Granted Patent
Utility
US 4,922,989 · App. 06/787,140
Treatment of mechanical pulp to remove resin
Inventors:
Ake Backlund, Olof Ferritsius, Goran Tistad
Patented Case
View Patent ↗
Granted: May 8, 1990
Filed: Oct 15, 1985
Inventors
Ake Backlund
Olof Ferritsius
Goran Tistad
Assignee (at issue)
Kamyr AB
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.