Example Analysis of Plastic Film Recycling and Utilization Methods

Waste plastics are diverse in variety and in various forms. In practice, many methods have been created for recycling. Here are some examples for reference.

1, the addition of the film

Films are a large group of plastic products. They have a wide range of types and they have a short service life. They are one of the main types of recycling and recycling applications, and they are used according to their purposes and examples.

(1) Agricultural film, agricultural film mainly includes plastic film and shed film, plastic film is mainly PE film, PE, PE/EVA, and PVC film are used in the shed film. When recycled and recycled, PE and PVC film should be separated. The film is generally dirty, and often contains dirt, sand, grass roots, nails, iron wire, etc., to remove iron impurities and cleaning, recycling method is mainly granulation, if, with manual sorting, cleaning conditions, After washing, the dried film can be directly used to produce plastic products such as pots, buckets, plastic flanges, etc. by hot extrusion.

The use of recycled agricultural film pellets is as follows

1. PE recycled pellets, PE renewable pellets can be used to still produce agricultural film, can also be used to make fertilizer packaging bags, garbage bags, agricultural reclaimed water pipes, fences, tree supports, pots, barrels, waste bins, geotextiles, etc.

2, PVC recycled pellets, PVC recycled pellets can be used to produce heavy bags, agricultural water pipes, soles, etc.

Packaging films, packaging film materials include cellophane, PE, PVC, PP, EVA, PVDC, PA, PET and various composite films. The single-layer packaging film of a material, after being sorted and washed, can be directly made into a plastic product like a farm film or granulated and made into various products. Composite films include composite films of different plastics and films made of plastics and paper, aluminum foil, and other materials. Recycling after recycling is more complicated such as:

Multi-layer plastic composite film, multi-layer plastic composite film PE/PP, PE/EVA/PE, PE/adhesive/PA/adhesive/PE, PP/PVDC, etc. The material is separated. Solvent separation can be used.

The paper-plastic composite film and paper-plastic composite film must be separated from paper and plastic prior to recycling. This is also a paper-plastic composite separation method. The separation equipment is a chrome-plated hollow barrel with electric heating. The barrel is equipped with a blade. The hollow cylinder, the cylinder and the hollow cylinder rotate in opposite directions. The broken paper-plastic mixture is added to the cylinder. The plastic on the heated mixture in the cylinder is melted and discharged into the lower part of the cylinder. The air in the hollow cylinder is Take away the exhaust gas.

Aluminum-plastic composite film, aluminum-plastic composite film is BOPP / aluminum, PE / aluminum, etc., used for a variety of food packaging, after the use of aluminum-plastic composite soft packaging bag is actually a mixed waste, recycling is more difficult. The method of treatment abroad mainly recovers heat from incineration. China has a method of burning aluminum and crushing and adding fillers to make low-grade crude products. The effect is not ideal. Here is an example of the use of aluminum conductivity, manufacturing antistatic functional materials, the process is as follows:

Aluminum-plastic composite waste - washing - crushing - sieving - pellets - aluminum powder - additives - extrusion - semi-finished products - extrusion - finished products

The aluminum-plastic composite scrap was cleaned, crushed and screened on a 10-day sieve, and then pelletized. This process can be used with a pelletizer from Beijing Plastic Machinery Factory. The granulation process conditions were water spray: 95 degrees water, 0.8 liters, feeding time: 3 minutes; pumping time 5 minutes, grinding time 10 minutes, 15 kilograms each time. The pellets are then extruded using 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. The product can then be obtained by extrusion granulation. For conductive materials.

3. PET film, in the plastics industry, PET is mainly used as film and bottle, and the film can be used as packaging, decoration, tape-based or capacitor insulation, PET film is also used as a film base, PET is also used for fiber, film and fiber The physical viscosity of PET is higher than PET PET bottle. Therefore, there are also slight differences in recycling.

The scrap produced by PET film and fiber production plants can be used to wait for polyester/epoxy powder coatings. Generally, these scraps have a relative molecular weight of about 20,000 and a melting point of 260 degrees Celsius or more, which is a single linear PET. By dehydrating such scraps with a polyol at 250 to 260 degrees, a low-melting oligomeric polyester having a molecular weight of about 2000 to 5000 can be obtained. Oxidation Polyester Addition of dibasic anhydride and esterification agent at 200 to 220 degrees to obtain a product with an acid value of about 3.05 mgKOH/g, a softening point of about 85 to 105 degrees, and a glass transition temperature of 50 degrees or less. Used for making polyester/epoxy powder coating.