摘要 |
Apparatus for making filter plugs wherein the extent to which the tow is stretched or the rate of transport of a uniformly stretched tow to the wrapping mechanism is controlled by a testing unit which determines the resistance of filter plugs to axial flow of air therethrough. Alternatively, the speed of the garniture belt in the wrapping mechanism is regulated as a function of changes in resistance to flow of testing air transversely across successive increments of a uniformly stretched tow. |