What are the types of greenhouse films?

There are four kinds of greenhouse films commonly used in China: the first is PVC greenhouse film; The second is polyethylene (PE) shed film; The third is ethylene-vinyl acetate polymer shed film; The fourth is to dim the agricultural film. These kinds of greenhouse films have similarities and differences in performance, so their application effects are different. (1) polyvinyl chloride (PVC) shed film has good heat insulation, light transmittance and weather resistance, is soft and easy to form, and is suitable for being used as the outer covering material of greenhouses, greenhouses and small and medium-sized arch sheds. Disadvantages are that the specific gravity of the film is large (1.3g/cm3), and the coverage area of the shed film with a certain weight is less than that of polyethylene film (PE) 1/3, and the cost is increased; Hard and brittle at low temperature, easy to soften and relax at high temperature; After the additive is precipitated, the surface of the film is evacuated, which affects the light transmission. Residual film can't be burned, because chlorine gas will be produced. The main products of PVC shed film are as follows: ① Ordinary PVC shed film does not add anti-aging additives in the film-making process, and its service life is only 4-6 months, which can produce one-season crops, waste energy, increase labor and investment, and is gradually being eliminated. ② Adding anti-aging additives into raw materials, and calendering to form PVC anti-aging film. The effective service life is 8- 10 month, and it has good light transmittance, heat preservation and weather resistance. It is the main material for covering greenhouses and small and medium-sized arch sheds, and is often used for early cultivation in spring and late cultivation in autumn. ③PVC drip-free anti-aging film (PVC double anti-sagging film) has both anti-aging and drip-free characteristics, good light transmittance and heat preservation, no drip-hanging for 4-6 months, and a safe service life of 12- 18 months. It has a wide range of uses, and it is the first choice of covering material for high-efficiency and energy-saving solar greenhouse, and the effect is better as covering material for greenhouse. ④PVC weatherproof and drip-proof dustproof film not only has weatherproof and drip-proof performance, but also has less plasticization and dust absorption after surface treatment, which improves the light transmittance and is more conducive to winter and spring cultivation in solar greenhouses. (2) Polyethylene (PE) shed film is light in texture (specific gravity is about 0.96 g/cm3), soft, easy to shape, good in light transmittance and non-toxic. It is suitable for all kinds of shed film and plastic film, and it is the main agricultural film variety in China. Its disadvantages are: poor weather resistance and heat preservation, not easy to bond. If the greenhouse film is produced, additives such as anti-aging agent, anti-dripping agent and heat preservation agent must be added to meet the production requirements. The main products are as follows: ① Ordinary pe shed film (also known as PE blown agricultural film) is a kind of white film produced by direct blow molding of raw materials without adding anti-aging additives, which is widely used in greenhouses and small and medium-sized sheds. Generally, the shed is locked in spring and autumn, and its service life is only 4-6 months. Only one crop can be planted, which wastes energy, increases labor force and is gradually eliminated in production. ②PE anti-aging film (also called longevity film, anti-aging film) is made by adding anti-aging additives to PE resin and blow molding. The thickness of this plastic film is 0.08-0.12mm, and its service life is 12- 18 months. It can be used to cultivate two or three crops, which not only prolongs the service life, reduces the cost and saves energy, but also greatly improves the yield and output value. It is a key agricultural film variety popularized in protected cultivation. ③PE non-dripping anti-aging film (also known as double anti-dripping film and long-life dripping film) has good drip resistance, weather resistance, light transmittance and heat preservation, the anti-fog effect can last for 2-4 months, and the anti-aging life can reach 12- 18 months. It is a comprehensive and widely used agricultural film variety, which can be used not only in greenhouses and large, medium and small sheds, but also in energy-saving sunlight. ④PE insulation film, a covering material, can prevent infrared radiation from reaching the atmosphere, and can increase the greenhouse temperature 1-2℃, which has a good application effect in cold regions. ⑤PE multifunctional composite film has many functions, such as non-dripping, heat preservation, weather resistance, long service life and so on, and some of them have the function of blocking ultraviolet rays, which reduces ultraviolet rays in the shed. Some can inhibit the formation of sclerotium and conidia of botrytis cinerea. Service life reaches 12- 18 months. (3) Ethylene-vinyl acetate polymer (EVA for short) shed film: (EVA is added in a certain proportion). Ethylene-vinyl acetate copolymer is a new agricultural film material used in agriculture in recent years, and the agricultural film made of it has better light transmittance, heat preservation and weather resistance than PVC or PE agricultural film. Compared with other greenhouse films, EVA plastic film mulching can increase the yield by about 10%, can be used continuously for more than 2 years, does not deform before aging, is easy to recycle after use, and is not easy to cause soil or environmental pollution. (4) Dimming agricultural film The dimming film made by adding functional additives such as rare earth into PE resin can selectively transmit light, which is a new covering material that can make full use of solar energy. Compared with other greenhouse films, it has good thermal insulation effect in greenhouse, strong biochemical effect on crops, early maturity, high yield, nutrition improvement and other functions for different crops, and rare earth can also absorb ultraviolet rays and prolong the service life of agricultural films. Among them, the purple light film (leek film) special for leafy vegetables is made by adding purple masterbatch and weather-resistant, heat-insulating and drip-proof masterbatch into the film, and blowing to form the film. The film is slightly blue-purple, reducing strong light, increasing temperature, early growth period, high quality and high yield. Suitable for planting leeks and various green leafy vegetables. For more information, please consult Renshou Boyi Plastic Co., Ltd., thank you!