Granted Patent
Utility
US 4,289,727 · App. 06/105,351
Method for extrusion of tubular films
Inventor:
F. John Herrington
Patented Case
View Patent ↗
Granted: Sep 15, 1981
Filed: Dec 19, 1979
Inventor
F. John Herrington
Assignee (at issue)
Mobil Oil Corporation
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.