Herbert Blades made important contributions to two major DuPont innovations: Tyvek and Kevlar. After paper-like fibers were made accidentally from high density polyethylene, Blades figured out a polymerization process to make them reliably. For this work he was co-inventor on the patent for Tyvek non-woven sheeting which has many uses, especially in building construction. For the Kelvar development, Blades developed a commercially viable process to spin fibers from the polymer.
His innovative process had three components. First, he discovered that a relatively high concentration of polymer could be dissolved in 100% sulfuric acid if the solution was heated. (100% sulfuric acid has no water in it and is not a corrosive acid). The resulting solution had a low enough viscosity that it could be spun rapidly through a small hole (spinnerette). Next Blades discovered that instead of spinning the fiber directly into a water bath, leaving a small air gap led to fibers that were significantly stronger. Finally, he determined that the water “quenching” of the fiber occurred extremely fast. His spinning innovations made it possible to spin Kevlar fibers economically and at high speeds.