The Kawabata Evaluation System (KES) is used to make
objective measurements of hand properties. The KES instruments measure
mechanical properties that correspond to the fundamental deformation of fabrics
in hand manipulation. Five different tests can be performed using KES and the
main mechanical characteristics produced, are described below.
The Kawabata system of instruments, featured in the fabric
hand laboratory, measures properties of textile fabrics and predicts the
aesthetic qualities perceived by human touch. The Kawabata Evaluation System
(KES) includes five highly sensitive instruments that measure fabric bending,
shearing, tensile and compressive stiffness, as well as the smoothness and
frictional properties of a fabric surface. This evaluation can include
measurement of the transient heat transfer properties associated with the
sensation of coolness generated when fabrics contact the skin during wear. KES
provides a unique capability, not only to predict human response, but also to
provide an understanding of how the variables of fiber, yarn, fabric
construction and finish contribute to the perception of softness. A standard
specimen size of 20 x 20 cm is used in three replications. All measurements are
directional, except for compression, and are made in both the lengthwise
direction, and in the crosswise direction of the sample. Appropriate instrument
settings are used for the material being tested.
Scientifically designed protocols used to determine
subjective ratings or rankings of fabric softness are also conducted in the
laboratory. These studies analyze tactile response to the texture, softness,
and other hand properties of fabric materials. Human panel evaluations, used in
conjunction with the KES are useful for engineering desirable hand qualities
into textile materials.
The system was developed by a team lead by Professor
Kawabata in the department of polymer chemistry, Kyoto University Japan. The initial work started in 1968 and the system became commercially available in its present
form since 1978.
The system was originally aimed at the objective evaluation
of fabric hand, but the sensitivity and comprehensiveness of the tests offered
by the system led to its widespread application in other areas such as product,
process development process control.
Read
Full Article
The
authors are associated with Applied Chemistry Research Centre (Textile
Section), PCSIR Laboratories Complex, Off University Road, Karachi, Pakistan
