Expert Interview: Additive Manufacturing Technologies CEO, Joseph Crabtree, on Why Post-Processing is Crucial for 3D Printing

Post-processing has often been described as 3D printing’s ‘dirty little secret’. A necessary, yet highly manual and labour-intensive part of the 3D printing process, post-processing remains a huge challenge for companies looking to scale their additive manufacturing (AM) operations. However, this could all change, thanks to advancements in post-processing automation.  
 
In this week’s Expert Interview, we’re joined by Joseph Crabtree, CEO of Additive Manufacturing Technologies (AMT), a UK-based company that develops automated post-processing solutions. With Joseph, we discuss why post-processing is important, how AMT’s post-processing technologies work and what the future holds for the industry.   
 

Can you tell me about AMT Technologies?

We were formed in 2017, in Sheffield in the UK where our facilities include R&D operations, technical support, sales and applications development. 
 
We’ve got a fully-owned manufacturing facility in Hungary, where we do all of our engineering, design work and manufacturing. That’s quite a unique selling proposition of ours – the fact that we do all the design and manufacturing in-house. We’ve just opened up a 20,000 square foot facility in Austin, Texas, which is going to serve the US markets, and we’ve also just employed our first employee in the APAC region as well. We’re expanding globally and very rapidly.
 
The aim of the company is to truly enable industrial AM. So until now, companies have been regularly using AM for prototypes with some transitioning to low volume production applications, but really, what we’re trying to do is help scale AM technology from low volume applications to full industrial capabilities. We want to make 3D printing a viable alternative to traditional manufacturing.
 
To be honest, as an industry, we’re a long way from that. A lot of buzzwords are used, but actually, the biggest problem today is with 3D printers. Everyone has been concentrating on developing bigger, faster, better printers. That’s only one part of the puzzle. People are starting to focus more on the materials being printed, to bring costs down and increase material availability. 
 
But the challenge remains that the parts coming off the 3D printers at the end of the process are often not suitable for end-use parts. 
 
And when we talk about end-use parts, we’re talking about parts that could be used in surgical operations in the medical industry, or in footwear, aerospace interior applications, under-the-hood automotive applications, or in space applications, for example. None of these examples can be used directly from a 3D printer, unless you post-process or finish them. 
 
And that bit has been overlooked until now because the focus has been on the 3D printers. It wasn’t so much of an issue for producing low volumes of parts. The trade-off here was that while manually finishing the parts increased costs, the margins on these parts were higher. 
 
Now that companies are assessing AM for production applications, at higher volumes, the margin is absolutely critical. When post-processing can account for up to 60 per cent of the part’s cost, it can become prohibitive and something needs to be done about it.
 
Our company focuses on the post-processing chain, and what we mean by that is everything after the print. So, in the case of powder-based AM, this includes the de-powdering stage and surface modification of the part, which means smoothing, sealing, colouring and otherwise enhancing the performance of a part. 
 
The final step is inspection and quality control. AMT is bringing all of these steps in the process chain together with an automated end-to-end solution. It is a technology-agnostic approach, in that we work with all 3D printing technologies. 
 
We are also focused on polymers and, specifically, thermoplastic polymers, which is in essence, powder bed and extrusion-based technologies. More than 95 polymers are validated for our systems. And in actuality, our goal is to provide that end-to-end automation system to the part.
 
Now with the investment from DSM Venturing and Foresight Group, Williams Advanced Engineering, we can actually complete what we call ‘the polymer to part ecosystem’. So essentially, what we’re doing is considering the entire ecosystem for the first time. We look at the materials, we look at how to design the materials for 3D printing, and subsequently optimise the printing process according to material selection. 
 
Fundamentally, what we’re doing is material science, combined with mechanical engineering and automation. The post-processing stage enables the tailoring of mechanical properties of the printed part, such that the overall mechanical properties are improved compared with the part that comes directly off the machine. 
 
Combining all of this is absolutely critical for us, and that’s why all of our systems are industrial, targeted specifically at the industrial end-user. 
 

What are some of the current challenges companies face when it comes to post-processing specifically?

 
The biggest problem is lack of awareness. So until fairly recently, not only did companies not understand about 3D printing, but they also had no idea that once you get a 3D printer, you have to do some post-processing to the part. 
 
It’s a very difficult situation because the 3D printer manufacturers are never going to sell you a printer and say that the initial output is poor quality and, therefore, you’re going to have to buy an additional piece of equipment. 
 
They never spoke about post-processing, but the time and costs of post-processing far eclipse any of the benefits achieved through increased printing speeds. What we hope to enable, is for the printer manufacturers to get further market penetration, allowing them to offer a complete solution to their customers. 
 
It’s something no one ever really wants to talk about. This means that education is a challenge in this regard, especially for those customers who are coming into the market now. 
 
As a result, companies buying a 3D printer for the first time may know very little about 3D printing and are now facing the challenge of post-processing. Therefore, it’s about educating end-users and showing them that it’s not a series of discrete independent machinery items that you need to buy to make this process, say, a one-touch button solution, as maybe some of the promotional videos would have you think. 
 
The second big aspect is that there is no other technology on the market, apart from ours, that is truly automated. Yes, there are post-processing technologies but, typically, they are rehashes of very well-known technologies. None of them are digital. 
 
Currently, you need to be skilled in all those nuanced operations that require this ‘black art’ to run. So that’s really a major challenge. And, at the moment, there aren’t any options for post-processing that are really innovative, as well as a digital incentive.
 
The biggest single challenge, in terms of technology we’ve seen, is depowdering. No one has come up with a truly automated unpacking and depowdering solution that requires no human intervention. That is a real challenge. It’s not just a depowdering and automation challenge, it’s a machine learning, machine sorting challenge, and those are the common challenges that we are tackling. 
 

AMT’s PostPro3D system [Image credit: AMT]

Do you think that we will get to the point where we will have a fully automated depowdering solution?

 
We have partners we’re working with to develop real solutions for this. It’s a big unlock for them, because again, if you’ve got your powder bed and you need to remove your parts, there’s currently no other way to do it than manually. Even traditional tumbling solutions still need a lot of manual intervention, because one thing humans are very good at is delicate and difficult operations: identification of things (like powder on the part), removing said powder without destroying the part and sorting parts etc. We’re working towards automating these steps to improve time and cost efficiencies. 
 

How does your PostPro3D technology work?

 
PostPro3D is our core technology. It was based on IP licensed from the University of Sheffield and then developed with an Innovate UK grant. It’s been in development for about 8 years in terms of fundamental research, followed by industrial research. 
 
It is a chemical vapour smoothing process that uses proprietary chemicals to smooth the surface of a 3D-printed polymer part. 
 
By smoothing the surface, we don’t just mean making it aesthetically pleasing, we’re actually engineering the surface of the part. The chemical solution seals the surface and removes the porosity of the part. It also prevents water ingress or gas ingress and actually enhances mechanical properties. The result is a part that has high elongation at break and better fatigue properties. 
 
In addition to that, there are all of the elastomeric materials that we can process, which couldn’t be processed even with mechanical methods, for example. The PostPro3D can post-process parts printed using highly engineered polymers like ULTEM, nylons, TPU, & TPE, etc. 
 
The PostPro3D is the first machine with surface modification technology that we brought to market. It is an industrial piece of equipment designed for industrial end users, with a process chamber size close to 100 litres to process higher volumes of parts. 
 
We’ve also brought out the PostPro3D Mini. It’s physically a third of the size of the PostPro3D, significantly cheaper but using the same flagship technology to extend usage to research institutes, smaller service bureaus and people who may only have one printer. And that’s appropriately priced to be accessible to those people, so they can then try the technology before they commit to anything bigger or expand operations.
 
The benefit of our process is that all of our parts and processing have gone through cycle toxicity testing and it is currently going through FDA medical approval, etc. So that’s really important when we talk about regulated, industrial end-use applications. 
 
In addition, complementary to that technology are our colouring technologies. We have our unique, patent-pending technology on colouring, which allows us to colour and smooth a part at the same time, so you can add colour while smoothing. That, then, also opens a whole variety of other applications. 
 
On the other side, we’ve got our de-powdering systems, which, as I mentioned, we are currently trialling with some of our production partner companies. These allow us to automatically unpack the powder bed, de-powder and remove the parts from powder bed AM systems. 
 
Eventually, we’ve got to tie it all together. We’ve got metrology, or inspection systems, that have been developed, in conjunction with the University of Nottingham, and the clever bits are actually in the algorithms and machine learning, not in the hardware. So they’re low cost, which means that we can use them in line with our systems and quality check parts as we go through our processes. 
 
And then the final part is the end-to-end automation, which we call our digital manufacturing system — or DMS — which allows us to automate the entire process.
 

You mentioned that you’ve validated 95 polymers with your solutions. Are you considering metal parts in the future? 

Great question. My background is actually in metallurgy. I graduated from the University of Sheffield in the field of metal additive manufacturing. 
 
But, while metal is my background, I chose polymers, because they are easier to deal with. Metal is a big challenge, because of the industrial type of processes required. 
 
We have filed IP on metal post-processing, and we’ve developed solutions for quasi-metal components. For example, Desktop Metal’s technology is an extrusion-based process in a polymer carrier, with a metal part clipped inside of it. So we actually have IP and are able to, for example, smooth Desktop Metal parts before they become sintered, and we can then smooth the uncured part. By the time it comes out, you have a nice smooth metal bar.
 

What does your recent investment round mean for the company going forward?

 
It’s completely transformative. We’ve been a revenue-generating company from the first year of our existence, which is really important because it means there’s a great product-market fit. So we’re not developing things that are not needed. 
 
What this funding allows us to do, is to accelerate our global growth. It allows us to finish off our facility in Austin and expand properly to the APAC market and in Europe. 
 
But more importantly, this funding enables us to remain agnostic, unlike other companies.
 
It was because we wanted to remain agnostic that we chose DSM as a materials chemical company. This gives us access to all the materials and chemistry expertise that they’re renowned for on the traditional and additive manufacturing side, but, essentially it also allows us to drive towards a complete industrial AM ecosystem that can only benefit us. 
 
But then on the other hand, we’ve got Foresight Group, Williams, which is a billion-pound VC. This gives us access to all of their materials chemistry, analytics expertise, Formula One engineering provenance of the last 50 years, plus all the data analytics, engineering costs, product optimisation, design optimisation, etc. Finally, Foresight Group gives us access to huge VC power capital markets.
 
Additionally, through the sales channels, it gives us a network of sales, marketing and potential distribution, which is ready to go. So, it really accelerates our journey to scale up.  
 

We’ve spoken a lot about the challenges with post-processing, and how you’re tackling that. Moving aside to talk a little bit more generally about 3D printing, what are some of the challenges you still see in the industry that could still be potential barriers to entry?

 
For us, again it’s the same challenge. Companies looking to adopt 3D printing are faced with so much choice. And it’s really about breaking down the hype surrounding it. There isn’t as much marketing hype as there was, but there is still quite a lot. 
 
Besides, I still think one of the biggest challenges is that for many companies the technology is just not ready to bet on. For instance,  if you buy a CNC machine today, you can be machining parts tomorrow — and machining parts to a very high quality. Similarly, if you buy an injection moulding machine and have a tool, you can do the same. I’m simplifying a bit, but broadly speaking, this is a challenge the AM industry faces.
 
If you buy a 3D printer, the material, all of that considered equipment; you still can’t make good quality parts. And I think that therein lies the problem: we’re still far from getting to a process where you could, for example, make a million parts. 
 
A perfect example is our stand at Formnext. We’re building out just over six and a half thousand individual 3D-printed parts, connected by aluminium components. The structure is 4 meters by 6 meters by 14 meters. That’s a huge structure. And you suddenly ask yourself, why no one has done it before, and the problem is, because for 6000 components that are identical or suitable from a repeatability & reproducibility point of view, it’s just very difficult to do. It would take a month of development to get to the point where you’ve got a stable process. 
 
So really, when we’re near the point where the processes are stable, where we’ve got repeatability and reproducibility, that’s where we achieve industrial processes. 
 
Another thing is that we need to stop thinking of 3D printing as a batch process. Think of it rather as a continuous process instead, with a full process line and end-to-end automation. 
 
I think part of the problem is that a lot of people have been around 3D printing for too long, watching it grow up. However, we’re now seeing a new revolution, whereby people are truly looking at it as an industrial technology, but in order for that to actually work, a mind-shift is required. And that’s why our company is so fortunate, because not everyone in it is from 3D printing. So we bring a very different perspective to the process.
 

Can you share how you’re constructing your stand at Formnext? 

 
This year we have an 86 square meter stand, which is constructed almost like a lattice structure. Each node is a series of interconnected 3D-printed parts, and we build up the structure from these individual components that form cubes, and the cubes form the structure, which is 4 meters high. But the point is, it’s very lightweight. The entire structure weighs no more than 120 kilograms. 
 
We believe it’s the first time anyone has tried to do this. Without post-processing, it would be extremely difficult to achieve. Obviously, we’re using our tolerance threaded joints, intricate internal geometries, and so on. And what is key here, is that without the technology that we’ve developed, we would not have been able to produce this. We’d have been able to print the parts, but would not have been able to finish them and get them to the right quality required to actually build something.
 

Are there any exciting trends or developments that you are excited about personally? 

 
I’m excited that people are recognising post-processing as an issue and want to do something about it. It’s great to see post-processing being taken seriously at last. 
 
In AMFG’s AM industry landscape, it was interesting to see that there are 2 or 3 post-processing companies. For me, that was a great visual representation of the fact that, of all the 3D printing companies, there are only a few in post-processing. 
 
But people are definitely talking more about it, and education is really imperative here. Because if you don’t know about it, you don’t know it’s a problem. So we need to educate before we can sell, and also educate ourselves in terms of what our users require. 
 
The other exciting trend is that we’re now seeing industrial players coming into the market, and I don’t mean printer manufacturers, I mean users of the technology. So companies are genuinely looking for 3D printing applications and are now seriously considering 3D printing, and that’s a great trend. 
 
Ultimately, we need to focus on real-life applications – they may not be as exciting as PR-focused, high-profile applications, but they show that the industry is maturing. 
 
I’ll give you an analogy: when was the last time someone came to you and said, ’Look at this injection moulded part, just look how great it is’. You don’t care, no one cares, it just doesn’t matter. That’s what we need to get out of our heads and just get on with the new technology. And the time will come when no one will know the difference.
 
We’ve already started, and we show people by saying, ‘Look, this is an injection moulded part’, and they don’t even blink. Then we show them a 3D-printed part that we have post-processed and they say, ‘Oh my God, that’s amazing’. We need to get past that and be able to just accept it as another manufacturing technology. 
 

What do the next 12 months look like for AMT?

 
The next 12 months will see very rapid growth, both in terms of our expansion and revenue.
 
We will also be launching our end-to-end DMS system late next year, which will include de-powdering, smoothing, colouring and inspection — fully automated. And that’s really our focus as we enter 2020 – to link those elements together, so we can really offer an end-to-end post-processing system in the truest sense of the word. 
 
To learn more about AMT, visit: https://amtechnologies.co.uk/