bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Spread Width on the Structure, Properties,. and Production of a Composite Yarn
Authors: Wu Wen-Yean , Lee Jiunn-Yih
Published: March 2008

This study describes the effects of the spread width of polyester multifilaments on the structure, properties, and production of a composite yam. The results show that the special structure of a composite yarn blended evenly with spread multifilaments and cotton fibers has excellent yarn properties with a spread width of about 8 mm. These properties include high tenacity, good abrasion resistance, a low irregularity and imperfection index, especially for hairiness, with only about 10% of normal cotton- rich spun yarn. In addition, the lower twist is enough to producing a good composite yarn. There is an economic advantage of about 33% more production when spinning composite yam with a lower twist, compared with normal cotton-rich spun yarn.
Extracting and Quantifying a Polyester Fiber Finish Using On-line SFE/FT-IR with Intermediate Trapping
Authors: Jordan Sheri L. , Taylor Larry T. , Seemuth Paul D.
Published: March 2008

On-line supercritical fluid extraction / Fourier transform infrared spectrometry was applied to a complex polyester fiber finishing system consisting of seven components. Off-line extractions of these components with 100% CO2 revealed that they ranged in extractability from 25-100%. Due to certain analyte solubility limitations, intermediate trapping was used for quantitative recovery of the finish for subsequent on-line infrared analysis. Ultimately, a calibration curve was developed from finish standards. The percent finish on yarn was calculated using the SFE method and compared with that from conventional solvent extraction.
Mechanism of Nep Formation in Air-Jet Texturing
Authors: Sengupta A.K. , Kothari V.K. , Sensarma J.K.
Published: March 2008

Experiments conducted to investigate the reasons for nep formation in air-jet tex turing indicate that neither periodic tension variations in feeder yarn nor differences in tension levels between the two parallel fed ends have any significant effect on nep formation. Insufficient and inhomogeneous opening of filaments inside the nozzle is primarily responsible for nep formation; higher levels of interfilament friction and lower vortexing intensity contribute to insufficient opening of the filament bundle. We therefore suggest that neps in air-jet textured yarns are formed because the filament bundle does not open in the nozzle. Partial opening results in one kind of nep, while complete lack of opening causes another kind in the succeeding part of the unopened section of the yarn.
Effect of Topical Applications of Antioxidants and Quenchers on the Photoyellowing of Fluorescently Whitened Wool Fabric
Authors: Auer P.D. , Pailthorpe M.T.
Published: March 2008

Wool that has been optically whitened with fluorescent whitening agents is susceptible to photoyellowing at a much accelerated rate compared to unwhitened wool. This effect is especially noticeable when the wool is exposed in the presence of moisture (the "wet" state). Topical applications of several antioxidants and singlet oxygen quenchers applied to fluorescently whitened wool fabric have been evaluated with regard to their effect on "wet" and "dry" exposures to ultraviolet radiation. A com pound from the sulfide class of antioxidants was most effective for wet exposures. This effect was moisture related. A hindered phenol antioxidant had the greatest effect on dry exposures. A nickel chelate compound was equally effective for both wet and dry states. The decrease in the tryptophan content of wet exposed fabric was related to the degree of yellowing that developed in the fabric.
Fiber Hygroscopicity and Perceptions of Dampness
Authors: Plante A.M. , Holcombe B.V. , Stephens L.G.
Published: March 2008

A series of dampness perception trials has determined the influence of fiber type, fabric moisture content, and ambient conditions on the subjective assessment of dampness in fabrics. Twenty subjects evaluated four fabrics of different fiber types ( wool, cotton, polyester, and a wool / polyester blend) at five levels of moisture content at 25°C and three levels of relative humidity (25, 50, and 75%). The trials revealed that dampness perception and fiber hygroscopicity were interrelated. Wool, which is highly hygroscopic, was perceived to be significantly drier than weakly hygroscopic polyester at 25% relative humidity. The differences in dampness perception became smaller as the ambient humidity increased, and also as the moisture content of the fabrics increased.
Compression of Greystate Fabrics as a Function of Yarn Structure
Authors: Dupuis Dominique , Popov Gueorgui , Viallier Pierre
Published: March 2008

Data analysis of the compression of a fabric can only be done using a mathematical model to smooth the results. The best formula is Van Wyk's, although the meaning of the physical parameters is very difficult to define for a fabric. On the basis of Van Wyck's equation, a study of the compressibility of a fabric whose weft is made of multiple threads (classic ply-yams, open-end, combed or carded) shows that the struc ture of a fabric has a higher value than the structure of a thread. The mechanical properties of a fabric are supposed to be essentially due to its construction and, to a lesser extent, to the threads from which it is made.
Nep Level as an Index of the Structural Inhomogeneity of Air-Jet Textured Yarn
Authors: Kothari V.K. , Sengupta A.K. , Sensarma J.K.
Published: March 2008

Results are reported for experiments conducted to correlate different structural in homogeneity parameters of air-jet textured yams, such as number of neps per thousand meters, number of thick places per thousand meters, CV% of yam linear density, CV% of yam strength, and CV% of loop frequency. All these parameters are highly correlated, and so the various indices of structural inhomogeneity can be represented by only one of them. Number of neps per thousand meters has been suggested as the index of structural inhomogeneity of air-jet textured yarns due to its quick and easy assessment, high degree of sensitivity to changes in raw material and process parameters, and very high correlation with other parameters.
Fibrous Carboxymethylcellulose by Pad Roll Technology
Authors: Rácz Ilona , Deák András , Borsa Judit
Published: March 2008

Statistically designed experiments have been made using partial carboxymethylated cotton fabric. The effects of three reaction parameters (concentrations of sodium hy droxide and monochloroacetic acid and time period) on wet pickup and carboxyl content are presented using polynomial models. Monochloroacetic acid concentration seems to be the leading factor among the parameters investigated. Poor reproducibility of the drying process could be one possible barrier to industrial applications of car boxymethylation.
Zero-AOX Shrinkproofing Treatment for Wool Top and Fabric
Authors: Hesse Andrea , Thomas Helga , Höcker Hartwig
Published: March 2008

The glow discharge treatment of wool in nonpolymerizing gases like air, oxygen, and nitrogen is presented as a new zero-AOX pretreatment for shrinkproofing wool top and fabric. Modification of the wool fibers is restricted to the outer 30-50 nm, and consists of plasma etching and surface oxidation. The former is responsible for the abrasion of the fatty acid layer from the cuticle and parts of the exocuticle-A; the latter introduces new anionic groups, i.e., sulphonate and carboxylate functions. Car boxyl groups derive from a backbone oxidation of the protein chains in the cuticle cells. Sulphonate groups are generated by oxidation of disulphide functions. Surface modification applicable to both wool top and fabric results in an increased hydro philicity of the fiber surface and has an excellent shrinkproofing effect in combination with a new shrinkproofing resin.
Zero-AOX Shrinkproofing Treatment for Wool Top and Fabric
Authors: Hesse Andrea , Thomas Helga , Höcker Hartwig
Published: March 2008

The halogen-free shrinkproofing resin presented in this work is based on the natural protein collagen and a crosslinking agent, which provides a covalent linkage between the wool and the resin (collagen). Glycidylacrylate and the trifunctional epoxide Araldit PT 810 are applied as crosslinkers. Almost complete shrink resistance of wool fabric and top is achieved using the collagen / Araldit resin with plasma pretreated material. In combination with the oxidative plasma treatment described in Part I, the additive collagen treatment appears to be an effective substitute for the chlorine /Hercosett process.
Microbial Damage to Cotton
Authors: Allen S.J. , Auer P.D. , Pailthorpe M.T.
Published: March 2008

Microbial damage to raw cotton is a common problem in many parts of the world, and tests currently available to identify and quantify it are reviewed and evaluated. These tests include cuprammonium hydroxide fluidity tests, pH determinations, re ducing sugar determinations, microscopic techniques, and staining methods. The tests have been used to evaluate possible microbial damage to cotton from two Australian growing seasons. Between-laboratory variations in the use of these methods are dis cussed. Shadecloth and overhead sprinklers are used in field plots to simulate adverse weather conditions and promote microbial damage. The effect of microbial damage on the color difference between dyed lots is also determined.
Dimensionless Groups for the Equilibrium Sorption of Polysulfonated Acid Dyes by Polyamides
Authors: Arora Manpreet S. , McGregor Ralph
Published: March 2008

The equations of a Donnan model for equilibrium sorption of ions by polymers are expressed in dimensionless form and extended to cover the sorption of polysul fonated acid dyes by polyamide fibers. New expressions for key dimensionless groups are developed, and these groups are used to describe and analyze the equilibrium sorption of CI Acid Blue 45 by polyamide fibers. Improved estimates of key sorption parameters are obtained. This extension of the dimensionless group approach makes possible its application to the simulation and control of practical dyeing processes for ionic dyes.
Analysis of Blend Irregularity in Yarns Using Image Processing
Authors: Watanabe Akira , Konda Fujio , Kurosaki Shi-Nya , Nishimura Yosiro
Published: March 2008

In Parts I and II of this series, we discussed the precision and efficacy of an image processing system for evaluating blend irregularity in blended yarns using three kinds of model yams, and reported on the application of that system to actual blended yams. That system involved converting original images into trivalued images (black fibers, white fibers, and gray background), which enabled quantitative evaluation of the blend irregularity on the surface of a short length of yarn (about 4 mm). However, that system required threshold values for converting original images into trivalued images, and also needed a considerable amount of processing time and experience. This study deals with a new system to evaluate blend irregularities by measuring line sense (a series of intensity values) around the center line along a yarn axis without converting the original image and by analyzing the distribution of the intensity values. This method saves processing time and provides a real-time evaluation of the blend state ( fiber arrangement). We have studied the feasibility of evaluating blend irregu larities by means of measuring line sense with this system using two kinds of model yams, where the numbers of component fibers, blend ratios, and blend states are known. We also discuss application of the system to actual blended yams.
The Potential of False Twist to Assist in Handling Low Strength Cotton Slivers
Authors: Jeddi A.A.A. , Oxenham W.
Published: March 2008

In a preliminary investigation aimed at improving the processing of lightweight slivers (<3 ktex), the effect of low levels of twist on sliver strength is quantified. This is followed by trials to determine whether a passive false-twist unit (spiral) can be used to impart temporary strength to assist the transfer of sliver from a supply can to the next processing machine. The generated level of false twist is studied, and the spiral is subsequently used on a roving frame to process different sliver weights at various drafts. The experiments show that false-twist can offer a potential technique for dealing with low strength and lightweight cotton slivers. From the results, it appears that such a device has little effect on drafting regularity.
A New Single Fiber Tensile Tester1
Authors: Hebert Jacques J. , Thibodeaux Devron P. , Shofner Frederick M. , Singletary Jeannine K. , Patelke David B.
Published: March 2008

A new instrument for single fiber tensile testing is evaluated and data from two cotton species are presented. The instrument allows rapid accumulation of data that, before inception, were extremely tedious and labor intensive to obtain. Results include tensile strength and percent elongation at different gauge lengths and rates of extension, and an optical measure of fiber diameter or ribbon width as well as an indication of the extent of convolutions.
Fiber Crimp Analysis by Fractal Dimension
Authors: Muraoka Yoichiro , Inoue Kjyohiro , Tagaya Hisako , Nishizawa Kazuo
Published: March 2008

A box-counting method for determining the fractal dimensions of crimped fibers is discussed in detail. Using nylon 6 crimped filament magnified figures, an application of the method is demonstrated where the box-counting dimension ( DB) of nylon 6 has a distribution of 1.00-1.65. Eight animal fibers, cotton, and two other synthetic crimped fibers are also characterized by DB distributions of 1.00-1.32. Modified random Koch curves are used to simulate crimped fiber shapes and to examine the relationship between Hausdorff's dimension ( DH) and DB.
Analysis of the Performance of a Textile Vacuum Extractor
Authors: Broadbent Arthur D. , Xiao Xing Kong
Published: March 2008

The influence of process variables on the performance of a textile vacuum slot extractor is examined using a factorial plan of experiments and statistical analysis of the results. The major factors influencing the water content of a 50/50 cotton /polyester fabric after vacuum extraction are its initial water content, the vacuum level, and the viscosity of the liquid removed. The effects of fabric speed and slot width are less important. A relationship between the final water content of the fabric and the op erational variables is derived, including the effects of interactions between some vari ables. The agreement between experimental and predicted water contents for inter mediate values of process variables confirms the absence of pronounced curvature of the model.
A Simulated Evaluation of Photofading of Crystal Violet in Polymer Substrates
Authors: Toda Tamako , Hida Mitsuhiko , Fukunishi Koushi
Published: March 2008

Photofading of crystal violet (CV) in nylon and polyester films is suppressed with the progress of decay. Photofading of the dye in polymer substrates is explained on the basis of two models: a distribution of photochemical reactivity sites for the dye, and a bimolecular reaction mechanism for fading. Simulation results using the first model are compatible with experimental results for nylon, whereas the simulation derived by combining both models corresponds well to the photofading behavior of CV in polyester. Results from the fluorescence measurements by pulse fluorometry also support the first model.
Test Method for Cloth Fell Displacement Caused by Relaxation
Authors: Vangheluwe Lieven , Kiekens Paul
Published: March 2008

A test method is presented for measuring cloth fell displacement during relaxation of fabric yarn combinations on a tensile tester. The equipment consists of a CCD camera, a frame grabber, and appropriate software. The method is used to analyze the cloth fell displacement of twenty different fabrics. The influence of fabric parameters is determined using statistical techniques.
Tandem Spinning
Authors: Sawhney A. Paul S. , Kimmel Linda B.
Published: March 2008

A new concept of tandem spinning to produce true, all-staple, core-wrap yarn at high speeds was first disclosed in a paper that reported the results of an initial feasibility study. That study successfully demonstrated the viability of tandem spinning, although it did so by using separate elements of air-jet and friction spinning technologies in a "phased" or sequential manner. Continued research has resulted in the development of a totally integrated tandem spinning system, which produces a unique, all-staple, core-wrap, composite yarn continuously and without interruption. The resulting tan dem spun yarn is torque-balanced, soft, yet strong. The production speed is at least ten times greater than conventional ring spinning and twice as fast as the phased or sequential tandem spinning reported earlier. Yarn counts up to 30 tex (Ne 20's) have been successfully spun on a prototype machine in a textile pilot plant. The resulting yarn quality is satisfactory for downstream processes, including weaving. Preliminary studies indicate that the properties of fabrics made with the unique tandem spun, core-wrap yarns are also satisfactory. Significant commercial potential is envisioned for the new spinning system. Large-scale spinning and weaving trials are currently underway for commercial evaluation. Patent applications have been filed to protect the invention domestically and internationally.
Effects of Opening Roller Speed on the Fiber and Yarn Properties in Open-End Friction Spinning
Authors: Ülkü S. , Özipek B. , Acar M.
Published: March 2008

The opening roller system for fiber separation in an open end spinning process is known to cause considerable fiber breakage. We have investigated fiber breakage at different opening roller speeds and the relationship between breakage and the properties of friction spun yams made from cotton, polyester, viscose, and acrylic fibers. A high level of fiber damage caused by the opening rollers occurs at high speeds. The level of damage differs from one sort of material to another. There is a great deterioration in properties when yams are processed at high opening roller speeds.
Effects of Biofinishing on Cotton /Wool Blended Fabrics
Authors: Chikkodi Shridhar V. , Khan Samina , Mehta R.D.
Published: March 2008

Enzymatic degradation, which improves surface properties by digesting protruding loose fibers, is gaining popularity because of its beneficial effects on the environment. In this study, two cotton / wool fabrics of different blend composition are treated with both cellulase and protease enzymes, applied at two different concentrations and con ditions. In general, the enzyme treatments have significant effects on the physical and aesthetic properties of the blended fabrics, which is statistically evident from a one- way analysis of variance. Subjective means of evaluations are also used to assess fabric hand and pilling resistance. The enzyme treatment reduces protruding fibers, and more direct evidence of their absence is provided by SEM examination.
Diffusion and Microporous Structure of Acrylic Blend Fibers During the Coagulation Process
Authors: Qin Jian , Liu Zhaofeng , Pan Ding , Li Fanting
Published: March 2008

Using a microscope-television-video camera system, the diffusion coefficients of blend acrylic polymer dopes in the coagulation of a wet spinning process are determined in both dimethylformamide and aqueous NaSCN solvent systems, along with the effects of various dispersing polymers and their composition and content (blend ratio) on the diffusion coefficients. The relationship between the diffusion coefficients and the microporous structure is discussed.
Selected Properties of Predominantly Cotton Staple-Core Knitted Fabrics
Authors: Kimmel L.B. , Sawhney A.P.S.
Published: March 2008

This study of single-jersey knit fabrics is the first to examine the basic properties of staple-core knits. Prior studies revealed certain functional and aesthetic advantages of woven staple-core fabrics when compared to 100% cotton or intimate-blend fabrics of the same construction. In this study, nominal 20s count staple-core yams have been spun on a ring spinning frame that incorporates patented modifications. The staple-core yams contain a high tenacity polyester core and a cotton sheath comprising two-thirds of the yam. The fabrics are knitted on a single-feed jersey knitter with a 88.9 mm (3.5-inch) diameter, 20-gauge cylinder. Fabric properties are examined after five home-laundering cycles, in the greige state, after scouring, and after scouring and heat setting. The staple-core knits are stronger, less permeable, and significantly more abrasion resistant than the cotton controls. They also show less differential shrinkage and look consistently better than the controls after laundering. Greater spirality is evident in the greige staple-core knits than in the cotton knits, but the skewness of all fabrics decreases with additional processing. Skewness is substantially eliminated by substituting S- for Z-twist staple-core yam. Relaxed S-twist staple-core fabrics are also denser and greatly more abrasion resistant than comparable Z-twist knits. This suggests that a reduction of yam torque might further improve the superior properties and performance of staple-core knits. Additional study is required to optimize heat setting procedures and provide meaningful discussion of the dimensional stability of staple- core knit fabrics.
Confocal Laser Raman Microprobe Studies of Keratin Fibers
Authors: Jurdana Lucia E. , Ghiggino Kenneth P. , Nugent Kerry W. , Leaver Ian H.
Published: March 2008

A laser-based Raman microprobe/confocal microscope has been used to provide structural information on the constituent proteins in several keratins including wool, human hair, and feathers. Depth-profiling studies have revealed differences between the outer (cuticle) and inner ( cortex ) regions of human hair fibers with respect to the molecular orientation and chemical composition of the constituent proteins. Raman microprobe measurements are applied to the identification and distribution analysis of textile auxiliaries on wool fibers. The advantages and utility of the Raman micro probe technique for investigating single textile fibers are also discussed.
An Exploratory Study of Mercerized Cotton Fabrics by DRIFT Spectroscopy and Chemometrics
Authors: Kokot Serge , Stewart Shona
Published: March 2008

Diffuse reflectance infrared spectra of differently mercerized cotton poplin fabrics are interpreted with the aid of fuzzy clustering and multivariate chemometrics methods (PCA and SIMCA). Fuzzy clustering analysis of spectra from blank, slack, and stretch mercerized samples shows that three clusters can be identified, and this conclusion is supported by the PCA display method and SIMCA classification. Spectra from slack mercerized samples, treated at three different temperatures, are also readily discrim inated by the same three chemometrics methods.
Mechanics of a Hybrid Circular Braid with an Elastic Core
Authors: Hopper Robert H. , Wallace Grant J. , Popper Peter
Published: March 2008

A mathematical model based on four modes of operation is developed to predict the tensile response of a hybrid circular braid encompassing an elastic core. Model inputs include parameters characterizing the initial geometric configuration and ma terial properties of the hybrid. Output parameters are forces, strains, modes of operation, and hybrid geometry. The results show that a hybrid braid can display a unique syn ergism when the braid is in contact with the core but not yet locked, since its tensile response exceeds the sum of its components acting alone. While this analysis idealizes braid geometry and excludes explicit treatment of yam crimp, it incorporates primary influences including nonlinear yam tensile response, large deformations, yam failure, and varying hybrid deformation modes.
Analysis of the Smoothing Effect of the Card Cylinder Using Simulation
Authors: Cherkassky Arkady
Published: March 2008

The first part of this series discussed a two-dimensional mathematical model of the carding process. This part discusses the algorithm of simulation for a carding process using the state variables, which take into consideration a transference of fibers in the longitudinal and transverse directions, obtained in terms of mathematical equations. An experimental investigation is reported for estimating model parameters that char acterize diffusion of fibers in the transverse direction. The least-squares method with a log-scale is used to process experimental data for a linear approximation of the weight function in the transverse direction. The weight and unit step functions in the transverse direction are obtained using simulation. Realization of random processes is achieved in ten parallel sections in the output of a carding machine. The graphs of profile change for coefficients of variation show a smoothing effect in the carding process. A new system of statistical characteristics for two-dimensional textile material irregularity is used for quantitative estimation of this effect. A statistical analysis of the simulation results shows a decrease in the irregularity by length, width, and area of a web.
Analysis of Fabric Deformation in a Roll-Making Operation
Authors: Ghosh T.K. , Peng H.
Published: March 2008

The effects of various process and material parameters on fabric roll making have been discussed in the earlier parts of this series. A number of theoretical models have been proposed to better understand the roll-making process and its effects on the state of stress in a fabric roll. In this analysis, the influence of varying winding tension is investigated. If winding tension can be controlled as a function of fabric properties, undesirable levels of stress in the fabric can be minimized. The principles demonstrated here can be used to develop a process control system.
Structure and Chemical Composition of Silk Proteins in Relation to Silkworm Diet
Authors: Ito Hiraku , Muraoka Yoichiro , Yamazaki Takashi , Imamura Toshikatsu , Mori Hajime , Ichida Masatoshi , Sumida Motoyuki , Matsubara Fujiyoshi
Published: March 2008

We investigate the structure and chemical composition of silk proteins produced by silkworms reared entirely on an artificial (A) diet, and compared those with worms entirely on a mulberry leaf ( M ) diet. The artificial diet has tofu-cake as its main component. Two types of cocoons (A and M) are used as sample materials. The dissolution behavior of the A sericin in hot water is different from that of M sericin; the amount of A sericin dissolved (28%) is higher than that of M (24%), and the dissolution rate of A sericin is also higher. Both sericins are separated into four fractions according to dissolution rate in hot water, and the amino acid composition (AAC) of each fraction is determined. Although the AAC of unfractionated A sericin is almost the same as that of M sericin, the AACs of the fractionated sericin from the A sample are distinguished from those from the M sample. AACs of the A and M fibroins are also evaluated and found to be almost identical within experimental error. The x-ray diffraction pattern of the A fibroin is also nearly the same as that of M fibroin. The artificial diet used in this study affects the dissolution behavior and chemical com position of sericin proteins, but does not affect structure and chemical composition of fibroin proteins.
Influence of a Quaternary Ammonium Surfactant on Alkaline Hydrolysis of Heat-Set Poly( ethylene Terephthalate) Fibers
Authors: Niu Shouhua , Wakida Tomiji , Ogasawara Shinji , Fujimatsu Hitoshi , Takekoshi Shoji
Published: March 2008

The hydrolytic behavior of heat-set poly ( ethylene terephthalate) (PET) fibers is compared in the presence and absence of a quaternary ammonium compound, do decylbenzyldimethylammonium chloride (DBDMAC). Alkaline hydrolysis without DBDMAC depends on the heat-setting temperature, showing a minimum weight loss at around 140°C and becoming more marked with increased NaOH concentration, hydrolysis temperature, and time. Alkaline hydrolysis is accelerated by DBDMAC for all PET fibers over the whole range of heat-setting temperatures. The fibers set at lower temperatures, however, have much larger increases in weight loss than those set at higher temperatures by alkaline hydrolysis in the presence of DBDMAC. The rate en hancement of alkaline hydrolysis by DBDMAC decreases with increased heat-setting ' temperature or degree of crystallinity of the fiber, and may preferentially occur in the amorphous regions of the fiber.
Dyeability of Artificially Aged Cotton Fabrics
Authors: Yatagai Mamiko
Published: March 2008

A cotton fabric has been artificially aged by dry heat at 150°C with or without initial exposure to ultraviolet light. The observed property changes in the aged cotton samples include a loss of breaking strength, a decrease in moisture regain, yellowing, and an increase in carbonyl or carboxyl content. Dyeability is examined to characterize the physical and chemical changes in the aged samples. Dye uptake with direct dyes decreases as heating time increases, which can be attributed to increased crystallinity and the formation of carbonyl and carboxyl groups. The decrease in dye uptake is more remarkable with the larger molecular sized dye than with the smaller dye, in dicating that some changes have occurred in the size of the pores that accept dyes. From the adsorption isotherms, we see that the dye adsorption mechanism is not similar for untreated and aged samples, due to chemical structural changes such as the formation of carbonyl and carboxyl groups. The slight increase in basic dye uptake is also attributable to carboxyl group formation.
A Parametric Study of Fabric Drape
Authors: Bijian Chen  , Govindaraj Muthu
Published: March 2008

This paper presents a study of the effect of important fabric mechanical properties on drape. The study uses a mathematical modeling technique to simulate fabric drape. Young's modulus in the warp and weft directions, shear modulus, Poisson's ratio, and fabric thickness are the parameters studied in this work. Results of the analysis indicate that all of these characteristics have varying degrees of influence on drape. The validity of using experimental values of fabric mechanical characteristics obtained from the Kawabata evaluation system for fabrics is discussed. The most important requirement for obtaining a good simulation is the use of correct values for these parameters, obtained experimentally at conditions similar to drape.
A Semiempirical Model for the Ballistic Impact Performance of Textile-Based Personnel Armor
Authors: Cunniff Philip M.
Published: March 2008

A parametric model has been developed to predict the performance of body armor systems under impact by a chunky steel projectile of arbitrary mass, shape, impact velocity, and impact obliquity. The model, which is based on a six-dimensional non linear regression analysis of extensive test data for Kevlar 29, is capable of predicting the performance of these body armor systems with user-defined areal density. The model partitions the energy absorbed by the body armor system into strain and kinetic energy; at impact velocities well above the ballistic limit of the system, the predominant mechanism of energy absorption is through kinetic energy transfer. The implications of this fact on the design of lightweight armor systems are discussed, along with the development of the model and suggestions for its use in designing, optimizing, and evaluating the functional utility of body armor systems.
Improving Sun Protection Factors of Fabrics by Applying UV-Absorbers
Authors: Hilfiker Rolf , Kaufmann Werner , Reinert Gerhard , Schmdt Erika
Published: March 2008

Designing and modifying fabrics in such a way that they offer high protection against UV-light ("UV-cutting") is a relatively new application. Thin, untreated fabrics made, for example, from cotton, silk, polyamide, and polyacrylonitrile offer sun protection factors (SPF) only in the range of 3 to 5, i.e., their UV-cutting effect is inadequate when the sun's irradiation is intense. The SPFs of fabrics can be increased in a variety of ways, using thicker fabrics or applying UV-absorbers. In this article we are presenting a model that makes it possible to predict SPFs of fabrics as a function of a diversity of parameters, such as fabric type, thickness, and porosity, as well as UV-absorber ( or dye or optical brightener) type and concentration. Important parameters for achieving high SPFs are identified. The model is confirmed by experimental data. We also provide data about how long it takes until reddening of unprotected skin is observed under various conditions.
Carding of Tender Wool
Authors: Carnaby Garth A. , Burling-Claridge G. Robert
Published: March 2008

This is the first of two papers dealing with a new conceptual model of fiber breakage in carding. This model is a departure from the integrated approach previously taken by one of the authors, and instead builds up the description of fiber length distributions after carding from the contributions of individual fibers. This paper first develops the underlying conceptual model of how carding affects individual fibers, and sets up the basis for a computer simulation model to be developed from the theoretical model. Fibers are chosen systematically according to an initial length-area bivariate distribution and are individually subjected to hypothetical capture by a single carding element. The fiber's cross-sectional area along its length is explicitly considered, including the effects of fiber tenderness. The resulting fiber length-area distribution is then processed to yield the familiar hauteur and barbe length after carding distributions.
Evaluating the Temperature and Humidity Characteristics of a Solar Energy Absorbing and Retaining Fabric
Authors: Furuta Tsunekatsu , Shimizu Yoshio , Kondo Yoshiyuki
Published: March 2008

A solar energy absorbing and retaining fabric has been developed by incorporating a zirconium carbide compound into the core of the filaments. The resulting fabric absorbs visible and near infrared solar rays and converts them into thermal energy; it also reflects body heat. In this paper, we describe the basic solar energy absorbing and heat retaining properties and applied tests under a wide range of environmental con ditions. In addition, we describe the new fabric's complex effects when worn with breathable fabric.
Characterizing Lateral Contraction Behavior of Spunbonded Nonwovens During Uniaxial Tensile Deformation
Authors: Bais-Singh Smita , Anandjiwala Rajesh D. , Goswami Bhuvenesh C.
Published: March 2008

An experimental method based on video recording and image analysis is presented to characterize the lateral contraction of spunbonded nonwoven fabrics during uniaxial tensile deformation. A systematic study reports the effect of specimen dimensions on the nature of lateral contraction of a nonwoven fabric. Lateral contraction measure ments are made over the entire profile of the specimen, thus examining the validity of Saint Venant's principle to justify the assumption of homogeneous strain in the region of measurement. Some important observations are reported, which in future will influence the methodology of measuring transverse strains corresponding to applied longitudinal strains in a uniaxial test.
Effects of Laundering on the Sensory and Mechanical Properties of 1 X 1 Rib Knitwear Fabrics
Authors: Mackay Colina , Anand Subhash C. , Bishop David P.
Published: March 2008

Acrylic, cotton, and wool 1 × 1 rib knitwear fabrics have been subjected to up to 50 laundering cycles using a variety of washing and drying conditions. The dimensional, mechanical, and tactile properties of new and washed fabrics are determined and evaluated using standard test procedures. In Part I, we establish the techniques for predicting the final, fully relaxed dimensions of knitted fabrics. We determine fully relaxed k-constant values and the influence of fiber type and washing and drying methods on these values. In Part II, we will discuss the changes in mechanical and tactile properties that occur in these fabrics with repeated washing.
Part II: Comparison of Disc-Ring and Woolen Ring Spun Yarn Structure and Properties
Authors: Lawrence C.A. , Chiu S.F.
Published: March 2008

The structure and properties of disc-ring yams made from five commercial 80/20 wool/nylon blends are compared with conventional woolen ring spun yams of the same blends and equivalent yam counts. Blends with the highest percentage of coarse wool fibers produce disc-ring yams with tensile properties similar to the woolen ring spun yams, but the former have better evenness properties. Tracer fiber studies reveal that the structure of disc-ring yams consists of a disordered arrangement of the con stituent fibers. Analysis of the yarn cross section shows that with the disc-ring yarn, fiber packing density increases from the center to the outer zone of the yam. The woolen ring-spun yam shows the converse tendency. In general, disc-ring yams are more bulky than woolen ring spun yams.
Industrial Fiber Processing and Machine Design: Mathematical Modeling, Computer Simulation, and Virtual Prototyping
Authors: Roberts William W.
Published: March 2008

Mathematical modeling and computer simulation of industrial fiber processing technologies are discussed, with focus on the motion, dynamics, transport, and col lection of fibers within specific representative classes of gas flow environments and machine design configurations of importance in the industrial setting. Desired capa bilities are evident in capturing dominant physical processes and fundamental dynamic mechanisms underlying gas-machine, fiber-machine, fiber-fiber, and gas-fiber inter actions. Simulations on high-speed computers demonstrate powerful predictive ca pabilities of optimizing fiber movement, manageability, and control; optimizing input- fiber characteristics to produce output products of higher quality; and virtual proto typing and optimal design and redesign of fiber processing machinery. Strong potential benefits may be possible for "next generation" prototype technologies and machine designs to be considered for large-production fiber processing industrial facilities and machinery manufacturers.
Mechanical Property Modification of Aramid Fibers by Polymer Infiltration
Authors: Mathur A. , Netravali A.N.
Published: March 2008

High performance organic fibers such as Kevlar, which are highly fibrillar in nature, possess excellent mechanical properties under tension but exhibit very poor strength in compression due to poor interfibrillar attraction. This study involves infiltrating polymeric materials into single aramid filament networks to improve interfibrillar adhesion and thus modify their mechanical properties. Wet-never-dried aramid fibers are used in this study, but it is still necessary to further open the fibrillar network with concentrated sulfuric acid to effectively infiltrate the polymer. While there is significant improvement in tensile strength after polymer infiltration, this is offset by a loss in strength due to the acid treatment. However, there is a significant increase of over 33% in compressive strength as a result of infiltration. The infiltration technique shows excellent promise and could be used for tailoring the properties of fibers with fibrillar morphology for selective end-use applications.
Surface Defect Geometry/Tensile Failure Relationships of Aminolyzed Poly(ethylene Terephthalate) Fibers
Authors: Holmes S.A.
Published: March 2008

Poly(ethylene terephthalate) fibers have been aminolyzed in aqueous n-butylamine and n-butylamine vapor. Aqueous aminolysis causes short cracks to form perpendicular to the fiber axis, whereas vapor aminolysis results in continuous cracks parallel to the fiber axis. At a given treatment time or molecular weight, the breaking load of the vapor aminolyzed fibers is less than that of the fibers aminolyzed in aqueous amine. The differences in strength are considered in light of Prevorsek's model of melt-spun fibers. The amine vapor apparently breaks primarily extended chain tie molecules, and the attack of the aqueous amine is concentrated in unoriented amorphous regions. Scanning electron photomicrographs of fractured fiber ends and fibers stressed to 60, 75, and 90% of their mean breaking load provide further evidence of the different locations of attack.
Structural Anisotropy, Failure Criterion, and Shear Strength of Woven Fabrics
Authors: Ning Pan  , Yoon Mee-Young
Published: March 2008

For structural and load-carrying applications, more detailed information about woven fabrics, which are increasingly used as reinforcements for composites, is desirable for design purposes. This paper investigates the issues related to woven fabric strength. First, the direction dependence or anisotropy of tensile strength as well as the breaking strain and initial modulus of the fabrics are examined experimentally. A harmonic expression is then adopted to approximate the experimental results so that this tensile strength anisotropy can be expressed analytically. Moreover, the Tsai-Wu failure cri terion is used, assuming it is valid for woven fabrics, at least at the first quadrant where failure stresses are all tensile. Unknown coefficients in the failure criterion are deter mined based on the experimental results. Fabric shear strength is then predicted based on the measured uniaxial tensile strengths of the fabric at the principal and off-axial directions. Influences of various directions of the off-axial tensile test on predictions of fabric shear strength are also studied.
Starch Fibers: Processing and Characteristics
Authors: Eagles Dana , Lesnoy Daniel , Barlow Sandra
Published: March 2008

Two methods for producing fibers from high amylose corn starch are presented, and the physical and chemical characteristics of fibers made following both methods are detailed. These characteristics are described in relation to the process used to convert the raw material into fiber and in relation to the raw material properties.
Fine Structure and Selected Properties of Dry- and Wet-Spun Butyrylchitin Filaments
Authors: Urbanczyk G. , Lipp-Symonowicz B. , Jeziorny A. , Dorau K. , Wrzosek A. , Kowalska S. , Sztajnert E.
Published: March 2008

The macro- and fine structure of dry- and wet-spun butyrylchitin filaments are studied using high, medium, and low molecular weight butyrylchitin. Density, optical, mechanical, and thermal properties and physicochemical properties such as solubility and dyeability of the filaments are examined.
Generating Fiber Length Distribution from the Fibrogram
Authors: Krowicki R.S. , Thibodeaux D.P. , Duckett K.E.
Published: March 2008

Theoretical fibrograms were generated from fiber length distributions, and new fiber length distributions were then generated from these theoretical fibrograms for two, three, four, five, and six significant digits using differential and algorithm methods. A minimum of four significant digits of fibrogram data appears to be generally required to generate fiber length distributions for short, medium, and long varieties of measured fibers to closely simulate actual fiber length distributions using either the differential or algorithm method. The algorithm method takes fewer steps to generate a fiber length distribution than the differential method.
Mechanical and Dyeing Properties of Wool and Cotton Fabrics Treated with Low Temperature Plasma and Enzymes
Authors: Nam Sik Yoon  , Yong Jin Lim  , Tahara Mitsuru , Takagishi Toru
Published: March 2008

Cotton and wool fabrics were treated with low temperature oxygen plasma or en zymes or both and examined for their mechanical and dyeing properties. Plasma- treated cotton showed reduced strength, while the rate of weight loss in subsequent cellulase treatments decreased compared with untreated cotton. Equilibrium uptake of a direct dye remained unchanged regardless of plasma or cellulase treatment. The rate of dyeing increased, however, although the difference was slight, in the order of plasma treatment < untreated < cellulase treatment = plasma/cellulase treatment. Plasma pretreatment of wool caused an increase in strength and a higher rate of weight loss in the subsequent protease treatment. When wool was dyed with a leveling acid dye, equilibrium dye uptake did not change with plasma or protease pretreatment, but the dyeing rate increased with the plasma pretreatment With a milling acid dye, both increased greatly in the order of untreated < protease treatment < plasma treat ment < plasma/protease treatment. From these results, we assumed that plasma attacks the surface of the fiber, and the enzyme affects mainly the inner part of the fiber. This was confirmed by scanning electron microscopy. The polymerization of enzyme with a water-soluble carbodiimide did not show any strength retention effect in enzymatic treatment of cotton and wool.
Fiber Speed and Yarn Tension in Friction Spinning
Authors: Konda Fujio , Okamura Masaaki , Ali Akbar Merati  , Yokoi Teruyuki
Published: March 2008

To investigate fiber speed inside the transport channel, fiber flow and yarn tension are measured at the same time on a friction spinning machine. Fiber speed at the fiber flow detection point is calculated using the number of fibers in a cross section of the channel at the detection area, the number of fibers in the cross section of sliver, and the speed of sliver feeding. The cross correlation method is used to obtain the time lag between the variation of yarn tension and the number of fibers in the channel cross section. The mean fiber speed between the fiber flow detection point and the yarn-forming zone is calculated from the time lag. Fiber speed in both cases is calculated for various levels of suction air pressure. The results of this research show that fiber speed decreases from the beginning to the end of the transport channel, and increases with increasing suction air pressure in the yarn-forming zone. On the other hand, calculating the value of the correlation coefficient demonstrates that there is a high correlation between yarn tension variation in the yarn-forming zone and the number of fibers in the channel cross section.
Effect of Humidity on the Drying Rates of Carpet Tiles
Authors: O'Dell David R. , Carr Wallace W.
Published: March 2008

The effects of humidity on the drying rates of carpet tile depend on both gas stream temperature and flow rate, and are much larger in the warm-up and constant rate periods than in the falling rate period. The existence of inversion temperatures is investigated for carpet tile drying. For a given flow condition, an inversion temperature is the temperature at which the drying rate in a superheated steam environment equals that in air. Inversion temperatures are 177°C and 214°C for the low flow and high flow conditions of this study, respectively.
Effect of Suction Air Pressure in Friction Spinning on Yarn Properties
Authors: Konda Fujio , Okamura Masaaki , Ali Akbar Merati
Published: March 2008

We have studied the effects of suction air pressure on the structural parameters and mechanical properties of yarn. Changing the amount of suction air pressure improves the fiber extent in yam and yarn appearance. Therefore, photographic and fiber tracing methods are used to evaluate, respectively, yam appearance and fiber extent in the yam. To consider the effect of suction air pressure on yarn diameter, yam tension at the yarn-forming zone and yam diameter are measured simultaneously on a friction spinning machine using various levels of suction air pressure, and then the relationship between them is considered using the cross correlation method. The results show that at high suction air pressure, yarn di ameter, yarn unevenness, and yam irregularity decrease, while fiber extent in the yarn and twist efficiency increase. On the other hand, the value of the correlation coefficient demonstrates that there is a high correlation between variations in yam tension and yarn diameter. The results of yam mechanical property measurements show that at high suction air pressure, yam tenacity increases and yarn elongation decreases. Results are reported from experiments on 100% cotton yams.