Granted Patent
Utility
US 4,331,623 · App. 05/944,837
Polymer flow through die
Inventors:
Bernard Zurkoff, Bennie M. Lucas
Patented Case
View Patent ↗
Granted: May 25, 1982
Filed: Sep 22, 1978
Inventors
Bernard Zurkoff
Bennie M. Lucas
Assignee (at issue)
El Paso Polyolefins Company
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.