|
Economically viable bottle-to-bottle
recycling becomes possible for the first time ever: In co-operation
with the Bühler Technology Group, Schmalbach-Lubeca has developed
an improved recycling system for the production of new beverage
bottles from post-consumer PET containers. Under the system reclaimed
PET bottle flake can be pelletized without predrying using a 12-screw
"ring" extruder.
The improved process has
the advantage that recycled PET pellets can now be offered at an
even more attractive price than before, and that they are of equivalent
quality to virgin material.
The Model RE ring extruder will be part of an upgraded
continuous recycling system for food-grade PET. The Model RE has
12 corotating, closely intermeshing screws arranged in a circle.
The system will feed washed PET flake without predrying into the
Buhler ring extruder, which will remove moisture along with any
organic impurities or volatiles. Melt will then be pelletized and
sent into a continuous solid-state polycondensation process, also
engineered by Buhler, raising the PET's I.V. to bottle grade again.
Schmalbach-Lubeca developed
the Supercycle technology, with which post-consumer PET bottles
can be turned into food-grade PET pellets in a two-stage process.
Compared to the existing
process, the optimized Supercycle process, which is based on the
Bühler bottle-to-bottle recycling technology, has the advantage
that two previously separate function steps were combined and developed
into one continuous process:
 |
In a ring extruder, the
post-consumer PET material is dried and freed completely from
any organic impurities, such as flavours. |
|
In the continuous solid
state polycondensation (SSP) process, the polyester is refined
to plastic pellets of greater material strength and thus gains
the same properties as virgin PET pellets. |
The combination of these two functions increases
output and reduces both energy consumption and production cost at
the same time. In addition, the process is particularly environmentally
compatible, since it is based exclusively on thermal and mechanical
process stages without the need for chemical treatment of the material.
The US FDA has approved this bottle-to-bottle recycling system.
The resulting PCR-PET is acceptable for contact with all types of
food, even when hot-filled or pasteurized above 150° F.
|