PolyJet 3D Printing: Digital Materials

“Digital Materials,” as Stratasys calls them, are combinations of 1 or more discrete resins that are jetted together to create a unique mixture (and hence mechanical properties) within a part.  This is not the same as pre-blending resins and then feeding them into a printhead or SLA vat – it’s something unique to material jetting as the digital materials can be adjusted on the fly, without any additional purging or preparation needed.  It’s an amazing technology that proves useful across multiple applications, outlined below.

1. Color Blending on the Fly

Similar to how our FDM Machines have separate heads for model and support materials, so they can rapidly switch between the two during printing, our Polyjet machines are capable of printing several different materials during each pass of the head.  Our machines accept two model materials (plus supports), or six model materials plus support in the case of our full-color J750 machine.  This allows them to print multiple materials in different areas of the part, or variable blends of materials throughout.  This is made possible by the extremely small size of the jetting droplets, allowing materials to blend like Ben-Day dots in the Sunday Funnies

Our J750 is Pantone verified to create a very wide gamut of colors using its core clear, white, black, cyan, magenta, and yellow channels.  For example, this kids toy -- straight off the printer (after support removal).  
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2. Rubberlike: a Range of Durometers in a Single Print

This technology allows the printer to blend Stratasys’ Agilus flexible, rubber-like material with standard rigid materials to create rubber-like prints in a range of durometers, from Shore 30A to 85A (or even higher, to create a polypropylene-like material).  ​

Shore30A part (black) resting on a rigid part (white)

Since the blending is done on the fly, different parts of the print can have different properties, as in these parts with mixed rigid and rubberlike sections, simulating an overmolding process

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Rigid part with rubber-like outside layer (image courtesy of Stratasys)

We can even combine rubber-like with full color, as shown in our example swatch below

Details about the mechanical properties of Agilus30 can be found on Stratasys’ website here.

3. Digital ABS: ABS Mechanical Properties with Polyjet Print Quality

Digital ABS takes this idea to the limit, varying the blend of the high-impact material RGD 515 material with the high-temp, rigid RGD 531 throughout the part based on the geometry, to optimize the mechanical properties.  The software places more of the high-impact-strength flexible material on the outsides of the part where it’s needed for toughness, while blending in more of the high-temp, rigid material through the core of the structure for stiffness.
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Details about the mechanical properties can be found here

Check out this video from Stratasys showing what you can do with this material!
​The Toughest Ever PolyJet Material: Digital ABS Plus

4. Conclusion

Digital materials give Polyjet printers the ability to create parts that aren’t possible in other resin-based printing processes.  With the ability to vary the blend of multiple materials throughout any given print, they can create parts that are strong and tough, soft, and/or colorful while maintaining excellent print resolution and dedicated supporting materials that wash away easily.