Method of manufacturing combined elastic or elastomeric yarn

Abstract From the Canadian patent

A composite yarn is disclosed having a spandex core yarn (10) with a thermoplastic wrapping yarn (22) arranged in twisted relationship round the core yarn in a series of S and Z twists. The invention lies in the feature that the core and wrapping yarns are free to move relative to one another. Several methods of producing the composite yarn are disclosed. One method (Figure 1) utilises fully orientated nylon as the wrapping yarn. A second method (Figure 2) starts from partially orientated nylon or polyester yarn and a third method (Figure 3) starts from partially orientated yarn which is fully drawn prior to twisting around the core yarn.