Polymer material extrusion 3D printing is one of several really interesting markets for polymer additive maufacturing, and one that’s largely been responsible for the significant growth in public and corporate awareness of 3D printing technology which occurred since around 2011. Material extrusion is often referred to as Fused Deposition Modeling –the trade name for the process which was pioneered by Stratasys –but also such terms as Fused Filament Fabrication (FFF) and others. The term “material extrusion” is the proper terminology when considering that all 3D printers operate under a certain set of common characteristics, but you can call it whatever you want, as long as you know what it really is. What’s more important than the term you use to describe it, is how this particular 3D printing process has evolved in the last two years, and where this continued evolution will take it in terms of adoption and opportunity in the next five.
To characterize where the technology is at today with regards to the printing of polymers (far and away the most common implementation of the process), material extrusion could generally be described as a flexible and cost-effective process for low to medium volume manufacturing and functional prototyping. It’s most popular iteration is gantry-based three axis systems using direct drive hot-end extruders for 1.75-mm filament materials. However, as a highly flexible process, many different implementations have been developed –and this is really where the beauty of material extrusion can be found. It can be tinkered with and altered in some pretty amazing ways, a couple of which we’ll highlight as examples of where things are headed.
Use of true thermoplastic materials is a primary strength of material extrusion technology, and as new competitors in the material extrusion 3D printing market continue to grow by leaps and bounds, the resulting supply chain of available thermoplastic filaments has exploded. Thermoplastic filaments can be augmented with fillers and additives, and special chemical formulations of feedstock material to create hybrid thermoplastics (such as PC-ABS) is possible. Small changes in the hardware utilized by extrusion printers can enable processing of these more advanced and diverse materials, as the thermal control capabilities of both the extruder and print environment are augmented.
Shortcomings of common implementations of material extrusion are mechanical strength issues in parts in the vertical axis (or ‘Z’ axis) due to the poor inter-layer adhesion of layer by layer thermal extrusion, as well as overall relatively lower productivity of the actual deposition process necessary to achieve detailed prints with most systems. Surface quality of prints is also poor by comparison to other processes, though can be tailored based on printing speed and feature size requirements. To improve on shortcomings of the process, a number of increasingly interesting technical evolutions are now in the early stages of commercialization.
For a couple of years now, there have been a wide variety of relatively lower cost material extrusion systems designed to be fairly modular, accepting various aftermarket or upgraded extruders which are an area of technical development all their own. Alterations like heated print beds that can automatically level themselves are becoming standard features in the market. But these changes are only based on the classic polymer material extrusion printer design. What we’re equally excited about are based on significantly different visions of the technology which we believe will contribute to material extrusion 3D printing technology growing to become a more widely utilized tool for direct manufacturing.
Things like swarm manufacturing cells using a dozen or more relatively small, lower cost extrusion printers in unison through networking, as well as multi-axis extrusion systems, hybrid additive/subtractive extrusion printers, and much more, are all development trends SmarTech believes will usher in the next wave of adoption in extrusion technology. These principles all leverage the great adaptability of the process to make it scalable and accessible, while improving on its shortcomings in creating very strong parts through all three axes. This is to say nothing of the continued advancements in extruders themselves, which are becoming more and more controllable.
Material extrusion 3D printers already generated the most hardware revenue worldwide in professional and industrial environments in 2017. We expect that the widespread support and continued visionary approaches to extrusion printing of polymers will continue to make extrusion 3D printing a huge global opportunity. But it won’t be one that comes to pass without casualties –only those that can continue to innovate based on better part outcomes relative to costs will survive the next evolution of the market.
By: Scott Dunham, Vice President of Research, SmarTech Publishing