Fibre Dynamics in a Revolving-flats Card: An Assessment of Changes in the State of Fibre Mass during the Early Stages of the Carding Process

A study is made of the changes in the state of fibre mass fed to the taker-in and transferred to the cylinder during the operation of a revolving-flats card. On the basis of the results of experimental work, an estimate is made of the actual draft at the taker-in/cylinder transfer region. The results confirm that extensive opening to the point of single fibres takes place at the taker-in stage but that there are still many tuftlets present in the fibre mass transferred to the cylinder. Image analysis of high-speed video photographs show that these tuftlets were elongated and orientated by a small draft at the taker-in/cylinder transfer region. It is found that each rear fixed fiat contributes to the breakdown of tuftlets, reducing the number of tuftlets fed to the cylinder by about 60%. The method developed for this study can he used to assess the effect of the taker-in and the rear fixed flats on the degree of fibre-mass opening.