EXPERINECE WITH EVENNESS TESTERS.

With the development of a new generation of evenness testers for synthetic fiber laboratories, a number of improvements could be achieved and accordingly the application range of these instruments extended. In this paper, reference is made to experience obtained with the new evenness testing instruments in operation in synthetic fiber laboratories. The laboratory testing instruments taken into consideration provide the following information: diagram of the weight per unit length variations; irregularity U or coefficient of variation CV; spectrogram for the detection of periodic weight per unit length variation; and denier variations. It is concluded that new drawing-off systems have made possible the measurement of undrawn, partly drawn and elastomeric yarns. In this way, the manufactured yarn can be checked even at the first processing stage and faulty packages diagnosed.