Jobst U. Gellert
Mold Masters
Inducted 2012
Jobst U. Gellert ( – 2019) is one of the most prolific inventors in Canadian history, having been awarded 825 patents worldwide, 199 of which are U.S. patents. He is credited for patenting the first commercially viable hot runner system in 1965. With his wife Waltraud, he has built Mold-Masters Limited from a start-up to a leading worldwide supplier of hot runner systems. Although a debilitating stroke forced him to retire as CEO in 1999, Mr. Gellert continues to be a creative inspiration to the company he founded.
Mr. Gellert’s involvement with injection molding and mold making began in his native Germany. He received accreditation as a Master mold maker in 1956 and emigrated to Canada two years later. He and Mrs. Gellert founded Mold-Masters in 1963. Although hot runners began appearing in the early 1960s, they were far from realizing the benefits they now provide. They could not be used with many resins without burning, splaying, stringing, or other defects. In 1965, Mr. Gellert filed for a patent on technology that addressed this problem by providing for cast-in beryllium-copper heating elements positioned outside the melt channel.
Mr. Gellert also invented technologies for melt distribution manifolds, hot runner nozzles, actuation methods, and mold designs that solved many issues plaguing the first hot runner systems. This led to hot-runner molding being adopted globally, a trend he supported with further research, development, and refinement of the technology he pioneered. Working from the impetus provided by Mr. Gellert, Mold-Masters today has seven manufacturing facilities and 23 service locations worldwide, sells and supports its products in 78 countries, and employs more than 1,300 people.
Areas of Expertise: Plastics processing, Plastics tooling