PRINCIPLE OF MEASURING FABRIC STIFFNESS BY CLARK METHOD.

This paper outlines the way to measure the bending length of comparatively stiff fabrics by the Clark method, and presents the theoretical basis of this method. The authors derived the relation theoretically between the bending length and the hanging length of the specimen at the critical angle at which swing back occurs on the assumption that the test specimen is completely elastic. This theory is applicable to measure the bending length by the Clark Stiffness Tester, which correlates well to the 41. 5 degree cantilever method. But the Clark method gives approximately 10% smaller values than the 41. 5 degree cantilever method.