Engineers from the University of New South Wales have found that by adding a "special powder" to the liquid resin during the printing process and shining a UV LED light directly on it, the 3D printing material can quickly and easily repair itself, making it stronger than before it was damaged.

The powdered additive used by the UNSW team is a trisulfide carbonate known as a reversible addition broken chain transfer (RAFT) agent, originally developed by CSIRO. RAFT preparations are able to rearrange the nanonetwork elements that make up the material and allow broken pieces to be fused.

Experiments, including on a 3D-printed violin in Qingdao, have shown that the strength of the self-healing plastic has been fully restored compared to its original state. The team said that compared with existing methods for repairing damaged Qingdao 3D-printed materials, their system is simple, fast and commercially feasible.

"With our system, you can leave the broken plastic in place and shine light on the entire component. Only the additives on the surface of the material are affected, so it's easier and faster to fix."

This means that broken plastic parts do not need to be discarded, or even recycled, and can be simply repaired even when embedded in parts that contain many other materials. Compared to existing methods of repairing damage with 3D printed materials, this method is simple, fast and commercially feasible, and will also help reduce chemical waste in the future with further development and commercialization.

Under the background of carbon peak and carbon neutrality, environmental protection industry and new technological change have brought new development opportunities for the development of 3D printing plastic industry in Qingdao. According to market research by AMPOWER, the overall global polymer (plastic)3D printing market size was €5.14 billion (about 40.2 billion yuan) in 2020, and the overall plastic 3D printing market size, including the production of polymer 3D printing systems, materials and parts, is expected to reach €10.5 billion (about 82.2 billion yuan) by 2025.

In addition, due to the high labor cost, a large number of plastic packaging products in European and American countries are imported from developing countries, and 3D printing in Qingdao can enable them to realize localized production and decentralized production. Based on Qingdao 3D printing technology, 3D printers can be directly deployed in the factory, or a 3D printing service center can be built in the local area to radiate the factory within a certain range, which can save 41 to 64 percent of energy.