Recycled PET or rPET is obtained from plastic bottles. By recycling them, we are able to transform them into new containers. Through this article, we explain the advantages of favoring recycled PET and how PET is recycled.
What are the advantages of recycled PET?
When we talk about the interest of recycled PET, it is interesting to pause for a moment on certain figures:
The CO2 saving of recycled PET compared to normal PET is not negligible. Indeed, for 1 kg of PET we have approximately 3.25 kg of Co2 rejected while we drop to 0.5 kg for 1 kg of recycled PET, i.e. nearly 85% of Co2 savings. Also, with recycled PET, no additional petroleum is used. The PET that our supplier uses to make recycled PET comes from waste collection in Europe.
PET can be recycled between 4 and 7 times.
Is recycled PET of lower quality? More economical ?
Recycled PET has exactly the same properties as petroleum-based PET. It is therefore of the same quality and its use to contain food or cosmetic products is completely authorized.
The only difference is that sometimes recycled PET is slightly darker: a memory of past lives. Indeed a good part of the PET collected in the sorting channels is dyed and a tiny part of the dyes remain in the recycled PET, giving it its darker color.
Like many recycled materials, recycled PET is more expensive than regular PET. But it is by promoting its use that the sorting sectors are organized, become more efficient and thus recycled materials become more competitive!
What is the recycled PET cycle?
Step 1: PET collection
The first step in PET recycling is us. Indeed, by sorting our waste and depositing our empty PET packaging in the dedicated waste bin, we ensure the start of the PET recycling cycle. Once our waste has been collected, it goes in a truck to the nearest sorting centre.
Step 2: The sorting center
In the sorting centre, these same PET plastic packaging are separated from the rest of the collection. They are then compacted into huge cubes called plastic bales to facilitate their transport to regeneration factories.
Step 3: Grinding into flakes
In the regeneration plants, additional sorting is carried out to eliminate the last unwanted elements. These packagings are then crushed and reduced in the form of flakes.
Step 4: Separating caps and labels
Regeneration plants then “clean” the PET flakes by stripping them of all other constituents of the bottle.
How are PET flakes cleaned?
The sequins will be washed inside machines resembling large vats using hot water and detergents. Combined with the mechanical action of machines, fine particles, labels and their glues are eliminated.
How is PET separated from the other constituents of the bottle?
Then, the flakes from the HDPE caps are separated from the PET flakes using a flotation system. All flakes are placed in water and depending on their density, lightweight materials such as HDPE will float while heavier PET will sink. These two types of flakes are then sent to their respective PET bottle recycling machine streams.
Step 5: The last optical sorting
To improve the quality of the flakes, regenerators sometimes carry out a final purification step by optical sorting. For this, we use different detection methods and cameras that will identify the last undesirable elements among the PET flakes.
A blowing system then separates the PET flakes from other types of plastic.
There are also different types of PET flakes: those in clear PET (from transparent or light blue bottles) and those in dark PET (from dark blue, green or colored bottles). Because these plastics do not have the same final applications at all, it is important to separate them well.
Step 6: Extruding the PET
The PET flakes will then begin an extrusion phase. It consists of melting the flakes at 280°C in a huge machine to produce rods which will be cooled in water and then cut to form granules. There are clear pellets from light PET and colored pellets from dark PET.
Step 7: Purification of the granules
The PET granules are then purified by polycondensation.
What is polycondensation?
It is a succession of chemical reactions during which several molecules combine to form a single molecule by eliminating a single molecule (the unwanted by-product).
The purified granules are then drained and dried before being packaged for transport to recycling plants.
Step 8: PET pellets
PET pellets are purchased by new companies that aim to make new products from recycled plastic.
Step 9: New PET products
In recycling plants, PET granules will be used to manufacture many everyday objects, such as bottles of water or fruit juice, duvet stuffing, fleece scarves, etc.