A process of producing an assembled yarn, including the steps of providing two or more yarns moving downstream from a supply to a take-up, inserting alternating-direction zones of twist into at least one of the yarns, the at least one yarn having an area of zero twist between said alternating direction zones of twist, combining the at least two yarns to form a single, integrated yarn strand, and intermittently exposing the yarn strand to an air blast to create a zone of intermingled yarns at spaced-apart points along the length of the yarn strand to prevent torsional movement of one yarn relative to the other yarn. According to one preferred embodiment of the invention, the step of exposing the yarn strand to an air blast includes the step of intermingling the yarns at the areas of zero twist.