SATRA STD 119 Wrinkleometer
This is mainly used to assess the tendency of upper materials to form pleats or wrinkles where 'shortening' occurs during the lasting operation, especially around the toe and seat areas.
It is particularly useful for testing synthetic upper materials which are prone to this problem.
A strip of upper material is held between two clamps. They are brought together by a predetermined amount to correspond to the shortening. A perspex bar is then pressed down and the material can be checked for folds or wrinkles. The degree of shortening is increased progressively until unacceptable wrinkles occur.