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Kennon, W. R. "The measurement of nonwoven fabrics." Thesis, University of Manchester, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521193.
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Jearanaisilawong, Petch 1979. "A continuum model for needlepunched nonwoven fabrics." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44751.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008."June 2008."
Includes bibliographical references (p. 159-166).
Nonwoven fabrics are sheet structures created by bonding or interlocking a web (network) of fibers through mechanical, thermal or chemical processes. In general, the mechanical response of nonwoven fabrics exhibits two major characteristics. First, the mechanical response can vary significantly when the fabric is loaded along different directions, depending on the existence of a preferential orientation in the fiber arrangement and/or in the pattern of inter-fiber bonding/entanglement. Second, the mechanisms of deformation include elastic and inelastic components, accompanied by an irrecoverable evolution of the texture of the fiber network. In this work, we propose a three-dimensional, large strain continuum model for the constitutive behavior of nonwoven fabrics that accounts for the fiber network characteristics responsible for its anisotropic behavior, and captures the effects of deformation mechanisms at the micro-scale (fiber and bonds/entanglement) level. The model consists of two constitutive components: a nonlinear elastic component representing the resistances to recoverable deformation mechanisms, and a non-linear inelastic component representing the resistances to irrecoverable deformation and texture evolution. For nonwoven fabrics in which the anisotropy of fiber orientation is combined with random entanglement processes, we propose to capture the combined effects of fibers and junctions orientation distributions using a single tensorial representation of the network anisotropy (fabric ellipsoid). An orthotropic elastic constitutive model for the elastic response of nonwoven fabrics is then formulated based on this structural measure and deformation mechanisms of the network structure. The inelastic component of the model is then prescribed in terms of an evolution law for the fabric ellipsoid.
(cont.) A needlepunched web of high strength polyethylene fibers, "Dyneema Fraglight", is selected as the representative material, to be used as a test case to validate the proposed modeling approach. The model is shown to capture the macroscopic nonlinear anisotropic elastic-inelastic response of the fabric in planar deformation, as well as the underlying micromechanical deformation mechanisms, such as fiber stretch, and irrecoverable evolution of fabric texture. The proposed model can be used to predict the mechanical behavior of nonwoven fabrics and can be combined with other continuum models to aid in the design of multi-component structures. In addition, the proposed elastic formulation can be used to model different classes of anisotropic network materials, such as biological tissues, and tissue engineering scaffolds.
bu Petch Jearanaisilawong.
Ph.D.
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Mvubu, Mlando Basel. "Studies on acoustic properties of non-woven fabrics." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/19387.
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This study is divided in to two main parts. The first part deals with the optimization of process parameters of needle-punched non-woven fabrics for achieving maximum sound absorption by employing a Box-Behnken factorial design. The influence of fibre type, depth of needle penetration and stroke frequency on sound absorption properties were studied. These parameters were varied at three levels during experimental trials. From multiple regression analysis, it was observed that the depth of needle penetration alone was the most dominant factor among the selected parameters, which was followed by the interaction between depth of needle penetration and stroke frequency. Fibre type was the least dominant parameter affecting sound absorption. A maximum sound absorption coefficient of 47% (0.47) was obtained from the selected parameters. The results showed that for a process such as needle-punching, which is influenced by multiple variables, it is important to also study the interactive effects of process parameters for achieving optimum sound absorption. The second part of the study deals with the effect of type of natural fibre (fineness), and the blending ratio (with PET fibres) on the air permeability of the needle-punched non-woven fabrics and then it proceeds to study the effect of the air-gap, type of natural fibre (fineness) and blending ratio (with PET fibres) on sound absorption of needle-punched non-woven fabrics. These parameters are tested individually and their two way interaction (synergy) effect using ANOVA. The air-gap was varied from 0mm to 25mm with 5mm increments, three natural fibre types were used and all were blended with polyester fibres at three blending ratios for each natural fibre type. The Univariate Tests of Significance shows that all three parameters have a significant effect on sound absorption together with two two-way interactions, with the exception of the Blend Ratio × Air Gap two-way interaction which was not significant. It was found that the sound absorption improves with the increase in the air-gap size up to 15mm after which sound absorption decreased slightly with the further increase in the air-gap up to 25mm.
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Austin, Andrew Nicholas. "Modelling the electromagnetic properties of conductive nonwoven fabrics." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/17009/.
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This thesis presents micro-structure models of wet-laid conductive nonwoven fabrics allowing the sheet conductance and shielding effectiveness to be simulated and compared to experimental measurement. Conductive nonwoven fabrics are used within the aerospace and defence industries to provide lightweight, functional electromagnetic enhancement to composite structures. They are materials borne from stochastic processes with anisotropic distributions of fibre and parameters that vary from point to point on the local scale. Monte Carlo models of the material’s micro-structure have been constructed by writing a series of algorithms which pseudo-randomly generate the material’s structure by incorporating key physical parameters such as the density, areal concentration and fibre angle distribution. To define the last of these parameters, a completely new optical method has been developed making use of the Hough Transform. These models have predicted the anisotropic sheet conductance to within 1-2% of experimental values, with an estimated inter-fibre contact resistance of Rj = 8.6kΩ, and a measured geometry factor of Φx = 0.727, Φy = 0.273. Analytic models of the material are derived from first principles enabling the rapid calculation of the sheet conductance, whilst also providing an understanding between the key parametric relationships. The analytic model, Monte Carlo model and experimental measurements are compared and give good correspondence. The micro-structure models are finally applied to a full wave electromagnetic simulation technique and shown to produce close correlation to polarisation specific measurements of the shielding effectiveness. High frequency (up to 200GHz) simulations of lightweight nonwoven structures suggest an eventual fall in the shielding effectiveness, attributed to the material’s sub-wavelength apertures.
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Patel, Suneer Vipin. "Modeling the bending stiffness of point bonded non-woven fabrics." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/9500.
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Wijeratne, Roshelle Sumudu. "Biaxial Response of Individual Bonds in Thermomechanically Bonded Nonwoven Fabrics." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/86517.
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Thermomechanically bonded spunbond nonwoven fabrics contain discrete bonds that are formed by melted and fused fibers. Through equi-biaxial tensile testing and simultaneous image capture, the mechanical response of individual bonds was studied through loading in the preferential fiber direction, the machine direction, and in the direction that is perpendicular, the cross direction, of the fabric web. Independent biaxial force and displacement data were collected and analyzed, and the maximum force and stiffness of the bonds in the machine and cross directions were found to be statistically different. After scaling the maximum force and stiffness by a relative basis weight parameter, a fiber orientation parameter, and the width of the bond itself, the peak force and stiffness in the machine and cross directions were found to no longer be statistically different. This indicates that basis weight, fiber orientation, and bond size dictate the biaxial mechanical behavior of the bonds. Furthermore, significant fiber debonding was observed in all the bonds tested, effectively suggesting bond disintegration into the individual component fibers during testing. Digital image correlation, using the captured images, was utilized to calculate local and average Eulerian strains of the bond during the initial stages of the test. The strain experienced by the bonds in the machine direction was always positive and increasing as the biaxial load increased. The strain in the cross direction, however, experienced increasing and decreasing strain. Local strain maps revealed the highly inhomogeneous strain response of the bonds under biaxial loading.Master of Science
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Sanad, Reham Abdelbaset Elsayed. "The measurement of drape for nonwoven and conventional textile fabrics." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/5046/.
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The importance of the drape properties of fabrics on final garment appearance and fit has been long understood and a great deal of research has been carried out in this area. More recently, nonwoven fabrics have begun to create interest among the apparel and fashion design community. In this study, the conventional method of measuring fabric drape was compared with garment drape measurement using an alternative drape measurement system based on an image analysis technique. Garment drape was investigated using dresses suspended on a mannequin. A garment chosen was a shift dress because of its relatively uncomplicated style and shape. Hydroentangled nonwovens were selected as they show good performance and similarity to conventional fabrics in terms of physical and mechanical properties. A graphical user interface was developed to carry out the image analysis and to calculate drape values identifying and determining 23 drape parameters. A range of fabrics including conventional (knitted, woven) and nonwoven fabrics were compared in terms of FAST properties, drape coefficient and drape values. Some nonwoven fabrics were found to give similar performance to some conventional fabrics and better than others. Subjective assessment of the fabric range was carried out in terms of drape amount and preference. Low agreement was found between individuals with regard to preferred drape amount and high agreement with respect to actual drape amount. Nonwovens were found to be better preferred over some conventional fabrics. Most of the drape values of fabric and garment were found to have poor correlations.
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Asimakopoulos, V. "An experimental study of friction between skin and nonwoven fabrics." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1418062/.
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Incontinence is a common health problem among the human population, especially females. Although there have been many efforts to develop cures not all sufferers can be fully cured. A way to deal with this large portion of incontinence sufferers is pads. The continuous usage of pads creates some problems, though. The most common cause of these problems is friction between pads and skin. In order to describe friction, David Cottenden developed a mathematical model for describing friction between a conformable sheet and a curved surface. Previous work has already validated the model for strips of nonwoven fabric on rigid convex prisms and low – half angle cones . The aim of this project was to extend the validation to (i) large – half angle rigid cones (whose surfaces approximate to portions of the body); (ii) human volar forearms and (iii) highly compliant cylinders. In the first part of the project I validated the model for an example nonwoven fabric on rigid (Plaster of Paris) cones with half angles of 25°, 35° and 45°. As predicted by the model, the data for all fabric footprints on all cones fell on the same master curve, within experimental error. In the second part of the project, I used the volar forearms of young and older female participants. In this way I had the opportunity to test the model on real human skin (smooth and wrinkled) and different substrates (firm and flaccid tissues) as they varied between young and older subjects. Moreover, I observed the changing geometry of arms during experiments, especially the behaviour of – often wrinkled and flaccid – older arms and see how the model responded. I used strips of five different nonwoven fabrics investigating not only how the substrate affected the model, but also how behaviour varied between fabrics. The agreement between experimental data and model predictions was excellent for all fabrics. In the third part of the project, I used the same five fabrics on compliant cylinders made of soft silicone membrane “skins”. These cylinders helped me investigate how the model responded for extreme deformations (rucking) which were much greater than humans could have tolerated. Again, agreement between experiment and model was remarkably good. In summary, all three blocks of experimental work provided further validation of Cottenden’s model, increasing confidence that it can be used in future work to understand friction over the curved surfaces of the body and help develop products kinder to the skin.
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Battocchio, Francesco. "Manufacture and characterisation of spunbonded nonwovens." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708457.
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Ogunleye, Christopher Olarinde. "High performance nonwovens in technical textile applications." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1021011.
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The aim of this research was to establish the optimum processing conditions and parameters for producing nonwoven fabrics best suited for application in disposable and protective wear for surgical gowns, drapes and laboratory coats. Carded and crosslapped webs, of three basic weights (80, 120, and 150g/m2), from greige (unscoured and unbleached) cotton, viscose and polyester fibres, were hydroentangled, using three different waterjet pressures (60, 100 and 120 bars), on a Fleissner Aquajet hydroentanglement machine. An antibacterial agent (Ruco-Coat FC 9005) and a fluorochemical water repellent agent (Ruco Bac-AGP), were applied in one bath using the pad-dry-cure technique, to impart both antibacterial and water repellent properties to the fabrics, SEM photomicrographs indicating that the finished polymers were evenly dispersed on the fabric surface. The effect of waterjet pressure, fabric weight and type and treatment on the structure of the nonwoven produced, was evaluated by measuring the relevant characteristics of the fabrics. As expected, there was an interrelationship between fabric weight, thickness, and density, the fabric thickness and mass density increasing with fabric weight. An increase in waterjet pressure decreased the fabric thickness and increased the fabric density. The water repellent and antibacterial treatment increased the fabric weight and thickness. The antimicrobial activity of the fabrics was assessed by determining the percentage reduction in Staphylococcus aureus and Escherichia coli bacteria population. The maximum percent reduction at 24hrs contact time for both bacteria ranged from 99.5 to 99.6 percent for all the fabric types. The standard spray test ratings for the three treated fabrics ranged from 80-90 percent, whereas that of the untreated water repellent fabric was zero, while the contact angles for all the fabric types exceeded 90 degrees, indicating good resistance to wetting. It was found that the tensile strength of the fabric in the cross-machine direction was higher than that in the machine direction, for both the treated and untreated fabrics, with the tensile strengths in both the MD and CD of the treated fabrics were greater than that of the untreated fabrics, the reverse being true for the extension at break. An increase in waterjet pressure increased the tensile strength but decreased the extension at break, for both the treated and untreated fabrics. The finishing treatment decreased the mean pore size of all the fabrics, the mean pore size decreasing with an increase in fabric weight and waterjet pressure. An increase in waterjet pressure and fabric weight decreased the air and water vapour permeability, as did the finishing treatment, although the differences were not always statistically significant. The polyester fabrics had the highest water and air permeability. Hence low weight fabrics of 80 g/m2, which were hydroentangled at low water jet pressures of 60 bars, were suitable for use in this study due to their higher air and water vapour permeability as well as higher pore size distribution. These group of fabrics thus meet the requirements for surgical gowns, drapes, nurses’ uniforms and laboratory coats.
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Edwards, Nicholas William Moses. "Removal of bacteria from solid surfaces by wiping with nonwoven fabrics." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/17978/.
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Healthcare associated infections are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes, with or without a biocidal liquid, to remove pathogenic bacteria from frequently touched surfaces. Considerable research has been conducted on the role of biocides in disrupting microbes such as bacteria, but less is known about the influence of wiping surfaces with nonwovens regarding their removal. This research considers the role of intrinsic and extrinsic factors on the removal of bacterial contamination from model healthcare surfaces. The extent to which systematic changes in wipe fibre surface energy and nano-roughness influence removal of bacteria from a polymer surface in dry wiping conditions was studied. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulose II) and polypropylene (PP), with different surface energies and nano-roughnesses, were experimentally manufactured. The surface energy and nano-roughness of lyocell substrates were modified by either oxygen or hexafluoroethane plasma treatment. Static wiping of an inoculated surface under dry conditions produced bacterial removal efficiencies of between 9.4 colony forming unit (CFU) % and 15.7 CFU % versus control, with no significant difference (p < 0.05) in the relative removal efficiencies of E. coli, S. aureus or E. faecalis. Dynamic wiping increased peak wiping efficiencies to >50 CFU % versus static wiping (p < 0.05), depending on fibre type and bacterium. Under dynamic wiping conditions, nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis. Considering both intrinsic and extrinsic factors of wiping and design factors on the removal of pathogenic bacteria, the single most important parameter affecting bacterial removal efficiency was impregnation with biocidal liquid (p < 0.05). However, dynamic wiping in the dry state and with water alone without biocide still resulted in substantial removal. Bacterial removal was therefore not conditional on the presence of a biocide. For 100% lyocell wipes impregnated with biocidal liquid, removal of E. coli, S. aureus and E. faecalis improved by increasing the fabric basis weight and hand weight wiping pressure to their maximal values (150 g.m-2 and 13.80 kN.m-2 respectively). For 100% polypropylene wipes, the same conditions maximised the removal efficiency of S. aureus. For E. coli and E. faecalis, a reduction in the hand weight wiping pressure to 4.68 kN.m-2 was required to maximise the removal efficiency with 100% polypropylene. Generally, the lyocell wipes were more effective in removing bacterial contamination than 100% polypropylene wipes. The removal and destruction of pathogenic bacteria partly by wiping relies on their transfer to fibre surfaces within the wipe. The extent to which the surface properties influences specific bacterial removal was investigated in terms of polymer composition and surface roughness, as well any residual antimicrobial activity conferred to the surface by the biocide. It was determined that there was no significant difference in removal of E. coli, S. aureus and E. faecalis from plastic, ceramic or metal surfaces by either 100% lyocell or 100% polypropylene nonwoven wipes (p < 0.05) during wet wiping. No significant residual antimicrobial activity was seen form the biocide deposited on clinical surfaces after wiping (p < 0.05). Therefore, regular disinfection of clinical surfaces, with a “one wipe, one surface” policy should be implemented.
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Wang, Xueqin. "Morphology distributions in thermally point bonded nonwovens." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/8696.
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Moyo, Doice. "Characterisation and optimisation of waterjet impact forces and energy parameters during hydroentanglement." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1020134.
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Hydroentanglement is an important technique of bonding fibres to produce nonwovens using high velocity waterjets as the primary bonding tool. The work reported in this thesis addresses the gap in scientific knowledge and understanding, both theoretical and experimental, related to the impact forces and energy of the waterjets used in the hydroentanglement process. The current study focused on the impact forces and energy involved in, and the optimisation of, the hydroentanglement process. The results of the experimentally measured waterjet impact forces have been used to characterise the waterjets as well as to verify empirically the theoretical models currently available for explaining the mechanics of the hydroentanglement process. Since the process of supplying pressurised waterjets consumes a great deal of energy, the study of energy consumption and efficiency of the system has been critical. A method was proposed and used to determine the coefficients of velocity and water discharge of an industrial machine set-up, helping explain the mechanism of energy transfer during hydroentanglement and to concurrently optimise the process. Furthermore, a response surface experimental design was used to optimise the hydroentanglement of viscose and Polylactic acid (PLA) fibres into nonwovens. The selected Box-Behnken design, with four factors, namely the waterjet force, machine processing speed, input weight and fibre type, was employed to investigate the multivariate process factors and their interactive effects on physical and mechanical properties of nonwovens. Two sets of experiments, the later for validation, were performed to study the energy transfer efficiency. The results of the relative energy transfer to bond the fibrous web showed that it was possible to produce nonwovens using lower input energy without compromising the quality of the products. The optimum waterjet pressure and machine speed used to produce the Abstract nonwoven with the highest tensile strength for the least amount of energy supplied were identified.
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Konopka, Amy Elizabeth. "The Effect of Anisotropy on In-Plane liquid Distribution in Nonwoven Fabrics." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010925-125929.
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AbstractKonopka, Amy Elizabeth. The Effect of Anisotropy on In-Plane liquid Distribution in Nonwoven Fabrics. (Under the direction of Behnam Pourdeyhimi)Anisotropy has been shown to be an influencing factor of many nonwoven structural properties such as the bending rigidity and the tensile strength. The effect on liquid distribution (a very important property in many nonwoven applications), however, has not been determined. In this study the effect on anisotropy on a material's in-plane liquid distribution is examined. By using the new NCRC GATS device, which enables the in-plane liquid distribution and the recording of the spread to occur simultaneously, it was determined that the liquid distribution was indeed influenced by the structural anisotropy. Also determined was the effect of the testing method on the wicking rate of the material. A comparison between conventional test methods and a newly developed test method, which utilizes the NCRC GATS and a hollowed plate, were made. It was determined from the results that the new method is the only method that measures the intrinsic wicking of the material.
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Cottenden, D. J. "A multiscale analysis of frictional interaction between human skin and nonwoven fabrics." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1301772/.
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Various hygiene products, notably incontinence pads, bring nonwoven “topsheet” fabrics into contact with individuals’ skin. This contact can damage the skin in various ways, including abrading it by friction, a mechanism enhanced by the presence of moisture. In recent years skin-nonwoven friction has been the subject of significant experimental study in the Continence and Skin Technology Group, UCL, in the course of which methods have been developed which can detect differences in friction between a chosen nonwoven and equivalent skin sites on different individuals under fixed conditions. The reasons for these differences are unknown; their elucidation is one focus of this work. The other is to establish the influence of coarse geometry on the dynamics of a tense nonwoven sheet sliding over a substrate and interacting with it by friction. The first part of this work (“microfriction”) is primarily experimental in nature, and involves two separate experiments. The first involves using a microscope with a shallow depth of field to determine the length of nonwoven fibre in contact with a facing surface as a function of pressure; the second consists of measuring friction between chosen nonwovens and a skin surrogate at a variety of pressures and speeds whilst simultaneously observing the behaviour of the interface down a microscope. Both techniques were extensively validated, and the data from the two experiments were then compared. It had originally been intended to conduct the friction experiment on skin (the other experiment does not require it), and though all equipment was developed with this in mind and all relevant permission was sought and obtained, it was not eventually possible. Instead, a skin friction surrogate (Lorica Soft) established in the literature was used. Data from this show that Amontons’ law (with respect to load) is obeyed to high precision (R2 > 0.999 in all cases), though there is the suggestion of sublinearity at low loads. Detailed consideration of the friction traces suggests that two different friction mechanisms are important, and comparison with the contact data suggests tentatively that they may correspond to adhesion between two different populations of contacts, one “rough” and one “smooth”. Further work applying these techniques to skin is necessary. The second aspect of the work is “geometric friction”; that is, the relationship between the geometry of a surface (on the centimetre scale and upwards) and the friction experienced by a compliant sheet (such as nonwoven topsheet) laid over it in tension. A general equation of motion for slippage between sheet and surface has been derived which in principle allows for both objects to deform and interact according to any plausible friction law. This has then been solved in integral form for Amontons’ law and a low density strip exhibiting no Poisson contraction sliding over any surface with zero Gaussian curvature; closed form solutions for the specific cases of a prism and a circular cone have then been derived and compared. Experimental verification has been provided by a colleague, which shows very good agreement between theory and experiment. It has also been shown that, taking a naïve approach, the classic model for a rigid cylinder can be applied even to a quite extreme cone with experimentally negligible error. NB All prior copyrighted material (diagrams in all cases) has been removed from this edition to facilitate electronic distribution. They have been replaced with boxes of the same size, so pagination is identical with the complete version.
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Sarin, Siddartha. "Liquid transport mechanisms in cotton-polypropylene laminated nonwoven fabrics influencing pesticide penetration." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-01102009-063449/.
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Chen, Li. "The effects of abrasion on liquid-fabric interaction of selected nonwoven fabrics." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-02132009-171632/.
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Pai, Chia-Ling. "Morphology and mechanical properties of electrospun polymeric fibers and their nonwoven fabrics." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65763.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011.Cataloged from student submitted PDF version of thesis.
Includes bibliographical references.
Electrospinning is a straight forward method to produce fibers with diameter on the order of a few tens of nanometers to the size approaching commercial fibers (on the order of 10 prm or larger). Recently, the length scale effect on physical properties has attracted great attention because of the potential to produce new materials with unique behavior. In general, the behavior of commercial fibers can be investigated by traditional experiments, and that of nanofibers can be studied by molecular dynamics simulation or Monte Carlo technique. However, the transition of their properties from the bulk to the nanoscale materials is not well understood. Electrospinning provides us a bridge to understand the properties of fibers transiting from the behavior of the bulk material to that of the nanofibers. Among these areas, I am interested in the possible remarkable changes in mechanical properties that may occur in electrospun fibers due to the size effect, where the comprehensive understanding is still lacking. My research objectives are to understand mechanical properties of electrospun polymeric fibers as a function of their size, structure and morphology. The first part of my research is to study internal structures and external topographies of electrospun fibers, and to understand their effect on mechanical properties. Amorphous polystyrene (PS) and semicrystalline polyacrylonitrile (PAN) were dissolved in a high boiling point solvent, dimethylformamide (DMF), for electrospinning. When electrospun in a high-humidity environment, the interior of these fibers was found to be highly porous rather than consolidated, despite the smooth and nonporous appearance of the fiber surfaces. The formation of interior porosity is attributed to the miscibility of water, a nonsolvent for the polymers in solution, with DMF. The resulting morphology is a consequence of the relatively rapid diffusion of water into the jet, leading to a liquid-liquid phase separation that precedes solidification due to evaporation of DMF from the jet. When electrospun in a low humidity environment, the fibers exhibit a wrinkled morphology that can be explained by a buckling instability. Understanding which structures and morphology form under a given set of conditions is achieved through the comparison of three characteristic times: the drying time, the buckling time and the phase separation time. The structures and morphology have important consequences for the properties of the fibers such as their mechanical strength and stiffness.
(cont.) Secondly, we studied the size effects of single electrospun fibers on their stiffness and strength. The Young's modulus and yield strength of individual electrospun fibers of amorphous poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) have been obtained in uniaxial extension. The Young's modulus is found to exhibit values in excess of the isotropic bulk value, and to increase with decreasing fiber diameter for fibers with diameter less than roughly 500 nm. The yield stress is also found to increase with decreasing fiber diameter. These trends are shown to correlate with increasing molecular level orientation within the fibers with decreasing fiber diameter. Using Ward's aggregate model, the correlation between molecular orientation and fiber modulus can be explained, and reasonable determinations of the elastic constants of the molecular unit are obtained. Finally, we identified a relation of stiffness between single electrospun fibers and their nonwoven fabrics. This is of interest because adequate mechanical integrity of nonwoven fabrics is generally a prerequisite for their practical usage. The Young's modulus of electrospun PA 6(3)T nonwoven fabrics were investigated as a function of the diameter of fibers that constitute the fabric. Two quantitative microstructure-based models that relate the Young's modulus of these fabrics to that of the fibers are considered, one assuming straight fibers and the other allowing for sinuous fibers. This study is particularly important for meshes comprising fibers because of our recent discovery of an enhanced size effect on their Young's modulus as well as the tendency towards a curved fiber topology between fiber junctions. The governing factors that affect the mechanical properties of nonwoven mats are the fiber network, fiber curvature, intrinsic fiber properties, and fiber-fiber junctions. Especially for small fibers, both the intrinsic fiber properties and fiber curvature dominate the mechanical behavior of their nonwoven fabrics. This thesis helps us to understand the mechanism behind the enhanced mechanical behavior of small fibers, and to identify determining parameters that can be used to tailor their mechanical performance.
by Chia-Ling Pai.
Ph.D.
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Platnick, Brian Scott. "Improving quality on a nonwovens line." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/43595.
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Lutseke, Nothando Sazikazi. "An investigation into the properties of cotton fibres as used in nonwoven fabrics." Thesis, Rhodes University, 1989. http://hdl.handle.net/10962/d1018241.
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The purpose of this investigation was to determine the properties that characterise cotton fibres in the various stages in the CPNF process as well as to determine which fibre characteristics a r e required to entangle the fibres to produce a successful CPNF . The criteria adopted in this work for a successful CPNF include: 1. the tensile strength of the fabrics 2. a well-defined pattern 3. absorbency and wicking The properties selected for investigation were 1. the cotton fibre surface (using SEM and DSC analyses) 2. the degree of degradation of the cotton fibre as a result of the CPNF process (using cellulose fluidity measurements) 3. the non-cellulosic content of the fibre (using IR, DSC, and Chemical analyses) 4. fibre friction 5. absorbency and wicking 6. tensile properties Analysis of the results indicates clearly what the fundamental properties of the cotton fibre must be for a successful cotton CPNF to be manufactured. The conclusions also indicate the necessary properties a man-made fibre must have to produce a successful CPNF.
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Tshifularo, Cyrus Alushavhiwi. "Comparative performance of natural and synthetic fibre nonwoven geotextiles." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/21362.
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The aim of this work was to establish a range of suitable process parameters which can be utilized to produce needlepunched nonwoven fabrics for geotextile applications. Nonwoven fabrics were produced from 100% PP, a blend of 50/50% PP/kenaf and 100% kenaf fibres. The depths of needle penetration of 4, 7 and 10 mm, stroke frequencies of 250, 350 and 450 strokes/min and mass per unit area of 300, 600 and 900 g/m2 were utilized for producing the fabrics, on a Dilo loom. The effect of depth of needle penetration, stroke frequency and mass per unit area on the fabric properties, namely, tensile strength, puncture resistance, pore size, water permeability and transmissivity were analysed. In addition, the effect of chemicals, namely, 10% ammonium hydroxide (NH4OH), 10% sodium chloride (NaCl) and 3% sulphuric acid (H2SO4) solutions on degradation of the fabric was also studied. The results have shown that density, thickness and nominal weight of the needlepunched nonwoven fabrics were related to each other and they were influenced by stroke frequency, depth of needle penetration and feed rate of the needlepunching process. The increase in nominal weight of the fabrics also increases thickness and density of the fabrics. The tensile strength and puncture resistance of the fabrics increased with the increases in stroke frequency, depth of needle penetration and fabric mass per unit area. However, lower tensile strength and puncture resistance were achieved in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area. Bigger pores were resulted in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area, however, pore size decreased with increases in stroke frequency, depth of needle penetration and mass per unit area. Water permeability depends on the pore size, properties of the fibres, stroke frequency, depth of needle penetration and mass per unit area. Higher tensile strength and higher puncture resistance were achieved in the needlepunched nonwoven fabrics produced from 100% PP fibres, therefore, they are suitable for some load-bearing geotextile applications, such as reinforcement and separation. However, higher water permeability was achieved in the fabrics produced from 100% kenaf fibres, therefore, they are ideal for geotextile applications where good water permeability is required. Higher values for transmissivity were obtained in the fabrics produced from a blend of 50/50% PP/kenaf fibres, therefore they are suitable for drainage applications. The fabrics produced from a blend of 50/50% PP/kenaf fibres achieved better values of tensile strength, puncture resistance, pore size and water permeability in comparison to that produced from 100% PP and 100% kenaf fibres. However, better tensile strength and puncture resistance were achieved in the fabrics produced from 100% PP fibres and bigger pore size and higher water permeability were achieved in the fabrics produced from 100% kenaf fibres. Therefore, it can be suggested that the nonwoven fabrics produced from a blend of 50/50% PP/kenaf fibres can fulfil almost all requirements of geotextile applications, such as, filtration, separation, reinforcement and drainage. The fabrics produced from 100% PP fibres were not damaged or deteriorated when treated with all the three chemicals due to chemical inertness of polypropylene. However, the fabrics produced from a blend of 50/50% PP/kenaf and 100% kenaf fibres were damaged and deteriorated when treated with H2SO4.
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Falloon, S. S. "An experimental study of friction between wet and dry human skin and nonwoven fabrics." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1458878/.
Full textAbstract:
Many people who have urinary incontinence manage it with the use of absorbent hygiene products, such as pads. Long-term use of these products can lead to abrasion by friction between the topsheet (a nonwoven fabric) and the skin, and is exacerbated when the skin is wet. However, the nature and mechanisms of friction between skin and nonwovens are poorly understood, hindering progress to improve products. Most work on skin friction to date has involved the use of skin surrogates or real skin in the dry state only. Moreover, only a narrow range of different nonwoven fabrics have been investigated. The work described in this thesis aimed to improve understanding of friction between nonwoven fabrics and human skin, and was divided into four main blocks. In the first, friction was measured between a skin surrogate (Lorica Soft) and 13 different nonwoven fabrics, varying in structure, fibre material and manufacturing techniques. Amontons’ law was closely obeyed for all nonwovens (that is, coefficients of friction were independent of normal force) and the data were used to select a representative subset of five nonwovens for subsequent work. In the second block of work, an in vivo study of friction was conducted between the subset of (five) nonwovens and the dry volar forearm skin of 19 female volunteers (aged 20-95 years). It was found that Amontons’ law also held for all of these measurements, despite the general viscoelastic nature of human skin, the range of skin types (from smooth and firm to wrinkled and flaccid) and the difference in ages. The coefficient of friction for a given fabric varied considerably between participants (an increase of up to 101% of the lowest coefficient value), but the fabrics were generally ranked in the same order for all volunteers. The third block of work involved the measurement of wet friction between the subset of five nonwovens and volar forearm skin of five of the study participants. In general, the coefficient of friction increased with skin wetness/hydration by up to a factor of thirteen until the skin was damp/moist. The relationship for very wet skin (with surface water) – thought to be lubricated – was unclear and varied between participants and between nonwovens. However, further work would be required to locate and quantify the excess water in and on the skin, in order to more accurately evaluate the contribution of water to friction. Finally, in the fourth block of work, the fibre footprints of nonwovens against a surrogate skin surface (glass microscope slide) were examined, providing insight into how friction is mediated by the interface. Total fibre contact length was always extremely low (typically 0.3-1.6 mm · mm-2) and increased linearly with the log of pressure, usually due to an increase in the number of contacts and sometimes because of an increase in the lengths of existing fibre contacts.
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Fan, Xiuling Broughton Roy. "Value-added products from chicken feather fibers and protein." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Polymer_and_Fiber_Engineering/Dissertation/Fan_Xiuling_15.pdf.
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Isikel, Lale. "Design and characterization of nonwoven fabrics for gas diffusion layer in polymer electrolyte membrane fuel cell." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/ISIKEL_LALE_21.pdf.
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Jearanaisilawong, Petch 1979. "Investigation of deformation and failure mechanisms in woven and nonwoven fabrics under quasi-static loading conditions." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30296.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004."September 2004."
Includes bibliographical references (leaves 107-115).
The mechanical responses of high performance ballistic woven and nonwoven fabrics under in- plane quasi-static loading conditions have been investigated. The investigations focused on the responses of fabrics at the mesostructural level as well as at the macroscopic level under uniaxial tensile and in-plane shear modes of deformation. A number of experimental methods have been developed, including techniques to test individual fibers (coupon fiber test), techniques to test fabric specimens with the aid of custom-designed fixtures, and techniques relying on image analysis to capture the deformation response of the fabric. Two continuum models have been developed for each type of fabric based on the deformation and failure mechanisms observed in the experiments. The models are able to capture essential features of the in-plane deformation of the fabrics in a computationally efficient framework.
by Petch Jearanaisilawong.
S.M.
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Gahide, Severine. "COMBINATION OF HYDROENTANGLEMENT AND FOAM BONDING TECHNOLOGIES FORWOOD PULP AND POLYESTER FIBERS IN WET LAY NONWOVEN FABRICS." NCSU, 1999. http://www.lib.ncsu.edu/theses/available/etd-19990216-135019.
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This project searches for synergism between two binder technologies, specifically 1) low levels ofhydroentanglement energy which avoid excessive fiber loss but do not give adequate fabric strength, abrasionresistance or strain recovery, and 2) low levels of binder which do not degrade fabric aesthetics. The mainsteps were to 1) determine the fiber loss while hydroentangling, by testing three fabric weights and severalspecific energy levels for a 50% wood pulp and 50% polyester, and then 2) combine both technologies, fortwo fiber blends, at three levels of specific energy and four levels of binder add on. We found that: 1. Thecarrier screen mesh size, during hydroentanglement, was a critical factor for making the desired fabrics. 2.The fiber loss during hydroentanglement increases linearly with increasing specific energy, in the rangestudied. 3. The fabric basis weight has a very weak influence on the fiber loss during hydroentanglement. 4.Fabrics hydroentangled from one side only or on both sides lose the same amount of fibers. 5. The physicalproperties -strength, load at 5% strain, abrasion resistance- are greatly improved with an add-on of binder,while different levels of hydroentanglement energy input were found to be less significant. 6. Thehydroentangled and foam bonded fabrics are softer than those which were foam bonded only. 7. Theaddition of foam bonding up to 5% did not affect the softness of the hydroentangled fabrics. 8. The hydrogenbonding effect is shown to be significant at these levels of hydroentanglement and binder add-on. 9. Thefabric bending rigidity can be correlated with the Young's modulus of the bonded fabric for a 60% woodpulp fabric. 10. The abrasion resistance behavior is very different depending on the side tested: foam free orfoamed.
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Hennessey, Ann M. "Use of physiological and perceptual dimensions of clothing comfort to evaluate nonwoven protective fabrics through wear testing of limited-use coveralls." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/45213.
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The purpose of this research was to identify nonwoven protective fabrics designed to have improved comfort properties over a fabric currently used in limited-use chemical protective clothing by using physiological and perceptual dimensions of comfort. Fabrics that are both waterproof and breathable have potential for use in chemical protective clothing by repelling liquid while allowing the diffusion of moisture vapor from the body. Microporous laminated fabrics used in chemical protective clothing allow moisture to evaporate from the body and move through the fabric while preventing liquid chemicals from coming in contact with the skin. Five fabric types were evaluated by wear testing coveralls and measuring selected physiological and perceptual responses of five subjects performing moderate-intensity exercise in thermoneutral and hot, humid environments. Physiological responses included skin temperature, body temperature, heart rate, sweat rate, and fluid loss. Perceptual responses included moisture sensation, thermal sensation, Rating of Perceived Exertion, and overall comfort. In the thermoneutral environment, results show heart rate to be the only variable affected by the different fabric types, while time effect was significant within all dependent variables. In the hot, humid environment, skin and body temperatures were significantly affected by fabric type, while time effect was significant within all variables except skin temperature. The environment effect was significant within all dependent variables except RPE and heart rate. Based on the statistical insignificance of subjects' overall comfort responses in both environments, it can be said that the differences in the physical characteristics of the fabrics may not be great enough to affect the wearer's comfort level. However, two of the four fabrics were determined to have potential for further investigation. Further research comparing experimental fabrics with fabrics used widely in industry will continue the effort of improving the comfort of limited-use protective clothing.Master of Science
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Segura, Alcaraz María del Pilar. "Empleo de textiles en aplicaciones de absorción sonora." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/159786.
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[ES] Esta memoria de tesis presenta una contribución al estudio de los materiales textiles en el campo de la absorción sonora. En concreto, se ha trabajado con la asociación de una capa absorbente fibrosa constituida por una estructura laminar no tejida cuya composición es poliéster y una capa resistiva a base de tejido de calada también compuesta de poliéster. El objetivo de este trabajo consiste en evaluar las variaciones que provocan los cambios en distintos parámetros de construcción de la capa resistiva, sobre el comportamiento del conjunto ante el sonido. Para abordar el problema se emplean distintos tejidos de calada, tales como telas simples, múltiples, acolchadas y rizo, con diferentes parámetros de construcción. Se mide el coeficiente de absorción de sonido al aplicarlas a diferentes espesores de estructura no tejida de poliéster, empleando el tubo de ondas estacionarias. Tras analizar los resultados obtenidos, se observan diferencias en los coeficientes de absorción de sonido alcanzados, las cuales se explican atendiendo al espesor del no tejido, pero también se observa la influencia de las características constructivas de los tejidos empleados. Finalmente, se emplea el diseño de experimentos para obtener la combinación óptima de parámetros que proporciona el mayor coeficiente de absorción de sonido para un tipo de tejido dado en todas las frecuencias estudiadas. Se concluye que, la modificación en la absorción de sonido de una estructura no tejida al aplicar una capa resistiva de tejido de calada, es lo suficientemente significativa como para ser tenida en cuenta a la hora de diseñar productos textiles para acondicionamiento acústico y que el diseño de experimentos constituye una herramienta de gran utilidad a este fin.[CAT] Aquesta memòria de tesi presenta una contribució a l'estudi dels materials tèxtils en el camp de l'absorció sonora. En concret, s'hi ha treballat amb l'associació d'una capa absorbent fibrosa constituïda per un no teixit de polièster i una capa resistiva a base de teixit de calada de composició polièster. L'objectiu d'aquest treball consisteix a avaluar les variacions que provoquen els canvis en diferents paràmetres de construcció de la capa resistiva, sobre el comportament del conjunt davant el so. Per a abordar el problema s'empren diferents teixits de calada, com ara teles simples, múltiples, encoixinats i ris, amb diferents paràmetres de construcció. Es mesura el coeficient d'absorció en aplicarles a diferents grossàries de no teixit de polièster, emprant el tub d'ones estacionàries. S'observen diferències en els coeficients d'absorció de so obtinguts, les quals s'expliquen atenent la grossària del no teixit, però també a les característiques constructives dels teixits emprats. Finalment, s'empra el disseny d'experiments per a obtenir la combinació òptima de paràmetres que proporciona el major coeficient d'absorció de so per a un tipus de teixit donat en totes les freqüències estudiades. Es conclou que la modificació en l'absorció de so d'un no teixit en aplicar una capa resistiva de teixit de calada és prou significativa per a ser tinguda en compte a l'hora de dissenyar productes tèxtils per a condicionament acústic i que el disseny d'experiments constitueix una eina de gran utilitat a aquest efecte.
[EN] This thesis report presents a contribution to the study of textile materials in the field of sound absorption. Specifically, we have worked with the association of a fibrous absorbent layer consisting of a polyester nonwoven and a resistive layer based on openwork fabric. The objective of this work is to evaluate the variations that cause the changes in different construction parameters of the resistive layer, on the behaviour of the whole before the sound. To address the problem, different openwork fabrics are used, such as single, multiple, quilted and curl fabrics, with different construction parameters. The absorption coefficient is measured when applied to different thicknesses of polyester nonwoven, using the standing wave tube. Differences are observed in the sound absorption coefficients obtained, which are explained according to the thickness of the nonwoven, but also to the constructive characteristics of the fabrics used. Finally, the design of experiments is used to obtain the optimal combination of parameters that provides the highest sound absorption coefficient for a given type of tissue at all frequencies studied. It is concluded that the modification in the sound absorption of a nonwoven when applying a resistive layer of openwork fabric is significant enough to be taken into account when designing textual products for acoustic conditioning and that the design of experiments constitutes a very useful tool for this purpose.
Al departamento de Ingeniería Textil y Papelera y a la unidad docente de Alcoy del departamento de Mecánica de los Medios Continuos y Teoría de Estructuras, por facilitarme los medios necesarios para realizar todas las actividades que han sido necesarias. A Jaime Ramis Soriano, por recibirme en el laboratorio de Grupo de Acústica Aplicada del IUFACyT de la Universidad de Alicante.
Segura Alcaraz, MDP. (2020). Empleo de textiles en aplicaciones de absorción sonora [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/159786
TESIS
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Yeh, Ji-Chang, and 葉吉昌. "Fabrication of TiO2/Graphene Oxide Composite Nonwoven Fabrics by Electrospraying." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7798c9.
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Sahbaee, Bagherzadeh Arash. "Abrasion and pilling resistance of nonwoven fabrics made from bicomponent fibers." 2007. http://www.lib.ncsu.edu/theses/available/etd-11082007-101206/unrestricted/etd.pdf.
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Dutton, Kathryn Christine. "Consumer acceptance of nonwoven fabrics for apparel and accessory end-uses." 2009. http://www.lib.ncsu.edu/theses/available/etd-05152009-121131/unrestricted/etd.pdf.
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Tsai, Cheng-Ping, and 蔡政坪. "Optimization of the processing parameters for the needle punching nonwoven fabrics." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/jtmud8.
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碩士國立臺灣科技大學
高分子系
94
In this thesis polyester fiber and polypropylene fiber are adopted as the materials. The roller card, cross-lapper machine, and needle punching machine are used to manufacture the needle punching nonwoven fabrics. The characteristics are the tensile strength (longitudinal and transverse) and tear strength (longitudinal and transverse), and utilize the Taguchi experimental method in the thesis. These parameters include arrangement of needles in the needle board, the sort of fiber material, the amount of fiber feed, the swing speed of the cross-lapper machine, the conveyor speed of the cross-lapper machine, penetration depth, needling density, and the size of the needles. They are considered as the control factors, which can affect the results of the tensile strength and tear strength. The L18(21×37) orthogonal array together with the Analysis of Variance (ANOVA) approach are employed to find the significant parameters and the optimum process conditions. In the experiment, the maximum tensile strength and tear strength of the nonwoven fabrics, the better. Therefore the larger-the-better target characteristic is chosen. Grey relationship analysis combined with Taguchi experimental design method is applied to get the optimal processing parameter of multiple quality characteristics, and the five confirmation experiments are performed. The tensile strength and tear strength of the nonwoven fabrics in optimum conditions are corresponded with 95% confidence interval. This reveals that experiments are reproducible. Finally, the control factors are taken as the inputs of Artificial Neural Network (ANN) and the tensile strength and tear strength are taken as the outputs of ANN for implementing the prediction system of needle punching nonwoven fabrics. The percentage errors of prediction are all within 5%. This indicates that the prediction system constructed has precision forecast capability.
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Chang, Chun-Cheng, and 張畯棖. "Evaluation of Process and Bullet-resistant Properties of High Modulus Composite Woven Fabrics and Compound Nonwoven Fabrics." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/49408961359911017702.
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碩士逢甲大學
紡織工程所
95
The primary objective of body armor research is to develop a low cost, lightweight, wearable garment system with ballistic impact resistance. Non-penetration trauma caused by ballistic impact is a target of ballistic resistant performance. In the study, composite fabrics were fabricated by the hand lay-up procedure. The composite fabrics had 5 plies which are bonding with polyvinyl butyral resin. The composite fabrics were consisted of Kevlar woven fabrics and glass woven fabrics. The compound nonwoven fabrics were fabricated by laying the spread high performance filaments between two layers polyamide 6/low melted polyester web and were punched to form a sandwich structure. Impact resistance of composite fabrics and compound nonwoven fabrics were evaluated by falling weight impact test. Bullet resistance of composite fabrics and compound nonwoven fabrics were performed on shooting test of bullet apparatus. The function of composite fabrics is blunt bullet to promote the protection factor of bulletproof vest. The role of compound nonwoven fabrics is to decrease the indentation depth of ballistic impact caused by the transmission and dissipation of energy. Composite fabrics and compound nonwoven fabrics were combined with the commercial bulletproof vest to improve its ballistic resistant performance. Shooting test was performed according to standard of type Ⅱspecification in NIJ 0101.04. The results indicated that improved bulletproof vest had less weight and cost than raw bulletproof vest in similar ballistic resistance. The ballistic results showed that weight and cost of bulletproof vest of K5 composite woven fabrics+V400 compound nonwoven fabric+24-layer unidirectional fabrics were reduced to 18.3 % and 45 %. Besides, the bulletproof vest of K5 composite woven fabrics+V400 compound nonwoven fabric+20-layer unidirectional fabrics had much less weight and cost, and then it conformed to standard of type Ⅱspecification in NIJ 0101.04.
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Wang, Fang, and 王方. "A Study on Manufacturing of Roof Waterproofing Nonwoven Fabrics by Needle-Punching." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/60416352263898003919.
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Filiz, Selcuk. "Evaluating the potential use of highloft nonwoven fabrics for rain gutter applications." 2003. http://www.lib.ncsu.edu/theses/available/etd-08212003-170405/unrestricted/etd.pdf.
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張憲宏. "A Study on Evenness of Fiber Enntanglement of Needle-Punching Nonwoven Fabrics." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/59082421865052216374.
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碩士逢甲大學
紡織工程研究所
83
The evenness of needling distribution & fibers entanglement is the major factor to manufacture the high quality needle punched nonwoven fabrics. In the needle punching process, the unevenness of fiber entanglement will exhibit a contrasty mark on the nonwoven fabric. From the mechanical properties analysis, the uneven phenomena of fiber entanglement were caused by repeat needling at the same position. Those fabrics will have a inferior quality. In this study, we manufacture the needle punched nonwoven fabrics with 2 denier polyester staple fiber. According to the needle arrangement on needle board, we set stroke frequency feeding speed and delivering speed to analysis the influences on the needling distribution. we compared the optimization of the needling distribution by computer simulation with the needle punched pattern of the nonwoven fabrics, then we modified the program according to the deformation of fabrics which is affected by web drafting and punching in the needle punching process. From the results revealed, the needle punched pattern and the simulating pattern is accordable after modified and then the fabrics have a good quality and needling distribution.
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Yang, Zong-Zhe, and 楊宗哲. "Impact of Processing Parameters on the Electret Effect of Polypropylene Nonwoven Fabrics." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/u5xx2p.
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Yeh, Cheng-Wei, and 葉政瑋. "Fabrication and characterization of Novel Multifunctional Hybrid Materials for PET/PA6 Nonwoven Fabrics." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/79649796019101393169.
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碩士崑山科技大學
材料工程研究所
100
A series of some novel hybrid materials prepared via sol-gel process has been synthesized from methyltrimethoxysilane and titaninm-n-butoxide with heterocyclic thiazole azo dyes. The start material thiazole was synthesized from thiourea, acetophenone derivative and iodide to get the thiazole intermediate. The 4-phenyl thiazole regards as coupling component were coupled with p-methoxy aniline as diazo component at ice bath, to give the heterocyclic thiazole azo dyes. SiO2/TiO2/thiazole azo dyes hybrid materials were synthesized via sol-gel process with precursor system. Alternatively, the heterocyclic thiazole azo dyes processed with hydrolysis-condensation reaction by the constant ratio of vinyltriethoxysilane and methyltrimethoxysilane and titaninm-n-butoxide in appropriate proportion under catalyst. The structures of the SiO2/TiO2/ thiazole dye hybrid materials are characterized by FTIR, 29Si-NMR and energy-dispersive X-ray spectroscopy (EDS) analyses. Furthermore, the processed PET/PA6 Nonwoven were evaluated the morphology structure by scanning electron microscopy (SEM) analysis. From the SEM images are illustrated the sheet evenness coating layer on the PET/PA6 bi-component nonwoven to confirm the reaction of hybrid materials with PET/PA6 bi-component nonwoven. The washing fastness, evenness, water contact angle, air permeability, and weatherability were evaluated on PET/PA6 bi-component nonwoven dyed with the SiO2/TiO2/thiazole azo dyes hybrid materials. After modification with SiO2/TiO2/thiazole azo dyes hybrid materials, the processed PET/PA6 Nonwoven indicating improved weatherability and water repellent; dyeing and finishing were also able to be achieved in a single bath, thus lowering processing costs.
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Pan, Jiunn Anne, and 潘俊安. "Studies of the immobilized enzyme onto the nonwoven ( P.E./P.P./ Acrylic acid ) fabrics." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/38748401752352944525.
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Chen, Yen Ling, and 陳燕玲. "A Study of Fiber Arrangement on The Physical Properties of Thermal-Bonding Nonwoven Fabrics." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/72433124600243889728.
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Huang, Kuo Cheng, and 黃國健. "A Study of the Corona Discharge on the Electrostatic Voltage of PP Electret Nonwoven Fabrics." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/37968115861877898243.
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碩士逢甲大學
紡織工程學系
88
The research on air Filter has became a main topic in the world along with increasing atmospheric pollutions. At present，the electret filter in nonwoven form is one of the most effective filter for holding the micro particle. Accordingly，it is urgent for us more intensively in researching the manufacturing techniques of electret filter . This study deals with the researches of manufacturing the electret nonwoven fabrics by the corona discharge。The advantages of using corona discharge are simplicity of setup required，high speed of charging and low facility requirements. The parameters in this study，which are electric field intensity (decided by air gap , the distance between electrode barrel and corona wire，corona high voltage、distance between corona wires )，temperature (quench ) and discharging time。The experiments are carried out in case of non-spark discharge for investigating the optimal electric field intensity of pp nonwoven fabrics. Under the optimal electric field intensity condition, we evaluated the effect of temperature on the pp fabrics in the heating zone. After the evaluation，we inverstigated the quenching effect on the electrostatic potential of pp fabrics based on the same working condition. Controlling discharge condition plays an important role for corona discharge. The experimental results show that the optimal discharge conditions in the study are as follows : electric field intensity is 41 kV/m，under the condition of distance between electrode barrel and corona wire is 5 cm、the corona voltage is 15 kV , the distance between wires is 12 cm. This condition can not only achieve stable electrostatic voltage but also prevent ravage structure of nonwoven fabrics. Although high temperature can drive lots of electroons in primness、it is essential to adopt a quench processing because that the nonwoven fabric possess a high conductivity in heating state. This will helps the nonwoven fanric decrease electrostatic potential decay. Long discharging time of corona discharge increases electrons deposited in the surface of fabrics and electrostatic potential.
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Ko, Fang Kun, and 柯枋坤. "A Study on Manufacturing of Poison Gas-Resistant╱Fire- Resistant Nonwoven Fabrics and Its Physical Properties." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/94181064657519299171.
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Lou, Ching-Wen, and 樓靜文. "Fabrication and Electric Properties of the Ply Yarn and Its Fabrics Produced by Polypropylene Nonwoven Selvage." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/7954kb.
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Huang, Ding-Kuo, and 黃定國. "The Study Near-Infrared Ttransmittance Used in an On-Line Optical Transmission Inspection of Equipment Nonwoven Fabrics." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84179566671411069800.
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博士國立中央大學
機械工程學系
103
The purpose of this thesis study is to develop a method of optical transmission inspection of the basis weight on-line, by combining the modified least squares and optical processing technique. A near infrared light transmission inspection is applied production of equipment nonwoven fabrics to detect the basis weight and support the producing quality. Using least squares method, the parameter transfer equations of the piecewise polynomials functions between the measured voltage and the nonwoven basis weight are found. Supervised learning method is adopted to improve the producing capability. Obvious, the equations and supervised learning method is effective to improve measures the range, producing capability and support the producing quality. This process is developed to significantly target toward improving the mass quality analysis of the nonwoven material. The real-time scanning width piecewise least squares method and area-based strategy for determining based on the process quality of nonwoven manufacturing. To avoid the influence of ambient factors, the compensation controls device are adopted and successfully showed. Subsequently, the modified least squares method is used to obtain the suitable parameter transformation between the measured voltage and the nonwoven fabrics basis weight. The piecewise least squares method was obtained as the parameter transfer equation. We consider estimating and testing Cp with the presence of on-line basis weight measurement errors. To obtain the true process precision Cp are presented to practitioners for their factory applications. In this study, a NIR transmission-based inspection for the basis weight of to improve quality production process, to avoid production flaws and to reduce the production costs are the major issues of the manufacturing industry. The apparatus basically consists of a light emitter mounted parallel to a light receiver. The light is emitted from the light emitter. Residual light is received by the receiver after being transmitted through the nonwoven fabric. An equation acquired by using the Beer–Lambert law, the parameter transfer equations of the equation functions between the measured voltage and the nonwoven basis weight are found. Optical inspection techniques can be also used in which the optical modulated to find a modified equation, then obtain the non-woven basis weight inspected on-line and verified by quality capability of process. A modified equation that can be used to reduce the uniformity and decrease the basis weight density. The potential of an optical sensor with increased sensitivity the range for finding the equations, near infrared light detecting the basis weight for a nonwoven material, to predict quality capability of nonwoven fabrics. In the proposed algorithm the supervised learning for finding polynomials the equations between the measured voltage and the nonwoven basis weight are found, the error deviation inspection works online and accuracy prediction. The verification accuracy prediction has been conducted to illustrate the performance of the proposed inspection algorithm by a dynamic of experiments nonwoven fabrics.Parameter transfer equations, is adopted to improve the producing capability. It is shown that the capability index of process Cp is over 1.66 under 1000 testing samples when the supervised learning algorithm is used.
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Gahide, Severine. "Combination of hydroentanglement and foam bonding technologies for wood pulp and polyester fibers in wet lay nonwoven fabrics." 1999. http://www.lib.ncsu.edu/etd/public/etd-231510231992530/etd.pdf.
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Wright, T. M., C. M. Carr, Colin A. Grant, V. Lilladhar, and S. J. Russell. "Strength of hydroentangled fabrics manufactured from photo-irradiated poly para-phenylene terephthalamide (PPTA) fibres." 2014. http://hdl.handle.net/10454/7413.
Full textAbstract:
NoPhoto-irradiation of poly para-phenylene terephthalamide (PPTA) fibre is normally associated with deterioration of physical properties. Nonwoven fabrics produced from 100% photo-irradiated PPTA fibres might therefore be expected to yield fabrics with poorer mechanical properties compared to those produced from non-irradiated fibres. To test this hypothesis, the bursting strength of hydroentangled fabrics manufactured from photo-irradiated PPTA fibres was explored. Prior to fabric manufacture, virgin PPTA staple fibres were photo-irradiated under controlled lighting conditions (xenon short arc lamp with a luminous flux of 13,000 lm) for 0, 5, 10, 20, 40, 60 and 100 h. The photo-irradiated fibres were then hydroentangled to produce nonwoven fabrics. Photo-irradiation exposure of PPTA fibre up to 30 MJ m 2 was not found to be detrimental to fabric bursting strength and at irradiation energies of 5e10 MJ m 2 a small, but statistically significant increase in fabric bursting strength was observed compared to fabrics manufactured from non-irradiated fibre. This may be linked to a change in the surface and skin properties of the PPTA photo-irradiated fibres identified by atomic force microscopy (AFM) following photoirradiation.
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Xu, Zhan-Hong, and 徐展宏. "The Application of Compound Nonwoven Fabrics with Polyester Filament and Nylon Staple Fiber in the Cushion Layer of Bullet-proof Vest." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/rkvv4v.
Full textAbstract:
碩士逢甲大學
紡織工程所
91
Abstract The bulletproof vest was important for the protection of the human body. The index of bulletproof structure and property was non-penetrating damage caused by the hitting of bullet. The transmitting and dissipating of energy in high velocity impacting of the bullet decreased the indentation depth of bulletproof multi layers fabrics broken partially by impacting of bullet. The transmitting and dissipating of energy were also the basic conditions in the cushion materials. In this study, we laid the spread polyester filament on the pre-punching polyamide web with low melted polyester staple fibers to form sandwich structure by the covering of another web. After the bonding of needle punching and thermal calendar, we got the compound nonwoven fabrics. The original cushion material of the bulletproof vest was replaced with the compound nonwoven fabrics. We evaluated the buffer effect of the compound nonwoven fabrics in the bulletproof complex fabrics by the deformation of the backing material in the shooting test of bullet. We changed the content of low melted polyester staple fibers, needle punching density and the content of polyester filament to discuss the influences of these parameters on the buffer effect of the compound nonwoven fabrics in bulletproof complex fabrics. We further investigated the cushion effect with various laminated type and position of the compound nonwoven fabrics. We expected that the compound nonwoven fabrics were superior to original cushion material of bulletproof vest in butter effect. We further hoped to decrease the manufactured cost of bulletproof vest. The results show that the best process condition of the content of low melted polyester staple fibers was 30%, the best process condition of polyester filament fineness was 3000 deniers, the best process condition of the content of polyester filament was 500 g/m2, and the best process condition of the needle punching density was 300 needles/cm2. The results show that the improving of non-penetrating damage in human body was significant. The adaptable laminated type and position of the compound nonwoven fabrics in bulletproof complex fabrics could get the best butter effect. And the deformation of the backing material with the bulletproof complex fabrics in the shooting test of bullet was less than 1 cm.