Fine Celled CFC-Free Rigid Foam - New Machinery with Low Boiling Blowing Agents

Abstract

This article describes newly developed high pressure dispensing and nucleating equipment, which is designed for making fine cell foams using soluble low- boiling blowing agents (LBBA) and sparingly soluble nucleating gases, such as N₂ and no ble gases. The underlying concepts for handling, processing and metering of LBBAs have been developed from a systematic investigation of LBBA solubilities in polyols, using modelling as well as experimental measurements. In addition to the usual dispensing func tion, the equipment incorporates facilities for LBBA loading and for quantitative deter mination of dissolved and dispersed gaseous LBBA. The commercial viability of these features, under conditions simulating global industrial practice, is exemplified by present ing properties of fine-cell foams produced by using HFC-134a and HCFC-22/142b blends, in combination with tailor-made polyols, isocyanates and formulation additives.

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References

Jeffs, G.M.F. and D.J. Sparrow. 1990. Proc. Utech 90 Conf., p. 31.

Dwyer, F.J. , R.C. Parker , K.M. Thrun and L.M. Zwolinski. 1991. Proc. SPI/ISOPA Polyurethanes World Congress, p. 752.

Pitzer, K.S. and L. Brewer. 1961. Thermodynamics, 2nd Edition, McGraw-Hill.

Thoen, J.A. , H.J.M. Grünbauer and G.F. Smits. 1992. Accepted for presentation at the ACS Symposium on Foams.

Hildebrand, J.H. , J.M. Prausnitz and R.L. Scott. 1970. Regulated and Related Solutions, Van Nostrand Remhold.

Prausnitz, J.M. and F.H. Shair. 1961. A.I.Ch.E. Journal, 7:682.

Smits, G.F. and J.A. Thoen. 1991. Proc. SPI/ISOPA Polyurethanes World Congress, p. 412.

Grünbauer, H.J.M. , X. Fanichet , E. Kuhn , K. J. van Duin and G.J.B. Brands. 1991. Proc. SPI/ISOPA Polyurethanes World Congress, p. 571.