on the inside of the bend and a decrease on the outside is observed for some degrees of bending; however, for severe bending the packing density appears to decrease throughout.

Analytical results are presented graphically for the curvature and change in curvature of the filaments in a bent, twisted yam as a function of filament position in the yam cross section, yam twist, and radius of curvature. The most significant findings relate to the locations within the yam cross section of the maximum and minimum curvature and changes in curvature. A discussion of the classic geometrical model of a bent yarn as it relates to fiber mobility is included.
Factors Contributing to Hook Failure of Latch Needles in Weft Knitting
Authors: Kraus H. , Speetjens J. , Vrrgilio D.
Published: March 2008

One of the problems that occurs in high-speed knitting machinery is the event of hook breakage of the knitting needle. Many causes have been suggested for this. This article deals with a theoretical analysis into the nature of the cause of failure and describes a needle design feature that has proven to be effective in reducing the problem. It also reports a sequence of testing that supported the theoretical analyses.

The basic premise of the report is that acceleration forces imparted to the knitting needles via the cams on the machines are major factors contributing to hook failure. Upon selection of a stress level required to achieve fatigue failure at the needle hook, an acceleration force is calculated, and the value of the acceleration required to produce this force is readily obtained. This value for the acceleration is then used as the input for a dynamic loading analysis, which demonstrates how changes in the design of the main body of the needle can reduce the acceleration at the hook end of the needle, thereby reducing the forces that can cause fatigue failure.

By placing scallops or cutouts in the body of the needle near the driving butt, the stiffness-to-weight ratio of the needle is reduced, yielding lower accelerations at the hook. The conclusion is that the forces accompanying these accelerations are reduced, and that hook breakage can be reduced. The report also demonstrates how cams can affect needle life. Clearly, it is the cam design that determines the level of acceleration initially imparted to the needle butt, which in turn can be transmitted to the hook end of the needle.
Mechanics of Texturing Thermoplastic Yarns
Authors: Brookstein David , Backer Stanley
Published: March 2008

The structural model used in an earlier paper for analysis of steady-state mechanics of draw texturing is applied here to the case of process transients. In an earlier report on steady-state operation, expressions for threadline tension and torque were equated for cold zone and hot zone locations. In this treatment of transient operation, their time derivations are equated at hot and cold locations. Time derivatives of local twist (turns) and of local filament mass are also formulated for various threadline zones. A system of seven nonlinear differential equations is developed and solved numerically by digital computer. Values are obtained for time variations of threadline tension, torque, and local twist which follow upon disturbances of spindle speed or entry or exit roller velocity. Experimental values of threadline tension, torque, and twist are reported to be in close agreement with predicted results. The effects of oscillatory disturbances are also considered.
Modification of Fiber Surfaces by Monomeric Additives
Authors: Mares F. , Oxenrider B.C.
Published: March 2008

In contrast to commonly used polymeric fluorocarbon finishes, a new approach to the modification of fiber surfaces by nionomcnc fluorocarbon additives is described. The additives are not simply deposited on the fiber surface, as demon strated by examination with scanning electron microscope and by excellent durability of the modified surface to abrasion, home-laundering, and dry-cleaning. The additives are concentrated in the fiber polymer near the fiber surface and held there due to their miscibility with the polymer matrix and due to their insolubility in soap solutions or in dry-cleaning solvents. Concentration as low as 0.25% of the additives on the weight of the fiber results in excellent water and oil repel lencies. The modified fiber can be knitted and dyed without affecting the surface properties.
Fiber Crimp Characterization by Image Analysis
Authors: Sawyer L.C. , Chen J.C.
Published: March 2008

A method for rapidly and quantitatively measuring the two-dimensional crimp geometry of fibers using commercially available automatic Image Analysis instrumentation is described. The crimp frequency of a filament deknitted from a fabric is shown to be a useful indicator of fabric bulk. A macroscope device and a scheme for the measurement of three-dimensional geometry of crimp are outlined.
The Mechanical Properties of Textured Polyethylene Terephthalate Yarn
Authors: Gupta V.B. , Gupta D.P. , Mittal S.C.
Published: March 2008

Cummerciat polyethylene terephthalate multifilament yarn was textured using the spindle false-twist method over a range of heater temperatures and contact times and at various tension and twist levels. The decrimping extension, initial modulus, tenacity, and fiber clongation of the various samples were measured on a tensile tester. The changes in these mechanical properties as functions of the texturing parameters are described and their structural dependence dis cussed in this paper.
A Study of the Physical State of some Water-Soluble Dyes in Cellulose by p-Nitrophenol Adsorption
Authors: Giles Charles H. , Haslam Ronald
Published: March 2008

The p-nitrophenol adsorption method has been used to measure the specific surface of two direct dyes and an acid wool dye in various forms of cellulose. The state of association is then determined. At weak shade depths a monolayer of dye is formed on the internal surface of the substrate, but as the shade is deepened multilayers appear to form, and event ually these break up into three-dimensional aggregates. Association occurs more readily in "never-dried" regenerated cettutose film than in normal film and is not influenced by drying.

There is a correspondence between the state of association of C.I. Direct Blue 1 measured by the present method and heat of dyeing and specific gravity data of the same dye/film system, determined by Daruwalla and D'Silva.
The Effect of Absorbed Water on the Properties of Cotton and Fibers from Hydrophilic Polyester Block Copolymers
Authors: Wallenberger F.T.
Published: March 2008

This paper describes the effect of water on the fiber properties and the moisture-retaining ability of cotton in relation to hydrophilic model block copolymer fibers. These model fibers were made from hydrophohic polyethylene terephthalate segments and hydrophilic polyethylene oxide segments. Drawn, heat-set fibers having up to 20% of water-soluble seg ments with molecular weights of 4000, up to 5% with molecular weights of 20,000, and with many intermittent percentages and molecular weights, gave suitable model fibers with DTA melting points ranging from 240 to 259°C.

Increased moisture sorption affects these fibers as it affects cotton or rayon. It causes fiber swelling, reduced dry and wet glass transitions, and reduced wet and/or hot/wet recovery properties. The moisture reservoir within the fiber struc tures poses another product liability, because all hydrophilic fibers have slower drying rates than hydrophobic man-made fibers. Under hot/humid conditions this propensity causes prolonged wet clinging of garments to the body and requires higher energy use for drying of garments in home or commercial dryers.
Weft Insertion by Water Jet
Authors: Kimura Satoo , Iemoto Yoshiyuki
Published: March 2008

For the final purpose of making clear a mechanism of weft yarn insertion in a water-jet loom, the flow and configuration of the jet in the vicinity of the nozzle exit have been analyzed by utilizing the matched asymptotic expansion technique. Since in the present analysis the flow field, the nozzle profile, and the weft profile have been idealized, the results cannot indicate the actual phenomena in a strict sense. However, the following results have been obtained. The flow is per turbed by using the small parameter (the reciprocal of the cube root of the Reynolds number). The decreases of the radius of the core-flow region, the jet-radius, and the acceleration of the flow velocity near the free boundary of the jet have been calculate as a function of the distance from the nozzle exit. In order to calculate in detail the weft-insertion force, the other region near the weft surface is to be taken into account.
Photo-Oxidation Mechanisms in Wool. A Study of the Photoprotective Effect of a Thiourea/Formaldehyde Treatment
Authors: Leaver I.H.
Published: March 2008

Mixtures of thiourea and formaldehyde, when applied to natural protein fibers such as wool or silk, are known to inhibit the photo-oxidation and discoloration of these materials in sunlight. This paper examines the mechanisms underlying the photostabilization of wool by thiourea/formaldehyde (TUF). The photostabilization depends markedly on the spectral composition of the light source and involves a combination of processes which include quenching of uv-induced singlet- and triplet-excited species in wool and sensitization of the fiber to photobleaching in visible light. The photoyellowing behavior is closely related to the intrinsic luminescence properties of the fiber, and the role of the excited species in the photo-oxidation of wool are discussed.
A New Method for the Determination of Yarn Hairiness by Digital Fibrograph
Authors: Pai S.B. , Munshi V.G.
Published: March 2008

For the measurement of yarn hairiness, a simple and quick method has been devised on the Digital Fibrograph. model 230 A.
Cotton Protective Apparel for the Space Shuttle
Authors: Dawn Frederic S. , Morton Glenn P.
Published: March 2008

All the materials for use either in a manned space flight or in a flight experiment, including materials of the spacecraft, crew provision, and equipment, must be evaluated and meet certain performance criteria as established during the Mercury, Gemini, Apollo, and Skylab programs. In addition to testing for the primary requirements of flame-resistance, odor, offgassing products, flash- and fire-point temperatures, cotton textile items were also considered as candidate space-shuttle, in-flight apparel on the basis of skin sensitivity, comfort, electrieal resistivity, colorfastness, and general protective features exhibited under certain conditions of flame and heat exposure.

Chemically-treated flame-resistant cotton fabries that have been approved for space-shuttle apparel include a two-ply sateen (244 g/m2), a filling sateen (153 g/m2), and a two-ply, mercerized, single-knit jersey (187 g/m2). These fabrics are being used to fabricate the total flight ensemble from underwear to coverall and outer jacket. Fabrics for the outer garments were dyed to NASA-specified shades of blue with stable vat dyestuffs, compatible with the flame resistant treatment.

These cotton fabrics were treated first with commerciat phosphonium salts and subsequently cured with gaseous ammonia. The process is more commonly referred to as the tetrakis(hydroxymethyl)phosphonium hydroxide/ammonia (THPOH/NH3) method. A second finishing application was required in order for the finished textile items to meet the slightly oxygen-enriched environment of the spacecraft crew bay area. The final finishing process comprised adding on diammonium phosphate (DAP)/urea, drying, curing (90 s @177°C), and afterwashing. DAP is a more efficient flame inhibitant than the phosphonium polymer, thus the combination treatment served to impart higher resistance to ignition and sustained combustion, as required by NASA test standards.