Walt Schrenk
Dow Chemical Company
Inducted 2020
With a bachelor’s degree in science from the University of Michigan, Walt Schrenk (1933-2018) joined Dow Chemical Company in 1954 and rose to senior research fellow over the next 40 years. He was a prolific inventor and mentored countless researchers and engineers.
Schrenk is the father of coextrusion using feedblock technology, patented by his team in 1964. This technology is still used in many commercial processes, including cast film and sheet, blown film, and blow molding. It combines the different molten polymers in the feedblock and then spreads or shapes the stream in a standard die. This method proved considerably cheaper than a multi-manifold die and easily optimized.
After Dow was granted the patent, Schrenk adapted the technology to produce countless commercially important products, including SARANEXTM barrier films, other food packaging films, and multi-layer rigid containers for yogurt and other food and drugs. In the coming years, Schrenk would develop additional technology and receive patents for multi-layered sheets using an interfacial surface generator, birefringence interference polarizing films used in laptop displays, and infrared reflecting films used in automotive windshields and building windows.
With sixty-seven patents and more than thirty external publications, Schrenk was awarded the Herbert H. Dow Medal in 1991, the company’s highest research honor. The medal has only been awarded sixteen times in Dow Chemical Company’s history. Schrenk was also named a Fellow of the Society of Plastics Engineers (SPE).