A team of scientists from the University of New South Wales (UNSW) have demonstrated a way to help 3D printed plastic “cure” itself quickly and affordably in a major commercial breakthrough.

The team found that adding a special powder to the liquid resin used in the printing process can help repair materials if they are damaged.

Repairs can be done at room temperature and should only take place under LED lighting, which triggers a chemical reaction and melting of the fractured parts.

Currently, achieving the same result may mean having to disassemble products and subject broken components to a series of heating cycles.

It also takes around 24 hours to complete, compared to an hour with the new method.

While three-dimensional printing or additive manufacturing generally has less of an impact on the environment, it does not yet meet the strict definition of being environmentally friendly.

With a lot of plastic involved and printers that run for days on end, any delay caused by repairing breakages has traditionally involved extra time, money and waste, the research team spokesperson said, Dr. Nathaniel Corrigan.

But now they can be repaired easily and quickly, and in many situations damaged components can also be salvaged instead of being thrown away to start over.

“There’s an obvious environmental benefit because you don’t have to re-synthesize a whole new material every time it’s broken,” Corrigan said.

The powder additive used is a trithiocarbonate or RAFT agent originally developed by CSIRO. Trithiocarbonate is derived from the reaction of hydrosulfide with carbon disulfide. It allows you to reorganize the network of elements that make up the printed material and to merge them

“We are increasing the life of these materials, which will reduce plastic waste. “

The powder additive used is a trithiocarbonate or RAFT agent originally developed by CSIRO.

Trithiocarbonate is derived from the reaction of hydrosulfide with carbon disulfide.

It allows you to reorganize the network of elements that make up the printed material and merge them.

This happens within about 30 minutes when the UV LED lights are shone directly at the broken plastic, with complete “healing” taking place in about an hour.

Experiments, including on a 3D printed violin, show that the strength of self-repairing plastic is fully recovered to its uninterrupted original state.

The team believes that commercialization is possible given the simplification and speed of their system.

“There are other processes that do this, but they rely on thermal chemistry to repair the material and it typically takes around 24 hours and multiple heat cycles to achieve the same type of result,” Corrigan said.

“Another restriction is that you need a high temperature heated furnace and obviously you cannot repair the plastic material in situ – you will have to dismantle it from the component first, which adds a level of complexity and complexity. delay.

“With our system, you can leave the broken plastic in place and light up the entire component.

“In a lot of places where you use a polymeric material, you can use this technology,” he said.

Corrigan and his UNSW colleagues Cyrille Boyer and Michael Zhang believe the technology could be used in a range of applications where advanced 3D materials are used in specialized high-tech components.

These include wearable electronics, sensors, and even shoe manufacturing.