XPS foamed sheet,also named as polystyrene extrusion plastic sheet (xps for short)has a perfect closedpore alveolate structure.its ensity,water absortption ,coefficient of heat conducting and the coefficientof steam pervasion are all lower than those of other sheet heat insulating materials and they have the characteristics of strong internsity,light material, airtight, anticorrosion,ageing resistance, low cost,etc.it has been widely used in the fields of heat preservation in the construction industry and the highway,railway,airport,square of the heat preservation and household fitment.it is the generally acknowledged andthe best heat insulator in the market at present