All four
blowing agents yielded properties generally similar to HCFC-22 blown foam.
Session 4 on foaming polyurethanes will include the following presentations: "HFC
blowing agents for rigid insulation foams," Lotbar Zipfel and Christoph Meurer, Solvay Fluor, Germany; "Recent developments in the use of HFC-245fa
blowing agent for rigid polyurethane foam," Saskia Walraedt, Honeywell, Belgium; "New developments in applications of methylal as
blowing agent for rigid, flexible, integral skin and microcellular polyurethane foams," Michel Beaujean, Lambiotte & Cie, S.
Figure 4 shows time snapshots of the calculated core
blowing.
Session D on "
Blowing agents" will explore developments in zero ODP (ozone depletion potential)
blowing agents for the rigid foam industry.
Isotron line of HCFCs used as physical
blowing agents for PUR, PS, and PE.
In closed-cell foams, the ever-changing climate for
blowing agents is said to require quick and accurate measurements of heat transmission, and state-of-the-art data acquisition is essential.
As the uncured slab expands (from thermal expansion, curing or sponging caused by
blowing agents), the probe rides on the sample surface and a read-out of the expansion is graphed on the TA recorder.
Highlighting new BA-14 CoEx system, claimed to be the industry's largest six-layer coex machine designed for lab use, and the new tandem-blow process for simultaneous top and bottom
blowing of two bottles per parison, tail-to-tail.
As the blades pull back and
blowing is completed, the plastic self-seals and forms a ribbed structure.
The conversion to "cleaner"
blowing agents in the polyurethane foam business is largely done, and now much effort is being directed toward optimizing formulations to deliver better foams that are also easier to process and lower in cost.
In addition to these exothermal products, a separate line of endo-thermal
blowing agents is available.
