„Planstic“: The Filament of the Future?
An environmentally friendly alternative to conventional PET has recently been developed in Hong Kong. It is a 3D printing material that can be dissolved almost completely if required. The filament, made from plant leaves and polymeric waste, is called „Planstic.“
High Biodegradability: Leaving Behind Very Few Microplastic Particles
In the face of the looming consequences of climate change, the new filament could be an important step towards climate neutrality if it is soon ready for mass production. „Planstic“ has highly entropic fibers that attract natural enzymes. These accelerate the decomposition of the material when it is discarded and ends up in the soil, for example. After only eight weeks of decomposition, “Planstic” is completely degraded, leaving behind what can be considered a small amount of microplastic particles. In order to analyze the biodegradability of the filament, the research team deposited it in composted soil after it was completed. This revealed that the enzymes in the base of the leaf decomposed „substances that are difficult to degrade“ such as cutin. Interestingly, the less stable surface of the material also improved the rate of degradation by allowing microorganisms to come into contact with the material and speed up the process, contributing to „almost complete plastic degradation.“
There is a Difference to Allegedly Biodegradable Plastics
„Planstic can reduce the cost of secondary pollution cleanup and can be generally used in daily life to solve the plastic degradation problem worldwide,“
the researchers‘ paper states. But why doesn’t this work with plastics that are considered biodegradable?
„The main problem with biodegradable plastics is that plastic items labeled ‚biodegradable‘ can only be broken down into smaller pieces. This is not an improvement over conventional plastics“,
it continues. This means that, for example, disposable packaging that is labeled biodegradable simply breaks down into many pieces in reality and thus continues to pollute the environment in many cases.
How is The New Filament Produced?
The plastic that makes up the „Planstic“ solution is infused with plants, and uses natural enzymes to break down tiny polymer particles much more efficiently. The material is made from the combination of redbush leaves and ground PET. These elements are mixed in a boss box, plasticized and thus made printable. In addition, leaves of Cersis chinensis are integrated, which naturally contain long fibers that can be easily degraded. The reinforcement of these fibers improves the properties of the filament at the crossing points. A blend of 80 percent fibers and 20 percent PET was ultimately chosen. This blend is deposited into a series of microstructures using a Nanoscribe Photonic Professional GT2 3D printer. During the development process, an SEM image showed that the material could be printed into parts with fine structures as small as 160 nm. That makes it more flexible but at the same time less stable than a conventional plastic bag.
Method is Promising For The Future
According to the researchers the method is promising for the future. Because many polymers used for 3D printing contribute to the world’s microplastic problem as much as other plastics, researchers are working to develop bio-alternatives that contain various natural elements, from soil to insect droppings.