Interview: AMT and DTI on how they created new 3D printing food-contact applications

“Food-contact applications are definitely a place where 3D printing will take a bigger piece of the cake, it’s only the tip of the iceberg for us with surface treatment. It’s a market that will grow a lot in the coming years, so there’s a big potential there.” That’s how Mads Østergaard, Team Manager at The Danish Technological Institute (DTI), described the future of Additive Manufacturing Technologies’ (AMT) post-processing systems. In an interview with 3D Printing Industry, both Østergaard and Noud Steffens, CRO of AMT, explain how their collaboration has created new applications for AMT’s PostPro3D machines.

AMT is a Sheffield-based post-processing specialist which is known for its PostPro3D automated smoothing systems. The company’s machines offer a cost-effective alternative to finishing parts using sanding or chemical treatments and are compatible with components created using a range of 3D printing techniques. The Danish-based DTI on the other hand is a research and technology business, which employs over 1,000 specialists and has over 10,000 clients. The company deploys its multiple technologies to drive innovation within a variety of industries ranging from building and construction to renewable energy. 

The two businesses began working together earlier this year, when DTI reached out to AMT, proposing a new application for its PostPro3D system. “DTI were developing parts for use in food processing plants and they needed food-contact testing approval for it,” explained Steffens. “The main benefit of using the PostPro3D in these applications is that it makes the surfaces very smooth and well sealed, so the uptake of food waste is very low. The other big benefit is that it becomes very easy to sterilize.” 

Utilizing the sealed surface finish provided by AMT’s systems, DTI was able to produce components that meet EU regulations on food and skin-contact related applications. As a result, the PostPro3D could now be used to create new opportunities for 3D printed parts, in areas where food or skin-contact is necessary, and cleanliness is essential. Steffens emphasized the untapped potential for 3D printing in food-contact related industries. 

“In additive manufacturing, food processing is an important market that has a high need for parts that are 3D printed. This is especially true in the manufacturing environment, for tools, spare parts, and jigs and fixtures.” 

DTI has used AMT's PostPro3D (pictured) to produce food-contact related parts. Image via AMT.
DTI has used AMT’s PostPro3D (pictured) to produce food-contact related parts. Image via AMT.

AMT’s solution to DTI’s food-contact conundrum 

DTI began to test plastic 3D printed components for its customers in food production industries last year, who were requesting parts with a surface finish that would comply with EU regulations. This demand created an opportunity for the company to produce a component that could be used in food-contact areas but was post-processed in a new and unconventional way. At first, DTI tested a manual method of post-processing, but while the process did meet EU safety standards, it didn’t have the required scope for scalability. 

Other commonly-used post-processing techniques such as tumbling weren’t considered viable either. While the tumbling process makes the top surface of parts appear to be smooth, their inner channels remain exposed. As a result, if these post-processed components were to be used in food-contact industries, foodstuff could be caught inside the part, and contaminate the production process. Moreover, parts produced using Selective Laser Sintering (SLS) alone, would not have a sufficient level of finish to be used in food-contact industries either, and novel post-processing was needed as a result. 

Having seen the PostPro3D demonstrated at Formnext 2019, DTI realized the potential applications of the technology, and reached out to AMT, to begin their partnership. Using the PostPro3D’s Chemical Vapor Finishing technology, DTI was able to produce parts that had a sealed final surface, preventing any food from entering the pores of the material.

“If you have a high surface roughness, what happens is the food, or whatever the part is in contact with, will go into the pores of the part, making the part dirty and difficult to clean,” explained Giorgio Ioannides, Business Development Manager at AMT. “Whereas if you smooth them, and you seal the surface, it makes it much easier to wipe clean. You need to have a ‘close to injection molding’ component, otherwise, bacteria will just culture within the part.” 

Established in 1906, The Danish Technological Institute (DTI) has over 70 research labs that serve the needs of customers in 65 countries. Image via DTI.
Established in 1906, The Danish Technological Institute (DTI) has over 70 research labs that serve the needs of customers in 65 countries. Image via DTI.

AMT and DTI’s successful certification 

In order for these post-processed 3D printed parts to be used within the manufacturing process of contact-sensitive industries such as food processing, they would first need to pass a series of regulation tests. These assessments are designed to make the components safe for use, by ensuring that no cross-contamination takes place, and none of the part’s plastic migrates into the foods being processed. Certification requires passing four tests, which involve the component being immersed in an oven, incubator or refrigerator, and submerged in various levels of isooctane and up to 95% ethanol solutions. 

The PostPro 3D-finished parts successfully achieved the certification for five different areas including food and skin contact, and microbiological testing, offering the potential for new applications of 3D printed components. “ DTI trialed several post-processing technologies in the industry, and we were the only ones that could hit all the requirements that they had, said Steffens. “We now have a whole line of certifications in place, and we will continue to make sure that our customers and their users will be compliant with local regulations. That drives growth in the industry.”

While Steffens hailed the certification as an important step forward for 3D printing, he also acknowledged the limitations to what they’d achieved, emphasizing that you can’t earn “general approval” for 3D printed parts. “It doesn’t give a waiver for everybody who’s using printing technology and targeting those applications. It’s a direction for customers that using the PostPro3D can be an advantage in targeting these applications.” As a result, other companies wanting to use 3D printed components in similar contact-based applications would need to be re-tested for compliance with the regulations. 

To complicate matters, the requirements for certification differ greatly depending on which foods and skin surface the component will come into contact with, and in what region the testing takes place. In North America for instance, the regulations are different from those enforced in Europe, and parts will have to meet a different set of criteria in order to be used there. AMT’s successful tests, for instance, were only conducted under EU regulations, and the parts have not yet been tested under U.S. Food and Drug Administration (FDA) rules. 

Gaining FDA approval remains a future priority for AMT, but Steffens stressed that the successful tests only represent the first step in the development of its PostPro 3D machine. “You can’t do everything at once, it has to be step-by-step. First, you have to have a customer that’s really interested in these kinds of markets, and there needs to be a demand for something like this. I see us first going to the FDA in the US, and if we can achieve those [certifications], then we’ll go for others.”

Using the PostPro3D, ATI was able to produce parts with a sealed surface finish, preventing food waste from entering the material's pores (pictured). Image via AMT.
Using the PostPro3D, ATI was able to produce parts with a sealed surface finish, preventing food waste from entering the material’s pores (pictured). Image via AMT.

Future applications of the PostPro3D 

While successful testing doesn’t grant blanket approval, certification does open a variety of new food-processing applications for the PostPro3D. According to Steffens these range from “meat production to ice creams or chocolate,” and areas where AM has been more traditionally applied, should not be discounted either. 3D printed tooling and spare parts, for example, can now theoretically be used in areas where food handling takes place. The sealed surfaces provided by the PostPro3D allow such components to be properly sterilized, making food processing plants a potential new area for 3D printed parts. 

Additionally, both Steffens and Østergaard were excited by the prospect of using AMT’s systems to post-process parts for the medical sector. While Steffens suggested that AMT could develop in the future if it was approached by a customer, Østergaard said it was something that DTI was already actively working on. “We have some companies within the medical segment, not just producing implants, but equipment for X-ray machines in hospitals, that are also looking into this better cleanability for their products. It’s definitely somewhere we can increase our market share,” said Østergaard. 

DTI is also testing a metal-detectable powder using AMT’s PostPro system, a product that could also improve safety within the food industry. For components used in food-contact industries, this powder could make any plastic that’s transferred into the food, easily detectable. This could act to alleviate concerns of early adopters, as it would reduce the risk of defective foods leaving the factory, and DTI claimed to already have customer demand for this feature. “Some of our customers have machines for producing pizzas,” explained Østergaard. “They are monitoring 100 percent of the products coming out of their plant, so they demand that every part in their plant is metal detectable.”

Overall, due to the potential unlocked by AMT”s PostPro 3D system, 3D printing could now be used in a wide variety of new industries ranging from skincare to new medical care applications. Østergaard concluded by reiterating the benefits of the technology, and the possibilities it creates for companies such as DTI. “There’s a very big opportunity here, not just for us, and we now have a lot of good examples from within the food industry, with products that have shown that this can be used, and will be used in the future.”

The development of AMT’s PostPro3D 

AMT has updated its PostPro3D system and worked with other companies since its launch in 2018, to develop new applications for its post-processing technology.

At Formnext 2019 for instance, the post-processing specialist launched its new Digital Manufacturing System (DMS). Described as a comprehensive post-processing system, the DMS used AMT’s proprietary technology to provide an automated and digital solution for the entire manufacturing workflow.

AMT also collaborated with blasting equipment manufacturer, Leering Hengelo, to launch two new de-powdering systems for printed parts in April 2020. AMT subsequently launched its PostProDP and PostProDP Pro machines, which are designed to automatically clean excess powder off laser powder bed fused parts.

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Featured image shows the PostPro3D, which was used by DTI to produce food-contact related parts. Image via AMT.