Stratasys 3D printers offer two main technologies through which multi-color printing can be accomplished. PolyJet technology is the most widely known that allows you to 3D print multi-color, multi-material parts and is known for its detailed and realistic results. Surprisingly, many people do not know that single-print, multi-colored prints are also possible when using Fused Deposition Modeling (FDM) technology. Using Stratasys 3D printers and GrabCAD Print software, the process is actually very simple.
Multi-Color Printing Using FDM
There is a wide range of colors available for the most common FDM materials like ABS and ASA. When using FDM technology to print, the color of the filament you are using is the exact color your print will be. If you can’t find a material filament that matches the exact color you need, there are other post-processing methods you can use like dying or painting.
When 3D printing multi-colored parts using FDM you must use the same material throughout the entire part. For example, you cannot go from printing in black ABS to white ASA. Fortunately, common materials like ABS, ASA and PLA come in dozens of colors. Other specialty materials like PC-ABS, or other polycarbonates, typically only come in a single color and would be better for adding multiple colors after printing.
To print a multi-colored part using an FDM 3D printer you will have to pause the printer at each color change. During the pause you’ll need to switch out the color of the material, then resume printing once it reaches temperature. The pause will occur BEFORE the printer begins the layer you selected, and then that layer, and every other layer after, will be in the new replaced color, so keep that in mind when selecting your pause layer.
You will also want to change the material promptly when the job pauses. It does not have to be immediate, but you don't want to have a paused print waiting for several hours. Similar to if you run out of material during a print, long printing delays can lead to suboptimal layer adhesion between the paused layers. This is just a general best practice and not specific to different colored materials.
Inserting a Pause in GrabCAD
To insert a pause, first import the part into GrabCAD and generate a slice preview. Once that process completes, the Slice Preview menu will be open. In this menu, you can go through the part layer by layer and check it for any potential problems. To add a pause, simply go to the layer you would like to start the pause at and click the Add Z Pause button. The layer will then highlight blue, confirming your selection. You can add multiple pauses for each time you would like to change colors.
During printing, once the machine pauses, all you will have to do is unload the current model material and load the new color. Since you will be using a different color of the same material type, you do NOT have to replace the support material. Once the new model material color is loaded, simply press resume on the machine and the print will continue.
Now that you know how to create a multi-color print with your Stratasys FDM 3D printer you can test and produce colorful parts and prototypes. With a variety of colors for the most common FDM materials, you will have different options available to successfully print your design.
Do you want to learn more about FDM materials? Click below to download our white paper, Thermoplastics: The Strongest Choice for 3D Printing.