US Patent Issued on Sept. 9 for "Waterproofing and breathable polyolefin roofing membrane by extrusion lamination and sequential stretching" (Canadian, American, Chinese Inventors)

ALEXANDRIA, Va., Sept. 10 -- United States Patent no. 12,409,640, issued on Sept. 9.

"Waterproofing and breathable polyolefin roofing membrane by extrusion lamination and sequential stretching" was invented by Wenyi Huang (Wilmington, Del.), Lisa Bertolo (Kingston, Canada) and Jiaqi Wang (Shanghai).

According to the abstract* released by the U.S. Patent & Trademark Office: "Reinforced microporous polyolefin sheets comprise one or more layers of a microporous polyolefin and a non-woven fabric at least partially embedded in the microporous polyolefin. The reinforced microporous polyolefin sheet is made in an extrusion lamination process by which a polyolefin sheet and non-woven fabric are laminated, followed by sequential cold and hot stret...