High-density polyethylene (HDPE) Rope is Known for its large strength to density ratio. Polypropylene (PP) ROPE also known as polypropene rope , it is rugged and unusually resistant to many chemical solvents, bases and acids. A rope is a linear collection of plies, yarns or strands which are twisted or braided together in order to combine them into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting.