US 12,264,226 B2
Blowing agents in polymer foam processing systems
Samuel Edward Dix, Newton, NH (US); and Levi A. Kishbaugh, Groveland, MA (US)
Assigned to Trexel, Inc., Wilmington, MA (US)
Filed by Trexel, Inc., Wilmington, MA (US)
Filed on May 16, 2022, as Appl. No. 17/745,766.
Application 17/745,766 is a continuation of application No. 16/447,201, filed on Jun. 20, 2019, granted, now 11,332,593.
Application 16/447,201 is a continuation in part of application No. 15/926,882, filed on Mar. 20, 2018, abandoned.
Application 16/447,201 is a continuation in part of application No. 15/909,873, filed on Mar. 1, 2018, granted, now 11,559,927.
Prior Publication US 2023/0113531 A1, Apr. 13, 2023
Int. Cl. C08J 9/08 (2006.01); C08J 9/12 (2006.01)
CPC C08J 9/122 (2013.01) [C08J 9/08 (2013.01); C08J 2201/03 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method comprising:
providing a hopper of a polymer foam processing system;
supplying polymeric material to the hopper;
supplying chemical blowing agent to the polymeric material in the polymer foam processing system;
supplying physical blowing agent comprising nitrogen to the polymeric material in the polymer foam processing system;
conveying a mixture of the polymeric material, the chemical blowing agent and the physical blowing agent comprising nitrogen in a downstream direction in the extruder, wherein the nitrogen is present in an amount between 0.025 and 1.50 weight percent based on the total weight of polymeric material;
decomposing the chemical blowing agent to form carbon dioxide that is present in an amount between 0.2 and 3.0 weight percent chemical blowing agent;
accumulating a shot of the mixture of polymeric material and blowing agent; and
injecting the shot into a blow mold to form a blow-molded polymeric foam article.