Varieties and descriptions of membranes for greenhouses

Release time:

2023-03-08

Classify： Company News

We know that the membrane of the greenhouse is a special plastic film to be used in the agricultural production and construction of facilities, and its performance in light transmittance, heat preservation, tensile resistance and aging resistance are better than ordinary agricultural film. It is of great significance to the growth, yield and income of greenhouse crops.

Fenggong electric film reel summarizes that there are four main types of membranes in greenhouses:

(1) Polyvinyl chloride (PVC) shed film has good heat preservation, light transmission, weather resistance, softness, easy to shape, and is suitable as an outer covering material for greenhouses, greenhouses and small and medium-sized arches. The disadvantage is that the film ratio is large (1.3 g/cubic centimeter), and the covered area of a certain weight of shed film is reduced by 1/3 compared with polyethylene film (PE), and the cost increases; It becomes hard and brittle at low temperature, and it is easy to soften and relax at high temperature; After the additives are precipitated, the membrane surface is vacuumed, affecting the light transmission, and the residual film cannot be burned and treated because of chlorine gas.

(2) Polyethylene (PE) shed film has light texture (specific gravity of about 0.96 grams / cubic centimeter), soft, easy to shape, good light transmission, non-toxic, suitable for making various shed films, mulch films, is the main agricultural film varieties in China. Its disadvantages are; Poor weather resistance and heat preservation, not easy to bond. If the production of greenhouse film, additives such as aging resistant agents, drop-free agents, and heat preservation agents must be added to meet the requirements of production.

(3) Ethylene-vinyl acetate copolymer (referred to as EVA) shed film: (add a certain proportion of eva), EVA resin is a new agricultural film material used in agriculture in recent years, and the agricultural film manufactured by it has stronger light transmission, heat preservation and weather resistance than PVC or PE agricultural film. EVA agricultural film cover can increase the yield by about 10% compared with other shed films, can be used continuously for more than 2 years, does not deform before aging, can be easily recycled after use, and is not easy to cause soil or environmental pollution.

(4) Dimming agricultural film in PE resin added rare earth and other functional additives made of dimming film, can selectively transmit light, is a new type of covering material that can make full use of sunlight energy, compared with other shed film, the greenhouse heating and insulation effect is good, crop biochemical effect is strong, different crops have early maturation, high yield, improve nutrients and other functions, rare earth can also absorb ultraviolet rays, prolong the service life of agricultural film. Among them, the special purple light film for leafy vegetables (leek film) is to add purple masterbatch and weather-resistant, heat preservation, and drop-free masterbatch to the film, and blow mold it into a film. The film is slightly blue-purple, reducing strong light, increasing temperature, early growth period, high quality and high yield. It is suitable for the cultivation of leeks and a variety of green leafy vegetables.

Key words: Chenhe, Fenggong

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