Extrusion International 1-2019

44 Extrusion International 1/2019 RECYCLING – CASE STUDY food packaging films should be pro- cessed, as this promised higher sales revenues. However, it turned out that the DRD-dry cleaning process can only separate a small proportion of food fats adhering to the films. This lim- ited the throughput at the extruder, whose degassing system managed to “degrease” the plastic melt only up to a throughput of 350 kg/h – one third of the maximum output. The conclu- sion was that it would not work with- out changing the concept. Specialization as a success factor Now– it was the year 2013 – struck the hour of Peter Daalder. He bought the two DRD and after a call to MAS boss Schulz, who acted as a middleman, the cascade extruder and accessories. Thus, the technical conditions for the founding Daly Plastics sister company Caroda Polymer Recovery (named af- ter Peter Daalder’s daughter Caroline) were given. The commercial basis was the decision to specialize in the future on the processing of agricultural and industrial films (= pallet over-packag- ing, with a high proportion of LLDPE shrink films) (Images 2 and 3). The Caroda polymer plant after some optimizations and with the support of MAS hit the ground running very well. Above all, the filter technology had to be optimized: Finally between the extruders of the cascade a contin- over. The consequence for Europe must be a turnaround to higher plas- tic recycling rates. Looking back, I am glad that I was impressed by his argu- ments. From that day on, I prepared myself mentally for self-processing and started it in 2013. The prophecy of Helmuth Schulz, who died in Sep- tember 2017, came true on January 1, 2018, when China closed its borders for used plastics withmore than 0, 5% impurities closed. This has torn deep holes in the balance sheets of plastic exporters with no in-house process- ing. Since we were already process- ing a large part of our collected plas- tic volume ourselves at that time, we were only marginally affected.” Errors drive you smart However, before the concept was up and production could begin, a num- ber of opportunities had to be taken and technical points set. A major ar- gument for contacting MAS was the waterless DRD (Double Rotary Disc) dry cleaning system. Because Daly Plastics intended to get along without a wet-washing process and the relat- ed expensive sewage sludge disposal when processing agricultural films. Since mainly granular soil particles and moisture had to be removed, at- tempts were made with the waterless DRD (Double Rotary Disc) dry clean- ing system of MAS, which proceeded satisfactorily. In the meantime, Daly Plastics relies entirely on MAS ma- chine technology when processing pre-sorted and flake-finished films. The cleaned film-flakes can be pro- cessed on the MAS cascade extrusion line, consisting of the conical co-rotat- ing twin-screw extruder MAS 93 (Im- age 1), a TA-90 single-screw extruder and a continuous disc filter between the two extruders to high-quality granules. But a short time after the plant went into operation a Daly Plastics cus- tomer for plastic waste changed his strategy. Instead of continuing with processing agricultural films on his MAS recycling system, starting in 2013 Image 6: Partial view of one of the three operatingMAS cascade extruders. From left to right: MAS 93 extruder, MAS disc filter, MAS TA90 extruder with subsequent fine filtration system and granulation Image 7: MAS sales engineer Gerald Badegruber and DALY Plastics shareholder Peter Daalder, visibly satisfied with the long-termperformance of theMAS systems, the first of which has been running for more than 30,000 hours in 4-shift operation