Subjective and Objective Measurement of Fabric Hand

Fabric hand attributes can be obtained through subjective assessment or objective measurements. Subjective assessment is the traditional method of describing fabric handle based on the experience and variable sensitivity of human beings. Textiles are touched, squeezed, rubbed or otherwise handled to obtain information about physical parameters. The subjective assessment can also be described as a psychological reaction from the sense of touch, as the tactile sensitivity of people varies according to age, skin hydration, cultural aspects or gender of the test person. In the clothing industry professional trained handle experts sort out the fabric qualities.

Objective assessment has a different primary goal: it is to predict fabric hand by testing relationships between sensory reactions and instrumental data. In 1930 Peirce described first a way of measuring some fabric mechanical properties related to fabric drape and fabric hand. Lindberg and Dahlberg later established the relationship of properties and garment appearance in 1961. The KES-F system (Kawabata hand evaluation system for fabrics) was developed in Japan by the Hand Evaluation and Standardization Committee (HESC, established in 1972) organized by Professor Kawabata. In this fabric objective measurement method scientific principles are applied to the instrumental measurement and interpretation of fabric low stress mechanical and surface properties such as fabric extension, shear, bending, compression, surface friction and roughness. The fabric handle is calculated from measurements of these properties. Since then, it has been widely used in the studies of fabric mechanical properties. In parallel Postle conducted research on fabric handle and methods of linking the fabric objective measurements with the subjective assessments.

SiroFAST (Fabric Assurance by Simple Testing) is the most recently developed integrated set of instruments and test methods available for fabric objective measurement. SiroFAST measures the mechanical and dimensional properties of fabric that can be used to predict performance in garment manufacture and the appearance of the garments in wear. SiroFAST was developed in Australia by the CSIRO Division of Wool Technology to meet industry's need for a simple, reliable method of predicting fabric performance. Despite SiroFAST simple appearance, it is based on considerable research into the relationships between measured fabric properties and fabric performance.

Fabric objective measurement, in particular SiroFAST, is currently being used by fabric and garment manufacturers in many pans of the world in a wide variety of applications. The difference between tactile properties and objective measurement of mechanical properties was connected quantitatively by a number of statistical techniques. These studies conducted in Japan and Australia had led to an important step towards handle standardization.

Today's most exact devices, the Kawabata Evaluation System (KES) and the Fabric assurance by simple Testing (FAST) method, both systems measure similar parameters using different instrumental methods. Additional techniques consist of the ring or slot tester, which tests are less accurate but faster and cheaper to handle. However, although objective assessments are precise from a mechanical point of view, these methods have not been commonly used in the textile and clothing industry. Even today many companies still use subjective evaluation to assess fabric properties. The main reason for this situation is the repetitious and lengthy process of measurement and the lack of knowledge for a good interpretation of the test results.

Now let us have a look at the various fabric properties.

The Properties of Fabrics

The properties of fabrics can be loosely described as either functional or aesthetic.

• Functional properties relate to the failure (normally mechanical) of the fibers or yams that make up the fabric during use.
• Aesthetic properties are the most highly subjective and complex features of fabrics. They include appearance and handle, and involve visual or tactile aspects of the fabric, rather than simply the nature of fabric, yarns or fibers.