TWIST DISTRIBUTIONS OF THE ALTERNATE TWIST BY AIR-JET FALSE TWISTER

In the previous papers was discussed the twisting mechanism of air-jet twister, in which high pressure air tangentially ejected to the inner surface of the cell from the small holes forms a vortex. Furthermore the new alternate twisting method using air-jet false twister was shown.In this paper the twist distributions of alternately twisted yam are discussed on the basis of the law of superposition: the twist of the indicial response at the supply of air is superposed on the twist at the stop of the air supply. The results obtained are as follows:1) From the law of superposition, the alternate twists can be expressed for single twist (1) and for ply twist (2) where t: timef1 (t): twist of indicial response when air was supplied to the twisterf2 (t): twist of indicial response when air supply was stoppedT: time of one cycleτ: time to supply air in one cycleL: time of phase lagα: constant2) It is found that the alternate twist varies in accordance with the ON-OFF ratio of the supplied air, and the twist distributions calculated by equation (1) and (2) agree with those of experimental values.3) The twist number of the plied yarn decreases in case of air supplied to two twisters in the form of phase lag, and this is also recognized by the calculation.4) The alternate twist can be calculated by the superposition of the twists of the indicial response.