A pioneer in the development of molds and molding techniques for the plastics industry. With the formation of Newark Die Co. in 1918, began establishing many basic moldmaking concepts that are still in practice today.
John Hohl was the acknowledged "master" of the precise and intricate specialty of die hobbing, which enabled the production of duplicate, uniform mold cavities from a single master. This accelerated dramatically the ability to produce multi-cavity molds with uniform, identical plastics parts being molded.
Contributed to the improvement of plastic molding methods through unique, patented mold devices and techniques that greatly accelerated the growth of the injection molding industry. Created designs that were vital to the construction of test molds for use in research institutions and universities. During 1936-37, constructed for Charles F. Burroughs a special laboratory injection press with a complete set of experimental molds to establish such basic data as molding pressures, temperatures, counteracting forces, and flow speeds of different materials under varying molding conditions. These data contributed to advancements in injection molding machine and mold design.
He is survived by two daughters, Ruth and Ethel, and five grandchildren.