The previous post featured and in-depth look at Stratasys FDM Technology and the 10 thermoplastic materials used in that technology. In this third post we will focus on the second major 3D printing technology: Stratasys PolyJet™ technology. (Click here to see full size chart above.)
PolyJet technology produces parts made of UV cured polymers. The process used is much like an ink jet printer; however, the “ink” is a liquid polymer. The unique nature of the liquid polymer, and the PolyJet process, can create parts not available through other 3D printing technologies.
But like FDM thermoplastic materials, there are different liquid polymer materials that result in prototypes with unique characteristics. In the case of PolyJet technology, there are 17 different UV cured polymers that are organized into six categories that each represent a physical attribute or characteristic:
- Rigid opaque
- Simulated polypropylene
- High temperature
Transparent Liquid Polymer Materials
Transparent liquid polymer materials are used to create fine transparent models including: bottles, safety glasses, glass, visualization of liquid flow, artistic models. Two available transparent materials are nearly colorless, smooth and very dimensionally stable. Available for most PolyJet printers but not all.
- RGD720 – Has a yellow tint to the transparency, this material created parts that remain transparent no matter the thickness of the part.
- VeroClear – the clearest material and it can be post processed into a very transparent part. The thicker the part the less transparent the part.
Rigid Opaque Liquid Polymer Materials
Rigid opaque liquid polymer materials are used to create meticulously detailed models to show fine details in color with smooth finish when attention to detail is paramount. There are two “families” of Vero materials.
Used in any of the PolyJet printers, all the Vero Family materials have the virtually the same material properties. The reason behind the “plus” designation is interesting. The VeroWhite and VeroBlack was created first then, Stratasys scientists they created VeroBlue and VeroGrey. They liked the properties of VeroBlue and VeroGrey and redesigned Vero White and VeroBlack. They then renamed those materials as VeroWhitePlus and VeroBlackPlus.
- VeroWhitePlus, The parts created look fantastic right off the machine. VeroWhitePlus can be used in all the PolyJet printers.
- VeroBlue is the softest of the Vero family. Best for Bean Blasting or sand blasting.
- VeroBlackPlus, finished part is black and is mostly used when black is a desired shade of the completed part. VeroBlackPlus will not run on the Eden 260VS printer.
- VeroGrey – paints the best. Most of parts created and finished via painting use VeroGrey.
The colors are Cyan, Magenta, and Yellow. They have the same materials properties as the Vero Family above. However, they are only available for and used by ConnexC3 printers. The Vero material properties and the color is uSed to merge with other materials to achieve color in your model. More uses of Vero Color in digital printing will be discussed in the next installment of this blog.
Simulated Polypropylene Liquid Polymer Materials
Simulated polypropylene liquid polymer materials are used when you need either flexible or tough parts created which include parts like containers, packaging, automotive components etc. There are two simulated polypropylene materials, and each has distinct and different characteristics. Durus is ideal for flexible designs, while Rigur is a good material for snap fit testing. The parts created with simulated polypropylene are tough and usable.
- Durus Most flexible of all the PolyJet “rigid” materials and slightly translucent, it is not recommended for snap fit application because it bends too easily.
- Rigur (formally Endur) – RGD450 Hardest material for the smaller machines. Good for snap fit testing.
Rubber-like Polymer Materials
Rubber-like liquid polymer materials are ideal when your functional prototypes require rubber like flexibility. The differences in the Tango materials in this category are mainly seen when comparing shore values. The TangoPlus shore values are low (more flexible) and the Tango materials are higher (less flexible). The Tango materials can be printed on the Objet 30 Prime up to the Objet 1000. Note that the TangoPlus materials cannot be printed on any of the desktop Objet printers, so you will need the EdenVS up to the Objet 1000to use TangoPlus.
- TangoBlack – created first of the tango family, TangoBlack has native shore value of 60-62, second highest shore value.
- TangoGrey – Has the highest native shore value of 73-77.
- TangoPlus – Has the lowest native shore value of 26-28 (softest), is yellow tinted and somewhat transparent and easer to tear than TangoGrey and TangoBlack.
- TangoBlackplus – Has the lowest native shore value of 26-28 (softest), is black and easer to tear than TangoGrey and TangoBlack.
High Temperature Liquid Polymer Materials
High temperature liquid polymer materials are ideal for heat resistant application:
- RGD525 – Creates very stiff parts. It holds accuracy under heat conditions. Can be placed in an oven to increase the heat deflection temperature. It is good for plating. This is the materials you would need if you are testing pipes, fixtures, and household appliances. Works well with application with hot air and hot water. Can be created with PolyJet printers starting with the Objet30Pro and Objet30Prime, EdenV/VS, all Connex and the Objet 1000.
Bio-compatible materials are ideal for biological applications that require 3D printed parts intended for use on live subjects:
- MED610 – Is functionally the same as Vero clear. However, this materials has several suitable applications for parts created requiring skin contact of over 30 days and short term mucosal-membrane contact of up to 24 hours. The material has five medical approvals according to the harmonized standard ISO 10993-1. These include; 3D printing of dental and orthopedic surgical guides, customized fit of surgical guides. Can be created with PolyJet printers starting with the Objet30Pro and Objet30Prime, EdenV/VS, all Connex and the Objet 1000.
With all of the unique options in PolyJet materials, picking the correct PolyJet materials for your project can be simple or could be complex. You may quickly see a material that aligns with your needs or may be faced with a choice between several appropriate materials. The best strategy is to call someone from Prototyping Solutions to help you create a benchmark project. This will allow you to test your part to identify the best material. And if you find you need to print a custom application that uses more than one of these materials in a single design, my next post will be about understanding the digital PolyJet process that can combine materials from the six categories.
Click to read more posts in our series on choosing materials: