PLA has been a focus at Sulzer Chemtech for many years – even before the current surge of interest in ‘green’ solutions. Sustainable Plastics talked with Alex Battù, sales manager of the PLA team at the company, about the challenges involved in building systems to produce this bioplastic, compared to conventional materials.
So, starting with the obvious question - when and why did the company decide to become involved in PLA?
In recent years, PLA has gained significant market attention, with several large brand owners announcing evaluation of this material or even launching new solutions based on PLA as a sustainable alternative to existing fossil-based plastics in packaging, compounding and thermoplastic applications.
Sulzer has developed, firstly thanks to its work in the lab and then in the pilot plants, a flexible and robust technology to enable PLA producers to enter into the biopolymer market at customizable scale with various PLA grades, from low to high molecular weights, and various L/D contents.
We have been involved in developing the technology for over 25 years. Our process has been scaled-up from lab scale bench tests and extensive pilot testing, to large production capacities and it is nowadays state-of-the-art in PLA technology, ensuring stable operation, fast control and short residence time.
Thanks to our engineering and assembly capabilities, we develop and execute entire projects, from the first concept to an industrial scale plant using in house engineering, equipment, assembly, commissioning & start-up capabilities. The test centre makes it possible to carry out laboratory and pilot scale trials in order to validate the process for specific client requests.
Our company has also developed innovative key equipment as part of its PLA production offering, such as falling film crystallizers, loop and plug-flow reactors (SMXTM), Sulzer Mixer Reactors (SMRTM) distillation and degassing technologies, all of which are already well-established members of its technology portfolio.
We also design and implement equipment and integrated modular solutions for individual steps of the polymerization process. We offer several additional services to ensure that customers in the agricultural, chemical and fibre sectors can continuously benefit from their integrated PLA technology.
You said that PLA is generating an increasing amount of attention in the market. But what is PLA, exactly? What kind of feedstock is used today, and what will this be in the future? Can you give examples of some applications?
PLA is a versatile, bio-based and biodegradable polymer that can replace petroleum-based plastics in a wide range of applications. The technology we developed is feedstock agnostic. This means that process industries around the globe can use the local plant-based resources available to produce the necessary sugars. This possibility allows users to maximize the process’s cost-effectiveness, and the reliability of the supply chain, while minimizing the carbon footprint for raw material transportation. For example, sugar cane and its bagasse can be chosen as the raw material for PLA production in equatorial regions, while straw, corn or wood chips can be the most suitable options in moderate temperature zones.
Although I should point out: our technology starts from sugar. The development of second generation feedstock - extracting sugar from lignocellulosic feedstocks - is not our core business, but is an upstream activity. Give us the sugar and we can make PLA.
PLA can be used in many applications: thermoformed products, fibres and non-woven materials, films or moulding. It performs like traditional polymers — such as PET and nylon 6 — and it can be processed in casts made by blown film machines. It can be spun into fibre on conventional extruders. All these exceptional properties make PLA not only suitable for packaging, medical devices and implants, as well as electronic devices, but also for textiles, 3D printing processes and components for the automotive sector. And the possibility to produce PLA composites, such as foamed PLA, further expands the range of applications for this bioplastic.