Plastic packaging products refer to containers made of […]
Plastic packaging products refer to containers made of plastic raw materials for packaging items. Plastic packaging products have replaced packaging containers made of metal, glass, ceramics, wood and other materials in many ways, showing strong vitality. What we want to introduce to you is about the recycling method of plastic packaging products:
1. Physical method: pulverize the clean waste PET film or waste PET bottle and then use the extrusion granulation equipment to granulate into regenerated chips and directly mix them into new materials for use. The chemical structure of PET chips regranulated by physical methods has not changed, but the molecular weight is slightly reduced, which does not affect the use. The equipment used for recycling granulation includes twin-screw extruder and compression and densification extrusion granulator. The characteristics of these two recycling granulation equipment are that they do not need to be dried before processing and are directly fed with clean crushed materials. The extruder melts and plasticizes, and evacuates through the exhaust port. The melt passes through the porous die to produce PET particles of regular shape and uniform size, and the viscosity is very small, which can be completely recycled.
2. Chemical method: still taking polyester as an example, alcoholysis can be used. Because polyester is a high polymer made by esterification and polycondensation with PTA and EG as the main raw materials. Because the polycondensation reaction is a reversible reaction, under certain conditions, the PET side waste can be recycled clean PET crushed material by alcoholysis, and methanol or triethylene glycol is used to depolymerize the PET into monomers or partially depolymerize it under the action of alkaline catalysts. Oligomers, and then re-polymerize monomers or oligomers into PET resin for reuse in packaging materials or to make polyester staple fibers.