ASTM Circular Bend Test - PBI vs Common Composites
This video shows the stiffness testing of the PBI Lightweight Gold™ System according to ASTM D4032, Standard Test Method for Stiffness of Fabric by the Circular Bend Procedure. In this test, fabrics are pushed through a uniform orifice, and the force required to do so is measured. Stiffer fabrics require more force to be pushed through. On average, common composite systems require 32.8 pounds of force to flex the fabric, which is three times stiffer than the PBI Lightweight Gold™ System that takes only 13.1 pounds of force. Less stiffness equates to greater ease of movement in your gear and, ultimately, less stress experienced in doing your job.