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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

COMBINATION OF HYDROENTANGLEMENT AND FOAM BONDING TECHNOLOGIES FORWOOD PULP AND POLYESTER FIBERS IN WET LAY NONWOVEN FABRICS

Gahide, Severine 23 February 1999 (has links)
<p>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. <P>
2

Model Based Conceptual Communication Design in Coordination Systems

Kuehnen, Stefan Alexander 06 April 2001 (has links)
<p>KUEHNEN, STEFAN ALEXANDER. Model Based Conceptual Communication Design in Coordination Systems (under the Direction of Dr. Padmini Srinivasan-Hands and Dr. Samuel C. Winchester)The purpose of this research has been to investigate the feasibility of developing a model-based method for conceptual communication design in coordination systems. Business process modeling methodologies are surveyed and the methodology of choice, Actionworkflow?, is presented. As the basis for method development Language/Action and Speech Act theories, underlying the Actionworkflow? methodology, are examined for potential concepts aiding the development of the method. Their history and surrounding philosophies are presented. Critique of the Actionworkflow? methodology is presented and discussed.The major focus of the research is the development of the model-based method to conceptually design communications in coordination systems. Its development, structure and components are presented and explained. The method is illustrated with a simple, everyday-life, application example. Applications of the method to examine web-based e-commerce sites are presented. It has been determined that the application for these environments is insightful. The examples discussed are ebay, an auction provider, e-trade, an on-line broker, and priceline.com, a purchasing service applying a unique process for the purchase of services and goods. Consequently the application of the method to establish the feasibility of designing coordination support systems for textile new product development is provided. Coordination model development and design of communications are discussed in parallel. Application results show that the method can successfully be used for conceptually designing coordination support systems, although practical issues have to be further investigated.Finally underlying assumptions are displayed and discussed, model validation provided, performance evaluation, as to the goals set forth for the research undertaken, and recommendations for future research provided. <P>
3

Exploration of Micromachines to Textiles: Monitoring Warp Tension and Breaks during the Formation of Woven Fabrics

Gahide, Severine Francoise 13 June 2001 (has links)
<p>MicroElectroMechanical Systems, or MEMS, is an emerging high technology that has proven to be very successful in several industries such as medical, automotive and ink jet industries. The technology philosophy is to integrate sensors, actuators and electronics onto a silicon substrate (polysilicon batch) to form as small as a square millimeter micromachine at low manufacturing cost. Such advantages prompted investigating the potential applications of MEMS in textiles.Initially, we identified possible applications of MEMS technology in spinning, weaving, knitting, fiber formation, nonwovens, testing and evaluation, and dyeing and finishing. Based on a perceived real need and large potential market for a successful device, it was decided to concentrate efforts into the development of a MEMS based detection device to monitor warp tension and end breaks in weaving. Thus replacing the abrasive and passive traditional drop wire with gentle and active device that has the potential to expand the markets for weavers. A macro prototype device (sensors, software and hardware) to monitor warp tension and break was designed and built. Descriptions of the device components along with weaving specifics are given. To demonstrate the benefits of the device, several experiments were conducted. The experiments along with their results are reported. The experiments include: Simultaneously monitor tension of eight individual warp ends in real time  Identify complex weave patterns through matching tension fingerprint with weave floats and intersections Detect yarn tension trends while weaving Quantify variations of warp tension across beam width Identify variations of warp tension at the warp sheet edges Monitor the behavior of the warp let-off mechanism Detect broken warp yarns Assess warp yarn damage caused by using drop wiresBased on the results of these experiments, it can be concluded that monitoring individual warp yarn tension could provide a useful mean for woven fabric producers as well as weaving machine manufacturers. From these findings, the micromachine, an array of piezoresistive sensors, was designed and built.<P>
4

The Effect of Anisotropy on In-Plane liquid Distribution in Nonwoven Fabrics

Konopka, Amy Elizabeth 25 September 2001 (has links)
<p>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.<P>
5

Abrasion Characteristics of Ring-Spun and Open-End Yarns

Jones, Jeremy 20 November 2001 (has links)
<p> Jones, Jeremy. Abrasion Characteristics of Ring-Spun and Open-End Yarns. (Under the direction of Dr. Pam Banks-Lee and Dr. William Oxenham.) In the early 1980s, widespread claims in the knitting industry suggesting that the use of open-end yarns significantly increased the wear of mechanical components, especially knitting needles. Since then, many studies have attempted to explain this phenomenon and have yielded widely varying results. A study was conducted to compare the yarn properties of open-end yarn to ring-spun yarn. Identical yarns of varying parameters including yarn type, yarn count, and twist multiple were produced from the same raw cotton stock to eliminate variability in raw material. These yarns were tested for abrasiveness on a Lawson-Hemphill CTT (Continuous Tension Transport) tester. The device passes the yarn over a wire and records the length of yarn required to sever the wire. For this study the CTT was encoded to abrade a fixed length of yarn over the wire. The wire was then observed with both a Hitcahi ESEM (Environmental Scanning Electron Microscope) and a digital imaging microscope. The resultant images were examined for attrition and the abrasion values were evaluated using statistical analysis. It was confirmed that an increase in yarn count corresponded to a decrease in abrasion. Twist multiple had a noticeable effect on abrasion although the trends between yarn types, and yarn counts were inconsistent. Open-end yarn abrasion values were only slightly greater than their ring-spun counterparts, contradicting the claims of the knitting industry.<P>
6

Synthesis, Characterization, Application, and Evaluation of Reactive Sizes for Cotton Warps

Hamilton, Todd K. 05 December 2001 (has links)
<p>The purpose of this research has been to investigate the weaving properties of cotton yarns treated with three newly developed reactive sizing agents. N-methlyocarbamoylethyl starch, N-methlyocarbamoylethyl starch + poly vinyl alcohol (PVA), and N-methlyocarbamoylethyl starch + PVA + melamine formaldehyde have been studied as durable, non-removable sizing agents. Extensive work has been conducted to accomplish the objectives of the current research. The experimental activities have included: developing new reactive sizes; spinning a range of cotton yarns with three levels of twist multiple; preparing and applying size solution; testing mechanical and physical characteristics of sized yarns to evaluate their weavability; evaluating the stability of the sizing agents in woven structures; and performing statistical analyses to investigate the effect of size type, twist level, and solid concentration in the size bath on several yarn properties. <P>
7

Economic Analysis of using MEMS technology for monitoring warp tension and breaks in weaving

Kobaner, Can 02 January 2002 (has links)
<p>Micro-electro-mechanical-systems (MEMS) comprise a range of technologies that enable the fabrication of micron-sized, solid state devices such as sensors and actuators. MEMS manufacturing technologies enable the development of many exciting micro-scale or micro miniaturized products. This paper presents a decision model for evaluating the potential cost/benefit of different applications of MEMS for textiles. The objective is to determine the feasibility of replacing current warp tension measurement methods with MEMS. In order to accomplish this goal, a literature survey was conducted to document the current economic models and cost justification issues as well as the fundamentals of MEMS. From this survey, decision methodologies were identified and a decision model was established. To establish this model, Microsoft Excel (version Excel 2000) spreadsheet was used as a tool. The results from this model have been used to analyze the feasibility of using MEMS technology in measuring warp tension for textile applications.Finally, conclusions and recommendations for future applications have been covered.<P>

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