bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
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.
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.
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.
Vapor-Phase Deposition of Surface Polymers and Cross-Linking on Cotton Fabrics 1
Authors: Brenner W. , Rugg B. , Liu W. 
Published: March 2007

Vapor-phase deposition of selected polymers on cotton fibers offers certain potentially attractive characteristics over conventional liquid-phase textile processing. These include uniformity and completeness of coverage at low add-on's in the absence of solvents, lower reaction temperatures and/or shorter exposure times, and use of reactants normally sensitive to water and solvents, all or some of which may result in a more favorable balance of the performance properties of such polymer-coated cottons. High molecular-weight polyoxymethylene polymer deposits were obtained by the immersion of cotton fabrics in a suit able alkaline catayst solution at ambient temperatures and in air, followed by exposure of the catalyzed cloths to purified monomeric formaldehyde vapor. Polyamide polymer deposits were realized by modified interfacial polymerization tech niques, also under mild reaction conditions. The properties of these polymer-coated cotton fabrics were determined over a range of polymer add-on's, with emphasis on the effects of treatments with various cross-linking agents. Both methylo lamide-treated, polyoxymethylene-coated and diisocyanate-treated polyamide-coated cotton fabrics were found to exhibit significant improvements in wrinkle recovery and other performance properties with superior strength retention at re latively low polymer add-on's, compared to conventionally cross-linked fabrics.
Morphology of Secondary Wall Fibrils in Cotton
Authors: Peterlin A. , Ingram P. 
Published: March 2007

The secondary wall of cotton fiber contains well aligned helical macrofibrils of about 1000 Å diameter, changing sign in irregular intervals. The sign reversals are in some respect cross sections of enhanced mechanical strength, particularly in respect to swelling. The macrofibrils are composed of a great many microfibrils of varying width, which, as a rule, seem to be narrow, ribbon-like lamellae consisting of one single layer of elementary fibrils. The former have lateral dimensions of about 200 Å, the latter of about 50 Å, as may be derived from electron micrographs of stained samples. The mechan ical deformation of such a system of helices involves a relatively large amount of sliding motion of every single helix down to the smallest independent element which may be the microfibril or some larger agglomerate, e.g., the macrofibril. Surface forces between adjacent helices reduce the capability for sliding and, therefore, enhance the rigidity, elastic mod ulus, shape retention, and brittleness of the cotton fiber. From the absence of an equatorial small-angle, x-ray scattering maximum, one concludes that the lateral dimensions of elementary fibrils must appreciably vary in the cotton fiber, in spite of the fact that on single micrographs their thickness and packing seem rather uniform. In the longitudinal direction, the crystalline core exhibits some interruptions and the quasiamorphous boundary layers between adjacent elementary fibrils exhibit a great many interruptions at irregular intervals. If this is not an artifact, it can be interpreted as an occasional lateral extension of the less ordered material beyond the boundary layer, thus interrupting the crystal lattice of the fibril, and as crystalline bridges by which the fibrils laterally coalesce. The coalescence is favored in the (101) surfaces containing more hydrogen bridges per unit area than the (101) planes, thus producing single-layered lamellae of the microfibrils. Dark-field electron microscopy further re veals a finite extension of equally oriented crystal lattice blocks. The subsequent blocks in the fibril axis seem to have the same orientation of molecular chain axis, but are mismatched in the perpendicular direction. The corresponding screw dislocation planes between consecutive blocks seem to be less permeable to swelling agents than the quasiamor phous layers between the fibrils.
Synthesis of Methylol Fatty Alkyl Carbamates and Their Applications to Cotton
Authors: Bajaj P. , Sattur N.B. , Chipalkatti V.B. 
Published: March 2007

Work on the idea of built-in lubrication has been extended to methylol fatty alkyl carbamates having structural similari ties with stearoyl ester of 1,3-dichloropropanol-2. A study of the conditions of methylolation of the fatty alkyl carbamates, their isolation, and characterization by ir spectra and nitrogen and formaldehyde contents leads to the conclusion that the isolated methylol derivatives exist as mixtures of mono-and dimethylol carbamate, the greater the alkyl substituent in the carbamate moiety, the greater is the formation of the monomethylol derivative. Reactivity of these methytol carbamates with cellulose in the collapsed state is poor, but is improved in the presence of free formaldehyde or formaldehyde donors such as acetals. Cotton fabric treated with methylol derivatives of octyl, lauryl, and stearyl carbamates shows improvement in flex abrasion resistance at a wrinkle recovery level of 210-240° (Shirley), maximum improvement being shown by methylol stearyl carbamate and acetal. Although the specific attachments of these compounds with cellulose are not known, the likelihood of alkyl chain attachment is high, as observed by the effects of chain length on mechanical properties of the treated fabric. The treated cotton also shows mild water repellency as well as resistance to microbial attack due to the presence of hydrophobic and toxophoric groups.
Mixed Catalyst Systems for Reactions of Cotton with Dimethylolethyleneurea or Dimethyloldihydroxyethyleneurea
Authors: Berni Ralph J. , Gonzales Elwood J. , Benerito Ruth R. 
Published: March 2007

Substituted acetic acids or dibasic acids in combination with MgCl2 are active catalyst systems for the reaction between cotton and dimethylolethyleneurea (DMEU) or dimethyloldihydroxyethyteneurea (DMDHEU) at cure temperatures from 105-125°C. The reaction is primarily influenced by hydrogen ion concentration of the pad bath. Based on condi tioned wrinkle recovery of treated facrics, the order of increasing activity among the substituted acetic acid-Mgcl2 catalyst systems at 115°C in promoting the reaction of cotton with DMDHEU is as follows: acetic ≤ diethylaminoacetic < methylaminoacetic ≤ aminoacetic ≤ thiohydroxyacetic ≤ cyanoacetic ≤ hydroxyacetic acid. The order for the cotton-DMEU reaction is as follows: diethylaminoacetic ≤ acetic ≤ methylaminoacetic ≤ thiohydroxyacetic < hy droxyacetic ≤ aminoacetic ≤ cyanoacetic. Dibasic acids used with MgCl2 in the cellulose-DMEU reaction were more effective than either alone in increasing the amounts of bound nitrogen and formaldehyde and the wet recovery angles of the finished cottons. With DMDHEU, only the succinic acid-MgCl2 combination resulted in an increase in bound nitrogen over that observed with either catalyst used individually. With acids used singly or in combination with MgCl2, the pH of the pad bath was a primary factor in im proving wrinkle recovery with both DMEU and DMDHEU.