Process for producing an effect yarn

It is known to subject a sliver to a false twist treatment and use it as a core thread. Shortly upstream of or at the location of the false twist being imparted, the core thread has applied to it parallelised individual fibres which become wrapped around it. These individual fibres are to prevent the complete untwisting of the false twist. Such a yarn lacks the strength required for further processing. The novel process shall by contrast lead to a cored yarn of high tensile strength. A false twist textured synthetic polymer thread is made a cored yarn by applying the individual fibres to the thread before entry into the false twisting zone or in the already false-twisted state of the thread. The thread can preferably be moistened before the individual fibres are applied; the moistening fluid can have adhesive properties or be friction-increasing. Moreover, downstream of the point of application of the individual fibres there can be provided an entangling means for producing a bond between the core and the individual fibres. The resulting cored yarn has a high strength and is therefore highly suitable for processing into knitted materials.