5 Trends in 3D Printing to Watch

More Material Options

There’s a clear trend towards a greatly increased range of materials–both polymers and metals–that will soon become suitable for 3D printing. This can only expand the range of applications for component design and manufacturing.

On the polymer front, technology has progressed from a limited set of specialized polymers to a very broad palette of plastic materials. A very recent development is the emergence of rubber-like polymers, such as liquid silicone, that create flexible 3D printed structures, which should prove invaluable for manufacturing functional prototypes.

In metals, it’s possible to print an ever-growing list of steel grades, and other metals are being added to the Senvol Database every day. Titanium, aluminum, and nickel-based superalloys for the aerospace industry are just some examples of the metal material that 3D printing offers today.

In addition to polymers and metals, progress is being made on the use of specialized ceramics in 3D printing. And according to a Forbes review from 2016, even glass and graphene are potential candidates for 3D printing in the future. With more and more materials becoming viable every year, one can only imagine the potential applications for 3D printed parts in the future.

Experience is Driving Application Growth

Maximizing the potential of additive manufacturing requires a different approach to design. Understandably, it has taken time for that knowledge and experience to grow and mature. Whereas engineers first took conventional designs and just 3D-printed them, today there’s a better understanding of how to put material only where needed for strength or functionality. So, for example, you see more lattice and organic structures that can reduce weight significantly while maintaining or even improving strength.

A particular issue in metal 3D printing is handling of support structures. While supports printed in polymers are easily cut away afterward, the same is clearly not true for those in complex aerospace alloys. However, just as it took time to refine 3D printing techniques with polymers, the same is also true in metals. As the experience base both broadens and deepens, look for exciting new ideas in part design and orientation.

Rapid Tooling

Launching a new product into manufacturing invariably involves commissioning tooling, both for molding or casting, and for work-holding during processing. This can take weeks, even months in the case of complex mold tools. Costs can easily run into six, even seven, figures. When demand for the product is unknown and untested, the risk associated with this kind of investment can lead management to pause and reconsider.

3D printing is used increasingly to fabricate work-holding devices. While they may not have the durability of tool steel or weldments, they are often sufficient for producing pre-production and ramp-up quantities. Not only can this save money, it also significantly reduces the time needed to start production.

The same is true in mold tooling–whether it be patterns for sand molding, casting dies, or injection molding tools. When produced through additive processes, these may not have the strength and durability of hardened tool steel, but compensate with greatly reduced lead time and often lower costs.

Another development is that 3D printing allows for optimal placement of cooling channels. According to TCT Magazine, faster, more precise heating and cooling can lower cycle times by a third of the time, and can even improve overall part quality.

Hybrid Processes

Almost all 3D printed shapes need secondary finishing operations. Support structures are cut away, ridged surfaces are milled flat, and holes are drilled and tapped. In a small shop, the additional cost and space requirements of these machines may be difficult to justify. Additionally, unloading and transferring a printed part to a secondary subtractive process adds both cost and time, which runs counter to the “rapid” philosophy.

To remove this barrier (and perhaps to address a threat to their business model), several machine tool producers have sought ways to marry additive with subtractive processes. Using the DED approach and CNC milling machine architecture, these incorporate a material deposition module that is switched in and out of the tool holder as needed.

Where this thinking gets really interesting is in the potential for what we might call, “interrupted additive.” Visualize, for instance, a scenario where a threaded hole is needed inside a complex lattice structure. First, half of the structure is printed, including an internal boss. This boss is then drilled and tapped, after which, the 3D build resumes.

Plastics specialists might recognize this “interrupted additive” as an opportunity for co-molding. Imagine the benefits of being able to stop printing, place inserts or reinforcing pieces, and then resume!

Digital Engineering from Start to Finish

Just as subtractive machining needs design, programming, and verification processes, so too does additive. For reverse engineering, 3D scanning technology is evolving to produce denser and more accurate point clouds. In parallel, CAD software is also evolving to accommodate the particular needs of 3D printing. Future advances will likely include topological optimization capabilities to minimize the need for support structures and to speed the printing process.

3D printers themselves are becoming faster and more accurate. This is due partly to the new 3MF extension to the STL file format, as well as ongoing efforts to improve repeatability and reproducibility, or the ability to make exactly the same part on different machines. Larger printers with bigger build envelopes are also in development, which allows for potential part sizes and applications to increase.

After a build, it’s essential to ensure the structure is free from internal defects and fit for purpose. This is perhaps even more important than for parts made through subtractive processes, as there is little to no structural redundancy in case of internal defect. This requires inspection technologies capable of looking into and through the complex printed forms. While ultrasound techniques will have a role, verifying conformance to the design will only be achievable through CT scanning.

At Panova, we make it our business to follow and understand these advances so that we can properly advise and guide our clients. We’ve enabled our clients to experience the benefits of 3D printing first hand, as we’ve employed our in-house 3D printers to aid in the product design and development of many custom components. Our printers have allowed us to reduce their projects’ needs for part revisions and engineering hours, and have greatly increased the rate at which we develop and deliver their products.

Subscribe to our blog and revisit our entire series of blog articles on 3D printing, the biggest game changer to the manufacturing industry in the last decade.

Read Other Blog Posts From This Series:

• 3D Printing’s Benefits and Limitations
• The Technologies of 3D Printing
• 3D Printing: The Biggest Disruptor to the Manufacturing Industry in the Last Decade
• 3D Printing’s Evolution from Novelty Process to Mainstream Manufacturing  

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