PETpla.net Insider 06 / 2018

MATERIALS / RECYCLING PET planet Insider Vol. 19 No. 06/18 www.petpla.net 10 Recycling of post-consumer and post-industrial PET in a challenging environment Sorting things out in Alabama by Valentin Trotter The manufacture of a bottle made of rPET consumes 40% less energy than one made of virgin PET. This competitive edge in ecology is why Byron Geiger, President of Custom Polymers PET, Athens, Alabama, is dedicated to further invest in recycling. This endeavour is especially challenging in the United States – a country ranking amongst the lowest of the Western hemisphere with a recycling rate of PET bottles of only 28.4 %, according to the Recycling Report published in 2016 by “The Association of Plastic Recyclers” and the “American Chemistry Council”. Interview with Custom Polymers PET, April 2, 2018 We met: Byron Geiger, President As a consequence of this, Byron needs to import the pre-sorted raw material from 20 different US states in order to keep the plants work- ing to capacity. Thereby, he receives around 81,000 metric tonnes annually from communal collections, so-called material recovery facilities and other recycling processes. The purity of the collected material is with only 80% in poor condition - the European standard in comparison is of 99% - which makes the recycling process more extensive. After different processing steps 54,000t of recycled PET flake is gener- ated, and in addition around 13,600t of FDA approved granulate. This granulate is manufactured by an Erema plant. The majority of the latter is sold to PET bottle manufacturers. In total Custom Polymers PET recycles approximately 5% of the overall 795,000t recycled PET bottles in the USA, making it one of the leading PET recyclers in North America. The recycling process starts with the plastic bales being broken down. A system then sorts the plastic waste into PET bottles and other objects like cans, HDPE, PVC and household waste, even glass sometimes remains in the feedstock. Byron still uses such foreign material for example by sorting out and selling polyethylene bottles as a sought-after recycling material. Further, a shredder grinds the PET bottles into flakes. This allows a more thorough separation of the compo- nent parts. After passing through a water bath, all materials of a differ- ent density than PET are sorted from the flakes, such as the lighter HDPE and paper labels or the higher density sand. In order to sort out PVC which has the same density than PET, an optical sorter from NRT identifies such flakes by near infrared spectrometry and ejects them by compressed air. A second optical sorter of the same kind identifies and removes remaining foreign bodies, including metal parts, fibres or other plastics. The remaining PET flakes need to be separated by residual colours for different applications. The green ones go into fibre manufacturing. Only the transparent and blue ones go on for further production. After cleaning, drying and packing these flakes are either directly sent on to the processing industry or are being regranulated for the bottle produc- tion. For this, the flakes are dried once more to remove any residual moisture. After this, they are melted down and pressed through a fine sieve to remove the last of any impu- rities and to make it FDA-approved. The now liquid PET is extruded. After hardening in water, the PET strands are chopped into granulate. The clear granulate becomes opaque due to recrystallisation. New bottles entirely made from this granulate without adding any resin can be made. According to Byron, an impor- tant step forward to elevate the rate of recycled PET bottles to a com- parable level would be long-term investments in sorting technologies for PVC labels and lighter bottles. Up to now, air is used to separate lighter PVC labels from PET flakes. This technology, however, bears the disadvantage of blowing away flakes from thin-walled PET bottles too which will then end up as fuel for electricity generation – a rather inef- ficient way of sorting. Nevertheless, the separation process is indispen- sable since Byron needs to assure that the material is PVC-free which is reassured through frequent sampling in the laboratory. www.custompolymerspet.com RECYCLING S P E C I A L Tour Sponsors: Custom Polymers PET is the only recycling company in Alabama. (F.l.t.r.) Byron Geiger and Valentin Trotter