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

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 f ibre mass transferred to the cylinder. Image analysis of high-speed video p hotographs show that these tuftlets were elongated and orientated by a smal l draft at the taker-in/cylinder transfer region. It is found that each rea r 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 be used to assess the effect of the taker-in and the rear fixed flats on the degree of fibre-mass opening.