||Structure and physical property of Cotton-crepe fabric under varied relative humidity
HTET HTET HTIKE
Japanese traditional cotton crepe fabrics (chijimi) were studied to find the fundamental relationship among crepe structure, highly twisted weft yarn and effect of environmental humidity. The objective is to find the most dominant parameter to fabricate new outerwear wearing under varied relative humidity environment. Using the twist level of weft yarn varies the tensile property of crepe fabric. First of all, the tensile load-extension curves of highly twisted yarns (1000T/m, above 2000T/m) were compared under 10?90% relative humidity (RH). The extensibility (EM) of highly twisted yarns are higher than that of low twisted one under all RH, and the difference increased at humidity levels exceeding 60% RH. Then a fabric was fabricated using yarn (2200T/m) for weft yarn. Extensibility of this fabric is 16 ? 26% at 49N/m in the humidity range of 10-90% RH. Secondly, to improve both extensibility and recovery, the piqu? cotton crepe fabrics, after special embossed finishing, were used to investigate the effect of piqu? and crinkly structure on tensile properties under varied RH and in water at 25°C. The crepe fabrics with piqu? had higher EM and residual strain values than the non-piqu? samples under all RH conditions. The EM value of fabric in weft direction is equivalent to that of outer knitted fabrics. Extensibility of piqu? fabric showed above 40% at high humidity but resilience was 20%. Additional pique increases the extensibility and maintains the recovery below 70%RH. The Moisture Management Tester (MMT) was used to analyze the moisture transportation in both vertical and horizontal direction of these piqu? cotton crepe fabrics. Wetting time was about 2sec and wetting rate is also higher compared to the cotton plain fabric without crinkle. Finally, three pairs of pajama pants were tailored from selected piqu? cotton crepe fabrics, and three long-term hospitalized patients wore the pants for 12 to 18 months. Fabric after wear-wash cycles retains the piqu? shape. The EM increased and bending and shear properties decreased, thus generating additional softness.