Academic literature on the topic 'Fillet fabric with in-laid yarn'

The production technology of reinforcement filler for new multifunctional polymer based composites with weft-knitted structure had been proposed. In such reinforcement filler high-strength carbon fibers (CFs) from PAN precursors (wefts) were laid in a knitted fabric as straight continuous yarns, so in such case these CFs were not twisted by knitting machine to form the loops. Various kinds of chemical and inorganic fibers can be used as base yarn in this case, in particular glass, aramid, carbon fibers from hydrate cellulose and etc. Properties of multifunctional polymer-based composite materials with weft-knitted fillers depend upon fiber composition, relative content of weft and base yarns, scheme filler stacking (1D, 2D and 3D composites). The electrical conductivity of weft-knitted fabrics shows the strong anisotropy along high-strength fibers in comparison with looped rows, depending on the direction of high-strength CFs (weft). Investigation of shielding properties of polymer based composites reinforced by carbon weft-knitted fabrics showed the possibility of using them as shielding materials with the ability to absorb electromagnetic radiation.

In this study, a kind of novel flexible foam-core sandwich composite was involved. The flexible foam-core sandwich composites were fabricated based on 3D warp-knitted spacer fabrics. The foam-core was filled in the spacer fabric by using a kind of modified hydrophilic polyurethane foam. In order to investigate the effect of spacer yarn inclination angle on the compression behaviors. A compression test was carried out. The compression stress-strain curve was used to analyze the effect of 3D warp-knitted spacer fabric spacer yarn arrangement. According to the experiment results, it indicates that the spacer yarn arrangement could influence the anti-compression capacity of the sandwich composites obviously. Therefore, the spacer yarn arrangement of 3D warp-knitted spacer fabrics can be changed to meet specific end-use requirement for foam-core sandwich composites.

A polytitanocarbosilane (20-30 mass%)-xylene solution was infiltrated into a porous laminated composite with 35-40 vol% Si-Ti-C-O fabric of 11 diameter fiber and 15-25 vol% mullite filler, and decomposed at 1000°C in an Ar atmosphere. This polymer impregnation and pyrolysis method was repeated 8 times to produce the composites of 76-82 % theoretical density. The yarn (662-765 filament / yarn), fabric and composite provided the following average strengths : 1240 MPa for the yarn; 768 MPa for the fabric; 117 MPa for the composite. The fracture probability of the yarn, fabric and composite was well fitted by the normal distribution function. The tensile strength of the composite was interpreted by the product of the effective fiber content, the Young's modulus of the fiber and elongation of the composite.

Inlay yarn and laid-in stitches as important technical knitting elements have been commonly applied in the structural design and pressure control of compression textiles for certain healthcare and therapeutic purposes. In this study, complex weft laid-in stitches design changed the configurations of the studied elastic hoses and exerted significant impact on tension properties and pressure performance. The elastic hoses with laid-in structure involving more tuck loops generated lower tensile energy and elastic hysteresis in stretch. The resulting interfacial pressure thus generated showed a significantly increasing trend and better linear relationship with the raising of tension ratios. The hoses with longer floated inlay yarn increased the fabric extensibility but reduced tensile recovery. The geometric and morphologic deformations in stitches structure may impact the loop densities and compressive forces, thus varying the interfacial pressure generated during stretching. Laplace's law verified the interactive relations among pressure, tension, and curvature radius; however, its accuracy in the evaluation of pressure magnitudes of compression textiles needs to be further studied.

Shear thickening fluids have been extensively utilized in composite laminate structures to enhance the impact resistance in the last decade. Despite the contribution of shear thickening fluids to the protective systems, the mechanism behind the energy absorption behavior of shear thickening fluids is not fully understood. In the present study, various configurations of composite laminates were prepared and these structures were investigated under low velocity stab conditions. Contrary to the common idea of shear thickening fluid impregnation for fabrics, shear thickening fluids were used in bulk form and by means of this, pure contribution of shear thickening behavior to the energy absorption was investigated. To hold the bulk shear thickening fluids in the composite laminates, Lantor Soric SF honeycomb layers were filled with shear thickening fluids and Twaron fabrics were plied in the structures as the reinforcement. As a result of this study, it is stated that shear thickening behavior is insufficient to effectively improve the energy absorption performance of composite laminates; however, shear thickening fluids are beneficial to fabric based composites because the inter-yarn friction of fabrics is enhanced using shear thickening fluids as an impregnation agent rather than a bulk form.

An increase in the application areas of textiles has resulted in the need for improved and additional properties and functions, which should be provided by polymers with different functionalities or the addition of particles to the fibers. In the framework of this study, microsized talc particle-filled polypropylene (PP) fibers and yarns were produced and the mechanical, physical and thermal properties of the fibers and yarns were analyzed with respect to production parameters. The main motivation of the selection of talc as the filler material is to improve the thermal shock resistance and decrease the shrinkage of PP fibers and yarns. As a result of experimentation, it was observed that an increase of talc ratio decreases the tensile strength of fibers and yarns. However, this reduction does not seem to be an obstacle to produce fabrics. Furthermore, the addition of microsized talc particles in PP yarns dramatically improved thermal shock resistance and helped to decrease the shrinkage of these yarns.

Traditional ply-based and zone-based models are limited in their ability to account for the fiber directions resulting from the forming of fabric-reinforced composite wind turbine blades. Compounding the problem is the presence of defects such as resin-rich pockets of the polymer matrix due to out-of-plane and in-plane waves resulting from the manufacturing process. As a result, blades are typically overdesigned, unnecessarily increasing weight and material costs. In the current research, a methodology is presented for simulating the manufacturing process for fabric-reinforced composite wind turbine blades using ABAQUS/Explicit. The methodology captures the evolution of the yarn directions during the forming process thereby allowing for a map of the fiber orientations throughout the blade. A hybrid approach using conventional beam and shell elements is used to model the various fabric layers. Using experimental shear, tensile, bending, and friction data to characterize the mechanical behavior of the fabric layers, the model captures in-plane yarn waviness and changes in the in-plane yarn orientations as they conform to the shape of the mold, as well as out-of-plane wave defects as a result of the manufacturing process. Subsequently, after the fabric layers have been laid into the mold and the final yarn orientations are known, the structural stiffness of the blade resulting from the resin-infused fabrics can be calculated. The methodology can thereby link the resulting bending and torsional stiffnesses of the blade back to the manufacturing process. This paper discusses the methodology for determining the material properties of the beam and shell elements in their final orientations in the cured composite to predict the structural stiffness of a wind turbine blade.

This experiment presents a study carried out on the electric charge passing textiles for heat production in compression weft-knitted composite fabrics used for medical purposes. The aim was to flourish compression support of knitted structure with integrated highly sensitive metal (silver) coated polyamide multifilament yarns and to evaluate its heat origination attributes after stretching in different levels as well as changes of the temperature during the time. A flat double needle-bed knitting machine was utilized to fabricate the selected specimens together with elastomeric inlay-yarn incorporated into the structure for compression generation and silver coated polyamide yarn laid as ground yarn in a plated structure for heat generation. Six different variants depending on the metal coated yarn amount used and the fabric structure along with two types of the conductive yarn linear density were fabricated for this research work. Scanning electron microscope (SEM) images were preoccupied to show the morphology of conductive yarn and thermal pictures were captured to study the evenness of the heat over the surface of composite fabrics depending on conductive yarn distribution in the pattern repeat. The temperature profile of fabricated composite fabrics and comparison of the heat generation by specimens after stretching in different levels was studied

Green composite made from ramie fabric and polypropylene (PP) is a kind of recyclable and environmental friendly material. Ramie fiber tows have relatively good mechanical properties comparing with other bast fibers, and hence the fabric woven by ramie yarn shows excellent in-plane mechanical behaviors. PP can be fully recovered and recycling used for its thermoplastic character. Ramie fabrics reinforced by PP have better shape formability and maintenance. In this paper, we proposed a plain weave in sample dobby loom, and reinforced four laid-layers together by PP particle through hot pressing. The mechanical behaviors of the ramie-PP composite were tested by MTS-810 Material Testing System in weft and warp directions separately which were essential parameters to the following topology optimization in finite element analysis (FEA) software. A body of eco-power automobile consisting of shell and chassis was original designed in Pro/E® Wildfire 5.0. For the chassis is the main bearing structure, it is an important part in the eco-power automobile body and was chosen to be topology optimized. Fiber volume fraction and structure optimization of the chassis model are evaluated and simulated to guide the material formation of manufacture progress.

The present investigation is connected to the field of medical textiles, which includes the development and application of composite fibers. The aim of the paper is the processing and investigation of polyamide 6 (PA6)–amber composite fibers. The use of amber filler for the preparation of a new type of polymer composite fiber is described in detail for the first time. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and granulometry testing were used to test the structure and the size of the prepared amber particles. The obtained amber particles were characterized by an average size of up to 3 µm and a regular shape. Fourier transform infrared (FTIR) spectroscopy investigations showed that amber in the dispersed state does not change its chemical structure and contains one of the active compounds—succinic acid. The effect of the amber filler inclusion on the melt-spinning routes of fully drawn yarns (FDY) and pre-oriented yarns (POY) was determined. Amber composite fibers general use is medical fabric (compression socks and tights); it is biocompatible with skin cells.

Дисертація присвячена проблемі створення текстильних матеріалів, які мають здатність при розтягуванні збільшуватися в напрямку, перпендикулярному до прикладених сил, за рахунок будови матеріалу, а не за рахунок використання пряжі та ниток з відповідними властивостями. Виявлено геометричні структури аукзетик-матеріалів, які можуть бути реалізованими в текстильних матеріалах, зокрема трикотажних структури основов’язаного трикотажу, які виявлятимуть аукзетик-властивості, та обрані переплетення, в яких можлива реалізація таких структур. Теоретично визначено основні технологічні умови в’язання та параметри структури основов’язаних трикотажних аукзетик-матеріалів. Встановлено фактори, які впливають на коефіцієнт Пуассона основов’язаного трикотажу утоково-філейного переплетення, отримано рівняння для його визначення, в якому за основу прийнято геометричні розміри чарунки. Експериментально підтверджено правомірність застосування отриманих аналітичних рішень при виробленні матеріалів з від’ємним коефіцієнтом Пуассона. Розроблено принципи утворення сітчастих структур з гексагональними отворами чарунок та їхнє видозмінення в процесі вироблення за рахунок введення високрозтяжної нитки у вигляді повздовжнього утоку. Отримано рівняння регресії, які адекватно (з ймовірністю 0,95) описують залежності параметрів структури, розмірів чарунок та фізико-механічних властивостей трикотажу від рапорту філейного переплетення та варіанту розташування утокової нитки в структурі. Удосконалено метод дослідження коефіцієнту Пуассона з метою використання для трикотажних сітчастих матеріалів з чарунками великого розміру та розроблено експрес-метод виявлення аукзетик-здатності матеріалів.
Диссертация посвящена проблеме создания текстильных материалов, которые обладают способностью при растяжении увеличиваться в направлении, перпендикулярном приложенным силам, за счет структуры материала, а не за счет использования пряжи и нитей с соответствующими свойствами. В работе заложены научные основы создания текстильних аукзетик-материалов. Выявлено геометрические структуры аукзетик-материалов, которые могут быть реализованы в текстильных материалах, в частности трикотажных. Решена главная научная проблема - определены структуры основовязаного трикотажа, имеющие аукзетик-свойства, и выбраны переплетения, в которых возможна реализация таких структур. Значительное внимание в работе уделено основовязаным аукзетик-структурам с видоизмененными гексагональными ячейками, для получения которых в структуру базового филейного переплетения в качестве продольного утка вводится высокоэластичная нить. Введенный высокоэластичный компонент влияет на геометрические параметры ячеек, которые в сочетании с собственными соотношениями размеров сторон определяют отрицательное значение коэффициента Пуассона такого трикотажа. Сформулированы условия формирования ячеек гексагональной формы в трикотаже филейного переплетения. Выполнено геометрическое моделирование петель филейного трикотажа, на основании которого получены формулы для расчета длины нити в петлях разных видов, которые учитывают значения диаметра нити, высоты петли и расстояние между двумя соседними петлями ряда. В работе представлен теоретический анализ особенностей структуры трикотажа уточно-филейного переплетения, при растягивании которых коэффициент Пуассона принимает отрицательное значение. Обосновано взаимодействия уточных и грунтовых нитей в структуре филейного трикотажа в зависимости от технологических условий: взаимного расположения на машине уточных и грунтовых гребенок, их проборок, величины и направления сдвига за спинками игл. На основе математической обработки результатов исследования параметров структуры, размеров ячеек и физико-механических свойств разработанных основовязаных полотен получены уравнения регрессии, которые адекватно (с вероятностью 0,95) описывают зависимости исследуемых показателей от рапорта филейного переплетения и варианта расположения уточной нити в структуре. Основным технологическим фактором, определяющим аукзетик-свойства основовязаного трикотажа уточно-филейного переплетения, является относительное удлинение эластомерной нити перед входом в зону вязания. Предложена математическая зависимость для определения параметра, которая учитывает рапорт переплетения и размеры петель. В результате аналитических преобразований получено уравнение для определения коэффициента Пуассона основовязаных сетчастых структур, в котором за основу приняты геометрические размеры ячейки. Экспериментально подтверждена правомерность применения полученных аналитических решений при изготовлении материалов с отрицательным коэффициентом Пуассона. На основании корреляционного анализа результатов эксперимента выявлена зависимость коэффициента Пуассона аукзетик-трикотажа с видоизмененными гексагональными ячейками от таких соотношений размеров ячейки: отношение шага ячейки по вертикали к шагу ячейки по горизонтали, отношение шага ячейки по вертикали к высоте вертикальной стороны и тангенс угла наклона диагональной стороны ячейки к горизонтали. В процессе исследования размеров элементарных ячеек трикотажа, полученного чередованием в рапорте рядов трико и атласа, и аналитического расчета их соотношений показано, что лучшие аукзетик свойства достигаются в случае, когда уточная нить располагается поочередно, то на лицевой, то на изнаночной стороне трикотажа. У трикотажа, полученного чередованием в раппорте рядов трико и цепочки, лучшие аукзетик свойства достигаются в случае, когда уточная нить обвивает протяжки петель трико только одной системы нитей в одном или двух рядах. Кроме того, в результате исследований установлено, что абсолютное значение коэффициента Пуассона возрастает с увеличением количества как рядов трико, так и рядов цепочки в рапорте грунтового переплетения. В работе предложен экспресс-метод предварительной оценки аукзетик-свойств материалов и усовершенствован метод исследования коэффициента Пуассона с целью использования для трикотажных сетчатых материалов с ячейками большого размера. Разработаны технологические рекомендации для производства основовязаных аукзетик-материалов, способствующие расширению ассортимента и функциональных свойств текстильных материалов и обеспечивающие получение конкурентной продукции.
Doctoral dissertation devoted to the formation of textile materials, which became wider when stretched due to the structure of the material but not through the use of yarn with appropriate ability. Based on the method of system analysis and on the theoretical hypotheses, the geometric structures of auxetic materials, which can be implemented in the textiles, particularly in knitted materials, have been revealed. The main task - the creation of the warp knitted structures with auxetic-properties was solved and the selection of interlooping, which such structures can be realized in, was made. Main consideration is concentrate on the warp-knit auxetic structures with reentrant hexagonal cells. The basic principles of hexagonal cells' formation in warp knitted structures have been formulated as a result of the theoretical analysis of geometrical models of fillet interlooping. To achieve auxetic property, it is required to employ a high elastic yarn in the base structure. Introduced elastomeric component affects the geometric parameters of the cell, which in combination with ribs' length ratio define a negative value of the Poisson ratio. the length of the cell ribs is changed by the interlooping repeat (quantity of tricot and chain courses), and the angle of rib's inclination to the horizontal section is changed by the pre-tension of the elastomeric yarn and by its positioning in the structure. Analytical dependence for calculation the prior stretching of the elastomeric yarn has been obtained as a result of the geometrical modeling of auxetic warp knit structure. The equation to determine the Poisson's Ratio of warp net structures on the geometric dimensions of the cell has been determined as a result of analytical transformations, The dependencies of structural parameters, cell's size and mechanical properties of auxetic warp knit structure on the interlooping repeat and on the positioning of elastomeric yarn in the structure have been defined as result of mathematical processing of the experimental data. The method of Poisson's ratio test was improved for the purpose of testing of the mesh with large cells and the rapid method for identifying auxetic abilities of textiles was developed.

Surface water treatment plants in Trinidad are incapable of filtering highly turbid water. Water treatment operations are shut down whenever turbidity levels rise during or after rainfall. The aim of this research is to determine the physical properties of linen, burlap, crepe-backed satin and cotton fabrics and to compare their efficiencies as filter media for reducing turbidity in water. Scanning electron microscopy was used to generate images of each fabric. Fabric weave type was determined. Inter-yarn pore sizes, inter-fiber pore sizes, warp and weft spacings, warp and weft diameters and thicknesses were measured using ImageJ. Based on the properties examined, and execution of cross-flow filtration and perpendicular filtration tests, linen was the chosen fabric filter medium. Surface profilometry resulted in linen having the roughest surface of 685.5µm and the largest maximum profile height of 3632.4µm. Linen’s inter-yarn and inter-fiber pore sizes were 41.98µm and 22.37µm respectively. This fabric had warp and weft spacings of 400µm and 700µm respectively and was 400.39µm thick. Measurements also revealed warp and weft diameters of 13.26µm and 14.96µm respectively. Linen had a high tensile strength of 402N. Linen, had a hopsack plain weave and was tightly woven; it was 95.16% porous with a sediment retention capacity of 71%. Linen is a fabric material that could prove to be a very good filter medium. Also, Acono River water turbidity levels measured ranged from 2.47NTU to 23.93NTU. Soil types contained in the turbid water were gravels, sand and silt varying from 25mm to 0.075mm in size.

Fabric reinforced or textile composites are increasingly used in aerospace, automotive, naval and other applications. They are convenient material forms providing adequate stiffness and strength in many structures. In such applications they are subjected to three-dimensional states of stress coupled with hydro-thermal effects. Assuming that a composite material is a complex structure it is obvious that is hard to describe all its properties in terms of its parts properties. The properties of the composite depend not only on the properties of the components but on quality and nature of the interface between the components and its properties. As reinforcement two types of fiber fabric were used; first one is a simple type fabric of untwisted tows of carbon filaments while the second one is also simple type but as yarn and fill are used alternately untwisted tows of carbon and aramide filaments. There were some problems to be solved before molding: fabric stability during handling, cutting, imbuing the carbon and aramide tows are slipping one on each other leading to fabric defects; generally the epoxy systems do not adhere to the carbon fiber; in order to obtain a valuable material the nature of interface must be the same for polymer-carbon fiber and polymer aramide fiber. In order to solve these problems the two fabrics were covered (by spraying) with a thin film of PNB rubber. Into the rubber solution were also dispersed small amounts of clay (to create a better interface) and carbon black (to improve the electrical conductivity). The rubber presence solves the fabric stability problem; ensures the same type of interface between fibers and polymer matrix; ensures a more elastic interface between fibers and polymer matrix. This treatment induces modification on tensile behavior of fabrics. This study is about mechanical evaluation of such fabrics.

Abstract This paper presents a numerical tool for the design of the composites structures that allows to predict the mechanical behaviour of woven fabric composites, both in terms of global stiffness and damage process, and therefore to optimise the components dimensions and weight. Starting from an accurate study of the mesostructure of the material, finite element models are developed. To reduce the computational effort, a submodeling technique was used by employing two separate meshes: global and local meshes. Two idealised configurations are examined: they have a circular warp and fill yarn path and a lenticular cross-section. The mechanical response is estimated in terms of global stiffness and stress-strain curves of plain weave composites by simulating the damage process. The agreement between the FE global stiffness and experimental and analytical data is good. The FE results are very sensitive to the curvature of the yarns. Similar results were obtained for the FE stress-strain curves.

Abstract The hydrodynamic behavior of a plane fabric filter was investigated. The emphasis was put on the influence of cloth weave onto flow structure downstream from the filtering media. Experiments were performed on a 50:1 scaled-up glass model of a 3-ply twill textile sample used in water treatment applications. Air was used as working fluid. The Reynolds similarity criterion was applied to design the experimental facility used throughout this work. This entailed a mean flow velocity of 0.07 m/s. Particle Image Velocimetry (PIV) was used to observe and analyze the flow structure past inter-yarn pore models of various shape. Comparisons of mean velocity profiles upstream and downstream from the model were made to determine the distance over which wake effects remain noticeable case depending.

This paper examines the tensile behavior of SiC/SiC fabric composites. In the characterization effort, the stress-strain relation and damage evolution are studied with a series of loading and unloading tensile test experiments. The stress-strain relation is linear in response to the initial loading and becomes nonlinear when loading exceeds the proportional limit. Transverse cracking has been observed to be a dominant damage mode governing the nonlinear deformation. The damage is initiated at the inter-tow pores where fiber yarns cross over each other. In the modeling work, the analysis is based upon a fiber bundle model, in which fiber undulation in the warp and fill directions and gaps among fiber yarns have been taken into account. Two limiting cases of fabric stacking arrangements are studied. Closed form solutions are obtained for the composite stiffness and Poisson’s ratio. Transverse cracking in the composite is discussed by applying a constant failure strain criterion.

The principal sources of chlorine in the MSW feed to WTE power plants are food wastes (e.g., wheat, green vegetables, melon, pineapple), yard wastes (leaves, grass, etc.), salt (NaCl), and chlorinated plastics (mostly polyvinyl chloride). Chlorine has important impacts on the WTE operation in terms of higher corrosion rate than in coal-fired power plants, formation of hydrochloric gas that must be controlled in the stack gas to less than the U.S. EPA standard (29 ppm by volume), and potential for formation of dioxins and furans. Past Columbia studies have shown that the chlorine content in MSW is in the order of 0.5%. In comparison, chlorine concentration in coal is about 0.1%; this results in much lower HCl concentration in the combustion gases and allows coal-fired power plants to be operated at higher superheater tube temperatures and thus higher thermal efficiencies. Most of the chlorine output from a WTE is in the fly ash collected in the fabric filter baghouse of the Air Pollution Control system. This study examined in detail the sources and sinks of chlorine in a WTE unit. It is concluded that on the average MSW contains about 0.5% chlorine, which results in hydrogen chloride concentration in the WTE combustion gases of up to 600 parts per million by volume. About 45% of the chlorine content in MSW derives from chlorinated plastics, mainly polyvinyl chloride (PVC), and 55% from salt (NaCl) and chlorine-containing food and yard wastes. An estimated 97–98% of the chlorine input is converted to calcium chloride in the dry scrubber of the Air Pollution Control (APC) system and captured in the fly ash collected in the baghouse; the remainder is in the stack gas at a concentration that is one half of the U.S. EPA standard. Reducing the input of PVC in the MSW stream would have no effect on dioxin formation but would reduce the corrosion rate in the WTE boiler.