During gasworld TV’s lastest webinar, Air Gases Part 1, Pierre Foret, Director of R&D, Linde, talked about all things additive manufacturing, including the reasons behind its rapid growth in recent years and the innovative technology being developed by his team at Linde.

Additive manufacturing, or AM, is also known as 3D printing and is described as a way of creating three-dimensional objects layer-by-layer, with each successive layer bonding to the preceding layer. This is markedly different from traditional methods, which involve milling, machining, carving, or shaping.

Described by Foret as a ‘very innovative way’ of making objects, the advantages of AM in producing complex parts for various sectors of industry has seen it become a multi-billion-dollar industry, with projections showing a market value of nearly $26bn by 2022.

Within AM there are multiple processes, with one specific technology ‘dominating the scene’ for the past five years.

“The technology is called laser-powder bed-fusion, which uses a very fine metallic powder and a laser to create parts,” explained Foret.

Powder bed-fusion (PBF) methods use either a laser or electron beam to melt and fuse material powder together.

What is additive manufacturing?

He continued, “The reason why this technology is growing so fast is that it’s revolutionising the way we’re designing and producing parts. You can do designs that are impossible to do with other methods.”

According to Foret, the parts can be smarter, more efficient, and lighter, in addition to the supply chain being much smaller due to not needing to source as many different parts.

One industry that has seen exceptional benefits from its adoption of AM is the medical sector. Areas such as dentistry, orthodontics and anatomical models all feature a complexity inherent to the nature of the human body. The challenges presented by these complex structures are proving to be no match for the ever-advancing AM technology.

For AM to work, particular gas mixtures are required, with high end metal AM relying on key inert gases such as argon, nitrogen and helium for not only the print process itself but also metal powder production and storage and postprocessing.

When used for AM, argon allows for the creation of a controlled, inert environment, displacing oxygen and flushing out contaminants. This generally means large quantities of the gas are required. To support the growth and industrialisation of AM, Linde has developed a new process gas alongside a leading company from the medical industry.

“This process gas reduces the formation of by-products, less by-products means higher quality, it also enables a faster printing,” said Foret.

Ahead of climate change focused events such as COP26 another highly relevant topic raised during the webinar was sustainability.

Stating that AM is ‘not the solution to everything’, Foret was honest in his take on the sustainability of the technology. Avoiding any ‘greenwashing’, he said, “The technology offers so many advantages that can be used for a more sustainable way of producing goods.”

“We can build parts that are lighter and therefore use less material, less resources. We can produce parts that are smarter and better, improving the process, making it more efficient and more sustainable.”

Further development in R&D will be required to increase productivity while lowering the carbon footprint of the process, he admitted, although future innovations, such as the new process gas, are on the horizon.

He said, “The process gas, which I mentioned earlier and we are launching this year, has accelerated print speed, therefore less machine time and less energy is needed to produce a part.”

“And this is an example of how we want to contribute to increasing the sustainability of manufacturing.”