Selection and comparison of greenhouse transparent insulation covering materials
The greenhouse cover material is to isolate the crop from the outside environment, so that the crop is in a relatively closed and more suitable for growth in controlled environmental conditions. At present, there are three main types: plastic film, sunlight board and glass, and the comparison of the advantages and disadvantages of these three materials is mainly reflected in the following aspects:
1. Construction
Thin film greenhouse construction period is short, construction cost is low, easy to construct; The sun panel and glass greenhouse construction period is long, the construction cost is high, and the construction requirements are high, but the sun panel greenhouse construction cost is lower than the glass greenhouse cost.
2. Environmental protection
The damage of the film causes white garbage pollution; Sunshine board environmental protection, tasteless, non-toxic and pollution-free; Glass is recyclable and pollution-free.
3. Service life
The film is easy to age, low resistance to natural damage such as wind, rain and hail, easy to damage, and short life; High strength, heat insulation, light transmission, lightweight, service life of 3 to 10 years; The glass has high strength, corrosion resistance and is not afraid of ultraviolet light, so it is durable and can be used for more than 25 years.
4. Thermal insulation performance
Film greenhouse daytime temperature rise obviously, night temperature drop fast, resulting in summer daytime temperature is too high, winter night temperature is too low, is not conducive to crop growth, summer daytime cooling and winter night temperature rise need a lot of manpower and material resources, greenhouse planting cost is high; The thermal insulation effect of sunlight panels and glass greenhouses is better during the day and at night, and the planting cost of film greenhouse is low.
5. Lighting
The film greenhouse has a retaining wall, small area, low height, low film light transmission, no scattering function, so the film greenhouse lighting rate is low, the light is more concentrated; The sunlight panel and the glass greenhouse can be built in a large area, high height, five sides of lighting, so the lighting area is large, the sunlight transmittance of the sunlight panel can reach 90%, the glass transmittance can reach 97.5%, the lighting rate is good, the glass manufacturing has a certain degree of fog, so that the transmitted light scatters, the light is more uniform.
