Abstract: An improved apparatus capable of carrying out a continuous method of forming yarn elements from a supply roll of thermoplastic film, which method is characterized by slitting the roll into flat strips of preselected width, simultaneously subjecting the strips to heat and to a pulling or drawing force to elongate the strips which reduces their width and at the same time minimizes their subsequent stretch capability, and thereafter interengaging said strips on a textile-forming machine, such as a knitting or weaving apparatus, to form a desired product. The method is particularly adaptable to the production of an improved knitted bag formed of said flat yarn elements.