Cylindrical fibrous structures with graded pore size

US4726901A · kind A · utility

Assignee

• Pall Corporation · US

Inventors

• David B. Pall · Glen Cove, US
• Colin F. Harwood · Glen Cove, US
• Arthur Bradley · Floral Park, US
• Timothy R. Brennan · Old Westbury, US

Key dates

• Filing date: Mar 17, 1986
• Grant date: Feb 23, 1988
• Expiry date: Mar 17, 2006

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D2239/1233
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Cylindrical fibrous structures comprising a fibrous mass of nonwoven, synthetic, polymeric microfibers wherein the microfibers are substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining, the fiber structure having a substantially constant voids volume over at least a substantial portion of the structure and, preferably, a graded fiber diameter structure, both as measured in the radial direction. The structures are particularly useful as depth filters.