Abstract: A method of manufacturing insulation where carbon nanotubes are added to a polyurethane foam sheet widely used as an insulation substrate, where the cell structure of the foamed polyurethane foam is changed. Accordingly, the NVH performance in a middle and high frequency band of 1,000 Hz or more may be improved while minimizing an increase in weight (lighter than resin felt or glass wool). In particular, since at least one air layer is molded between two polyurethane foam sheets, noise passes through the at least one air layer in the middle of the polyurethane foam sheets when passing through the polyurethane foam sheets, where noise reduction performance may be further improved. In addition, since a mesh made of jute, along with the at least one air layer, is additionally provided between the two polyurethane foam sheets, the sound absorption performance of an insulation may be further improved.

Abstract: A load floor for a vehicle, by which, as the load floor is manufactured by including manufacturing a honeycomb structure with paper and adding polyurethane sheets to both side surfaces of the honeycomb structure, light and sufficient structural stiffness and a sound absorption effect are obtained through the honeycomb structure. As the polyurethane sheets are respectively provided on both surfaces of the honeycomb structure, sound absorption and insulation performances are obtained to further increase a sound absorption and insulation effect.

Abstract: A load floor for a vehicle, by which, as the load floor is manufactured by including manufacturing a honeycomb structure with paper and adding polyurethane sheets to both side surfaces of the honeycomb structure, light and sufficient structural stiffness and a sound absorption effect are obtained through the honeycomb structure. As the polyurethane sheets are respectively provided on both surfaces of the honeycomb structure, sound absorption and insulation performances are obtained to further increase a sound absorption and insulation effect.