Study on Transmittance of Plastic Shed Films with Bubble Structure

Abstract

In view of insufficient insulation of the typical plastic greenhouses in alpine regions, the study, with Numercial software, designed a plastic film with bubble structure and carried out five sets of comparative simulation experiments by changing the diameter of bubbles. The results of experiments show that in the visible light range (wavelength range from 300nm to 1100 nm), the transmittance increases with increasing wavelength, and it can be maximized when the diameter of the bubble is gradually changed. When the wavelength is less than 600 nm, the transmittance of the film is less than 60%. However, in the case of a film with a bubble structure, the transmittance of the film is significantly enhanced in the range of 300 to 600 nm, and it is also obviously improved at 600 to 1100 nm, especially at 700 to 1100 nm, it can still increase by about 10% and thereby exceeds 80%. The reflectivity is overall lower than that of the bubble-free structure, which further demonstrates that the structure proposed in this paper can further increase the utilization of solar energy from the aspects of increasing transmittance and reducing reflectivity.