On the basis of the ordinary transparent films, people have developed many feature films, and there are some function combination of multi-functional films, will now be single function barrier membrane is introduced as follows:
1. Longevity films by optimizing the common base resin, stabilizer, etc., prolong the service life of the films. Japan's longevity and PVC membrane can use 2 ~ 3 years, PET film can use 10 years; The CdF France PE film can use 1 ~ 2 years; Our longevity and PE film thickness of 0.05 mm (for the shelter) and 0.08 mm (for greenhouses) membrane service life can reach 1 ~ 2 years.
2. No pick membrane is higher than no drops of mulch requirements, rely mainly on hydrophilic plastic film drops, no drops can be added to membrane materials, can also be spread on the membrane surface. Another kind of multilayer extrusion composite films, rely on the middle low thermal conductivity of the resin system for thermal resistance effect, make films, both inside and outside surface can keep larger temperature difference so as to reduce films formation of droplets on the inner surface, this kind of membrane some also called no plastic film. In recent years, some strengthen the function of anti-fog, plastic film can effectively reduce or eliminate greenhouses in the fog, enhance crop daylighting effect:
Sunlight during the day 3. Thermal insulation membrane mainly wavelength the wavelength of 0.3 ~ 0.7 mu m people in the film, the heat temperature, soil to absorb a large amount of heat, air temperature at night to reduce soil to long wave infrared (5 ~ 10 microns) to heat dissipation, the effect of thermal insulation membrane is block of far infrared radiation through the night, to keep the temperature of the heat. Thermal insulation membrane by using infrared thermal resistance or low coefficient of thermal conductivity type (single or multi-layer co-extrusion composite -) and add the infrared absorption dosage form, the cost is low heat preservation effect is good. To improve the thermal insulation performance, the film should be controlled in a certain thickness.
4. Turn to ultraviolet light membrane and 510 ~ 560 nm visible light. Into crops needed light such as blue, green, red, or can improve the canopy temperature 3 ~ 5 degrees Celsius, so as to accelerate crop growth, increase crop yield and quality. All kinds of coloured film can be selectively through the light, suitable for different crops. Choose light membrane can be selectively through a certain wavelength of ultraviolet light, the rest of the block, so that neither affect the films aging resistance, and can provide the required for different crops ultraviolet light, is conducive to crop growth and improve the quality, and also can prevent diseases and insect pests.
5. Slow scattering films Suitable for low latitudes, the high temperature season, covered greenhouses. Is characterized by high light transmittance during morning and evening light weak, barn temperature is higher; At noon in a strong light transmittance is reduced, barn temperature is low. The flat membrane to prevent high temperature season and canopy temperature is too high, at noon to relative stable temperature, temperature effect is poorer, but the film is not suitable for wintering greenhouse covering the north.
6. Reflective film for double aluminized BOPE film, 500 ~ 1000 mm in length, thickness of 0.02 ~ 0.03 mm, the incident light has mirror reflection effect, in the winter and spring fruit growth and the sunlight greenhouse vegetable seedling will film hanging in the north of planting beds or seedbed, reflective effect of reflective film can increase the light intensity 40% within a certain distance to improve the quality of the seedlings and early fruit and vegetable production.
