Printing and 3D manufacturing

In my view, the most interesting product shown at last week’s Formnext show was the Carmel 1400 AM from XJet, which can be used to print either ceramic or metal. This technology is the bridge between 3D printing and graphics inkjet, sometimes referred to by the 3D crowd as being 2D.

The Carmel 1400 on XJet’s stand at Formnext 2017

The key to this system is that it jets the material as a fluid, much like a graphics printer jets ink, which is quite a unique approach. XJet calls this Nano Particle Jetting and it’s no coincidence that it sounds a lot like the Nanographic printing developed by Landa, just a 10 minute drive away in the Rehovot suburb of Tel Aviv. Both technologies are based upon materials handling of very small particles suspended in carrier fluids. Landa is using a heated belt to evaporate the carrier liquid –in this case water – while XJet uses a heated build tray to evaporate its fluid away.

It helps that most of XJet’s engineering team have come from Scitex, the former Israeli company that was at the forefront in developing digital workflows for offset printing and wide format inkjet systems for display graphics. Hanan Gothait, CEO and founder of XJet, explained that when he moved into 3D printing he put together a team of his former colleagues and first founded Objet: “Our dream in Objet was to develop a machine to do prototypes made in plastic. We merged with Stratasys and this company is the largest in the world today for prototypes in plastic.” Gothait then went on to set up XJet, saying: “I was lucky again to work with excellent people, hand picking them one by one. Our dream this time was to do a 3D printer – but not for prototyping – for production.” Today the company numbers some 85 staff. Gothait added: “We have ten printers working at home 24/7 unattended. I’m really proud of it.”

Hanan Gothait, CEO of XJet, presenting at the company’s Formnext press conference

XJet has developed two types of build materials, metal and ceramic, and seems currently to be concentrating on ceramic, more specifically Zirconium, which is useful for dental applications as well as some aerospace and fuel cell uses.

The material is supplied in a liquid, rather than a powder form, so the particles are suspended in a carrier fluid, though Gothait wouldn’t specify what kind of fluid other than to say that it’s not water-based. The advantage of a fluid suspension is that the individual particles can be very small, leading to very fine resolution, without any safety and handling issues. Most companies use spherical particles but in this case the particles themselves are completely random in their size and shape. Dror Danai, XJet’s chief business officer, explains that this leads to isotropic parts: “Using different sizes and shapes gives us perfect packing with 99.9 percent density.”

As well as the build material, the Carmel also jets a support material. Danai explains: “We use totally different materials for the metal and the support which means that there’s no limit to the geometry that we can do.” The support is automatically generated and easily dissolved away in a small bath.

Gothait says that the printheads are standard inkjet actuators from a well-known Japanese supplier. He estimates that each head should last a year to 18 months. There are 24 heads stitched together on a print bar so that each layer can be jetted in a single pass. These jet a five or six micron layer, which gives very high resolution parts. The parts are formed in the Carmel printers but all of the ceramic and most of the metal parts still need to heat treated in a separate furnace to bond the material particles together.

The build tray for the Carmel 1400 is 500 x 280mm. The Carmel 700 appears to be the same machine but supplied with a smaller 500 x 140mm build tray. In both cases the maximum build height is 200mm. Gothait said: “Inkjet is scalable so in the future we will be able to introduce larger trays.” He added: “We focus on smaller parts because you can put many parts on the tray and enjoy high throughput.”

The XJet materials are supplied as a fluid in these canisters, here propping up the company’s Flormnext 2017 stand.

The first unit has been delivered to Oerlikon’s Citim subsidiary, based in Barleben, Germany.  Citim was set up in 1996 and specialises in additive manufacturing,. It was acquired by Oerlikon at the end of 2016. Andreas Berkau, Head of AM Service Europe for Oerlikon, said it’s a fascinating technology, noting: “We are moving from prototyping to production and I think we have made a really big step.” He added: “The basic idea to use liquid ink opens the door to new applications. We can apply a new design to parts. We can print very fine layers and work with very fine detail. Instead of having a powder which brings a lot of problems you can use an ink which is safe and makes for a good environment.”

A second system is due to ship next month to Ohio, USA where it will be installed at the Youngstown Business Incubator. This is home to the National Additive Manufacturing Innovation Institute’s America Makes project, which is meant to accelerate the take up of 3D printing in American manufacturing.

Both of these sites have said that they will focus on producing ceramics for now.

Dror Danai, CBO of XJet.

Danai says: “In 2020 (which he later clarified to mean not before 2020) we will be able to print multiple materials. Maybe a mixture of stainless steel or Zirconium in the same part. All the way down to the drop level.” This, of course, is the next stage that many developers are working towards – being able to produce complex parts made up of multiple materials as a single process. But the XJet team clearly has the expertise and the experience necessary to pull off such a challenge.

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