Extrusion Technology for Lignin-Based Biomaterial
Largest Natural By-Product Blended with Thermoplastics
Swedish innovation company RenCom AB is working on a new type of bioplastics, the production of which is to be particularly energy-saving through the addition of lignin. For every kilogram of fossil-based plastic that is replaced by the new material, the CO₂ footprint is said to be reduced by about 5-6 kg.
Lignin consists of plant biopolymers and is a by-product of wood processing. According to the Swedish company, approximately 80 million tons per year are used in the pulp industry worldwide, making it the world's most important natural by-product in terms of mass. So far, however, it has been used almost exclusively (99%) for energy generation, i.e. it is not recycled.
Market launch planned for 2021
On the basis of comprehensive tests and investigations in the extrusion pilot plant of Coperion GmbH in Stuttgart, the companies were able to further develop the processing of this lignin-based material. With the aid of ZSK twin-screw extruder technology, RenCom will now be able to produce up to 1000 tonnes per year from the end of 2020. This is an important step towards launching the material on the market at the beginning of 2021, explained Christopher Carrick, Chief Executive Officer at RenCom. His company plans to further expand its cooperation with Coperion in the future.
RenCom has a patented material and process that energy-efficiently transforms lignin into renewable, degradable biomaterial, marketed under the name Renol. According to Rencom, after passing different process steps, including extrusion and compounding, it becomes a durable, reusable biomaterial that can be used for all kinds of plastic products, such as bags and glues. It can be used directly in existing production infrastructure without any modifications to machines or methods.
Extrusion technology for future-oriented biomaterial
Coperion has in cooperation with RenCom designed a complete extrusion system comprising a ZSK co-rotating twin screw extruder, gravimetric feeders, a strand pelletizing system, a lignin bag dump station and a big bag station to RenCom. According to Coperion, the ZSK Mv Plus series unites a balanced large free screw volume with high screw speeds and a high specific torque.
Thanks to the deeply cut screw flights thermal stress on the raw material is very low and product processing is very gently. By using the side feeder ZS-B, fillers and additives can be added to the process section according to the requirements of the end product. The complete system will be delivered in October. (kk)
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