Titan Pellet Printers: Revolutionizing 3D Printing | Voices AMplified | advancedmanufacturing.org

Contributing Editor

Select models of EXT Titan Pellet printers are available with up to three toolheads. Shown here (L-R) are the filament extruder, pellet extruder, and milling spindle toolheads.

Still working with filament but parts getting too large? SME had an opportunity to catch up with Rahul Kasat, vice president at 3D Systems Corp., about the company’s new Titan line of pellet printers. His answers might surprise you.

Rahul Kasat, vice president, 3D Systems Corp.

SME: During an interview at the 2024 RAPID + TCT exhibition, you pointed out numerous highlights and advantages of your new EXT 800 Titan Pellet printer. What are the key differentiators from other large-format 3D printers?

Kasat: Number one is our pellet extrusion technology. Prior to the acquisition by 3D Systems, Titan was one of the first companies to commercialize pellet-extrusion 3D printers, nearly nine years ago. Most other medium-to-large-format printers are still using filament. Filament extrusion (FFF/FDM) is significantly slower than pellet extrusion in most cases. Filaments are up to 10x more expensive than pellets. And pellets are also available in hundreds of formulations, so you’re not limited to just the materials that filament makers have chosen.

SME: What are the target parts/markets for the Titan line of printers? Where do they shine?

Kasat: The number one application of this technology is tooling production, across numerous manufacturing processes. There’s a lot of value for customers in the foundry industry for sand-casting patterns and core equipment, as well as the thermoforming industry for production molds. We also have customers producing layup tooling for composite forming and refractory molds and patterns. Compared to traditional toolmaking methods, Titan Pellet systems are saving these companies significantly on material costs while enabling them to improve quality and to be more responsive to their customers. That said, we also have customers making aerospace ducting, end-use automotive and HVAC components, signage, sculptures and even commercial furniture with EXT Titan Printers. The versatility of pellet-extrusion printing is remarkable.

SME: What should customers know before investing in a pellet printer? Software considerations? Workflow changes?

Kasat: Printing with pellets has some obvious differences from FFF/FDM printing although the process overall is very similar— melted thermoplastics deposited layer by layer according to the G-code from a slicing software system. We recommend Simplify3D for slicing, which is a program many of our customers are already familiar with, and Fusion 360 for milling toolpaths, again a program many have experience with already. We also have a program for combining printing and milling G-code into a single file so customers who opt for the milling toolhead can print and machine a part without any intervention. This frees up the operator to focus on other tasks and then come back to a fully finished part, ready for use.

SME: How about post-processing of pellet-printed parts? Any differences?

Kasat: Nothing significant. EXT Titan Pellet prints made with smaller nozzles and fine layers are difficult to distinguish from parts printed with filament. Very little, if any post processing is needed. On the other hand, pellet-printed parts made with larger nozzles tend to be heavier, stronger and thicker-walled than comparable filament prints. A benefit for post-processing is the ability to print very fast and then use a CNC machine, or our optional milling spindle toolhead, to smooth the surface and meet tight tolerances. Many customers also just use auto body filler and sanding to smooth out layer lines in applications where a smooth surface is needed.

SME: Are there any design constraints/considerations users should be aware of, both with large-format parts and pellet feedstocks in particular?

Kasat: Similarly to filament printing, designing parts and orienting them on the print bed to reduce the need for support material is beneficial. We offer nozzle sizes from 0.4 mm (for unfilled plastics) all the way up to 10 mm for very high deposition rates. So EXT Titan printers can produce parts with very smooth surfaces when using smaller nozzles. Obviously, larger nozzles will reduce surface quality while enabling faster print speeds. Most customers find nozzles in the 2-3-mm range are a sweet spot.

SME: Do you see pellet printers replacing filament-based FDM units at some point? It seems to me that pellet feedstocks would be more economical and present fewer problems than filament. Thoughts?

Kasat: For desktop printers, let’s say parts less than 12 inches (305 mm) in all dimensions, I think filament has an advantage despite the higher material costs and slower speeds. Pellet extruders are inherently bigger and more expensive than filament extruders; plus a reliable system for feeding pellets must be included, adding to cost and complexity. On the industrial side, particularly for parts with dimensions of 12-plus inches, the lower material costs and higher speeds of pellet printing begin to offset the added machine cost and size. Once you get above 24 inches (610 mm) in any dimension, the advantages of pellets are so obvious, it’s hard to imagine going back to filament. So I do think pellets might supplant most filament in larger formats.

SME: What kinds of parts or applications are pellet printers—or more specifically, the Titan line—not suitable for?

Kasat: Customers must understand the tradeoffs between part size, speed and surface quality, and make educated decisions on when to use pellet printers versus other technologies. Our sales professionals and AIG teams have expertise across all AM technologies, and they’re here to help.

SME: Are there any material limitations with pellet feedstock? Advantages? Kasat: Pellet printers without an actively heated chamber will struggle with any materials except PLA (polyactic acid) and PETG (polyethylene terephthalate glycol) unless using very large nozzle sizes and post-machining. EXT Titan Pellet systems have heated chambers to mitigate this issue and can even print fiber-filled PEKK (polyether ether ketone) and PEI (polyetherimide). We’ve touched on selection, cost and speed advantages ad nauseam, but in the context of this question, I would say there are several huge advantages of printing with pellets versus filament. Top on the list is the ability to print highly filled materials that would be too brittle to run through a filament extruder, as well as extremely flexible materials that would be too elastic to run reliably through a filament extruder. Similarly, pellet extruders open the door to the development of custom materials for a specific application.

SME: Pellet printers are relatively new. Did I miss any important points, capabilities or applications?

Kasat: One thing the EXT Titan Pellet platform gives our customers is great flexibility. They don’t need multiple machines to print tooling with machined surfaces one day, a large prototype the next and jigs/fixtures the next. These are tools so versatile that we have not even scratched the surface yet on the many applications where the platform could be a game changer

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Contributing Editor