Tint Meter | What Are the Properties of PE Film and EVA Film?

Time:2020/04/08 10:30:00 Browse:526

The greenhouse film is the basis of facility cultivation. Whether it is a winter-heated vegetable greenhouse or a general arch shed, a new greenhouse film should be replaced regularly to ensure the light and temperature in the greenhouse. The factors that determine the quality of the shed film mainly include the level of light transmittance, the quality of the mist removal and drip. They directly affect the environment inside the shed and determine the growth status and the degree of disease in winter vegetables. 
      The price of shed film is generally 0.7-2 RMB per square meter. Compared with other agricultural materials such as fertilizers, seedlings and pesticides, the investment is not high, but the role it plays is extremely important. In recent years, due to the poor drip of the shed film, the drip of the shed film in winter is serious. There have been many cases of outbreaks of diseases in the shed. How to choose a greenhouse film with good quality and high cost performance is a concern for many vegetable farmers. Next, we will introduce the advantages and disadvantages and performance of PE film and EVA film.

1. PE film (grouting film)

The advantage is that it is cheap and the light transmittance is good, up to 90%, but the thermal insulation, mist removal and drip resistance. There are many PE films, but we rarely hear them in the market. In fact, we often say that the grouting film is the PE film after spraying the anti-fogging drip on the inside.
      The grouting film defoaming and dripping period is short, generally in 3-5 months. The film is changed at the end of October and the beginning of November, which can basically guarantee the use in the deep winter period.

2. EVA film

In the past few years, most greenhouses in the north have adopted EVA film, which is mostly three-layer co-extruded. The inner layer is anti-fogging and dripping, the middle is thermal insulation, the outer layer is anti-aging. Its light transmittance has been reduced, generally only 85%. Overall, the performance of EVA membrane is relatively stable, of course, the price is higher, suitable for the temperature-sensitive eggplant vegetable production areas in northern areas.

3. Greenhouse film transmittance detection

Shed film refers to a plastic film specially made for plastic greenhouses and greenhouses. It is a building used to prevent and reduce the impact of insect pests and natural disasters for crops. It provides a good environment to improve crop yield and quality. The light transmittance of this shed film must be high and stable. Agricultural greenhouses are mostly produced in the spring, when the temperature is low, the light is weak for a short time. High and stable light transmittance is important for the indoor temperature and the photosynthesis of crops, so the new greenhouses are generally required to be transparent. Its light transmittance is more than 90% and the light transmittance of the greenhouse film used for more than 5 months is more than 55%. If you want to measure the light transmittance of greenhouse film, we usually recommend using LS116 tint meter to detect the light transmittance of plastic shed film.
      The LS116 tint meter conforms to the CIE photopic luminosity function standard. The tint meter has passed the inspection by the authoritative Chinese Academy of Metrology and obtained the inspection certificate.