bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential Oxidative and Reductive Bleaching of Wool in a Single Bath
Authors: Arifoglu Mustafa , Marmer William N. , Carr Christopher M.
Published: March 2007

A new bleaching process applicable to wool was developed in which an oxidative step (hydrogen peroxide) is combined with a subsequent reductive step (thiourea, thiourea dioxide, or sodium hydroxymethanesulfinate) in a single-bath process. Ox idative followed by reductive bleaching is normally a two- or three-step treatment done in separate baths. Effective bleaching with reduced time and equipment use is achieved by the new single-bath process with a specific order of reagent addition. Although the reductive stage of such a single-bath process may be achieved by the complete decomposition of unspent hydrogen peroxide and then addition of reductive substances such as thiourea dioxide or sodium hydroxymethanesulfinate with necessary pH adjustment, one may take advantage of the unspent hydrogen peroxide to form a reductive substance in situ by reaction with thiourea followed by an appropriate pH adjustment to 7-8. In all the cases above, greatly superior bleaching with less physical damage is achieved with the new process compared with conventional single- or multi- bath processes.
Design and Development of an Architecture for Computer-Integrated Manufacturing in the Apparel Industry
Authors: Malhotra Rajeev , Jayaraman Sundaresan
Published: March 2007

The U.S. Air Force's IDEF methodology and IDEFine® software have been selected for developing an apparel manufacturing architecture based on the evaluation criteria proposed in Part I. The apparel enterprise has been modeled in close collaboration with a major apparel manufacturer. The resulting as is function model has been refined to yield the to be function model, and the details of the to be architecture are discussed.
A Process for Combined Scouring and Bleaching of a Polyester / Cotton Blend in a Solar Oven
Authors: Gulrajani M.L. , Mittal R.M. , Gupta Sanjay
Published: March 2007

A simple "hot box" solar collector, reported in an earlier paper, was modified into a cylindrical circular trough solar concentrator for ease of fabric loading and uniform year-round heating. Combined scouring and bleaching of polyester/cotton suiting by a pad-batch method was done using sodium chlorite with comparable results. The paper discusses the design and performance of the modified solar oven and the results of combined scouring and bleaching of polyester/cotton blends.
Heat Loss from a Ventilated Clothed Body
Authors: Lamb George E.R. , Yoneda Morihiro
Published: March 2007

The heat flux from the surface of a hot body in an air stream was measured with a simple apparatus that obviates the need for a wind tunnel. Measurements were made with the body covered with a range of polyester nonwoven fabrics. The results were analyzed on the basis of Take-uchi's theory.
Pyrolysis Gas Chromatography of Wool
Authors: Marmer William N. , Magidman Paul
Published: March 2007

Pyrolysis gas chromatography was used to study the content of tyrosyl residues in wool and the depletion of those residues by chemical reaction with nitrous acid. Wool samples that had undergone nitrosation of varying duration were analyzed by Curie- Point pyrolysis coupled with capillary column GC and flame ionization detection. The inertness of phenylalanyl residues to nitrosation permitted phenylalanine to be used as an internal standard. Peak areas for phenol and para-cresol—pyrolysis prod ucts—were compared to peak areas for phenylacetonitrile—a pyrolysis product of , phenylalanine. There was a linear relationship between the ratio of those peak areas and the molar ratio of Tyr / Phe, as determined by amino acid analysis, and another linear relationship for mixtures of known composition of polypeptides poly-tyrosine and poly-phenylalanine, but with a large difference in the slope from the line generated from the wool data. The difference was probably related to the relatively high con centration of terminal phenylalanyl groups in the polypeptide, which would result in the production of relatively larger amounts of phenylacetonitrile in the synthetic ma terial than in wool. The overall results demonstrated that damage to tyrosyl residues during the chemical processing of wool may be easily assessed using pyrolysis gas chromatography.
Photofading Rate of Disperse Dyes in Acetate and Nylon 6
Authors: Honma Yoshio , Choji Noriko , Karasawa Mikio
Published: March 2007

We investigated the photofading behavior of CI disperse red 17 and CI disperse violet 1 in nylon 6 and red 17 in cellulose diacetate. The photofading rate of red 17 in nylon 6 was influenced by the concentration distribution in the film. The laminated film exposure method was applied to all systems, and the results indicate that the time required to reach a certain fading percentage increases exponentially with the film thickness. We assumed that the fading on the surface of the samples occurred in the first order of the dye concentration for the red 17-nylon 6 and violet 1-nylon 6 system, but in the zero-order process for the red 17-acetate system.
Influence of Mercerization and Crosslinking of Cotton Fabrics on Dyeing Kinetics of Direct Dyes from Finite Baths
Authors: Chrastil Joseph , Reinhardt Robert M. , Blanchard Eugene J.
Published: March 2007

Dyeing of cotton fabrics treated with dimethyloldihydroxyethyleneurea and trieth anolamine is discussed. Adsorption time curves from finite baths of untreated, mer cerized, and crosslinked cotton print cloths have been studied. Mercerization did not change heterogeneous diffusion resistance but increased adsorption equilibrium con stants, dyeing affinities, and diffusion coefficients. Maximum dyeing capacities of mer cerized cotton were lower. Crosslinking reduced most of the kinetic constants (rate constants, structural diffusion resistance constants, maximum dyeing capacities, ac tivation energies, and diffusion coefficients). Triethanolamine additive enhanced the kinetic constants and the dyeabilities of crosslinked cotton fabrics. The results indicated that in the crosslinked cotton, triethanolamine reacted preferably with the crosslinks and not with the remaining free reactive groups of cotton fabric.
Mechanics of Woven Fabrics
Authors: Seyam A. , El-Shiekh Aly
Published: March 2007

A wide range of tightly woven fabrics made from regular thickness warp ends and filling yams with pulse train irregularities was produced to test the validity of the theoretical weavability limit relationships developed in Part I of this study. The in vestigation includes periodic and random thickness variation filling yarns. The results show that the agreement between the theoretical and loom maximum fabric cover factors is fairly good up to eight-harness weaves.
Analysis of Factors Influencing Ring Spun Yarn Tenacities for a Long Staple Cotton
Authors: Deluca Lloyd B. , Smith Brent , Waters William T.
Published: March 2007

A family of yams from a particular Egyptian cotton was used to develop a method of determining the number of fibers broken, Part I, and the effective fiber length, Part II, acting in each yarn. The yarns were spun independently on a ring frame with wide ranges of yarn sizes and twist factors. The method of yam analysis was developed by evaluating the yarn data. Single-strand breaking tenacity was measured for each yarn. Fiber fineness was used to determine the number of fibers in each yarn after correcting for angle of twist. Yam tenacity was normalized first for total fibers and then for broken fibers in the yarn. Equations relating yarn twist to the normalized yarn tenacity data for different yarn sizes at a constant twist factor were determined for each twist factor. The shape of the family of curves of twist versus normalized yarn tenacity per broken fiber in the yarn permits an existing theory for determining the number of broken fibers in a yarn to be evaluated, as well as a comparison of experimental with theoretical yarn twist.
In Vivo Cutaneous and Perceived Comfort Response to Fabric
Authors: Hatch K.L. , Markee N.L. , Maibach H.I. , Barker R.L. , Woo S.S. , Radhakrishnaiah P.
Published: March 2007

We studied stratum corneum water content, water evaporation from the skin surface, capillary blood flow, and skin temperature under three different garments worn by ten female subjects exercising and resting in a hot, humid environment (29.4°C, 75% RH). Single jersey knit fabrics made from 100% 1.5 denier polyester, 100% 3.5 denier polyester, or 100% cotton were made into long sleeve T-shirts and pants. Measures of stratum corneum water content using a microwave probe, evaporative water loss using an Evaporimeter, capillary blood flow using a laser Doppler velocimetry instrument, as well as skin temperature, were assessed on the upper back at four times during the wear protocol. An analysis of variance showed that there were no statistically significant differences in the noninvasive skin measurements under the three fabrics. Statistically significant differences in the skin measurements did occur as the kind of activity differed during the wear protocol. Results are discussed in terms of the fabric thermal and mechanical data presented in Parts I and II of this series.
Photofading of Azo Pyridone Dyes in Solution
Authors: Wang Ping Yueh , Wang Ing Jing
Published: March 2007

The influence of various substituent groups on the absorption spectra and pho tostability of some azo pyridone dyes has been examined in N,N-dimethyl-formamide. On exposure to a spectrum of ultraviolet radiation, photoreduction is mostly caused by radiation of 254 nm. The primary photochemical reaction with azo pyridone dyes involves hydrogen abstraction from the amide solvent. Two electron-withdrawing substituents in the diazo component of azo pyridone dye exert a bathochromic effect and increase the fading rate, while introduction of an alkylol group to the coupling component results in hypsochromic shifts and a decrease in the fading rate.
Effect of Repeated Laundering on the Properties of Air-Jet Textured Cotton/Filament Composite Fabrics
Authors: Sengupta A.K. , Kothari V.K. , Srinivasan J.
Published: March 2007

We describe laundering and wrinkling trials on woven grey and dyed fabrics made from air-jet textured cotton/filament composite yams as weft. The tensile and bursting strength properties of the fabrics are not affected much by the laundering treatments. The textured yarn grey fabrics in general show higher relaxation with laundering, resulting in increased thickness, thermal insulation, and abrasion resistance, and re duced air permeability and tear strength. The greater strain relief due to laundering of the bulkier textured yam structure also helps to improve the crease recovery and wrinkling properties of these fabrics. Fabrics made with textured yams show higher wrinkle recovery than the parent yarn fabrics at various strain levels. The extent of whiteness gain in grey fabrics and color loss in dyed fabrics is almost the same in both the parent and textured yarn fabrics as a consequence of laundering treatments. The textured yarn fabrics, however, show higher color value than those from the parent yarn.
Hygral Expansion Behavior of Woven Wool Fabrics
Authors: Cookson P.G.
Published: March 2007

The interyarn forces present in an unset pure wool gabardine fabric and two other fabrics obtained by subjecting the unset fabric to different levels of permanent set by dyeing under different conditions have been assessed by determining the extent to which the length of the warp yarn changes on release from the fabrics at different regains. As the level of permanent set increases, the interyarn forces at saturation are reduced through stabilization of the bending strains. On drying, cohesive setting sta bilizes the residual bending strains, and this effect appears to be the dominant one in reducing interyarn forces. The effects of fiber deswelling in reducing interyarn forces (and of fiber swelling in increasing the forces) are relatively unimportant. At low regains, longitudinal strains in the weft yams are evident in each fabric. The changes in fabric geometry that occur are rationalized in terms of the combined effects of fiber swelling/deswelling and the interyarn forces.
Residual Pore Volume, Resilience, and Strength of Crosslinked Cotton Cellulose
Authors: Bertoniere Noelie R. , King Walter D.
Published: March 2007

Cotton printcloth was treated with dimethyloldihydroxyethyleneurea to five add- on levels. Magnesium chloride hexahydrate was the crosslinking catalyst. A reverse gel permeation chromatographic technique was used to follow changes in pore size distribution. Columns were prepared by settling water slurries of the ground cotton in a conventional manner. Three series of water soluble solutes were used to study the elution characteristics of the unmodified and crosslinked samples. The solutes were series of oligomeric sugars, ethylene glycols, and glymes (ethylene glycol dimethyl ethers). Progressive losses in the accessible internal volume occurred with an increasing degree of crosslinking across the entire distribution of pore sizes. Increases in resilience were accompanied by the expected losses in strength, which in turn were associated with decreases in the accessible internal volume of the fibers. Decreases in internal volume occurred in small, medium, and large pores to comparable degrees, i.e., strength losses were not associated with the loss of a specific pore size.
Effect of Fiber Length, Fineness, and Twist on the Bending Behavior of Polyester and Viscose Staple Rotor Spun Yams
Authors: Subramaniam V. , Srinivasamurthy H.V. , Muthukrishnan P. , Ramakrishnan A.M. , Gantayat P.K. , Rajeswari S.
Published: March 2007

The effects of fiber length, fineness, and twist of polyester and viscose staple rotor spun yams have been examined for their bending behavior using a bending hysteresis tester. For the polyester staple rotor spun yarns, use of shorter and coarser fibers leads to a higher magnitude of bending hysteresis, yarn bending rigidity, and bending re covery ; the percent reduction in bending hysteresis and yarn bending rigidity is greater for coarser, shorter fibers with increasing twist. For the viscose staple rotor spun yarns, use of longer staple fibers leads to increased bending hysteresis and yarn bending rigidity; the percent reduction in bending hysteresis and yarn bending rigidity is greater for longer fibers with increasing twist. An increase in twist leads to a drop in the bending hysteresis and yam bending rigidity, regardless of the length or fineness. Wrapper fibers do contribute to the bending behavior of rotor spun yams.
Texturing of Thermoplastic Yarns
Authors: Li Shipeng , Backer Stanley , Griffith Peter
Published: March 2007

An analysis of the heat transfer effectiveness of heating technologies pertaining to false twist yarn texturing has shown that contact heating used in modern commercial machines is limited as to further increases of the heat transfer rate. With a condensation heating process using high pressure steam, yarn temperature rise time can be reduced by a factor of ten when the steam condenses only on the outer yarn surface. A con densation heating chamber, a friction texturing system and a series of texturing ex periments conducted with them helped to establish the feasibility of such heating period reduction. With a condensation heating system, textured yarns possessing sat isfactory crimp and mechanical quality can be produced with much shorter heater residence times than currently used. Required minimum cooling zone residence times are also reduced due to evaporation of condensate on the yarn surface upon exit from the condensation chamber.
Video Scan Trashmeter Area Calibration
Authors: Taylor Robert A. , Godbey Luther
Published: March 2007

Images of ginned cotton are being digitized and captured in computers for trash content analysis of cotton prepared for market. These techniques are incorporated in video trashmeters to automate particle counting and trash area observations. Area measuring accuracy is controlled by properly locating the edge of each particle in the recorded image. Since less than 5% of each frame is represented by trash, particle edges are defined by the drop m reflectance from the background lint. This method is accurate for high grade cottons with small quantities of trash, but its accuracy is reduced for tinged and stained cottons and samples containing lightly colored trash particles. Video area measurements are reported for several cotton samples and for several simulated trash reference samples (dots painted on color tiles) to demonstrate improved calibration methods.
Effect of Dynamic Surface Tension on Foam Flow Through Fibrous Materials
Authors: Hirt Douglas E. , Prud'homme Robert K. , Rebenfeld Ludwig
Published: March 2007

A new experimental technique and method of analysis have been developed to study the flow of liquid foams in fiber networks. Foam is injected into the center hole of a compressed mat and the resulting radial spreading pattern is observed through the top transparent plate. The existence of a minimum critical pressure gradient for foam flow in porous media is demonstrated as the foam front spreads, slows down, and eventually stops. The radial position at which it stops is a function of the inlet pressure. A two-parameter fluid model is proposed that incorporates "critical pressure gradient" and fluid mobility parameters to describe the interaction of the foam with the porous material. From the model, radial pressure profiles are generated that predict a qualitative difference between the pressure distribution and spreading rate of a fluid with yield behavior (that is, a minimum critical pressure gradient) compared to the flow of a Newtonian fluid. From the position at which the foam front stops, the critical pressure gradient for foam mobilization is quantified. By numerically integrating the equation for the frontal advance rate and using experimental data, a value is obtained for the foam mobility. The mobility is observed to increase with increasing foam quality and remain relatively independent of the bubble size of the foam injected into the mat. The effects of dynamic surface tension on foam flow are also shown. Foams were generated from aqueous surfactant solutions at different concentrations, each with the same equilibrium surface tension but vastly different dynamic surface tensions. As the dynamic surface tension increased, foam breakdown occurred, resulting in a significant region of liquid saturation within the mat. This effect was attributed to the inability of the solutions with a higher dynamic surface tension to prevent film rupture and foam collapse.
Effects of Substituent and Aggregation on the Photofading of Some Azo Pyridone Dyes on Polyester Substrates
Authors: Ping yueh wang  , Ing jing wang
Published: March 2007

We obtained a series of monoazo dyes by diazotizing 2-hydroxy-4-methyl-5-cyano- 6-pyridone (as a coupling component) with mono- and di-substituted anilines, and we determined the electronic absorption spectra of the dyes, dyeing properties, fastness of the dyed fabrics, fading rate of the dyes, and their color parameters. We found that the series of monoazo pyridone dyes can be applied to the polyester fibers. We con cluded that adding electron-withdrawing substituents to anilines increases the pho tostability and improves the sublimation fastness of these azo dyes on polyester, while introducing the β-hydroxyethyl group to the coupling component results in an increase in the fading rate. On the other hand, when the dye yields a first-order fading rate curve, its lightfastness is very low.
Analysis of Fabric Deformation in a Roll-Making Operation
Authors: Ghosh T.K. , Peng H. , Banks-Lee P. , Hamouda H. , Shin D.H.
Published: March 2007

The analysis of stress and displacement fields within a fabric roll is presented as a continuation of Part I of this series of papers. A discrete continuum model is used again to describe fabric deformation during the roll-making ( batching ) operation. The roll of fabric is considered to be in a state of plane stress, and the fabric is assumed to be anisotropic. The rotational speed of the fabric roll during the batching operation or the resultant fabric winding speed is considered as a parameter in the analysis. The effects of fabric winding speed on the state of stresses inside the roll is investigated, as is the problem of nonlinear lateral compressional behavior of the fabric.
Statistical Analysis of a Continuous Infrared Dryer
Authors: Therien Normand , Cote Benoit , Broadbent Arthur D.
Published: March 2007

A combination of factorially designed experiments, mathematical modeling, and statistics is used to analyze the continuous drying of a cotton web by infrared radiation. Linear relationships between operational parameters and output variables are derived. The most important parameters affecting the drying are the distance between the emitters and the web, the emitters' temperature, and the web speed. With this dryer, heat transfer by convection is much less important than by radiation, so air is mainly used to evacuate the water vapor.
Measuring Beat-up Force on a Water Jet Loom
Authors: Bullerwell Arthur C. , Mohamed Mansour H.
Published: March 2007

Methods are described for measuring the beat-up force on a water jet loom and the dynamic calibration of the force transducer. Experimental results show that the warm- up time, loom speed, and shed timing have no effect on beat-up force, while the pick spacing and linear density of the filling yam have a considerable effect on the maximum beat-up force and the shape of the beat-up pulse.
Lateral Migration Control During Drying Using Methyl Cellulose
Authors: Lambert Allan H. , Harper Robert J.
Published: March 2007

A method developed previously was used to quantitatively assess lateral migration during controlled drying. Methyl cellulose in aqueous solution, which has a unique property of forming a gel when heated, was used to control lateral agent migration during drying of knitted cotton fabrics impregnated with crosslinking reagents. During drying, the reagent solution formed a gel and significantly restricted movement of water and reagents in the capillaries of the fabric. Effects of methyl cellulose concen tration on the rate and extent of migration were evaluated.
Effects of Structure and Finishing on the Mechanical and Dimensional Properties of Wool Fabrics
Authors: Wemyss Andrew M. , De Boos Allan G.
Published: March 2007

We have investigated the effects of the interaction between fabric cover factor and finishing on fabric properties with a systematically designed array of fabric structures and finishing treatments. Permanent setting induced in finishing had the greater effect on fabric mechanical and dimensional properties. For lightly finished fabrics with a low degree of set, the influence of cover factor was significant. For the entire range of plain weave and twill fabrics, the hygral expansion could be related to the weave crimp and the shear properties of the fabric. There was also a contribution from yarn cur vilinear expansion.
Analysis of Air Flow in Air-Jet Filling Insertion
Authors: Adanur Sabit , Mohamed Mansour H.
Published: March 2007

A qualitative analysis of air flow in air-jet filling insertion is given. The air flow in single nozzle air-jet insertion is unsteady and turbulent, and can be compressible or incompressible depending on the velocity. Dynamic air velocity measurements showed that the air velocity depends on two variables—distance and time. It increases with time (distance constant) and decreases with distance from the nozzle.
Effects of Apron Spacing and Break Draft on Double-Rove Yarn Quality in Short Staple Spinning
Authors: Subramaniam V. , Peer Mohamed A.
Published: March 2007

A study is reported of the effects of apron spacing and break draft in a ring frame on the tensile and regularity properties of a double-rove cotton yam, using a factorial analysis technique, produced on a short staple spinning system. The results show that the effect of apron spacing is less marked than that of break draft on the majority of the tensile and regularity properties studied. Overall, closer apron spacing and lower break draft in the ring frame improve all but one of the properties studied.
Stress Relaxation and Tensile Modulus of Polymeric Fibers
Authors: Van Miltenburg J.G.M.
Published: March 2007

With increasingly diversified demands on the mechanical properties of polymeric fibers, the question of whether properties can be varied independently or are related has become imperative. This report is concerned with the relation between tensile modulus and stress relaxation. The modulus-elongation curve of various fibers (poly ester, polyamide, viscose rayon, and aramid) strongly correlates with the residual stress in stress-relaxation experiments. Only in case of polyethylene are there some deviations. Theoretical and practical aspects pertaining to the experimentally observed correlation are discussed.
Quantitative Fiber Mixture Analysis by Scanning Electron Microscopy
Authors: Wortmann F.-J.
Published: March 2007

Results are reported of a round trial on the analysis of mohair/wool blends by scanning electron microscopy conducted under the auspices of the International Mohair Association. The identification of the fibers in a blend is based on the pronounced difference in the cuticle scale height at the distal edge for mohair and wool fibers which is readily detected in the scanning electron microscope. Twenty-one samples were analyzed by three laboratories. The results show good agreement between reference and analysis results and indicate that the major component of the analysis error is the random error inherent to the microscopical approach to fiber analysis.
Thermal Crystallization of Poly(ethylene Terephthalate) and Its Copolyesters: Effect of Degree of Polymerization and Copolymerized Components
Authors: Takeda Hiromu , Ehara Miki , Sakai Yoko , Choi Suk-Chul
Published: March 2007

The effect of the degree of polymerization and the copolymerized components on the thermal crystallization of poly(ethylene terephthalate) (PET) and its copolyesters was investigated at a temperature just above glass transition. The crystallinity of PET increased with the decrease of [ η], but the apparent activation energy of crystallization was scarcely influenced by [η]. Crystallization of PET appears to occur from a definite state of thermal motion of the polymer segment, the isoviscous state. Comparing undrawn PET with quenched bulk PET, the crystallinity and activation energy indicate that fiber formation near the spinning nozzle develops the aggregation polymer seg ments for crystallization. Crystallinity and the apparent activation energy of crystal lization for poly(ethylene terephthalate/isophthalate) and poly(ethylene terephthalate/ p-oxybenzoate) indicate behavior that is different from PET. The thermal motion of segments for copolyesters varies with the copolymerized components.
FT-IR Spectroscopy Study of the Ester Crosslinking Mechanism of Cotton Cellulose
Authors: Yang Charles Q.
Published: March 2007

Polycarboxylic acids are being developed as new nonformaldehyde crosslinking agents for cotton fabrics to replace the traditional N-methylol reagents. In this research, the mechanism of esterification between polycarboxylic acids and cotton cellulose was elucidated using FT-IR spectroscopy. All the infrared spectroscopic data support the hypothesis that cyclic anhydrides are formed as intermediates, which in turn esterify with cotton cellulose. The infrared spectroscopic data also demonstrate that cyclic anhydrides are very reactive and are able to esterify with cotton cellulose without a catalyst present and at a temperature much lower than the curing temperatures used for polycarboxylic acids. Therefore, the chief role of catalysts such as sodium hypo phosphite is that they accelerate the formation of a cyclic anhydride from a polycar boxylic acid.
Influence of Glycine on the Graft Copolymerization Kinetics of Methyl Methacrylate on Jute Fibers Initiated by Ceric Ion
Authors: Nayak N.C. , Das H.K. , Singh B.C.
Published: March 2007

We have studied the kinetics of the graft copolymerization of methyl methacrylate on jute fibers using a ceric ion/glycine redox initiating system, including the effects of concentrations of monomer, Ce(IV), and glycine on graft yield. In addition, we have investigated the effects of time, temperature, acid, amount of jute fiber, and some inorganic salts and organic solvents on graft yield. The most remarkable features of the investigation include the proposition of a mechanism and the suggestion of opti mum conditions for effective grafting.
Properties Influencing Coolness to the Touch of Fabrics
Authors: Schneider A.M. , Holcombe B.V.
Published: March 2007

The sensation of warmth or coolness to touch when skin is brought into contact with a fabric is a transient heat conduction phenomenon and contributes to the per ception of comfort of a garment. The aim of this study is to establish what fabric properties influence thermal touch sensations. Experiments were conducted in which the thermal response of skin contacting a fabric was simulated. The rate of temperature drop in the skin, which is a measure of the coolness sensation, is correlated with the outer layer thickness of the fabric, which can be estimated from sample thickness measurements at just two light pressures.
Structural Properties of Nylon 66 Carpet Yarns Observed with Near Infrared Analysis
Authors: Rodgers James E. , Lee Shirley
Published: March 2007

Heat significantly influences the supermolecular structure of nylon, which results in changes in the fibers' chemical and physical properties and the morphological re sponse of the yam systems during further processing. The near infrared analysis (NIR) technique has been used extensively to measure the heat-set temperature of nylon yams. Previous investigations have studied the effect of changes in heat history on the NIR spectrum of nylon carpet yams from a spectroscopic approach, in which the wavelength assignments and the rationale for specific wavelengths used on the heat set temperature NIR calibration equations were presented. In this paper, a crystallo graphic approach is used to examine the effect that changes in the heat history of Suessen heat-set nylon 66 carpet yams have on the NIR spectrum and the heat-set temperature NIR calibration equations, and various crystalline, thermal, and laser light scattering parameters of the Suessen heat-set nylon 66 yarns are measured. The NIR spectrum is responding to changes in the crystalline perfection of the nylon 66 polymer with changing temperature, specifically to changes in the C—H stretches in the Van der Waals plane. Agreement between the results of the various measurement techniques (crystalline, thermal, light-scattering, NIR) is excellent. A definite change in morphological response occurs at ∼190°C, which coincides with the Brill transition of nylon 66. The slight deviation from linearity in the NIR response below the heat set temperature of 190°C is due to the Brill transition.
Assessing Changes in Texture Periodicity Due to Appearance Loss in Carpets: Gray Level Co-occurrence Analysis
Authors: Sobus J. , Pourdeyhimi B. , Gerde J. , Ulcay Y.
Published: March 2007

Texture may be defined with respect to the global properties of an image or to the repeating units that compose it. We have attempted to isolate the periodic components of texture in wool carpets for the purpose of assessing the effects of wear on carpet textures. Texture is defined as any recurring spatial pattern of sampled gray level intensities. We restrict attention to textural features that reflect the physical charac teristics of the carpet tuft assemblies. Our test materials consist of four kinds of double ply wool carpets of differing textures divided into control, light, and heavy wear samples. Video images were recorded under several magnifications using a Truevision Vista board. Image files with 256 gray levels were converted to 32 levels using histogram equalization. Textural features were evaluated by computing gray level differences and second-order gray level statistics. We discuss results for spatial gray level depen dence (SGLDM) and gray level difference (GLDM) methods for a range of intersam pling distances. Results for our carpet series show that SGLDM and GLDM yield very similar trends, statistical trends within each method are correlated, overall, these mea sures are generally effective for differentiating the degree of wear as well as providing an indication of textural periodicity, and changes in frequency may be examined by subjecting SGLDM and GLDM statistics to spectral analysis.
Property Structure Correlations in Wool Fibers
Authors: Rao D. Rama , Gupta V.B.
Published: March 2007

We have compared the mechanical properties of wool fibers from three different breeds of sheep, Lincoln, Chokla, and Merino. The tensile moduli are highest for Lincoln, followed by Chokla and Merino fibers, but there is a reverse trend in the torsional modulus. The differences in mechanical properties are explained in terms of differences in the histological structure of the cortex, i. e., the content and arrangement of ortho and para cells, and they are correlated to crystallinity, molecular orientation, glass transition temperature, and matrix rigidity.
Variations in Yarn Properties Caused by a Series of Design Changes in a Friction Spinning Machine
Authors: Rust J.P. , Lord P.R.
Published: March 2007

The structure of friction open-end yarns made with a much modified DREF 3 friction spinning unit with replaced suction rolls and equipped with a comber roll assembly from a Platt 881 rotor spinning unit was studied and found to be dissimilar to that of ring spun yarns. Migration theory, as it is known in ring spinning, was inadequate for friction spun yarns. Classical tracer fiber studies allowed yarn structure to be characterized, and fiber extent was poor. Of the three fiber shapes found in the yam, two had characteristics of very poor fiber extent. A series of design changes was evaluated by characterizing yarn structure and measuring yarn properties. Two methods of fiber feed were compared: applying the fibers first to the ingoing roll with subsequent transfer to the yarn tail, and applying the fibers directly to the rotating yarn tail. Changes in comber roll design led to improved fiber orientation prior to assembly onto the yarn tail and, ultimately, to improved fiber length utilization in the yarn. The design of a blank beneath the nip of the suction rolls was used to restrain fluid turbulence in the nip. The fiber feed angle had distinct effects on yarn structure and properties.
Moisture Sorption Mechanism of Aromatic Polyamide Fibers: Stoichiometry of the Water Sorbed in Poly(para-phenylene Terephthalamide ) Fibers1
Authors: Fukuda Mitsuhiro , Ochi Miyuki , Miyagawa Mariko , Kawai Hiromichi
Published: March 2007

The water sorbed in a series of poly( para-phenylene terephthalamide) (PPTA) fibers (regular Kevlar, Kevlar 49, Kevlar 149, and a heat treated PPTA fiber) was characterized by analyzing the moisture sorption isotherm and thermodynamic quan tities derived from calorimetric measurements of heat of moisture sorption. The max imum volume of adsorbed water in Langmuir's monolayer fashion per unit mass of dry material vm normalized by the degree of noncrystallinity was much larger for the series of PPTA fibers than that for nylon fibers, such as 6, 66, and 46, possessing almost the same concentration of peptide groups as the PPTA fibers. The number of water molecules adsorbed in monolayer fashion per each peptide site in the noncrys talline region was around 0.4 moles/mole for the PPTA fibers and about 2.2 times larger than that for the nylon fibers, all at 30°C. The hydration enthalpy ΔHL at dryness and the hydration entropy TΔSL near dryness were -25 ∼-35 and -10 ∼ -12 kJ /mol, respectively, both at 30°C, when liquid water was taken as the ref erence. These values are about 1.5 times larger than those of nylon 6 fibers, large enough to assign the initially sorbed water in the PPTA fibers as doubly hydrogen bonded and in a highly ordered state like the crystal lattice of ice. These results indicate that the bulky and rigid phenyl ring in the aromatic polyamide chain opens the space for each peptide site to adsorb moisture more efficiently than the site in the aliphatic polyamide chain.
Equilibrium Sorption Isotherms of Indigo on Cotton Denim Yarn: Effect of pH
Authors: Etters J.N. , Hou M.
Published: March 2007

Apparent equilibrium sorption of indigo on cotton denim yam was determined at dyebath pH ranges of 13.1-13.3 and 11.1-11.3 under infinite bath conditions at 25°C. The equilibrium concentration of indigo on the cotton fiber is much higher for dyeings at the lower of the two pH ranges. The higher apparent affinity of the dye at the lower pH range is correlated with the mono-ionic form of indigo, and sorption is effectively described by the empirical Freundlich isotherm.
The Role of False Twist in Wrap Spinning
Authors: Miao Menghe , How Yan Lai , Cheng Kwok Po Stephen
Published: March 2007

Using a false twister for hollow spindle wrap yam spinning is supposed to facilitate operations. However, our investigation shows that a high level of false twist can sig nificantly influence yarn appearance and mechanical properties. Wrap yarn spun with a false twister has a tortuous structure, while wrap yarn spun without a false twister is smooth. Compared with equivalent zero false twist wrap yarns, false twist wrap yarns display a similar twist-strength relationship, but lower moduli and bending rig idities at increased wrap twist. Twist contraction of the yam core during initial wrapping is the primary cause for the tortuous structure of the false twist wrap yarns. When a false twister is used, the yarn core first contracts under false twist, and at the same time is wrapped with a low wrap twist because of the difference in rotational speed between the wrapper balloon and the yarn core. Then, as the false twist is removed from the core and further wrap twist is formed at the exit side of the false twister, the core recovers from twist contraction and buckles to form a helix under the tension of the wrapper.
Dynamic Wetting of Nylon 66 Using Aqueous Solutions of Anionic, Nonionic, and Mixed Surfactants
Authors: Carrión-Fité F.J.
Published: March 2007

The aim of this paper is to characterize dynamic wetting of a nylon 66 round monofilament using aqueous solutions of the following surfactants: sodium dodecyl sulphate (anionic), nonylphenol with 10 M ethylene oxide ( nonionic ), and mixtures of the two with respective molar ratios of 0.8:0.2, 0.5:0.5, and 0.2:0.8. Wetting ability is obtained as a function of several total concentrations of each surfactant and the mixtures, mainly below their critical micellar concentrations at a temperature of 25°C. Wetting ability is evaluated by means of the technique based on the Wilhelmy balance principle, and the advancing and receding contact angles are determined from the wetting hysteresis of the monofilament in the surfactant solutions.
Flow Characteristics of the Main Nozzle in an Air-Jet Loom
Authors: Ishida Minoru , Okajima Atsushi
Published: March 2007

In this research, the jet-flow characteristics under tank pressures of 2 ∼ 6 kgf/cm2 were studied to obtain basic data for an optimal design of the main nozzle in an air- jet loom. Furthermore, wefts were actually inserted in the nozzle and weft traction forces were measured. Axial changes of the nozzle jet speed and jet diameter below the tank pressure at which choking arises at the exit of the acceleration tube are largely different from those above that tank pressure. Choking arises within the upstream region in the acceleration tube (Mach 1), and the Mach number at the tube exit exceeds 1. When this happens, expansion waves occur owing to underexpansion, and the oscillation of compression and expansion waves can be seen in the downstream region. Therefore, the weft drag force F, which represents the weft-flying property in a nozzle, increases in proportion to tank pressure PT. But when the flow is choking at the exit of the acceleration tube, the drag force F becomes nearly constant, even at higher tank pressures.
Dynamic Moisture Vapor Transfer Through Textiles
Authors: Kim J.O. , Spivak S.M.
Published: March 2007

This study investigates new techniques for measuring the influence of fiber, type on fabric surface vapor pressure and temperature, which are related to sensations of cloth ing comfort. Microfine hygrometry and thermometry are used to measure dynamic changes in moisture vapor pressure and temperature on both surfaces of a two-layer fabric assembly under simulated body-clothing conditions. Findings show that fiber type significantly influences transient, comfort-related variables such as changes of inner surface vapor pressure and temperature. Polyester double layer assemblies exhibit the lowest inner surface temperature, but a much higher concentration of moisture vapor. Cotton assemblies show the slowest rate of inner vapor pressure accumulation with the highest inner surface temperature rise. Mixed fabric layers of cotton and polyester reveal moderate inner surface temperature peaks and moderate vapor pressure changes. Using a completely different methodology, this study reinforces other findings that fiber type and finish are indeed important to understanding transient changes in moisture vapor and temperature within fabric and clothing assemblies and their interior microclimates.
Identifying Local Deformation Phenomena During Woven Fabric Uniaxial Tensile Loading
Authors: Realff Mary Lynn
Published: March 2007

Experimental methods are presented for observing local fabric deformation during uniaxial tensile loading of a woven fabric. These experiments include the traditional ravel strip test as well as the use of video taping, encapsulation, and photographing fabrics varying in weave texture, yarn type (ring and rotor spun), and yarn size. Through these techniques, changes in yarn curvature and cross-sectional area ( shape ) are monitored along with the global stress-strain response of the fabric. Fabric response depends on both fabric structure and constituent yarn properties. By choosing fabrics in which single parameters, such as picks per inch, vary systematically, trends in fabric behavior can be tracked.
Crosslinking of Cotton Fabrics Premercerized with Different Alkalis
Authors: Chen Jui-Chin , Chen Cheng-Chi
Published: March 2007

A crosslinking treatment with dimethyldimethyloldihydroxyethyleneurea (DM- DMDHEU) is reported for cotton fabrics premercerized with different alkalis at normal (constant) length (warp and weft). The number of crosslinks per anhydroglucose unit (CL/AGU) and crosslink lengths (CL) are calculated from formaldehyde and nitrogen contents. Data on formaldehyde and nitrogen contents, physical properties, and num ber and length of crosslinks are discussed. The value of CL length for unmercerized cotton is higher than that for mercerized fabrics at the same pad bath resin concen tration, but CL/AGU for the former is lower than the latter. ΔDCRA and Δ W CRA values of the various premercerized cottons are ranked LiOH mercerized > NaOH mercerized > KOH mercerized > unmercerized fabric; however, the ranking of ΔTSR and ΔER values is in the order of unmercerized > KOH mercerized > NaOH mer cerized > LiOH mercerized fabric at the same nitrogen content and CL/AGU. The swelling of the various mercerized and crosslinked fabrics is ranked LiOH mercerized > NaOH mercerized > KOH mercerized > unmercerized fabric.
Heat and Moisture Transfer Through Nonwoven Fabrics
Authors: Woo Sang S. , Shalev Itzhak , Barker Roger L.
Published: March 2007

A theoretical model is demonstrated that provides a reliable prediction of thermal transmission through nonwoven structures. The validity of the model is confirmed in experiments that measure the thermal conductivity of various nonwoven barrier fabrics. The model is used to characterize the relative contribution of heat transfer mechanisms to the total heat transmission. It also provides a good explanation of the roles played by fiber and fabric variables in determining the thermal insulation of nonwoven barrier materials.
Effect of Crosslinking Agents on Water Repellency of Cotton Fabrics Treated with Fluorocarbon Resin
Authors: Sato Yukihiro , Wakida Tomiji , Tokino Seiji , Niu Shouhua , Ueda Mitsuo , Mizushima Haruo , Takekoshi Shoji
Published: March 2007

Cotton fabrics and cellulose films treated with fluorocarbon resin (Asahi Guard AG-480 ) with and without crosslinking agents (isocyanate blocked copolymer and aziridine) were washed and subsequently heat treated. Water repellency of the fabrics decreased with washing and recovered with heat treatment. The decreased water re pellency with washing was controlled by using the resin with a crosslinking agent. To investigate surface tension and surface chemical composition of the fabrics after washing and subsequent heat treatment, the contact angle to water and critical surface tension of the films were measured along with an ESCA analysis of the fabrics. Adding cross linking agents to the fluorocarbon resin treatment controlled the decrease in F1s intensity and the increase in O1s intensity with subsequent washing.
Mechanistic Role of Yarn and Fabric Structure in Determining Tear Resistance of Woven Cloth
Authors: Scelzo W.A. , Backer S. , Boyce M.C.
Published: March 2007

This paper is concerned with formulating and evaluating a model of tongue tear. The modeling approach taken is fairly general, and results recorded to this point have been encouraging. Although predicting tearing behavior from parameters determined prior to weaving is not yet possible, the implications of this work are important. The model accounts for the effects of yam pull-out, jamming, and stretching, as well as statistical variation in yam strength. Simulations are conducted where these effects are parametrically varied in order to assess their relative importance in contributing to tear strength. The effect of pre-loading on yam pull-out and the inclusion of jamming resistance are seen to have considerable influence on tearing strength. Furthermore, the success of the model's predictions based on these two principal components suggests a need for developing the mechanics of their associated, unconventional tests. With an understanding of such mechanisms, one can anticipate a fully predictive model of tear resistance based solely on yam properties and fabric geometry.
Bar Design for Length Compensation in Textile Winding
Authors: Falkner A.H.
Published: March 2007

In winding textile and other threads onto bobbins, the process of forming the wind by taking the point of take-up to and fro across the bobbin introduces length variations. These cause corresponding tension variations in the thread, which persist in the wound bobbin and which, in extreme cases, lead to breakage of individual fibers or the entire thread. These length variations are often compensated passively by a shaped bar, which should ideally maintain constant path length during the wind. A new theory is presented for designing the shape of the bar, and path length and tension variations are introduced at the edges of the bobbin where the cross motion reverses. Complete compensation for these effects is not possible using such a bar. The discussion is limited to cases of parallel bobbins as opposed to conical ones.
Influence of Production Speed on the Characteristics of Hollow Spindle Fancy Yarns
Authors: Baoyu Zhu , Oxenham W.
Published: March 2007

"Plain" and a "fancy" yarns were produced using a range of spinning speeds on a hollow spindle machine. The yarns were assessed for different characteristics using both subjective and objective tests, and the results obtained with the different techniques show good agreement. Clearly, there is a progressive change in the characteristics of the yarns with increasing production speed, which may be due to the increasing forces exerted on the staple component of the yarn.