<p>Bauer-Kurz, Ina. Fiber Crimp and Crimp Stability in Nonwoven Fabric Processes. (Under the direction of Dr. William Oxenham and Dr. Donald A. Shiffler.)In nonwovens, crimp characteristics of synthetic fibers are, along with finish, major contributors to processing efficiency, web cohesion, fabric bulk and bulk stability. However, the meaning of measurable crimp parameters and their influence on processing and fabric characteristics has not been quantified. The purpose of this study is to quantify the mechanical fiber behavior during crimp removal, and relate it to fundamental fiber properties, nonwoven fabric properties, and processibility in nonwoven equipment.Single fiber tensile tests in the crimp removal region have been performed on various fibers with the Textechno FAVIMAT and have also been monitored optically. Based on empirical evidence, a basic understanding of the physical crimp removal mechanism is obtained. A methodology is developed, to identify the true crimp removal region of the whole single fiber load-extension curve during a tensile test. A mechanical model accounting for the nonlinear load-deflection behavior during crimp removal is developed. According to this model, a logarithmic function can be used to describe the material behavior in the crimp node during crimp removal. This function is fit to experimental data and delivers two fitting parameters that characterize the shape of the experimental load-extension curve in the crimp region.The extracted characteristic crimp parameters are being evaluated in terms of fiber material characteristics, such as fiber type, crimp processing settings and carding performance during nonwoven production. A dependence of the shape of the crimp removal curve on crimping settings during crimp production is established. The characteristic crimp parameters are also correlated to the sequence of processing stages during nonwoven production and cylinder speed during carding.<P>
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-20001109-183351 |
| Date | 10 November 2000 |
| Creators | Bauer-Kurz, Ina |
| Contributors | William Oxenham, Donald A. Shiffler, Jeffrey W. Eischen, Hawthorne Davis |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-20001109-183351 |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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