Nuevas perspectivas sobre la evaluación del cayente de los tejidos de calada

Resumen

Drape indicators reported by textile researchers from 1950 to 2013 are examined. A total of 36 indicators were identified that are described in detail as regards geometric principle and calculation in order to unify existing designations for drape-related parameters. Also, two drape assessment techniques based on a digital version of the Cusick drape meter and a simplified version of the ring test were developed. A digital Cusick drape meter was used to determine the 36 indicators in a sample of 37 commercial woven fabrics spanning a wide range of composition, weave type and aerial weight. Correlation analyses allowed seven of the indicators to be selected. Principal component analysis exposed three common factors accounting for drape intensity, drape severity, and drape symmetry and shape variability, respectively. The results were also examined in graphical form by using cluster analysis in parallel. Finally, a criterion for distinguishing drape shape in fabrics with an identical drop ratio (%DR) in terms of four sequentially determined selected indicators was developed and experimentally validated. An additional set of 15 commercial drapery fabrics of variable composition, weave type and aerial weight was used to determine the seven selected drape indicators and 4 parameters of the UPC ring test. The results were subjected to canonical correlation analysis. A regression equation relating %DR to parameter h in the ring test was established. The test proved an effective tool for routine industrial control of drape in variously finished drapery fabrics. Another set of 42 commercial woven fabrics of variable composition, weave type and aerial weight was studied with both FAST equipment and the proposed ring method. Based on the results, formability, bending rigidity, and maximum extraction force and the time needed to reach it, are the four parameters best correlating the two methods. Regression equations relating the main FAST and ring test parameters were established via canonical correlations. The proposed ring method allows the simple, economical determination of fabric formability, which was only possible with FAST equipment before. A sample of 37 commercial woven fabrics also differing in composition, weave type and aerial weight was assessed by using the Kawabata (KES-F) system and the proposed (UPC ring) method. The KES-F parameters LT, WT, EMT B and 2HB were the most highly correlated with the parameters of the UPC ring method. Regression equations relating the major parameters of the two methods were established via canonical correlations. Finally, a woven fabric consisting of 100% PES was subjected to a silk-like finishing treatment at a pilot plant. An experimental plan involving 2 factors (soda concentration and vaporization time) at 3 different levels was used to assess the influence of process variables on fabric drape and hand, as well as to relate weight loss to specific properties of the finished fabric. Fabric weight loss exhibited statistically significant relationships with finishing process variables. Although the vaporization time influenced none of the studied drape indicators, it interacted significantly with the soda concentration -which affected three of the five indicators studied- in some cases.