Using 3D printing technology in college courses is a great way to prepare students for successful careers.  The variety of 3D printers on the market can help you navigate the constraints of space and budget, and you can share the applications and benefits of 3D printing across university departments. Of course, ample research on your 3D printer is recommended, and it can take a lot of work to know where to start. 

Fused Deposition Modeling (FDM) and Polyjet are two copyrighted processes, standard in most 3D printers. But what’s the difference? Both methods use layers to create the 3D model, but FDM uses a thermoplastic filament where Polyjet injects biopolymers into a printer bed. 

Here are the main differences between these two printing technologies. 

FDM vs. Polyjet Design 

Is your design a product run of 1000 or a single 3D print? FDM printers are able to produce accurate and dimensionally stable parts for longer than a Polyjet printer. The FDM prints also tend to be more durable and ready for end use. If your design is a highly sophisticated model of an anatomical part to be used for education, though, Polyjet is the best choice as the polymer injection process allows for much greater delicacy and detail. Polyjet 3D prints also have a smooth finish, while FDM prints retain the striation of the thermoplastic layers and sometimes require post-processing. Consider the applications at your university when considering which to choose.

FDM vs. Polyjet Pre-Process

Of course, there is always the cost consideration, both in purchasing and operating costs. There is a wide price range of both Polyjet and FDM 3D printers available on the market. Operation costs of both FDM 3D printers and Polyjet 3D printers are similar, but material costs can vary. For FDM 3D printers, you will need to replace the extrusion nozzles and build trays frequently, but this is still a lower cost than the expensive Polyjet print heads that need to be replaced after a certain number of hours. 

For set-up, both FDM and Polyjet are similarly easy in that there is only the need for power and water/plumbing hookups to run the 3D printers. There is also no need for special OHSA respiratory protections, as there is no powder used. Both processes are also available in machines that can be used in normal classroom settings, with a few larger exceptions.

The Stratasys J55 is an enhanced full-color Polyjet printer applicable in many settings! 

FDM vs. Polyjet Process

But how do they work in action? In terms of speed, both FDM and Polyjet tend to average out to the same elapsed times, but Polyjet can be faster in certain use cases. Even though it may have a faster build time, the other required steps in the process take much faster. Here, too, Polyjet and FDM are similar in that file uploading is relatively simple, and the process of changing materials cartridges and printheads isn’t time-consuming. You can simply set up the machine, close the hood, and press start. 

When resetting the machine after use, however, there are vast differences. The Polyjet requires a manual step of washing away the gel-material that the polymers inserted into a waterjet. FDM requires a manual removal of the 3D print supports or a soak to remove the soluble supports. This leads to a higher turnaround time. 

When considering the needs of your university, it may become clear whether you should choose FDM or Polyjet. For questions about your best fit, reach out to our experts!