Performance index of building membrane
Sep 25, 2022
Visible light transmittance: the percentage of visible light (380nm-780nm) passing through the glass/glass window film composite layer.
Visible light reflectance: the percentage of visible light (380nm-780nm) reflected by glass/glass window film composite layer.
Ultraviolet barrier rate: the percentage of ultraviolet light (280-380nm) reflected by glass/glass window film composite layer.
Solar transmittance: the percentage of solar energy passing through the glass/glass window membrane composite layer.
Solar reflectivity: the percentage of solar energy reflected by the glass/film composite layer.
Solar energy absorption rate: the percentage of solar energy absorbed by the glass/film composite layer. The absorbed solar energy can radiate to both sides of the glass/film composite layer at the same time. The side with high air flow speed will radiate more energy. Total solar transmittance: the sum of the part of solar energy passing through the glass/glass window membrane composite layer and the absorbed solar energy radiating inward. The unit of measurement for insulation rate is the heat passing through per square foot per hour (BTU/Hr./Ft. 2, where 1BTU=262 calories). The thermal insulation rate of transparent glass is generally 20 BTU/Hr./Ft. 2.
Total solar insulation rate: that is, thermal insulation rate, which is the sum of the solar energy reflected by the glass/glass window film composite layer and the absorbed solar energy radiated to the outside.
Shielding coefficient: the total solar energy transmittance of the glass/glass window film composite layer relative to the glass.
U value: the amount of heat radiation passing through each square foot per hour, per degree of internal and external temperature difference.
Performance requirements vary according to different applications. In general, the main indicators are visible light transmittance, visible light reflectance, thermal insulation, and ultraviolet barrier.
For construction safety film, the main indicators generally include tensile strength, peel strength, impact strength and tear strength.
