DURASTRAN® is the Monahan Filaments trade name for polystyrene and polystyrene-acrylonitrile copolymer (SAN) monofilaments. DURASTRAN® is recommended for light duty applications such as floor and counter sweeps and flaggable upright brooms, where its resistance to taking a set and its excellent flicking action (springiness) are an asset. Another advantage of DURASTRAN® is that it yields 20 to 25% more brushes per pound than PVC. These materials have excellent color and clarity, but have limited flex fatigue resistance compared to other Monahan Filaments fibers. In heavier applications, such as scrub brushes or industrial applications, their bend recovery, flex fatigue, and abrasion resistance may be limiting factors. They have excellent solvent resistance to water based solutions and alcohol, but SAN is resistant to common organic solvents except for strong solvents such as chlorinated hydrocarbons. Monahan Filaments PROSTRAN®, WYTEX® and PLYER® maybe better choices when exposure to solvents, high temperatures or heavy use is anticipated. Typical ovalities range from 1.04 to 1.20 with larger diameters having greater ovality.