bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nature of the Swollen State as Determined from Tensile Properties After Cross-Linking
Authors: Wade Ricardo H. , Vigo Tyrone L. 
Published: March 2008

Changes in internal fiber structure of cotton during swelling and tensioning were determined from the effects of these changes on physical properties imparted by cross-linking with dimethylolethyleneurea (DMEU). Cotton yarns were swollen with various agents and subjected to tension during swelling and subsequent washing. Dimethyl sulfoxide (DMSO), aqueous benzyltrimethylammonium hydroxide (BTOH), and solutions of KI and KCNS in NaOH were used as swelling agents. The effect on structure caused by repeated cycling between slack and original length during the base-swollen stage was judged from the effect of subsequent low-level cross-linking on physical properties. Resin pickup and distribution in the yarns were controlled by high-speed centrifugation. The type and concentration of swelling agent are related to the form and degree of tension needed during the swelling steps to produce optimum properties after cross-linking. Improvement of physical properties after cross-linking was found to correlate with increased crystallite orientation over a part of the range studied. The relationship between degree of conversion of native cotton to Cellulose II and energy-to-rupture values is discussed. The characteristic features of low- level cross-linking previously observed in the fiber fragmentation patterns of yarns treated with DMEU, centrifuged to a low wet pickup, and cured, were also seen in the samples repeatedly swollen and restretched prior to DMEU treatment, centrifuging, and curing.
Absorption of Formaldehyde by Wool
Authors: Reddie R.N. , Nicholls C.H. 
Published: March 2008

A radiochemical method has been used to follow the course of reaction of formaldehyde with wool. The amount of formaldehyde absorbed from aqueous solutions was dependent on the conditions of treatment. It was found that the pH of the solution, the concentration of formaldehyde in the solution, and the treatment time and temperature markedly affect the extent of the wool-formaldehyde reaction. The presence of salt in the solution has some modifying effect on the uptake of formaldehyde by wool, and there are some apparent differences in the effects of different salts. The amount of formaldehyde bound by the wool was affected by the rinsing conditi ons to which the formalized material was subjected, indicating that not all of the absorbed formaldehyde was present in the form of stable products; this was confirmed by the gradual loss of formaldehyde from formalized wool on exposure to the atmosphere.
Interaction between Polyethylenimine and Human Hair
Authors: Da Chow Carl 
Published: March 2008

An irreversible penetration of [14C] polyethylenimine into a human hair was demonstrated by radioactive-tracer technique. Under ambient conditions, 1% of the imine diffused into the hair in an hour. Desoprtion of the imine was rather slow; most of the imine could not be washed out by an untagged imine solution in 24 hr indicating a possible strong interaction between the imine and the hair. The results are assumed to be applicable to the untagged imine. The swelling rate of hair in distilled water and the swelling behavior of hair in the imine were studied by light micro scopic observation. When dry hair was wetted with deionized water, a 36 ± 7% swelling was found in 24 hr. The degree of hair swelling by the imine was much greater at pH 7 than at higher pH. The effect of pH, concentration, and temperature on the swelling of the hair in the imine and some aspects of the permanent-waving mechanism by using the imine have been postulated and discussed.
Effect of Tuft Characteristics in Opening Room on Yarn Properties
Authors: Sripathi R. 
Published: March 2008

This study deals with the effect of tuft size and its variation on lap uniformity, carding quality, and yarn properties. Three different types of tufts (small, big, and blend) have been covered in 40s, 80s, and 30s counts from suitable cottons and staple fiber. Results of this study show that, while opening the cotton in opening room, it is essential to ensure that the tufts are made into small and uniform size for producing even laps and better-quality yarns. Higher variation in tuft properties may affect count and strength variation significantly.
The Compression by Liquid Stress and the Permeability of Assemblies of Wool Fibers
Authors: Samson A. 
Published: March 2008

The permeability relationships and wet compressibility of scoured wool, card sliver, tops, and fabrics were determined by applying flowing water under pressure. Dry and wet assemblies of wool fibers were also compressed mechanically and the pressure-volume relationships obtained. Critical Reynold's numbers have been evaluated for flow through loose wool fibers, and the characteristics of the types of flow within compressible porous media have been discussed. Loose wool fibers when wet were more resistant to compression than an equal mass of dry fibers; also, fabrics were less permeable and compressible than equivalent areal densities of loose wool at pressures up to 8 atm.
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.
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.
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.
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.
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.
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.
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.
A Technique for Simulating the Stength of Kevlar 29 Yarn in a Woven Configuration
Authors: Ericksen R.H. 
Published: March 2008

To obtain maximum yarn strength translational efficiency in Kevlar 29 parachute webbings, the pick frequency must be reduced to the extent that the structure is too loose to be useable. As a result only modest efficicncy has been achieved in Kevlar 29 webbings. It has been shown that only part of the strength decrease is caused by the weaving process; hence, warp and fill yarn interaction during loading contribute to the loss in efficiency. A test fixture was developed to measure the strength of a yarn sample threaded through a series of wires or yarns. This enabled the effect of warp twist and ply on warp strength to be easily and quickly determined under simulated crimp conditions. It was found that yarn strength decreases with decreasing pick spacing in the fixture, as is observed in woven fabrics, and the magnitude of strength decrease varies with yarn twist. optimum fabric strength was predicted to occur at lower warp-twist levels than those established using conventional yarn tests. Comparisons were made between the simulation results and the limited data available for woven structures. A general correlation was obtained for cases where the warp yarns were compressed during fabric construction.
Lint-Cleaning Efficiency at Gins and Its Significance
Authors: Mangialardi Gino J. 
Published: March 2008

Cleaning efficiencies for two stages of saw-cylinder lint cleaning with full-scale commercial equipment were examined. It was shown from a 66-bale study that an average cleaning efficiency of about 35% per cleaner unit could be expected at field gins, but that the measured efficiency is affected significantly by both the initial foreign-matter content of the cotton and location of the unit cleaner within the lint-cleaning system. The higher cleaning efficiencies obtained when processing cottons of high foreign-matter levels were attributed to the presence, of large trash particles, which were readily extracted by the centrifugal action of the cleaner. This effect was also observed with the first cleaner of a two-stage lint-cleaning system. The cotton handled by the first cleaner is trashier than that handled by the second lint cleaner, therehy producing a higher cleaning efficiency with the first lint cleaner than with the second lint cleaner. It is pointed out that the efficiency is also affected by the amount of combing and centrifugal action developed by a lint cleaner.
The Noncrystalline State Within PET Fibers—Meaning and Characterization by Mechanical-Relaxation Measurements
Authors: Valk Giselher , Jellinek Günter , Schröder Ulrich 
Published: March 2008

The performance of synthetic fibers cannot be completely understood without any knowledge of the structure in the noncrystalline regions. X-ray diffraction measurements led to the conclusion that the noncrystalline regions in PET fibers can be divided into isotropic noncrystalline (amorphous) and oriented noncrystalline fractions, the amount of which is dependent on the thermal and mechanical history. But x-ray diffraction data, thermal analysis, and dyeing experiments left many effects unexplained: the dependence of glass-transition and dye uptake on thermal history, the real order-disorder situation within the noncrystalline regions, certain mechanical properties, and their time-dependence such as relaxation. The glass-transition temperature Tg of PET fibers, as determined by viscoelastic measurements, runs through a maximum depending on the heat-setting conditions. This can be explained by the assumption that the average size of crystallites reaches a minimum, and therefore the number of crystallites per unit volume shows maximum values at a heat-setting temperature of about 190°C. By raising the heat-setting temperature above 190°C, the crystal lites become larger. Segregation of the crystallites in the noncrystalline matrix occurs. If the network formed by the crystallites has its highest density, Tg shows maximum, and dye uptake, minimum values due to low molecular mobility. For the same reason the storage modulus in the rubber state has maximum values after heat-setting at temperatures around 190°C.