11. Jul 2019
When, in July 2018, legislation was enacted in Benin banning plastic bags and packaging, blown film manufacturer Asahel Benin Sarl. saw no other option than to convert its production lines from PE to a biodegradable product - which it will compound itself.
Under the new law, the import, production, sale, and possession of petroleum-based plastic bags and packaging are all forbidden.
Until that time, Asahel Benin had used virgin and recycled PE to manufacture its films that were then used predominantly in household products and in shopping bags for supermarkets.
When the new law took effect, the blown film manufacturer had to radically alter its production. Asahel Benin Sarl. turned to the compounding experts at Coperion. From this first contact, a cooperative partnership quickly arose, as did a new corporate strategy thereafter. Asahel Benin Sarl. ordered a laboratory-scale compounding system to develop a biologically degradable compound formulation that could be used in existing blown film manufacturing facilities. The lab-scale system includes a ZSK 26 Mc18 twin screw extruder, four highly accurate powder, pellet, and liquid feeders, as well as a water bath, an air wipe and a strand pelletizer type SP 50. Before the complete system could be delivered to Benin and put into service, it was assembled and tested intensively at Coperion’s Stuttgart location in the test lab.
Following a successful test and training phase at Coperion’s Stuttgart test lab, Asahel Benin Sarl. will be able to start producing biodegradable compounds in its home country.
Coperion contributed its process engineering expertise throughout the project, meeting challenges arising from the system’s complexity, and in particular relating to the twin screw extruder’s configuration. Configuring the twin screws for processing formulations with starch content, can be particularly challenging, as the melting zone in the extrusion process must both melt polymers and plastify non-meltable starch while adding liquid.
Coperion designed the compounding system for Asahel Benin Sarl. very flexibly in order to enable maximum freedom in developing a suitable formulation. The system allows materials to be added from many different components as well as intensive melt devolatilization. Following the die head with nozzle comes a water bath for strand cooling, dewatering of the strand surfaces using an air wipe, and a strand pelletizer.
David Romaric Tinkou is very satisfied with how the project went: “It was clear quite quickly that we needed a new business strategy to keep operating our blown film plants here in Benin. I’m very happy that with Coperion, I encountered experienced experts in the field of biodegradable compounds. Coperion delivered not only the necessary technology, but also shared the necessary process engineering expertise with me so that we can manufacture biodegradable compounds ourselves now in Benin.”
Peter von Hoffmann, General Manager Business Unit Engineering Plastics & Special Applications at Coperion, explained: “We’re thrilled that we could support Asahel Benin Sarl. in switching over their production in order to accomplish it more sustainably. Biodegradable compounds from renewable raw materials unite high production-technical demands with environmental sustainability. Particularly for manufacturers of short-lived household, industrial and agricultural products, these compounds represent a long-term, sustainable alternative to petroleum-based raw materials such as PE. Typical areas of application include single-use flatware, trash bags and trash can liners, food packaging, shopping bags, drinking straws, and agricultural films.”
Image: Coperion K-Tron biodegradable compounding system Benin; from left to right: Peter von Hoffmann, General Manager Business Unit Engineering Plastics & Special Applications; Levin Batschauer, Sales Manager Special Applications; Markus Fiedler, Senior Process Engineer (all from Coperion) and David Romaric Tinkou of Asahel Benin Sarl., in front of the ZSK system at the Coperion test lab in Stuttgart.