Additive Thinking

Fused Deposition Modeling (FDM) 3D printing significantly cheaper thanks to new gas mixture
Manufacturing & Process
18 November 2019

It is no secret that production quality and cost efficiency improvements - often remarkable ones - can be achieved if a supplier is willing to collaborate actively with customers. Especially when it comes to new production processes, such as FDM printing based on metal extrusion.

Fused Deposition Modeling (FDM) is a specific form of additive manufacturing suitable, among other things, for prototypes and small production quantities. FDM distinguishes itself from other techniques because the 3D printer does not have to be placed in an enclosed space, nor does it require any special safety measures. Originally, FDM used thermoplastics as a raw material, but now more advanced forms of FDM based on metals and polymers are  available on the market. The polymers are only needed for the production process, and do not appear in the final product.

Perfectly balanced

The FDM production process is based on metal extrusion and has three steps. After the actual printing, the printed piece is immersed in an aqueous substance, to dissolve the adhesive residues. Finally, the piece is given a heat treatment (sintering), during which any imperfections that have occurred during the printing process are removed.

The sintering process requires a perfectly balanced gas mixture, consisting of hydrogen (to remove the oxygen) and argon (to create an inert atmosphere). “The customer stated that the gas mixture had to be very pure, with the hydrogen content in particular remaining within strict limits,” explains Nadia Bakker, Offer Deployer Benelux at Air Liquide. “Air Liquide can supply gas mixtures with that kind of precision, but they are significantly more expensive than gas mixtures requiring a little less precision.”

The cost for such a precise gas mixture is about €300 - €400 for a 50 litre cylinder. And since a company printing full-time via metal extrusion uses two 50-litre gas cylinders a week, the cost of the mixture amounts to around €700 a week. A significant sum, with a major impact on the total cost of production.

Price reduction of up to 80%

Nadia continues: “We took the initiative of thoroughly studying the specifications requested by the customer. We noticed that the required tolerances for hydrogen were rather unusual. Compared with the reference, there was an upper tolerance of no more than 1% for hydrogen in the mixture, while the lower tolerance could be as great as 20%. As it is precisely that 1% margin that makes it so expensive, we decided to redefine the mixture to better fit in with Air Liquide’s filling process. As a result, we were able to reduce the sales price by around 80%.”

“This is good not only for the companies that use these printers, but also for the printer manufacturers, because they can now adopt a stronger market position,” says Nadia. The new mixture is already available for Benelux companies and in Scandinavia and will soon be offered in other countries.

Faster delivery

“It goes without saying that the new gas mixture is being received enthusiastically in the market. Because it was developed in close consultation with printer manufacturers, end users can be sure that the new mixture doesn’t breach warranty conditions. Moreover, it’s a lot cheaper, and it can also be delivered much faster than before,” Nadia continues.

“We are very satisfied because, through effort and knowhow, we’ve been able to offer our customers a better solution. And, of course, we’re happy to investigate whether we can also help to improve other additive manufacturing techniques or make them more cost-efficient. We’ve also developed a number of training courses for additive manufacturing companies on using gases safely. Often these companies have little experience with gases, and so training is of course a good thing.”

Would you like to find out how we can help optimise your additive manufacturing process, or learn more about our training on using gases safely? Please feel free to contact Nadia Bakker.