Issue 06/2021
Highlights: Coating Films, Flexibles, Bags Basics: Cellulose based bioplastics
Highlights:
Coating
Films, Flexibles, Bags
Basics: Cellulose based bioplastics
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Recycling<br />
Merging high-quality recycling<br />
with lowered emissions<br />
Changing the way we think about plastics is a task facing<br />
the entire value chain, but the main focus still lies<br />
where a product’s life meets its smelly end’ – on waste<br />
management. While keeping an eye on the ongoing need to<br />
reduce climate impact, we also need to broaden our recycling<br />
technology horizons. Ultimately, high-quality recycling is what is<br />
going to be needed to make the plastics economy truly circular.<br />
The Newcycling ® process<br />
APK AG was founded in 2008 with the vision of producing pure<br />
polymers with properties close to virgin plastics from mixed<br />
plastic waste, including multilayer film waste. Researchers and<br />
engineers at APK have developed a physical recycling process<br />
that combines mechanical recycling steps with a targeted<br />
solvent-based step – their Newcycling technology.<br />
Where is this process positioned on the spectrum of<br />
plastics recycling technologies? A comprehensive overview of<br />
technological innovation is badly needed in order to understand<br />
which elements each technology branch (mechanical/<br />
advanced physical or chemical) can contribute to creating a<br />
circular economy for plastics – and how these processes can<br />
complement each other.<br />
Recycling technology delineation<br />
APK’s technology is a physical (also referred to as material)<br />
recycling technology. The molecular structure of the polymer is<br />
kept intact, as is the case in standard mechanical recycling. This<br />
is the major difference in comparison to chemical processes.<br />
Recently, the delineation of innovative recycling processes has<br />
begun to become more refined and therefore clearer. The use of<br />
a solvent does not automatically designate the recycling process<br />
as being chemical. There are innovative approaches on both<br />
the physical side of the spectrum (dissolution, etc.) and on the<br />
chemical side (for example, solvolysis).<br />
Because physical, solvent-based recycling does not break<br />
down molecular chains, no energy needs to be invested in repolymerisation<br />
– one reason for the low carbon footprint of<br />
recyclates produced via such technology.<br />
Newcycling consists of the following steps:<br />
Waste from PA/PE multi-layer film production is first<br />
mechanically pre-treated, undergoing, among other things,<br />
shredding and classification. Next, the PE layer is dissolved and<br />
liquefied in a solvent bath, leading to separation of the polymers<br />
and polymer layers.<br />
The undissolved PA is then separated from the dissolved<br />
PE using conventional solid-liquid separation technology and<br />
the polymers are subsequently further processed in separate<br />
material streams.<br />
The PA is introduced into a twin-screw extruder, where it<br />
passes through various process sections and is processed into<br />
a high-quality PA melt, using very high dispersion performance<br />
and intensive devolatilization. Finally, it is pelletized into firstclass<br />
PA recyclates.<br />
Any remaining contaminants in the liquefied PE, such<br />
as degraded additives, inks, etc. are removed (purification).<br />
Then an additive package is added (re-additivation). Following<br />
pre-evaporation, the PE is likewise introduced into a twinscrew<br />
extruder, together with the solvent. There, intensive<br />
devolatilization of the liquid takes place, which has been<br />
precisely calibrated for this application so that even when PE/<br />
solvent ratios fluctuate, first-class results will be produced.<br />
The solvent is completely volatilized and added back into the<br />
Newcycling process in a closed loop. The PE remains in the form<br />
of a homogeneous, high-quality melt, which is then pelletized.<br />
The resulting PE recyclate is of a quality similar to that of virgin<br />
plastics.<br />
In April <strong>2021</strong>, the renowned recyclability certifier ARGE<br />
cyclos/HTP (Aachen, Germany) audited APK’s recycling facility<br />
in Merseburg, Germany, for conformance with the EuCertPlast<br />
certification scheme. The audit focussed on the suitability of<br />
APK’s plants for the recycling of post-consumer waste from<br />
plastic films as well as of waste from PE/PA multilayer film<br />
production. All test requirements were successfully fulfilled<br />
and in July <strong>2021</strong>, ARGE cyclos/HTP awarded APK the official<br />
EuCertPlast certificate.<br />
Recycing technology delineation (© APK)<br />
30 bioplastics MAGAZINE [<strong>06</strong>/21] Vol. 16