Tension in a Roving Withdrawn from a Bobbin

The roving tension between a guide rod and a traverse guide is the sum of the withdrawing tension T and the frictional force between the roving and a guide rod. The larger the withdrawing angle is, the larger the discrepancy between the observed and the calculated tension T and also the larger the variation of the observed value. The height of the guide rod under equal tension at the top and bottom of each bobbin layer is about 1/3 of the bobbin length. The maximum values of draft of each layer of bobbin are practically the same. So far as tension is concerned, the package can be made much larger than the present size.