An assembly for use in continuously forming a plurality of lengths of flexible noise attenuating cutting line for use in rotary vegetation trimmers. The assembly includes a breaker plate having a conically shaped inner portion and a planar outer portion. A plurality of extrusion dies are disposed in the outer portion wherein each die defines a die hold configuration at its lower end for the extrusion of one or more monofilament polymer strands therethrough, and a drive assembly is provided for rotating each of the dies at a predetermined speed such that upon directing a flow of molten monofilament polymer material onto the breaker plate, the material is directed from the inclined central portion onto the planar outer portion where it is extruded through the rotating dies to create a plurality of twisted strands of polymer material that upon cooling, stretching and heating, define lengths of flexible noise attenuating cutting line.