Granted Patent
Utility
US 4,906,331 · App. 07/185,352
Method of enhancing the cooking of wood chips for pulp production
Inventors:
Michael M. Blackstone, Cheng-I Chen, Thomas W. Woodward
Patented Case
View Patent ↗
Granted: Mar 6, 1990
Filed: Apr 12, 1988
Inventors
Michael M. Blackstone
Cheng-I Chen
Thomas W. Woodward
Assignee (at issue)
Betz PaperChem Inc.
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.