How is the agricultural plastic greenhouse film produced?

The main purpose of the agricultural plastic greenhouse film is to use it as a vegetable greenhouse to keep warm and moisturize the vegetables. According to the needs of greenhouse film use, different raw material composition formulas can be used to extrude blow molding ordinary greenhouse film, enhance greenhouse film, non-drip greenhouse film and longevity greenhouse film and other different products.
The performance of ordinary greenhouse film is the same as that of polyethylene film; the strength of greenhouse film is higher than that of ordinary greenhouse film, and the toughness is good; the long-life greenhouse film has good aging resistance, and the use time is longer than that of ordinary greenhouse film; The use of greenhouse film is characterized by less water mist on the membrane surface and good light transmission, and water droplets can flow into the ground along the membrane surface.
1. Raw material selection. Plastic greenhouse film molding can be selected from low density polyethylene and linear low density polyethylene. The blending ratio of the two raw materials, LDPE accounts for about 60%, and LLDPE accounts for about 40%.
The raw material for long-life film formation can be added with 0.4% anti-aging agent (such as di-tert-butylhydroxytoluene BHT) and 0.15% anti-oxidant in the enhanced greenhouse film formulation, and sometimes an appropriate amount of liquid paraffin should be added.
2. Equipment conditions. Due to the wide width of the agricultural plastic greenhouse film and the large amount of molten material for molding, a large-size extruder is required. Generally, a 2 mm film with a diameter of 90 mm should be used for the production of a film with a screw diameter of 90 mm. For a film with a diameter of 4 m, an extruder with a screw diameter of 150 mm should be used. In order to increase productivity and ensure the quality of raw material plasticization, a separate screw extrusion material having a barrier section is selected.
The molding die can be selected from a spiral structure. In order to reduce the weight of the mold, the lotus petal mold structure is adopted, and the mold body is lighter in weight, but the surface of the formed film has a plurality of melt wiring patterns.
3. Greenhouse film extrusion blow molding process parameters. Process temperature of each section of the machine: feeding section 140-160 ° C, plasticizing section 160-180 ° C, homogenization section 190-200 ° C. The molding die temperature is 180-190 °C.