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the amount of energy passing through the 380 nm and
the amount of energy passing through the 400 nm fil-
ter is calculated. If the ratio approaches 1, then the
object is classified as a PET bottle. In contrast, if
the ratio approaches 0, the object can be classified
as PEN [105]. The materials are then automatically
sorted from a conveyor belt.
PET can be chemically recycled by alcoholysis. It is
believed that a small amount of PEN in PET containers
will not hinder PET recycling.
Supercritical carbon dioxide acts as a plasticizer for
polymers. It has been proposed to introduce supercrit-
ical carbon dioxide in the depolymerization process to
facilitate the depolymerization process [106].
References
[1] Perepelkin KE. Polyester fibres ...