Extrusion International 2-2021

39 Extrusion International 2/2021 COMPOUNDING – CASE STUDY Thisnewcompoundingequipmentserves to expand upon Asahel Benin’s pilot sys- tem from Coperion which the company has successfully used to manufacture biocompounds since Benin’s July 2018 prohibition of plastic bags and packag- ing. Asahel Benin processes these bio- compounds on its blown film machines into biodegradable bags and packaging, making the company a pioneer among west African manufacturers of more en- vironmentally friendly short-life plastic products. The new STS 65 Mc 11 extruder and its pe- ripheral equipment are currently being in- stalledonsite.Asahel Beninwill beginpro- duction on this machine in spring 2021. Compounding Technology with High Flexibility Coperion designed Asahel Benin’s com- pounding machine to be very flexible in order to achieve maximum freedom in the production of biocompounds. For example, thanks to the highly accurate Coperion K-Tron feeders, the system can an air wipe, and the compound is finally pelletized in an SP 220 treasure strand pelletizer. Coperion ensured that all of the product- contact machine parts have high wear protection, further increasing opera- tional flexibility. Asahel Beninwill be able to process various raw materials, even highly corrosive and abrasive ones, on this compounding system for many years to come. Sustainable Corporate Strategy Since 2018, the import, production, sale, and possession of petroleum-based plas- tic bags and packaging has been banned in Benin. Prior to that time, Asahel Benin Sarl. had used both new PE pellets as well as recyclates for manufacturing the films that were then used predominantly in household products and in shopping bags for supermarkets. The new law was at once both a chal- lenge and an opportunity for Asahel Benin. The company switched its pro- duction completely to bio-based plastics. Following a successful test and training phase at Coperion’s Test Lab in Stuttgart, Asahel Benin Sarl. began manufactur- ing biodegradable compounds using a laboratory system built around a ZSK 26 Mc 18 in its home country. The company then processes these materials into bio- degradable bags and packaging on its blown filmmachines. handle a variety of raw materials, de- pending on the recipe. The four loss-in-weight feeders include two T35 twin screw feeders, one S60 sin- gle screw feeder as well as a liquid feeder. While the S60 single screw feeder offers an optimal delivery of free-flowing ma- terials such as base resin pellets or granu- lates, the self-cleaning action of the T35 twin screw feeders makes them ideal for feeding particularly difficult powder addi- tives, such as starch or calcium carbonate. BothT35 twin screwfeeders are equipped withCoperionK-Tron’suniqueActiFlow™ smart bulk solid activator which reliably prevents the formation of material bridg- es or ratholes in the hopper. All four feed- ers aremounted on platform scales which feature patented Smart Force Transducer (SFT) single wire weighing technology. These scales provide accurate, stable and reliable digital loadmeasurement under a broad range of operating conditions. To- gether with the fast sampling rate of the KCM-III feeder controller this advanced weighing technology results in extremely high short-termaccuracy, which is particu- larly important in continuous extrusion processes. The biodegradable polymers are melted in the process section of the STS 65 Mc 11 extruder, andnon-meltable components, such as starch, are plasticized. Intensive dispersion and devolatilization of the melt results. After passing through the die head and nozzle the extrudate goes through a water bath for strand cooling, the strand surfaces are then dried using Blown Film Manufacturer in Benin Expands Biocompound Capacity Blown fi lmmanufacturer Asahel Benin chose a Coperion compounding systembuilt around an STS 65Mc 11 extruder to further expand production of bio-based compounds (Photo: Coperion, Stuttgart) To expand sustainable production, west African blown filmmanufacturer Asahel Benin Sarl. has ordered a second Coperion compounding system specifically for manufacturing bio-based compounds. This system, built around an STS 65Mc 11 twin screw extruder with side feeder, includes four Coperion K-Tron feeders for high-accuracy feeding of powders, pellets and liquids, as well as an SP 220 treasure strand pelletizer with a water bath and an air wipe Coperion GmbH Theodorstr. 10, 70469 Stuttgart, Germany www.coperion.com Coperion K-Tron high-accuracy loss-in-weight feeders can be out fi tted with an ActiFlow smart bulk solid activator to prevent ratholing and bridging of dif fi cult powders (Photo: Coperion K-Tron, Niederlenz)