By: Amross Ferido, Date: 02/12/2018

PolyJet Technology is a 3D printing/additive manufacturing technology that produces smooth, accurate parts, prototypes, and tooling. PolyJet creates parts with photopolymer resins. As the name implies, photopolymer resins are polymers that change properties with exposed to light, often in the ultraviolet or visible region of the electromagnetic spectrum. PolyJets work similarly to an ink jet printer, but instead of dropping tiny droplets of ink, PolyJet printers jet droplets of liquid plastic (photopolymer resins), which are then cured with UV light to be solidified.

Much like the common 3D printers, which are Fused Deposition Modeling (FDM), the designs are printed layer by layer until complex forms are produced. Some of the more advanced PolyJet machines are capable of building parts made of different materials leading to each model to be more accurate in terms material property (examples are heat resistance and durability), and also in their physical properties (i.e. soft, rigid, clear, opaque, colorful etc.) The versatility and accuracy of PolyJet Technology enables designers to predict future needs, manufacturers to produce better, more efficient, products, and enables researchers to utilize a more innovative way to save lives. However, the potential of PolyJet doesn’t stop there, its usability is also in the film, fashion, and medicine industry. It is helping the world strive to a more advanced and innovative future.

PolyJet Technologies were first created by Object Geometries Ltd. Object Geometries Ltd., was a corporation involved in the design, development, and manufacture of photopolymer 3D printing systems. It was created in 1998 and was based in Rehovot, Israel. Object Geometry merged with Stratasys in 2012. Stratasys, Ltd. is essentially, a very similar company as Object Geometries in that they were both beginning to manufacture/engineer 3D printers that were integrating the use of photopolymer resins. Eventually, Stratasys was able to hold patents on several associated printing materials that are used in PolyJet and PolyJet matrix polymer jetting technologies.

Like many 3D printing machines, the user must first create a 3D model, using a 3D modeling software, and then to save it as an STL file. The designs for the ideal PolyJet application includes molds, and detailed prototypes. Additionally, PolyJets are capable of printing models in different materials in one single prototype, which can lead as an advantage to other types of 3D printing. For instance, it is possible to print models made of rubberlike parts with different shades of color.The more common type of 3D printing is called Fused Deposition Modeling (FDM), where the machine creates layers of melting thermoplastic material to a semi-liquid state and drawing out each layer and then moves to the next layer. However, PolyJet can create much smoother surfaces, complex geometric structures, and more precise models. PolyJets can print models with different physical properties, and variable material properties, while FDMs cannot. PolyJets are also much faster in printing than FDMs.

MultiJet is a similar type of modeling. Where both technologies utilize jets that spray droplets of photocurable polymers. Given their many similarities, their differences are in the nuances. Such nuances include the steps taken when removing the part;

PolyJet printers are one the most precise types of printers. It works similar to that of inkjet printing, but instead of ink droplets, PolyJets use fine print-head nozzles to deposit droplets of photocurable liquid material onto a build tray. The layers that PolyJets are capable of are within 16 microns and accuracy down to .1 mm.

These are examples of PolyJet 3D-printed models:

As mentioned previously, like many 3D printers, PolyJets require a 3D model base, that is saved as an STL file. The STL file is then sent to the printer’s interface software which then slices the digital model into layers and determines how the layers will be printed. The liquefied photopolymer materials are deposited onto the print bed one layer at a time. Every time a layer finishes the layer is exposed to UV light, which hardens the layer. Promptly afterwards, a gel-like support material is printed to surround the part to hold the layers in place. This process repeats until the model is complete.

These types of machines are intended for general use. However, due to the complexity of creating 3D models and the interface it requires a bit of technical experience. Nonetheless, the main factor that makes users to be technical users are that these types of machinery are typically found in more established corporations, not really in homes, is because of the price.

PolyJet Technology are not for the parsimonious. These machineries typically cost around $20K minimum and can range up to more than$200K. For instance, the Object24 - 3D Desktop Printer is considered a "mid tier" PolyJet. This cost about $20K (left). As for a high end Polyjet printer, Object500 and Object350 - Connex3, is an example, and costs about $330K(right).

Since Stratasys has a patent on PolyJet Technology, it is the primary manufacturer and maker of PolyJet 3D printers. Additionally, they are also the main providers of the materials that are used in the printers. This is not to say, that there aren’t companies developing similar products that could prove to be competitors for Stratasys. One of which is the MultiJet technology which is advertised by 3D SYSTEMS. Given the price of a PolyJet printer, the primary owners of PolyJet systems are major companies whose main role is rapid prototyping.

Most companies who provide services for PolyJet printing typically vary their prices depending on; the application, the material, and the size.