Fabric softness is one of the terms most often used by consumers to describe clothing comfort performance. Fabric softness has multiple meanings, which can be related to compression and/or to smoothness and flexibility of fabrics, depending on the fabrics being handled and their end-uses. the evaluation of comfort is often related to ambiguity and subjectivity which hinder the potential to be applied widely in the clothing industry.
Since Peirce first proposed to use low-stress mechanical properties to characterize fabric handle, a series of measurement apparatus and methods have been reported, such as flexometer and WIRA instrumentation tester ; however, these testers are only focused on the measurements of a single property of fabrics, which makes it difficult to evaluate fabric handle that is considered a comprehensive behavior induced by multiple physical natures. The most well-known modern system available for the standardized evaluation of fabric touch properties mainly includes Kawabata Evaluation System for Fabrics (KES-F) [10] and Fabric Assurance by Simple Testing (FAST) [11]. However, the two sets of general fabric handle systems mentioned above adopt multiple devices to test different physical–mechanical properties, and then synthesize the fabric mechanics indices obtained by each testing equipment to characterize the fabric touch properties. Although these two systems can measure different mechanical properties of fabrics, the separate testing methods are easy to cause measuring errors when a fabric is tested by different sensors and devices based on several samples, bringing obstacles to the comprehensive performance evaluation of fabrics. Moreover, the fabric touch properties are not the simple summary of the mechanical properties measured from different devices. The Fabric Touch Tester (FTT) is relatively new equipment manufactured by SDL ATLAS, developed in collaboration with a team of researchers at The Hong Kong Polytechnic University. This device is used to measure the fabric handle in less than five minutes per sample. The device also makes distinction between the active and passive primary and global comfort indices where the active measurement is always the sensorial touch with fingers on the fabric face or outside, while passive refers to the feel when wearing the fabric which is on the inside of the fabric sample. The prediction models of comfort indices were developed by the FTT manufacturer and they are not publicly available, though once sufficient tests have been done with the FTT, the model coefficients can be determined via statistical analysis as a linear model is used.
By simulating the movements of pulling, pressing, kneading and rubbing by hand, the performance tests of the fabric such as bend, compress, friction and stretch were realized, and the softness, stiffness, smoothness, looseness and tightness of the surface were obtained, and then the comprehensive style was evaluated. FTT measures skin touch properties by simulating hand touch fabric movements of tensile, compression, pinch, knead, measuring bending, compression, friction, tension, get the indices of softness, stiffness, smoothness, tightness, objectively evaluate the hand and touch feel of fabrics.