Granted Patent
Utility
US 5,207,971 · App. 07/832,254
Extrusion of wrinkle-free blown film from high modulus resin
Inventor:
Richard J. Volungis
Patented Case
View Patent ↗
Granted: May 4, 1993
Filed: Feb 7, 1992
Inventor
Richard J. Volungis
Assignee (at issue)
Quantum Chemical 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.