ROLL-TO-ROLL EMBOSSING OF SUNLIGHT GUIDE FILM WITH WIDE OUTGOING ANGLE

摘要

The energy consumption of artificial lighting takes more than 20% of total energy consumption of a commercial building. The sunlight guide systems were used in window systems to guide the sunlight orientation to ceiling. A microstructured film designed and fabricated by roll-to-roll embossing capable for improving solar energy utilization was demonstrated in this research. The roller mold was fabricated by diamond turning lathe, and used for UV cured embossing process. After the embossing process, the 400mm width of sunlight guide film is fabricated. The microstructure of the film includes inclined and curved surfaces, and the pitch and height of microstructure is 18um and 21 urn. When the sunlight is illuminated on the inclined surface or curved surface, the incoming ray is subsequently reflected out from the outgoing surface by the internal total reflection.rnThe performance of specimen is measured by homemade measuring system including light source, photo detector, and rotation table. The research provides a sunlight guide film which is able to adopt 40c-70c elevation angles. Moreover, the outgoing angle is more than 30° in average above the transom's horizontal 90° outgoing angle. The outgoing angle is defined by the full width at the half maximum of outgoing light intensity. Finally, the experimental results show high energy efficiency and broad range of outgoing angle of the microstructured film. The film possibly saves 19% energy consumption of the artificial lighting in a building for the ideal room model.