With the development of the plastics industry, polyethylene greenhouse films are widely used in agricultural production, and various types of greenhouse films are derived. However, the formulation materials of each manufacturer are different, resulting in uneven quality and longevity.So in the case of equal quality, how to prolong life as much as possible, the following five points must be kept in mind:
① High temperature environment
If the agricultural film is exposed to high temperatures, especially in contact with the skeleton, hot spots are likely to form, and its maximum temperature can reach 80 degrees Celsius. This part of the agricultural film will be particularly prone to aging and damage.
This is also the reason why the sunshade net cannot be directly covered on the outside of the film. Directly covering the sunshade net outside the film will accelerate the aging of the film. In addition, it can also be tied with a white plastic tape or with a cloth strip to the place where the skeleton contacts the membrane to prevent the agricultural membrane from being damaged by high temperature.
② Film thickness
The thicker the film, the longer the aging resistance time. The aging of the PE material comes from ultraviolet radiation, so choose the agricultural film with ultraviolet absorber and ultraviolet stabilizer added in the formula. The agricultural film added with ultraviolet absorber is like coating a protective layer on the film. It is absorbed and converted into heat energy. The ultraviolet stabilizer can effectively extend the aging time of agricultural film, and even repair the injured molecular structure.
③ Chemicals
The rapid and healthy growth of crops is inseparable from pesticides, especially some pesticides and fungicides that contain sulfur or chlorine. Once they are in contact, they will destroy the stability of the agricultural film quality. If sulfur fumigation is used for sterilization in greenhouses, it is necessary to prevent sulfides from the burned gas, because sulfides can seriously reduce the service life of agricultural membranes. When burning sulfur, care should be taken not to let the temperature exceed 160 degrees Celsius in order to effectively prevent the generation of sulfides.
④ Installation method
The precautions in the installation process also play a very important role in the life of the agricultural film. The most common point is that there is no tension when installing the agricultural film. When the strong winds come, the agricultural film will constantly and quickly flap the skeleton, causing damage to the agricultural film. Therefore, when installing the agricultural film, the agricultural film must be tensioned evenly. If it is constructed in summer, the installation of agricultural film need not be too tight, because the installation of agricultural film in summer is too tight, and the shrinkage of agricultural film when winter temperature decreases may tear the film. If the construction is in winter, the film should be tightened to avoid swelling in summer.
⑤ Mutual influence
Films with different compositions will affect each other. For example, if the PVC film is used in the greenhouse in the previous season, if the agricultural film wants to change to the EVA film in the next season, please pay attention to remove the PVC film on the left and right shed walls. In order to avoid accelerated aging after the two films are in contact. It should be specially reminded that some vegetable farmers often use bicycle tires covered with bamboo pole heads. However, they do not know that this kind of article is also made of PVC raw materials, which is harmful to the shed membrane. If it is used, it should be replaced immediately.
As long as you pay attention to these five points in the process of use and installation, you can maximize the longevity of the agricultural film.