MONOFILAMENTS PRODUCED BY BLENDING VIRGIN WITH RECYCLED POLYPROPYLENE

Our research addresses the use of 100% recycled polypropylene from separately collected packaging waste in Slovenia for the manufacture of monofilaments. The goal of this research was to optimise the melt spinning of monofilaments and to compare the properties of monofilaments obtained from the virgin polymer and from blends of virgin and recycled polymer. Monofilaments were Spun from the pure virgin polymer, from a blend of 85% virgin and 15% recycled polymer, and from 50% virgin and 50%, recycled polymer. It was established that the addition of the recycled polymer to the virgin polymer lowered the crystallinity and average molecular orientation of as-spun monofilaments, which influenced the tensile properties of the monofilaments. Because of the poor miscibility of the virgin with the recycled polypropylene. which also contained some fractions of polyethylene. the as-spun monofilaments were porous, brittle and rigid, and had a high tendency to break.