Granted Patent
Utility
US 5,217,575 · App. 07/857,121
Process for oxygen bleaching using two vertical reactors
Inventor:
Ake Backlund
Patented Case
View Patent ↗
Granted: Jun 8, 1993
Filed: Mar 24, 1992
Inventor
Ake Backlund
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.