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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

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