Environmental Engineering Reference
In-Depth Information
9.5.2 Open-Loop Recycling
In open-loop recycling, two “lives” of the plastic are very different as shown
in
Figure 9.15
.
Figure 9.15
An illustration of open-loop recycling of PET into fiberfill.
In the right-hand part of the figure, the mechanics of recycling are
summarized in the second box as “Wash-Float-Dry.” Generally, the bottles
are prewashed, sorted, granulated, floated, and dried. Sorting is often done
manually but automatic sorters based on reflective near-infrared (NIR)
sensors operating at a speed of over 10 bottles per second are available.
The rejected items are automatically ejected off the stream to be discarded.
Modern sorting technologies are capable of providing recycled plastics that
are nearly 100% of one a single polymer type (Franz and Welle, 2003).The
