Open-Celled Polyurethane Foam Based Vacuum Panel Technology: A Fully Polyurethane Based Composite Technology for Vacuum Insulated Appliances

Abstract

Vacuum based insulation technology results, when introduced into appliances, in a substantial reduction in energy consumption of these appliances. This reduction depends on two factors: primarily on the vacuum panel technology used, but also, very importantly, on the quality of the polyurethane foam used to fill the confined space in the refrigerator walls after incorporation of the vacuum panels. ICI Polyurethanes has now developed both an open-celled, fine-celled polyurethane foam, eminently suitable for vacuum panel technology, and a polyurethane foaming technology, based on both CO₂ and physical blowing agents, including alkanes, specifically designed to complement the vacuum panel technology. This paper reports on the status of both technologies. Since the morphology and physical properties of the open-celled polyurethane foam are substantially different from existing vacuum technologies, a complete assessment of the technical requirements for the open-celled foam has been performed. We believe the cost effectiveness, weight and ease of production weigh heavily in favour of the polyurethane foam based vacuum technology. In addition, the specific requirements for the encapsulation foam will be presented in terms of flow performance, pressure and temperature build-up and adhesion towards several liner materials. Evaluation of our technology is ongoing with a number of appliance manufacturers.