Back to the future? Advanced Manufacturing enters a brave new era

Mark Ritchie, Xaar

Mark Ritchie, Xaar

Mark Ritchie at Xaar delivered an entertaining and informative presentation at the InPrint Forum in Munich on 24th June. So much so, he is speaking again at the InPrint Development Forum in Milan this week. The session is focused on functional printing and had a look into the future possibilities and developments of industrial inkjet printing. With the trend towards digitisation of manufacture, inkjet, one would think, with its maturing and increasingly confident place within industrial print should see further growth in its use.

However, Mark started by saying how difficult it is to predict the future.

Decca records rejected the Beatles back in the 1960’s stating there was ‘no future in guitar bands’. Instead they signed Bryan and the Tremeloes who didn’t go onto succeed. The rest is history.

The ‘Back to the Future Film’ set in 1985 is celebrating full 30 years ago and as Mark says it appeared they actually got some things right and some things completely wrong. Within the online section of the UK’s Daily Telegraph, they took a look at what did and didn’t happen. The pictures below are taken directly from this.

Back to the future highlighted the following:

1) Wearable technology
 
Here Marty McFly is seemingly wearing Google Glasses. If you also factor in the hi-tech sportswear and other intelligent textiles that are being developed this is prescient.

2) Video calls
 
With FaceTime, Skype, Google hangouts all being very normal aspects of working and family life Again this is a very accurate prediction that has come true in 2015.

3) Microwave meals
 
Unfortunately the microwave meal has had a lot of negative PR in recent years as processed foods obliterated by microwaves are proven to be very unhealthy. However the notion that technology can cook food in seconds is spot on.
Misses

1) Flying cars
 
Sitting in traffic on the M25 we have all wanted to ‘sprout’ wings and simply fly off. A negative side effect of progress means we are, generally speaking, a wealthier population that can afford to keep ourselves mobile despite being stuck a lot in stationary traffic. However flying cars haven’t reached commercialisation, let alone being in any kind of prototype phase.

2) Hoverboards
 
As cool as these look, it is a good thing that hover boards do not exist. Ensuring safety would be difficult as potential decapitation for pedestrians is considerable.

3) Power clothing
 
This is cool – so shoes that have laces, which actually in itself is very old technology
But are so intelligent they do themselves up.

4) Fax machines
 
Back to the Future felt faxes would still be a technology that we all use today.  Seems Donald Trump sent this one. However the reality is that faxes are hardly used these days.  

And it seems that smart phones (something I actually think Star Trek managed well to predict) and other intelligent devices do not factor whatsoever.

OK Mark, we accept that predicting the future is a tricky thing to do. 

So let’s start, with inkjet in mind, just ‘What is Advanced Manufacturing?

“In the context of industrial printing it is a functional application for material deposition, masking and layers in a manufacturing environment and it is not at all decorative print.”

Clearly this is extremely demanding development work where inkjet is being used to play key functional role. Is it fair to say that inkjet is at a formative stage of development in this area when compared with decorative print?

“To a large extent yes, the clue is in the word ‘Advanced’ Manufacturing. The tolerance in many applications for imperfection is nil.  With functional printing it is therefore automatically more challenging and more difficult for inkjet compared to decorative printing.

If you take industrial decoration, these applications were evolutions of the development work already completed for graphic print. Much of this was performed with multi-pass printing. A graphic is only a visual sign that is not asked to do anything else. However for functional production, you simply cannot have an error in it. If the print does not function then it doesn’t pass muster - it is as simple as that. 

Many functional applications require single pass printing processes to ensure high volume production and at the same time demand 100% quality reproduction. Drop placement and drop volume uniformity must be near perfect and if it is not reliable over time then it will not be implemented.

In addition, fluids are generally very different. Some applications demand the use of very aggressive solvents and this can damage printheads very quickly.  So the ink chemistry and  need to work in close collaboration with fluid manufacturers are very important to ensure the fluids are compatible with the printhead and ensure both the printheads and the associated electronics remain in good working order.”

So will inkjet not replace screen printing in this sector?

“Inkjet is already challenging incumbent analogue printing processes in a number of areas, but there will be no sudden transition as these processes will continue to develop. It is too early to say how far inkjet will replace traditional printing methods. But many of the applications currently screen printed are unsuited to inkjet printing at this stage. There is a gap that needs to be filled as many fluid suppliers do not yet fully understand the rheological requirements of the print head. A fluid may or may not be jet-able depending on a number of factors other than just fluid viscosity. 

For example, it is not possible to simply use a thinner screen printing ink in an inkjet printhead as this chemistry is designed to be thixotrophic. This means that screen printing fluids can be thick in substance on the screen when static to prevent it dripping through the screen, then when you stir, or shear, the inks they get thinner so that they flow. For an inkjet head you need a fluid to be Newtonian. That is where the viscosity remains constant, no matter the level of shear they are exposed to.
For Advanced Manufacturing there are a growing number of examples where inkjet is used such as printing the obscuration layer to the front of mobile devices and functional layers in touch screens where the inkjet process is being asked to do more and more. The interest in inkjet is in the precision dosage and features where inkjet delivers performance that no other technology can match. This is true of the work we have done with Canon Nanotechnologies Inc. to enable the patterning of CMOS disks using Nano Imprint Lithography. Our inkjet technology has helped Canon to deliver feature sizes down to 23nm and we are going to go further still. 

The work we are doing with the universities of Loughborough and Sheffield to bring their HSS (High Speed Sintering) technology to market will make 3D printing viable at volume. Again inkjet is the enabling technology that will allow printers to scale up to compete in some areas with injection moulding.

Applications like these demonstrate the increasing adoption of inkjet across industry as an advanced manufacturing process and underscores Xaar's efforts to extend its inkjet technology into new markets.  "While the development period has been extensive, the results are impressive and show that Xaar technology has the potential to deliver ultra-precise results within a highly demanding manufacturing application where imperfections are simply not allowed." 

Mark explains, “Imagine picking up your groceries in the supermarket and loading your car with packaging that was once injection-moulded and is now additive-manufactured using 3D printing. Imperceptible as this may be for the average consumer, for additive manufacturing it would signal the maturing of a technology that was once the reserve of prototyping. Additive manufacturing through advanced polymer sintering at high speeds is being explored by University of Sheffield spin-out FaraPack Polymers, as it investigates laser sintering for low-volume applications and high-speed sintering (HSS) for low and high volumes. 

The team is working alongside industry partners and with Loughborough University (which owns the patents for HSS) to exploit this manufacturing process with the aim to deliver a validated supply chain and a range of example products that show the time-saving, part properties and cost benefits of choosing this technique for high-volume orders.

FACTUM is the name the HSS project has been given by The University of Sheffield, and has been awarded £1.5 million in funding from the Technology Strategy Board (TSB) and industry partners. Leading the research is The University of Sheffield's Professor Neil Hopkinson, of the institution's Department of Mechanical Engineering, who was on the team that invented HSS at Loughborough University, where the intellectual property stayed when Hopkinson moved to Sheffield. "The HSS machine we've been using in this project to make parts is owned by Loughborough and loaned to Sheffield, as the research helps Loughborough to licence the technology, while Sheffield secures funds to develop new technology," he explained.
Today 3D Printing is well established however much of it is not inkjet. For example, laser sintering with metals is used and within say a Rolls Royce Trent Engine there is laser sintered 3D printed parts within the engine.  The  first Airbus 320 XWBhas over 1000 printed plastic parts. These provide a performance and economic benefit as the plane reduces weight quite significantly meaning that it uses less fuel.

The FACTUM project itself is at a point that is close to realisation but at the moment it is not fully commercialised. 

"We have a really strong partner in the fast-moving consumer goods field with Unilever," Hopkinson stated. "We believe this is the first time such a company has engaged in a publicly-funded project in which they have invested substantial resources of their own, with a target of using additive manufacturing for end-use products. Fast-moving consumer goods are produced in high volume and thus far that's not worked with additive manufacturing economically. The viability of additive manufacturing at high volume is one of the key unique features for this project.

That's one end of the production spectrum. BAE Systems and Cobham Technical Services represent the other side, with low volume, high-added-value products more usually associated with additive manufacturing. BAE is an aerospace giant, while Cobham Technical Services works in the field of space telecommunications equipment. Xaar is working with them and exploring the design freedoms and material possibilities and working with the technology in terms of improved product performance."

FACTUM has also signed up Sebastian Conran Associates to master the design opportunities afforded by the technology. His team decided upon the name of the project, choosing the Latin for 'to make' to allow the significance the technology will have on manufacturing to speak for itself. "It's a bit of a coup for us," Hopkinson admitted. "We think Sebastian Conran Associates is the first example of a long-established design brand that's really embracing additive manufacturing technology."

Optimising freedom of choice

David Chapman, who is responsible for developing Xaar's inkjet technology as an advanced manufacturing process, said FACTUM has the potential to "radically change the way we think about manufacturing, introducing new designs and business models that we cannot even imagine today".

"The fact that it has attracted the interest of the likes of Unilever and BAE Systems underscores this potential," said Chapman. "Inkjet is at the heart of this technology and by working with our supply chain partners, Xaar is committed to bring this technology to market. 

Project leader Neil Hopkinson "Xaar is really important because they are both integrating their systems into our machines and helping us with the supply chains for inks. We are trying to make the project more end-users focused, keeping supply chain companies outside of the core membership. This way we can create example products in these different sectors with maximum freedom of choice for materials. Xaar is critical to what we are doing."

The long-term vision for HSS is for it to compete with injection moulding and CNC machining but to achieve this, HSS must have a similarly open supply chain.
"So the supply of materials, the powders and the inks we use – even suppliers of machines themselves - we've intentionally kept them as noncore partners. We've developed a hinterland of supporting companies who are feeding into FACTUM. In this respect, it's very helpful to have Xaar on board to help us find suppliers and very helpful to have Unilever and BAE because they are so influential when it comes to getting material suppliers to commit their resources.

"We have no material suppliers as core partners to this project, so there's no opportunity for monopoly or control over the supply chain by any particular company," Hopkinson stated.

A first for inkjet and for 3D

In order to compete with a technology as ubiquitous as injection moulding the FACTUM team has been looking into using HSS for a wide range of products with diverse geometries, establishing how much it will cost to make each unit.

"Something interesting we found," Hopkinson said, "we're beginning to find some geometries where we expect it to be cheaper to use HSS than to injection mould for any production volume. To date, it's been the case that it's only cheaper to additive manufacture a product up to a certain production volume; thereafter it's cheaper to injection mould. But we've found for some geometries this is no longer the case. With HSS, we predict for a substantial range of products it will always be cheaper than injection moulding, which won't be able to compete on cost in these cases. We think this is a very profound first for additive manufacturing."

A material development

The FACTUM team is also investigating materials. The landscape of materials for HSS appears to be greater than for laser sintering, but not yet as wide as injection moulding. 

Interestingly, FACTUM has discovered materials that are difficult or impossible to laser sinter, but can be reliably high-speed sintered.

For instance this could be jetting plastic or jetting a chemical binder where it binds the particles together.  The speed is increased because the system can jet both the substance and the coating in one go, and also  because it is possible to  build a wide print swathe you can print a lot of parts on a single bed enabling multiple unit production. This means that you can build up a large number of parts very quickly when compared to a single printhead production system.

High speed sintering is a heat absorbing process. The fluids used absorb heat significantly more than the surrounding areas, and when an infrared lamp passes over the powder bed this causes the sintering process in the areas where the heat-absorbing fluid has been jetted. The other factor that HSS enables is the ability to mix two substances together such as different plastic polymer powders and this is reckoned to be cheaper to produce than even injection moulding.

No doubt it is an exciting project and should this reach fruition it has potential as a game-changer.

So, Back to the Future, Marty McFly clearly made some good predictions. But missed quite a few, not least 3D Printing. It seems that Star Trek, back in the 1960’s, at the height of the cold war space race, had writers with even better vision. 

Whatever happens with the FACTUM project, inkjet will simply increase its use within advanced manufacturing and its role in everyday manufacturing by disrupting, sometimes replacing and in other cases complementing the traditional technology.