A SURVEY OF THE POSSIBILITIES OF APPLYING PROCESS CONTROL TO THE WOOLLEN CARD

The paper is introduced by a short discussion on the irregularities present in the output of the woollen card with particular reference to the periodic nature of some of them. Based on experimental work done in connection with the W.I.R.A./B.E.P. “Autocount,”∗ control loops at various places on the card are assessed, emphasizing practical aspects that may arise owing to the nature of the measuring and regulating units. The problem is treated in a manner similar to that adopted by other industries, and in this treatment it is necessary to introduce some aspects of process control analysis. Appendices are added discussing this matter and one aspect of the movement of fibres through a card.