a honeycomb structure made of shaped polyethylene <br />foams glued to aluminium coated polyethylene foils.<br />Its high thermal performance is provided by a special <br />structure composed of a large number of low emissivity <br />cavities, protected from dust and excessive air movement. <br />Moreover, the low emissivity external films provide <br />additional thermal resistance, when associated with <br />air cavities.">