Abstract: A method of producing a slub fiber is disclosed in which a metered core yarn is fed into a vortex generator and an effect yarn under continuous low level tension is fed into the balloon formed by the core yarn at the exit of the vortex generator such that the point at which the effect yarn contacts the core yarn balloon is free to move randomly, allowing the said effect yarn to form a randomized slub effect.The combined yarns are then passed through a texturing jet to more permanently bind the yarns together.

Abstract: An interlocked yarn having a plurality of continuous filaments which have substantially no twist and having at spaced intervals along the length thereof at least one of the filaments encircling the other filaments to interlock the filaments together. The method of making the interlocked yarn includes feeding a plurality of continuous filaments into a fluid jet which has a fluid medium passing therethrough in a direction substantially counter to the direction of travel of the filaments. The interlocked filaments are pulled away from the fluid jet at a rate less than the feed rate. This produces an interlocked yarn having some of the filaments encircling the other filaments to provide an interlock at spaced intervals which eliminates the need to twist the bundle of filaments.

Abstract: Multi-cavity filaments having improved resilience and anti-soiling properties have continuous cavities along their length with each cavity having a vertex angle formed by two sides or legs of the cavity of between about 65.degree. and 140.degree.. The vertex angle of each cavity points substantially toward the center axis of the filament. The cavities are spaced from each other and from the periphery of the filament in a manner producing a filament having good physical and aesthetic properties.