Abstract: The present invention discloses a composite thermal insulator including a first transparent substrate layer, a second transparent substrate layer, and a near-infrared shielding layer positioned between the first transparent substrate layer and the second transparent substrate layer, and the near-infrared shielding layer is formed by dispersively fixing multiple nanoparticles containing tungsten oxide in polyethylene terephthalate. The composite thermal insulator can't change color under sunlight so that it can be used for light output controlling and thermal isolation.

Abstract: A method of manufacturing a near-infrared ray shielding film is disclosed. The method comprises: providing a raw material of PET; providing tungsten oxides-containing nanoparticles; blending the raw material of PET and the tungsten oxides-containing nanoparticles to obtain a polyester mixture with 80-99.99 wt % of the raw material of PET and 0.01-20 wt % of the tungsten oxides-containing nanoparticles; rolling the polyester mixture to obtain a polyester sheet; and biaxially-orientating the polyester sheet with a orientating rate of 1-100 meters per minute at 60-300° C.