In the context of the increase in global problems of plastic pollution, German scientific research institutions turn their attention to “edge waste” outside the traditional recycling system – disposable plastic packaging at home. The data shows that Germany generates around 5.6 million tonnes of plastic packaging waste each year, less than a third of which are effectively recycled. Most others are found in waste or discharge incineration systems.
But now, a study conducted jointly by the Fraunhofer Institute for manufacturing technology and advanced materials (IFAM) and the University of Applied Sciences (HSB) in Bremen is trying to break the cycle and leave these “waste” against high performance printed wires.
Recycling with high difficulties: challenges of complex ingredients
Unlike industrial plastic residues with clear sources and relatively clean sources, household plastic waste has always been considered a “dead angle” in the recycling of resources because of its disorderly materials and its serious pollution.
In response, Professor HSB Silke Eckardt said: “Plastic products after consumption can contain food residues, oils and different types of polymers, and direct treatment is impossible.” The team therefore established a complete process of purification of materials:
- Crush + Clean: Remove the accessories
- Floating separation: delete impurities with different density
- Close infrarge recharging technology: precise selection of polypropylene
- Refit + drying: Prepare the granules adapted to composite treatment
In the end, they increased the purity of polypropylene recycled at 99.8%, laying the basics of 3D printing.
From the bin to the wire: formation of preparation of industrial quality materials
After obtaining high purity plastic lozenges, the study was taken up by IFAM. They use industrial quality extrusion equipment to melt process polypropylene in high quality wires adapted to FDM / FFF printing.
Dr. Dirk Godlinski, project manager, introduced: “We accurately adjusted the different extrusion parameters – screw structure, temperature control, pressure distribution, etc. to ensure good homogeneity of metal materials, a smooth surface and a stable diameter, and are suitable for general public offices and industrial 3D printers.”
Currently, they have managed to print the first batch of functional parts (such as lids, etc.) and optimize the processing process more.
Extended value chain: evolving towards high performance functional materials
Based on the current results, the research team optimizes the entire recycling and preparation process more and plans to introduce reinforced loads such as glass fibers in the subsequent material system to obtain higher mechanical properties and thermal stability. “Our goal is not only to provide printable recycled plastic, but to build a functional material platform that can be used in demanding areas such as aviation and cars,” said Dr. Godlinski.
Professor Silke Eckardt added: “In the context of climate change and the shortage of resources, the value of the circular economy becomes more and more important. If difficult waste on the consumer side can be converted into a lasting source of materials, it will bring a really closed material to the manufacturing industry.”
Inspiration of the industry: 3D printing can become a new outcome for plastic regeneration
This research is not only an exploration of cutting -edge materials technology, but also opens up new ways for recycling and the use of plastic waste. With the trend of countries around the world to achieve the objectives of “zero waste” and “carbon neutrality”, the deep integration of 3D printing and recycled materials should inject greener connotations into additive manufacturing.
