The recycling method of PET is generally divided into physical and chemical methods, many foreign companies use chemical method, but because of its high cost, the application of the technology in China has been limited. In this paper, the technology content and process of recycling method are combed, and the hope it is helpful to the enterprise friends of the majority of renewable polyester industry.
There are two methods of PET synthesis: one is the condensation reaction of (TPA) and ethylene glycol (EG); one is the exchange reaction of two methyl terephthalate and EG. These two reactions are reversible reaction, under the action of excess water or alcohol, the reaction can occur under certain conditions, so that the PET can be decomposed into single or oligomers, and the use of monomer to synthesize food grade PET resin.
Hydrolysis is under a certain temperature and pressure, in different pH solution as the medium, bottle feed pet hydrolysis diacids and diols, general hydrolysis method must be treated with mechanical method, removal of impurities, the technology is complex, cost recovery is relatively high, and the impurity induced accumulation. TPA and EG are one of the important methods for the production of PET, which is a important method for the production of polyester. The PET hydrolysis method has been paid more and more attention. According to the different pH value can be divided into: neutral hydrolysis, acid hydrolysis and alkaline hydrolysis.
Then the physical recycling method
GREENMAX provide a new way: POSEIDON Series could do the PET bottle dewatering work for all kind of beverage with the package of plastic bottles like PET bottles, carton box, aluminum cans, etc.
The process is:
Empty plastic bottles are collected and taken to a Materials Recovery Facility, where they are separated from your other recyclable materials.Then,.The bottles are squashed, baled and sent to the reprocessing company.Later on,The bottles are dry cleaned and sorted using an optical beam which separates the different types of plastic.Last,.The bottles are then ground into flakes which are washed and sorted again. Depending on the kind of plastic, the flakes are either decontaminated using a chemical solution or melted down and sieved to form beads as the plastic cools.These beads and flakes can be melted down again and turned into new products. This can include packaging, drainage pipes, garden furniture or simply new plastic bottles.