PU/PIR Foam insulation sheets, backed with patterned aluminum foil, represent a new innovation in insulation materials. These sheets are characterized by their lightweight, durability, and excellent fire retardancy. With low thermal conductivity and minimal water absorption, they efficiently prevent sound reflections. The PU/PIR Foam is lightweight, reducing labor and installation time and costs. Besides being aesthetically pleasing and robust, these sheets are highly suitable for use in air conditioning and ventilation systems, making them an excellent new choice for air duct materials.