Estimation of the Long-Term Dimensional Stability Performance of Hydrocarbon Blown Rigid Polyurethane Foams for Insulation—A Novel Approach

Abstract

For years, HCs with zero ODP and low GWP have been used as alternative B.A. (blowing agents) in the appliance industries. The improvement of insulation performance and lowering costs are significant factors in the development of R-PU (rigid polyurethane) foams especially blown with HCs. The development of R-PU foam with a lower density for cost effectiveness is progressing at present. Positive experiences as to the long-term dimensional stability of pentane blown R-PU foam accelerated this movement. The most important factor in the development of R-PU foam with a lower density is long-term dimensional stability. In this report, we propose a novel long-term dimensional stability test and its appropriateness is discussed. The influence of formulation and the boiling point (B.P.) of B.A. on long-term dimensional stability have also been studied. The use of a blowing agent mixture of cyclopentane and iso- or n-pentane with a lower B.P. allowed the achievement of density savings. The understanding of the relation between the formulation and long-term dimensional stability is an important issue for the development of R-PU foam.

Outgassing of Rigid Open-celled Polyurethane Foam Used in Vacuum Insulation Panels Under Vacuum Condition

“…Rigid open-celled PU foams have been introduced as the core materials for VIPs because of advantages such as good insulation properties, thermal stability, low density, ease of handling, and reasonable cost. In this study, HCFC-141b, with zero ozone depletion potential (ODP), was adopted as the blowing agent to substitute for chlorofluorocarbon (CFC), which is being phased out as a blowing agent in the polyurethane foam industry [1]. A high open cell content, a fine cell structure, and a high level of compressive strength are necessary to get an excellent performance when VIPs are used as heat insulation material.…”