PETpla.net Insider 06 / 2020

MATERIALS / RECYCLING PETplanet Insider Vol. 21 No. 06/20 www.petpla.net 23 Now, coming to products, REFIT comprises additives and colours that are dedicated to plastic recycling and offer a broad-spectrum support in the form of aesthetics enhancers and mechanical boosters: Anti Yellow (AY) additives and IV enhancers. The colour of rPET varies a lot from sup- plier to supplier (and even from one batch to the other) and depending on the ratio of recycled PET used, the result can be anything from grey or pale yellow, to blue or greenish. The more recycled content the bottle has, the darker the end colour will appear. The AY range comprises different liquid additives able to balance the appearance of variations in material and to regain brightness, correct a greenish or greyish tone. Mechanical challenges, instead include a drop of the IV when using rPET. This happens because PET, after several production cycles, due to degradation, shows a reduction in the molecular weight: its chains are shorter, and the final product is mechanically weaker. Repi’s IV Enhancer combine shorter molecular chain to longer ones, thus increasing the IV of the material. Besides additives, colours can also come to the rescue. When a very dark rPET is used and an Anti-Yel- low additive is not enough, correc- tions through colour may be crucial. Repi’s Fumé colour range is made of shades like ambers, light blues, greens or greys, that are used at very low dosages (as low as 0.05%) so not to impact the recycling stream. The entire value chain of plastic packaging has been working hard and constantly for many years on making plastic recyclable and recycled. Now more than ever, I like to think that the world after the pandemic will be wiser and more collaborative on a global scale. I want to believe that we are learn- ing that blam- ing one solution against the other is not the right choice because, after all, each challenge has different facets and none of them can be overshad- owed. Let’s RE- focus instead on what “delivering the circular econ- omy” means, without forget- ting the carbon footprint impact of our choices. This is the only way to get to structured solu- tions, that will be effective and positive in the long run. Let’s be careful not to look at circular- ity with too narrow lens. www.repi.com RAW MATERIALS CARRIER SYSTEM Assuming pigments and active ingredients are similar, carbon footprint of carrier will make the difference COLOUR CONCENTRATION • Carbon footprint proportional to volume and weight being transported • High colour concentration (lower LDR) will lower the carbon footprint PROCESSING TECHNOLOGY • Energy efficiency depends on processing technology, e.g. polymer extrusion vs mixing & grinding • PACKAGING TECHNOLOGY • PACKAGING MATERIALS • Energy efficiency of packaging technology • Carbon footprint of packaging materials • Recyclability COLOUR CONCENTRATION • Carbon footprint proportional to volume and weight being transported • High colour concentration (lower LDR) will lower the carbon footprint • DOSING SYSTEM • COLOUR/ ADDITIVE CHANGE • Carbon footprint of dosing system (mass and materials) • Energy efficiency of dosing technology (faster change and therefore shorter transition time and production waste • Efficiency in setup and change of setup • LDR • Quantity of colour • Recyclability RAW MATERIALS TRANSPORT COLOUR/ ADDITIVE MANUFACTURING COLOUR/ ADDITIVE PACKAGING COLOUR/ ADDITIVE TRANSPORT PRODUCT PROCESSING PRODUCT LIFECYCLE UP TO WASTE DISPOSAL 1 2 3 4 5 6 7 PROCESS STEP DRIVERS RATIONALS Liquid colours vs masterbatches - carbon footprint comparison