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Development of the Weaving Machine and 3D Woven Spacer Fabric Structures for Lightweight Composites MaterialsBadawi, Said Sobhey 22 November 2007 (has links) (PDF)
The need for innovative lightweight materials are rapidly increased in the recent years, owing to their cost-effective, high-strength, environmentally-sound use of materials and process technologies, in addition to that they reduce the weight of a product. The characteristics of 3D-spacer fabrics as one of the most important lightweight materials in future are multifaceted not only owing to its extremely light materials, but also because of exceptionally high stiffness to weight ratio compared to other constructions. It is also one possible method for improving the properties of fabric-reinforced composites. It can enhance the through-the-thickness properties, such as shear strength, dimensional stability, damage, tolerance, and fracture toughness that are critical for many structural applications. Spacer fabric has been employed in high-technology applications because of its critical mechanical properties related to high tensile strength, tear strength and stiffness. Furthermore, its multidirectional structures allow with more reinforcement along the thickness direction leading to an increase in stiffness and strength properties. The fundamental aim of this thesis exists in the development of a new kind of woven spacer fabrics for the light weight composites materials, in an effort to weave spacer fabrics that can not be realized with the old technology which are mentioned above. Therefore, the work in brief focuses on two main goals: 1. Development of a new kind of spacer fabrics for composites in the lightweight constructions. 2. Development of special devices of a narrow weaving machine for standing the process of the new kind of spacer fabrics production. The slippage strength test had to be carried out for the floated warp yarns through the ground fabrics by using different elements of woven fabric structures variables represented in different fabric constructions, different weft densities and different repeats of constructions by using different materials. The importance of this test related to the backward-movement of the floated warp yarns which is the crucial stage in the weaving process of spacer fabrics during the backward-movement. The results of this test determine the required forces for the backward-movement, on the other side it is the best method to observe the behavior of structure elements during the backward movement. The results of the slippage strength had been statistically analyzed, and the weaving process for the spacer fabrics had been achieved. It was concluded that the best properties for the woven spacer fabrics and the optimum case for the weaving process on the test weaving machine had been achieved when the following items are realized: Development of the narrow weaving machine is closed in assisting operations, let-off and take-up and enhancement for take-up processes. Extra let-off and take-up devices must be constructed at the weaving machine. Extra let-off device has to be used for controlling the floated warp yarns of ground fabrics. On the other side, extra take-up and the developed take-up devices have to be used for controlling the woven spacer fabrics. The experimental results give fundamental knowledges for the next steps in research and development of woven spacer fabrics made of high-performance yarns on the wide weaving machine. / Die Ziele der Arbeit bestanden in der Entwicklung der Geometrie der Spacer Fabrics und der notwendigen Falteneinrichtung an der Bandwebmaschine. Spacer Fabrics werden ausschließlich aus zwei Deckflächen, die durch eingewebte Stege verbunden sind, gefertigt. Zur Entwicklung der Spacer Fabrics muss eine Doppelnadel-Bandwebmaschine mit zwei Webfächern eingesetzt werden. Für die Faltenwebeinrichtung werden der entwickelte Extra-Kettablass und der Extra-Abzug benötigt. Der Antrieb und die Steuerung des Extra-Abzuges erfolgen durch einen Synchronantrieb und der Antrieb und die Steuerung des Extra-Ablasses durch Pneumatik.Eine frei programmierbare Steuerung der Faltenwebeinrichtung ermöglicht eine sichere und optimierte Synchronisation zwischen Webprozess und Faltenbildung. Im Ergebnis einer systematischen Strukturentwicklung von Spacer Fabrics und der Simulation ihrer günstigen Herstellung mittles eines speziell entwickelten Slippage Strength Tests werden die optimalen Strukturen ermittelt. Die experimentellen Untersuchungen bringen grundlegende Erkenntnisse für die folgenden Forschungsschritte zur Entwicklung von gewebten Spacer Fabrics mit Hochleistungsgarnen auf Doppelgreiferwebmaschinen.
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Process development for the manufacturing of flat knitted innovative 3D spacer fabrics for high performance composite applicationsAbounaim, Md. 08 February 2011 (has links) (PDF)
Innovative 3D spacer fabrics made from individual planes and connecting layers present great potential as complexly shaped textile preforms in lightweight composite applications. As one of the most flexible textile manufacturing methods, flat knitting enables the production of intricately shaped textile structures. The major advantages coupled with flat knitting techniques include the ability to produce multi-layer reinforcements, a diminishing waste, reducing production time and near-net shaping. This research includes the further development of flat knitting technology and the manufacturing processes of innovative, customized 3D spacer fabrics for high performance composite applications. Novel 3D spacer fabrics have been developed in different geometries using glass-polypropylene commingled hybrid yarns for complex shaped thermoplastic composite components. Reinforcement yarns have been integrated into spacer fabric structures with up to 4 reinforcement layers to improve mechanical performance. Furthermore, the successful addition of “sensor networks” created by integrating functional yarns into the 3D spacer fabrics could be used for structural health monitoring. Innovative integration concepts, which accommodate different positioning of the reinforcement yarns into the knit structures, can be used to adjust the mechanical properties of the finished knit composites. Moreover, the tensile properties have been accurately predicted based on the mathematical models formulated. The developed flat knitted 3D spacer fabrics are very promising for applications in lightweight composites, mechanical engineering, protective textiles, civil engineering and architectural designs. / Innovative 3D-Spacer Fabrics bestehend aus individuellen Deckflächen und Verbindungsstegen bieten ein großes Potential als komplex geformte textile Halbzeuge für Leichtbauverbundwerkstoffanwendungen. Mit Hilfe des Flachstrickens, welches einer der flexibelsten textilen Herstellungsprozesse ist, lassen sich komplex geformte textile Strukturen herstellen. Belastungsgerechte Verstärkungen, Abfallreduzierung, endkonturnahe Fertigung sind nur einige der großen Vorteile der modernen Flachstricktechnik. Die Forschungsarbeit beinhaltet die Entwicklung der Flachstricktechnologie und des Herstellungsprozesses für innovative 3D-Spacer Fabrics für Hochleistungsverbundwerkstoffe. Neuartige 3D-Spacer Fabrics wurden in unterschiedlichen Geometrien entwickelt, in dem Glas-/ Polypropylen Commingling-Hybridgarn für komplex geformte thermoplastische Verbundwerkstoffkomponenten eingesetzt wird. Verstärkungsfäden wurden für hochmechanische Belastungen in die Spacer-Fabric-Strukturen in bis zu 4 Verstärkungschichten integriert. Die erfolgreiche Umsetzung und Entwicklung von Sensornetzwerken durch die Integration von funktionalen Fäden in die 3D-Spacer Fabrics kann für die strukturelle Zustandsüberwachung genutzt werden. Die innovativen Integrationskonzepte erlauben die differenzierte Orientierung von Verstärkungsfäden in den Gestrickstrukturen, wodurch eine starke Beeinflussung der mechanischen Eigenschaften der Gestrickverbundwerkstoffe herbeigeführt wird. Darüber hinaus wurden die Zugeigenschaften basierend auf den entwickelten mathematischen Modellen vorhergesagt. Die entwickelten flachgestrickten 3D-Spacer Fabrics sind sehr vielversprechend beispielweise für die Anwendung in Leichtbauverbundwerkstoffen, im Maschinenbau, in Schutztextilien, im Bauingenieurwesen und Architekturdesign.
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Development of the Weaving Machine and 3D Woven Spacer Fabric Structures for Lightweight Composites MaterialsBadawi, Said Sobhey 06 November 2007 (has links)
The need for innovative lightweight materials are rapidly increased in the recent years, owing to their cost-effective, high-strength, environmentally-sound use of materials and process technologies, in addition to that they reduce the weight of a product. The characteristics of 3D-spacer fabrics as one of the most important lightweight materials in future are multifaceted not only owing to its extremely light materials, but also because of exceptionally high stiffness to weight ratio compared to other constructions. It is also one possible method for improving the properties of fabric-reinforced composites. It can enhance the through-the-thickness properties, such as shear strength, dimensional stability, damage, tolerance, and fracture toughness that are critical for many structural applications. Spacer fabric has been employed in high-technology applications because of its critical mechanical properties related to high tensile strength, tear strength and stiffness. Furthermore, its multidirectional structures allow with more reinforcement along the thickness direction leading to an increase in stiffness and strength properties. The fundamental aim of this thesis exists in the development of a new kind of woven spacer fabrics for the light weight composites materials, in an effort to weave spacer fabrics that can not be realized with the old technology which are mentioned above. Therefore, the work in brief focuses on two main goals: 1. Development of a new kind of spacer fabrics for composites in the lightweight constructions. 2. Development of special devices of a narrow weaving machine for standing the process of the new kind of spacer fabrics production. The slippage strength test had to be carried out for the floated warp yarns through the ground fabrics by using different elements of woven fabric structures variables represented in different fabric constructions, different weft densities and different repeats of constructions by using different materials. The importance of this test related to the backward-movement of the floated warp yarns which is the crucial stage in the weaving process of spacer fabrics during the backward-movement. The results of this test determine the required forces for the backward-movement, on the other side it is the best method to observe the behavior of structure elements during the backward movement. The results of the slippage strength had been statistically analyzed, and the weaving process for the spacer fabrics had been achieved. It was concluded that the best properties for the woven spacer fabrics and the optimum case for the weaving process on the test weaving machine had been achieved when the following items are realized: Development of the narrow weaving machine is closed in assisting operations, let-off and take-up and enhancement for take-up processes. Extra let-off and take-up devices must be constructed at the weaving machine. Extra let-off device has to be used for controlling the floated warp yarns of ground fabrics. On the other side, extra take-up and the developed take-up devices have to be used for controlling the woven spacer fabrics. The experimental results give fundamental knowledges for the next steps in research and development of woven spacer fabrics made of high-performance yarns on the wide weaving machine. / Die Ziele der Arbeit bestanden in der Entwicklung der Geometrie der Spacer Fabrics und der notwendigen Falteneinrichtung an der Bandwebmaschine. Spacer Fabrics werden ausschließlich aus zwei Deckflächen, die durch eingewebte Stege verbunden sind, gefertigt. Zur Entwicklung der Spacer Fabrics muss eine Doppelnadel-Bandwebmaschine mit zwei Webfächern eingesetzt werden. Für die Faltenwebeinrichtung werden der entwickelte Extra-Kettablass und der Extra-Abzug benötigt. Der Antrieb und die Steuerung des Extra-Abzuges erfolgen durch einen Synchronantrieb und der Antrieb und die Steuerung des Extra-Ablasses durch Pneumatik.Eine frei programmierbare Steuerung der Faltenwebeinrichtung ermöglicht eine sichere und optimierte Synchronisation zwischen Webprozess und Faltenbildung. Im Ergebnis einer systematischen Strukturentwicklung von Spacer Fabrics und der Simulation ihrer günstigen Herstellung mittles eines speziell entwickelten Slippage Strength Tests werden die optimalen Strukturen ermittelt. Die experimentellen Untersuchungen bringen grundlegende Erkenntnisse für die folgenden Forschungsschritte zur Entwicklung von gewebten Spacer Fabrics mit Hochleistungsgarnen auf Doppelgreiferwebmaschinen.
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Process development for the manufacturing of flat knitted innovative 3D spacer fabrics for high performance composite applicationsAbounaim, Md. 01 February 2011 (has links)
Innovative 3D spacer fabrics made from individual planes and connecting layers present great potential as complexly shaped textile preforms in lightweight composite applications. As one of the most flexible textile manufacturing methods, flat knitting enables the production of intricately shaped textile structures. The major advantages coupled with flat knitting techniques include the ability to produce multi-layer reinforcements, a diminishing waste, reducing production time and near-net shaping. This research includes the further development of flat knitting technology and the manufacturing processes of innovative, customized 3D spacer fabrics for high performance composite applications. Novel 3D spacer fabrics have been developed in different geometries using glass-polypropylene commingled hybrid yarns for complex shaped thermoplastic composite components. Reinforcement yarns have been integrated into spacer fabric structures with up to 4 reinforcement layers to improve mechanical performance. Furthermore, the successful addition of “sensor networks” created by integrating functional yarns into the 3D spacer fabrics could be used for structural health monitoring. Innovative integration concepts, which accommodate different positioning of the reinforcement yarns into the knit structures, can be used to adjust the mechanical properties of the finished knit composites. Moreover, the tensile properties have been accurately predicted based on the mathematical models formulated. The developed flat knitted 3D spacer fabrics are very promising for applications in lightweight composites, mechanical engineering, protective textiles, civil engineering and architectural designs. / Innovative 3D-Spacer Fabrics bestehend aus individuellen Deckflächen und Verbindungsstegen bieten ein großes Potential als komplex geformte textile Halbzeuge für Leichtbauverbundwerkstoffanwendungen. Mit Hilfe des Flachstrickens, welches einer der flexibelsten textilen Herstellungsprozesse ist, lassen sich komplex geformte textile Strukturen herstellen. Belastungsgerechte Verstärkungen, Abfallreduzierung, endkonturnahe Fertigung sind nur einige der großen Vorteile der modernen Flachstricktechnik. Die Forschungsarbeit beinhaltet die Entwicklung der Flachstricktechnologie und des Herstellungsprozesses für innovative 3D-Spacer Fabrics für Hochleistungsverbundwerkstoffe. Neuartige 3D-Spacer Fabrics wurden in unterschiedlichen Geometrien entwickelt, in dem Glas-/ Polypropylen Commingling-Hybridgarn für komplex geformte thermoplastische Verbundwerkstoffkomponenten eingesetzt wird. Verstärkungsfäden wurden für hochmechanische Belastungen in die Spacer-Fabric-Strukturen in bis zu 4 Verstärkungschichten integriert. Die erfolgreiche Umsetzung und Entwicklung von Sensornetzwerken durch die Integration von funktionalen Fäden in die 3D-Spacer Fabrics kann für die strukturelle Zustandsüberwachung genutzt werden. Die innovativen Integrationskonzepte erlauben die differenzierte Orientierung von Verstärkungsfäden in den Gestrickstrukturen, wodurch eine starke Beeinflussung der mechanischen Eigenschaften der Gestrickverbundwerkstoffe herbeigeführt wird. Darüber hinaus wurden die Zugeigenschaften basierend auf den entwickelten mathematischen Modellen vorhergesagt. Die entwickelten flachgestrickten 3D-Spacer Fabrics sind sehr vielversprechend beispielweise für die Anwendung in Leichtbauverbundwerkstoffen, im Maschinenbau, in Schutztextilien, im Bauingenieurwesen und Architekturdesign.
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Flatstickad distanstextil : Formstickad 3D-struktur och fokus på vidhäftningsförmågan hos olika bindningar.Ewert, Mia, Ulfsson, Moa January 2018 (has links)
Sjöräddningssällskapet har sedan 1907 räddat liv genom frivilliga sjöräddare. De har en vision om att kunna effektivisera sina räddningsaktioner genom att skicka ut en drönare till olycksplatsen för att få en övergripande bild av händelsen och på så sätt kunna anpassa rätt utrustning och personal. Idén var att konstruera drönarens kropp i form av en textil 3D-struktur, detta skulle underlätta dess användning då den skulle bli flexibel och vid olycksplatsen kunna stuvas undan och förflyttas smidigare. Tanken är att drönaren ska ha en konstruktion som kan blåsas upp och bli styv för att sedan kunna tömmas på luft och bli flexibel. Syftet med denna studie är att ta fram en flatstickad distanstextil som ska fungera som en kropp till en drönare där förhoppningen är att den textila 3D-kroppen ska kunna formstickas som en vinge. I distanstextil skapas luftrum mellan lagren vilket möjliggör att en uppblåsbar konstruktion kan skapas. Genom att variera olika parametrar kan man även ta fram önskade egenskaper som styvhet, form, flexibilitet samt lättvikt. För att skapa en distanstextil som är styv i uppblåst läge krävs en beredning. Trikåvaror är generellt svåra att bereda, därför har studien undersökt olika trikåbindningars förmåga att vidhäfta mot beredningar. Den formstickade distansstrukturen i väfttrikå tillverkades på en flatstickmaskin, där formen skapades genom masköverhängningar. Genom att binda distanstråden på olika nålavstånd kunde ett ovalt tvärsnitt uppnås. För att undersöka olika bindningars förmåga att vidhäfta mot beredningar testades flatstickade 2D-prover. Bindningarna var slätstickning, pikévariant över 2 system, pikévariant över 4 system samt slätstickning med plätering. De olika beredningar som undersöktes var silikonbeläggning, polyuretanfilm, polyetenfilm tillsammans med polyuretanfilm samt en polypropenfilm. Syftet var att hitta en beredning som är lätt i vikt, luft- och vattentät. Ett vidhäftningstest utfördes på bindningarna slätstickning, pikévariant över 2 system samt pikévariant över 4 system med hjälp av en dragprovare för bestämning av de olika bindningarnas vidhäftning mot olika lamineringar. De tre bindningarna i kombination med laminering testades även för luft- och vattentäthet. Studien visar att det finns goda möjligheter att formsticka en flatstickad distanstextil som ska fungera som en kropp till en drönare. Resultatet visar att provkroppen som var stickad med pikévariant över två system samt laminerad med polyuretanfilmen gav bäst resultat vid utfört vidhäftningstest. Vid test av luftgenomsläpplighet visade pikévariant över två system med laminering av polyuretanfilm tillsammans med en polyetenfilm tätast resultat med låg luftgenomsläpplighet. Test för bestämning av vattentäthet visar att den slätstickade varan med en laminering med polyetenfilm och en polyuretanfilm gav bäst resultat. / Since 1907, the Swedish Sea Rescue Society has saved lives with the help of volunteer workers. Their vision is to be able to improve their rescue operations with quicker respond times by sending out a drone to the scene of an accident. The idea is to get a comprehensive picture of the scene, so they can adapt the right equipment and personnel for the job. The idea is to create a drone with a textile 3D structure, which would ease use as it would become flexible and easier to remove from the scene of the alarm. The drone should have a structure similar to a stand-up paddle board, where it can be inflatable and become stiff and then be deflated and folded and tucked away. The purpose of this study is to develop a flat knitted spacer fabric that will serve as a body of the drone, hoping that the textile 3D structure can be shaped like a wing. With spacer fabrics, space for air is created between the layers, enabling an inflatable construction to be created. By varying different parameters, one can also develop desired features such as stiffness, shape, flexibility and decrease weight. To be able to create a spacer fabric that is stiff when inflated, a finishing process is required. It is generally hard to find a finishing to a knitted fabric, therefore the study investigates the ability of different bindings on a knitted fabric to adhere to finishes. The shaped spacer fabric was manufactured by weft knitting on a flat knitting machine called Stoll CMS 822 HP. A wing shaped spacer and an oval cross section were achieved in this study. To investigate how the binding affects the adhesion of the finishing, three different bindings of flat knitted 2D- structures were tested. The bindings were: plain fabric (single jersey), pique structure over 2 feeders, pique structure over 4 feeders and plain fabric with plating. The finishing processes that were studied were silicone coating, a polyurethane film, a polyethylene film and a polypropylene film. The aim was to find a finishing with the properties of light weight, air and water tightness. An adhesion test was performed on the bindings plain fabric, pique structure over 2 feeders and pique structure over 4 feeders by a tensile tester to determine the adhesion between the tested bindings and finishes. These test specimens were also tested to determine resistance to water penetration and air permeability. The study shows that it is possible to create a shaped spacer fabric by flat knitting, that will act as the body of a drone. The result of the adhesion test shows that the test specimen with binding pique over 2 feeders and laminated with a polyurethane film performed the best. In the air permeability test the same binding showed the best result but with a lamination of a polyurethane film and a polyethylene film. The test to determine resistance to water penetration showed that the binding plain fabric was the best, with a lamination of a polyurethane film, and a polyethylene film.
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Silvering of three-dimensional polyethylene terephthalate textile material by means of wet-chemical processesOnggar, Toty, Abu Shayed, Mohammad, Hund, Rolf-Dieter, Cherif, Chokri 17 September 2019 (has links)
The aim of this research is to develop a wet-chemical silvering method for a three-dimensional (3D) textile material made of polyethylene terephthalate (PET) to prevent and eliminate biological contaminants in drinking water and other liquid-containing systems. Three-dimensional textile fabrics are particularly well-suited as silvered disinfection materials in water systems, because they have 3D structures, pressure-elastic textile design, and provide large contact areas. Furthermore, water can easily be passed through the structure. The developed wet-chemical procedures are based on aminosilane, which consists of at least two amine groups and is well-suited to form a silver diamine complex. The silvered textile material was coated with cationic silver. After the chemical reduction, the cationic silver turns into metallic silver on the surface of PET spacer fabrics.
The surface morphology of silver-coated spacer fabrics was analyzed and the uniform silver layer on the PET fiber surface was found. X-ray diffraction and energy-dispersive X-ray spectroscopy analysis spectrums showed that the silver was immobilized on the PET fiber surface. The layer thickness and the silver amount were also determined. The silvered spacer fabrics can be used in sealing and/or cooling water systems; therefore, the silver ion release in water was analyzed. Furthermore, textile physical tests for the measurement of breaking force and elongation were carried out. No significant change in breaking force and elongation was observed after silvering of PET spacer fabric.
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