Health & Environmental Research Online (HERO)


Print Feedback Export to File
8631558 
Meetings & Symposia 
Soluble or insoluble alternative blowing agents? Processing technologies for both alternatives, presented by the equipment manufacturer 
Taverna, M; Hufnagel, L 
1991 
Publ by Technomic Publ Co Inc 
Nice, Fr 
Polyurethanes World Congress 1991 
141-147 
English 
When looking at the substitution of hard CFC-11 and -12 as blowing agents in polyurethane foams, either gaseous HCFCs, HFCs or insoluble fully fluorinated fluorocarbons can be used. Gaseous HCFCs (like the 22, the 142b, or blends) or HFCs (like the 152a, the 134a, etc) require a special equipment and procedure solution to ensure precise metering and thorough dispersing into the formulation. This paper analyzes the various problems associated with these two families of products, and suggests two solutions: A controlled predilution method followed by a frothed foaming system for gaseous blowing agents. A controlled emulsification method for insoluble, fully fluorinated blowing agents. Equipment solutions procedures and advantages are expounded upon.