Abstract: The present invention relates to methods of twist-plying a fibrous product. In accordance with the proposed method, applied to each of two fibrous ribbons is a pulsating torque created by a vortex of air of an invariable direction. Apart from the pulsating torque, each fibrous ribbon is constantly subjected to an additional torque of the opposite direction. The amount of the additional torque is less than that of the pulsating torque and is equal to 0.1 - 0.8 of its amount. As a result, each of the fibrous ribbons acquires a sign-variable twist. The fibrous ribbons are thereafter joined together and, while untwisting on each other, they become interlaced, thereby forming the finished product. This makes it possible to enhance the quality of the product, to reduce the end breakage thereof, and to improve both the stability and reliability of the process.

Abstract: The apparatus for obtaining a self-twisted product from at least two filamentary strands relates to spinning equipment. The apparatus includes a mechanism for continuously feeding the strands, swirl chambers having each jet passages producing air swirls of opposite directions within these chambers and thus effecting the twisting of the strands, an arrangement for supplying air alternatingly into these jet passages, a device for uniting or plying the strands issuing from the chambers and a mechanism for winding the final product. In each swirl chamber, the jet passages are displaced relative to one another longitudinally of the chamber. In adjacent swirl chambers, the jet passages producing the air swirls of the same direction are arranged to that one of them is situated at the inlet end of its respective chamber, while the other one is situated at the outlet end of its chamber. In this way clogging of the jet passages is precluded, and the strength of the final product is increased.