Vliv anizotropie ohybové tuhosti na splývavost tkanin
Title Alternative:The Effect of Anisotropy Bending Stiffness of Fabric no their Drape
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Date
2012-01-01
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Technická Univerzita v Liberci
Abstract
Tato práce je zaměřena na zkoumání vlivu anizotropie ohybové tuhosti textilií na jejich splývavost. V teoretické části jsou představeny pojmy ohybová tuhost a splývavost s nejběžnějšími metodami a principy jejich měření. Zmapován byl dosavadní výzkum v oblasti ohybových a anizotropních vlastností textilií. V praktické části byla zkoumána ohybová tuhost a splývavost tkanin, které poskytla společnost Velveta a.s. Měření ohybové tuhosti kruhových vzorků bylo provedeno pomocí přístroje TH-7. Byl vyhodnocen stupeň anizotropie ohybové tuhosti v závislosti na dvou hlavních směrech, osnovy a útku, dále podle Cooperova teoretického modelu byl zahrnut i třetí diagonální směr. Splývavost byla naměřena na Cusickově drapemetru, doplněném o digitální fotoaparát pro zachycení profilu splývajícího vzorku. V počítači byly 2D obrazy upraveny a naměřeny splývající délky v třiceti-šesti různých směrech. Pro srovnání ohybové tuhosti a splývavosti byly vytvořeny polární diagramy, ze kterých byly spočteny plochy a obvody. Pomocí lineární regrese pak byly nalezeny vztahy mezi jednotlivými hodnotami ohybové tuhosti a splývavosti. Byla nalezena přímá závislost mezi ohybovou tuhostí a splývavými délkami. Prověřovalo se, zda je nutné mít pro měření na drapemeteru vždy jiný vzorek nebo zda lze měření provést opakovaně na jednom vzorku. Pomocí statistických výpočtů a grafického zobrazení se neprokázal významný rozdíl. Dále byl vypočten tvarový faktor pro ohybovou tuhost a splývavost. Tvarový faktor se ukázal s koeficientem splývavosti vysoce korelovaný, mohl by proto být dobrým predikátorem koeficientu splývavosti.
This thesis is focused on analyzing the effect of bending stiffness of fabrics on their drape. In the theoretical part, concepts of bending stiffness and fabric drape profile are introduced. The most common experimental methods for their experimental determination are presented. The state-of-the-art in the field of bending stiffness anisotropy research is presented. In the experimental part, there are presented results of the bending stiffness and drape profile measurements carried on fabrics produced by Velveta Co. Bending stiffness measurements of circular samples were measured on TH-7 device. The anisotropy in the stiffness bending along two main directions of the warp and weft were measured. The anisotropy degree was then evaluated. In addition, the third bias direction was considered according to the theoretical model by Cooper. The fabric drape profile was measured using Cusick drapemeter, which was supplemented by a digital camera in order to capture the profile of the fabric sample. The two-dimensional images were processed using PC and the drape profile lengths were measured for 36 different directions. In order to compare the bending stiffness and drape profile length values, the polar diagrams were created. Their areas and circumferences were calculated. The relations between bending stiffness and the drape profile length values were expressed using the linear regression method. The linear relation between the bending stiffness and the drape profile lengths was identified. It was checked, whether it is necessary to measure several different samples on a drapemeter or whether several measurements carried out on a single sample are still acceptable. Results of statistical calculations and a graphical analysis indicated that there is not any significant difference between the two aforementioned experimental procedures. Finally, shape factor for the bending stiffness and the drape profile coefficient were calculated. It was found that the shape factor is highly correlated with the drape profile coefficient and, thus, it offers a useful tool for the prediction of the drape coefficient.
This thesis is focused on analyzing the effect of bending stiffness of fabrics on their drape. In the theoretical part, concepts of bending stiffness and fabric drape profile are introduced. The most common experimental methods for their experimental determination are presented. The state-of-the-art in the field of bending stiffness anisotropy research is presented. In the experimental part, there are presented results of the bending stiffness and drape profile measurements carried on fabrics produced by Velveta Co. Bending stiffness measurements of circular samples were measured on TH-7 device. The anisotropy in the stiffness bending along two main directions of the warp and weft were measured. The anisotropy degree was then evaluated. In addition, the third bias direction was considered according to the theoretical model by Cooper. The fabric drape profile was measured using Cusick drapemeter, which was supplemented by a digital camera in order to capture the profile of the fabric sample. The two-dimensional images were processed using PC and the drape profile lengths were measured for 36 different directions. In order to compare the bending stiffness and drape profile length values, the polar diagrams were created. Their areas and circumferences were calculated. The relations between bending stiffness and the drape profile length values were expressed using the linear regression method. The linear relation between the bending stiffness and the drape profile lengths was identified. It was checked, whether it is necessary to measure several different samples on a drapemeter or whether several measurements carried out on a single sample are still acceptable. Results of statistical calculations and a graphical analysis indicated that there is not any significant difference between the two aforementioned experimental procedures. Finally, shape factor for the bending stiffness and the drape profile coefficient were calculated. It was found that the shape factor is highly correlated with the drape profile coefficient and, thus, it offers a useful tool for the prediction of the drape coefficient.
Description
katedra: KHT; přílohy: 1 CD; rozsah: 83 s.
Subject(s)
anizotropie, ohyb, ohybová tuhost, splývavost, predikce, tkanina, anisotropy, bending, bending stiffness, drape, prediction, fabrics