Method for making a foamed polyurethane filter

• US 2,961,710 A
• Filed: 01/04/1957
• Issued: 11/29/1960
• Est. Priority Date: 01/04/1957
• Status: Expired due to Term

• Current Assignee: Norman H. Stark
• Original Assignee: Norman H. Stark
• Inventors: Stark, Norman H.
• Application Number:
  US03/632,410
• Time in Patent Office: 1,425 Days
• US Class Current: 264/54
• CPC Class Codes: B01D 39/1676 of synthetic origin
• CPC Class Codes: C08J 2375/06 from polyesters
• CPC Class Codes: C08J 2483/00 Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
• CPC Class Codes: C08J 9/38 Destruction of cell membranes
• CPC Class Codes: C08J 9/42 with macromolecular compounds
• CPC Class Codes: Y10S 264/13 Cell size and distribution control while molding a foam
• CPC Class Codes: Y10S 521/918 Physical aftertreatment of a cellular product
• CPC Class Codes: Y10S 55/13 Polyurethane filters

Claims

6. A METHOD OF MAKING AN OPEN CELLED POLYURETHANE FOAM FILTER FOR USE IN FILTERING A FLUID TO REMOVE SOLID PARTICLES ENTRAINED THEREIN, COMPRISING FORMING A POLYURETHANE PLASTIC FOAM, SOAKING SAID FORM IN A WEAKENING AGENT CAPABLE OF EXPANDING THE FOAM TO WEAKEN ITS CELL WALL STRUCTURE, AND VIOLENTLY AGITATING THE WEAKENED FOAM BY MECHANICALLY WORKING THE SAME THEREBY TO INCREASE THE NUMBER OF INTERCONNECTING CELLS THEREIN.