Oct 14 2010
The exceptionally important role played by rigid polyurethane foams in the insulation of cold stores, refrigerated containers, refrigerated displays and refrigerators is set to become even more vital in the future. As the most effective conventional insulating material in this field of application, they make an invaluable contribution when it comes to saving energy and cutting CO2 emissions.
With urbanization constantly increasing the distance foodstuffs need to travel before they reach the consumer - particularly in the expanding megacities of Asia and Latin America - a functioning refrigeration chain is essential to safeguarding the supply of food to the inhabitants. With that in mind, Bayer MaterialScience is working hard to further improve the insulating properties and technical performance of rigid polyurethane foam systems for use in the refrigeration chain. Such measures would, for example, boost the energy efficiency of refrigerating appliances, thereby helping to conserve resources.
"We are committed to integrated solutions in terms of materials, processes and technologies, and develop these in close cooperation with refrigerating appliance manufacturers. In addition to improving energy efficiency, our main aim is to ensure high productivity in the manufacture of cooling systems," explained Dr. Reinhard Albers, an expert in technical insulation at BaySystems, the global umbrella brand for the polyurethane systems business of Bayer MaterialScience.
State-of-the-art household refrigeration appliances demonstrate the potential that rigid polyurethane foams offer when it comes to cutting CO2 emissions. The energy efficiency of such appliances depends largely on rigid polyurethane foams. If all old appliances with an energy efficiency rating lower than "A" were replaced by new, economical "A++" appliances, carbon dioxide emissions could be cut by around 22 million metric tons annually in the European Union alone. The resultant drop in energy consumption would be equivalent to around six percent of the energy savings stipulated in the Kyoto Protocol.
Rigid foams with nanopores
One area of research Bayer MaterialScience is pursuing could result in significant progress in the field of refrigerating appliance insulation within a matter of years. The plan is to use a new foam technology and microemulsions to create rigid polyurethane foams with "nanopores". The cells in conventional rigid polyurethane foams for refrigeration appliances currently measure around 150 micrometers. "With this new technology, we are aiming for cell sizes of less than 150 nanometers. This type of foam system would lead to a significant drop in the energy consumption of refrigeration devices," said Dr. Stefan Lindner, an expert in nanoporous rigid foams at Bayer MaterialScience. The smaller the pore size, the lower the thermal conductivity - and the better the insulating properties of the polyurethane foam.
Development work at BaySystems is also focusing on adapting the polyurethane formulations for rigid foams to new, more environmentally friendly blowing agents that have a far lower ozone depletion potential (ODP) and global warming potential (GWP).
Zero-emissions concept for cold stores
Cold stores are a core component of the portfolio covered by Bayer MaterialScience's EcoCommercial Building Program. This business model is designed to help decision-makers in the construction industry provide energy-optimized, sustainable building solutions and customized products for new construction projects such as kindergartens, schools and office buildings. "At present, we are working with selected partners to develop integrated energy and material concepts for cold stores. Customized rigid polyurethane foams play a central role in this process. The aim is to provide the know-how required to construct cold stores as zero-emission buildings," explained Dr. Thomas Braig, head of the EcoCommercial Building Program in the EMEA region.
A futuristic vision - a mobile refrigerator for supermarket trips
What might a trip to the supermarket look like in the future? The New Business section of Bayer MaterialScience and Folkwang University in Essen put their heads together to come up with an answer to this very question. The result was "Alohas" - a polyurethane-insulated, multifunctional cooler box equipped with an RFID chip. At home, the box serves as a normal refrigerator - but it can also be wheeled to the supermarket, just like a trolley. There, the cooling box's containers are filled with the right volume of goods, generating considerable savings in terms of packaging materials and interrupting the refrigeration chain for no more than a brief moment. "The excellent insulation provided by rigid polyurethane foam is fundamental to ensuring this concept actually works and that the goods purchased arrive home still fresh and in top quality condition," said Eckhard Foltin, head of the Creative Center at Bayer MaterialScience.
Refrigeration chain - not just for foodstuffs
Perishable foods are not the only products that benefit from a functional refrigeration chain that uses rigid polyurethane foam as insulation. Numerous pharmaceutical products, including many vaccines, have to be temporarily stored in refrigerated rooms on the manufacturers' premises and delivered cooled to pharmacies, hospitals and doctors' practices. Once delivered, they are again stored at low temperatures. One new field of application for rigid polyurethane foam is containers for transporting temperature-sensitive electronic goods.