A Continuous On-line Stress-strain Measurement for a Precise Prediction of Compacting Values in Finishing Treatment of Knitted Fabric

Bi-axial distortion of knitted fabric usually occurred in a dyeing process. It should be corrected by release the uneven residual stress before clothing process. Levelling machines are devices to stretch dyed fabric in transverse direction; and stabilize the fabric width. Distortion in longitudinal axial is further corrected by subsequent compacting process. Both of the stretching and compacting results are measured off-line and after the entire finishing process in current practices of dye-house. Rework is usually required when the overall fabric shrinking result fails to meet standards. Thus, technology on continuous on-line stress-strain measurement is urgently needed to predict a precise compacting value after levelling. Cost in the finishing process can be reduced if the rework cases are reduced. In the prediction of a compacting value, a row of sensitive stress-strain measuring devices is designed to measure the residual stress and elongation of the running fabric after the levelling process. An electro-mechanical magnifier is employed to enhance the stress-strain measurement. Young Modulus of the fabric is calculated from the measurement and used to predict a compacting value by a comparison with a standard modulus.