PolyJet, material jetting, is an additive manufacturing process that produces high resolution parts, prototypes, and models using a liquid photopolymer material cured with UV lights. The PolyJet process can produce parts with thin walls, complex geometries and multiple model materials in a single build. The PolyJet technology is best described by drawing a similarity to the standard inkjet printing process, but instead of jetting ink on paper, a print head jets liquid photopolymers onto a build tray where each droplet is cured.

With any 3D Printing technology, you need to start with a 3D model in STL format from CAD software. It is recommended that you check your STL file before sending it to the slicing software to prevent errors such as reversed normal, bad edges, holes in the mesh and noise shells which could cause printing errors. After the errors in the STL file are removed or corrected, the printer specific software slices the file into cross-sections or thin layers and sends it to the 3D printer.

Before printing begins, photopolymer resin is poured into the material container and heated, this allows the material to reach the desired viscosity. The PolyJet printhead then deposits droplets of this material on the build platform, as mentioned above. The printer starts to construct the object one layer at a time from the bottom up.

PolyJet material properties vary, ranging from rigid to rubber-like. The materials used in our printers are plastic and rubber-like materials (TangoBlack, VeroClear, Rigur, and ABS Like). This technology can also mix multiple materials together to achieve unique material properties and colors. Since the PolyJet printer has the capability to blend materials it can print parts with rubber like materials, that have a Shore A Hardness value ranging from 27-95. This process can also do rubber over molding, which makes this technology unique to other 3D Printing technologies. PolyJet materials are best suited for applications where accuracy, surface finish, and detail are essential components of the printed part. The material is solidified by ultraviolet light which is attached to the print head and simultaneously cures the material as it is printed. Once a cross-section is completed, the build tray is lowered slightly to make room for the next layer. These layers are 16 or 30 microns thick and are accumulated on the build tray until the part is complete. As the part is being built, a gel-like, dissolvable support material is added to give strength to fine and overhanging structures. The support material is easily removed by hand, with pressurized water, and after that the part is immersed in a chemical solution dissolving the rest of the support material leaving a clear, smooth finish. The PolyJet process is ideal for fast, inexpensive and high-resolution parts, prototypes, and models that require excellent detail, accuracy and a smooth surface finish. With the PolyJet process, ideas become a reality.

By: Cyb Llings Inc.