Philadelphia, Pennsylvania-As the US Environmental Protection Agency phases out HCFC-22 (hydrochlorofluorocarbon-22) across North America in "pour-foam applications" on 1 March 2008, which alternative to choose is a major issue, according to blowing agent supplier Arkema.
Arkema said that its technologists have shown that Transcend PUR blends are a suitable replacement for HCFC-22 for such formulations for rigid foams. These blends "offer foam manufacturers a new, viable and more cost-effective replacement option," the company said in a 5 April statement.
Arkema added that currently "evaluation quantities" of these blends are available. "Production quantities will be commercially available to meet customer requirements as the replacement deadline approaches," the company explained.
A combination of Transcend and HFC-134a ((hydrofluorocarbon-134a) "can produce foams having at least the equivalent and, in some cases, better overall performance compared to HCFC-22 and HFC-134a in generic pour-in-place rigid polyurethane foam formulations," Arkema said.
Easier handling results from Transcend use, the company said, as shown in lower vapour pressures and faster blowing agent addition time to the polyol pre-blend.
Also, formulations with 10-20 percent by weight of Transcend give improved flow, adequate dimensional stability and excellent adhesion, while thermal conductivity with Transcend PUR blends is, "fully acceptable," Arkema claims. epw"