Method of producing plastic foam

• US 3,121,130 A
• Filed: 07/22/1959
• Issued: 02/11/1964
• Est. Priority Date: 07/22/1959
• Status: Expired due to Term

• Current Assignee: Fred E. Wiley, John M De Bell
• Original Assignee: Fred E. Wiley, John M De Bell
• Inventors: Wiley, Fred E., DE BELL JOHN M
• Application Number:
  US03/828,862
• Time in Patent Office: 1,665 Days
• US Class Current: 264/53
• CPC Class Codes: B29C 44/468 in a plurality of parallel streams which unite during the foaming
• CPC Class Codes: C08J 9/04 using blowing gases generated by a previously added blowing agent
• CPC Class Codes: Y10S 264/04 Molding and forming bendable and flexible product from rigid preform
• CPC Class Codes: Y10S 264/14 forming integral skin on a foamed product

Claims

1. A METHOD FOR THE PRODUCTION OF A SUBSTANTIALLY UNIFORM FINISHED THERMOPLASTIC CELLULAR SHAPE FOAM COMPRISING FORMING A FOAMABLE COMPOSITION BY ADDING TO A THERMOPLASTIC POLYMER AT AN ELEVATED TEMPERATURE AND UNDER PRESSURE A FOAMING AGENT IN AN AMOUNT CAPABLE OF EXPANDING THE POLYMER UPON RELEASE OF PRESSURE AND RELEASING SAID SO-FORMED FOAMABLE COMPOSITION TO A LOWER PRESSURE BY PASSING SIMULTANEOUSLY THROUGH MULTIPLE ORIFICES AT A TEMPERATURE RANGING FROM BELOW TO ABOVE THE CRITICAL TEMPERATURE OF THE FOAMING AGENT THEREBY EXPANDING IN SUCH PROXIMITY THAT SAID FOAMING AGENT EXPANDS AND FOAMS THE POLYMER INTO A MULTIPLE OF EXPANDED, COALESCED POLYMER STRANDS.