Waste plastics are of various varieties and different forms, and many methods of recycling have been created in practice. The following are some examples for reference.
1. Recovery of film
Films are a big part of plastic products, with a wide variety and generally short service life. It is one of the main varieties of recycling and recycling. The following examples are by application and form.
(1) Agricultural film, agricultural film mainly includes mulch film and shed film, mulch film is mainly PE film, shed mold has PE, PE / EVA, PVC film, when recycling and recycling, PE and PVC film should be distinguished, agricultural The film is generally dirty, and often contains dirt, sand, grass roots, nails, wire, etc. To remove iron impurities and clean, the method of recycling is mainly granulation, if, with manual sorting, cleaning conditions, After cleaning and drying, the waste film can be directly used to produce plastic products such as pots, barrels, plastic flanges, etc. by hot extrusion.
The uses of waste agricultural film recycled pellets are as follows
1. PE recycled pellets, PE recycled pellets can be used to still produce agricultural film, can also be used to manufacture fertilizer packaging bags, garbage bags, agricultural recycled water pipes, fences, tree supports, pots, barrels, garbage bins, geotechnical materials, etc.
2. PVC recycled pellets, PVC recycled pellets can be used to produce heavy packaging bags, agricultural water pipes, shoe soles, and other packaging films. The materials of packaging films include cellophane (Sai Luo), PE, PVC, PP, EVA, PVDC, PA , PET and various composite films. Single-layer packaging film of one material can be directly made into plastic products or granulated into various products like agricultural films after sorting and cleaning. Composite films include composite films of different plastics and films made of plastic and paper, aluminum foil, and other materials. The recycling process after recycling is more complicated, such as: multilayer plastic composite film, multilayer plastic composite film has PE / PP, PE / EVA / PE, PE / adhesive / PA / adhesive / PE, PP / PVDC, etc. Before recycling, different materials must be separated first. Solvent separation method can be used for separation.
Paper-plastic composite film. The paper-plastic composite film needs to be separated from paper-plastic before recycling. This is also the method of paper-plastic composite separation. The separation device is a chrome-plated hollow cylinder with electric heating. The cylinder is equipped with a blade The hollow cylinder, the barrel and the hollow cylinder rotate in opposite directions, the broken paper-plastic mixture is added to the barrel, the plastic on the heated mixture in the barrel is melted, and the material is discharged from the bottom of the barrel. The air in the hollow cylinder Take away the exhaust gas.
Aluminum-plastic composite film, aluminum-plastic composite film has BOPP / aluminum, PE / aluminum, etc. It is used for various food packaging. The used aluminum-plastic composite flexible packaging bag is actually a mixed waste, which is difficult to recycle. The treatment method abroad is mainly incineration to recover heat. China has methods of incinerating aluminum, crushing and adding fillers to make low-grade crude products, and the effect is not ideal. Here is an example of using aluminum's conductivity to manufacture antistatic functional materials. The process is as follows: aluminum-plastic composite waste-cleaning-crushing-sieving-pellets-aluminum powder-additives-extrusion-semi-finished products-extrusion-finished products . The aluminum-plastic composite waste is washed, crushed and sieved for 10 days, and then agglomerated. This process can use the agglomeration machine of Beijing Plastic Machinery Factory. The process conditions of the pellets are water spray: 95 degrees water 0.8 liters, feeding time: 3min; pumping time 5min crushing time 10min, 15 kg each treatment The pelletized material is then extruded with an extruder to form a semi-finished product. This semi-finished product is then added to 20% aluminum powder, flame retardant, compatibilizer and other additives. As a conductive材料。