Granted Patent
Utility
US 4,225,321 · App. 05/868,235
Heat set and destretched polyester backing material in coated abrasive manufacture
Inventor:
Henry J. Swiatek
Patented Case
View Patent ↗
Granted: Sep 30, 1980
Filed: Jan 9, 1978
Inventor
Henry J. Swiatek
Assignee (at issue)
Carborundum 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.