Study Of Waste Agricultural Film Dry Process Granulitization And Utility Analysis

Supported by research cooperation between China and Korea on "technologies for intermediate stuff & final industrial goods from waste plastic film", study the dry process technology of waste agricultural plastic film granulitization, and discuss with this process the intermediate stuff application in China.To make the dry process more practical, waste plastic film was dried to remove impurity. Dry process granulitization means agricultural film was made into pellets without water. The influence of procedural parameters had been researched, such as slendemess ratio of extruder, type of cutting, composition of film, heating temperature, water content, soil content, cold water temperature. In different conditions, mechanical and thermal property of intermediate stuff from waste plastic film had also been compared. And the final industrial goods from dry process were commended, which can meet national criterions and trade standards about plastic, in order to offer tech support of waste agricultural plastic film recycling industrialization, which can be appropriate to China's needs.The experimental results showed that with drying procedure before waste agricultural plastic film granulitization soil can be separated effectively, and the higher drying temperature and longer time, the more separating effect. Besides, bigger slendemess ratio of extruder, higher temperature of extruder head and fluxing zone, bigger strainer aperture of die head can raise the pellets productivity. Added HDPE to LDPE film can improve mechanical property of intermediate stuff, but make melting temperature rise and extruding difficult. Generally, the more soil content, the bigger modulus in tension of intermediate stuff, but lower heat distortion temperature. It is the same to less water content and higher cold water temperature. The type of cold cutting is simple, but with this type pellets were trailing and bad regularities. The other way round, for hot cutting with pendular water ring, it needs high required of the machine and complex management. But with this type pellets were higher appearance quality and better properties. High heating temperature canmake energy waste and pellets property lower, but low heating temperature can result in operating trouble. So according to processing facilities and actual requirement, suitable cutting type and heating temperature should be chose. In this study the proper heating temperature of normal host extrude is 180"C,190°C,200 °C,210°C, and the auxiliary extrude's is 190 °C ,200 "C. The proper heating temperature of extrude with pendular water ring is 155°C,145°C,143°C,140°C,137°C. The key of dry process is technology of impurity separation, which is also the bottleneck. If the quality problem of intermediate stuff from waste plastic film isn't solved, the dry process of waste agricultural plastic film recycling industrialization won't be come true.Intermediate stuff from dry process granulitization can be used to produce PE pipes. These pipes are added to new material or HDPE to improve property, which can be quite up to various correlative standards.