Crimp Rigidity of a textured yarn gives a measure of its ability to recover from stretch. It is determined by measuring the percentage reduction of length of a skein of yarn immersed in water when a minor load replaces a major load.
For measuring crimp rigidity, a skein of known number of strands is prepared from the package of yarn under test. This skein is then immersed in water filled in a glass jar with a load of 0.1 g/denier/strand suspended on it. The length of the skein is measured on a scale. The load is then reduced to 0.002 g/denier/strand by replacing the major load by the minor load and the reading on the scale observed. Crimp rigidity is calculated from the readings obtained under the major and minor loads.