Edgar W. Spanagel had been studying a series of cyclic compounds under Wallace Carothers when he made a new polyester called polyethylene terephthalate (PET). But he was soon taken off this project when the push to bring nylon to market came to consume most of the efforts of the Carothers team. PET would become the polyester we're all familiar with today, but only after another company would rediscover it many years later.

Spanagel's greatest contribution to nylon was his discovery that nylon must be polymerized under pressure. Otherwise, hexamethylene diamine, one of the two chemicals used to make nylon, would evaporate from the reaction mixture. The result would be nylon of low molecular weight. Spanagel used an autoclave to carry out the polymerization under pressure, and good average molecular weights were acheived.

Spanagel also developed a means of sizing nylon, without which it could not be used to knit hosiery. Conventional sizes did not work with nylon. It was his own formula of boric acid and polyvinyl alcohol which made it possible to size the new fiber for knitting on a full-fashion fine thread hosiery machine.

Spanagel ws born in 1905 near Horicon Marsh, Wisconsin. He received his bachelor's degree from Lawrence College in 1928, the same yeat that DuPont hired Carothers. He earned his doctorate from McGill University in 1933, and upon graduation went to work for DuPont where he was assigned to Carothers' research group. Today he is retired from DuPont and lives in Wilmington, Delaware.