Processes - Additive Manufacturing
r PolyJet
In PolyJet (a proprietary technology by Stratasys) or MultiJet Modeling (MJM), liquid acrylic polymers are layered onto a build platform with a printhead with one or more nozzles and cured by exposure to UV lamps. The printhead moves across the platform in paths pre-defined by a CAD model during the process until a layer is completely printed. The UV lamps are located directly on the printhead and cure the plastic as soon as it has been applied. The intensity of the UV light is adjusted so that the uppermost layer does not cure completely, which achieves a stable connection between the superimposed layers. Once the last level has been printed, the UV lamps travel over the entire component several times to complete curing.
Advantages
Highly Accurate and Detailed Prints
PolyJet printing is known for its ability to produce highly accurate and detailed prints. The technology can achieve layer thicknesses as small as 14 micrometers (though usually the average is closer to 18 micrometers depending on the system you use), resulting in a smooth surface finish that requires little to no post-processing. This makes PolyJet printing an ideal choice for applications that require precise detail and high resolution, such as jewelry design, dental appliances, and architectural models.
Wide Range of Materials
PolyJet printing allows for the use of a wide range of materials, including standard resins, rubber-like materials, and transparent materials. This allows for greater flexibility in the design and manufacturing process, as engineers and designers can choose the best material for their application. Additionally, some PolyJet printers can mix different materials together, resulting in new materials with unique properties.
Quick Turnaround Time
PolyJet printing offers a quick turnaround time, making it an ideal choice for rapid prototyping and small-scale manufacturing. The technology can produce a fully functional model in a matter of hours, allowing for quick design iterations and adjustments. This can help to reduce overall production time and costs.
Versatility
PolyJet printing is a versatile technology that can be used for a wide range of applications. The technology is well-suited for both low- and high-volume production runs and can be used to create highly complex geometries that would be difficult or impossible to achieve with other manufacturing methods. This makes PolyJet printing an ideal choice for industries such as aerospace, automotive, and medical.
Disadvantages
Limited Build Volume
PolyJet printers typically have a limited build volume, which can be a drawback for larger-scale manufacturing applications. The size of the build tray is determined by the size of the printer, so larger parts may need to be printed in multiple pieces and then assembled, which can increase production time and costs.
Cost
PolyJet printing can be a more expensive option compared to other 3D printing technologies, such as Fused Deposition Modeling (FDM) or Stereolithography (SLA). The cost of the printer and the materials can be higher, which can be a barrier for smaller companies or individuals. However, the cost of PolyJet printing has decreased in recent years, making it more accessible to a wider range of users.
Limited Material Options
While PolyJet printing allows for the use of a wide range of materials, the options are still somewhat limited compared to other 3D printing technologies. For example, metal 3D printers can create parts made from metals such as titanium, stainless steel, and aluminum. Additionally, some materials used in PolyJet printing can be brittle and may not be suitable for some applications. While there are many material options for PolyJet printers, because of how they are hardened and cured using UV light, this does make them susceptible to damage from sunlight.
Capabilities
Disclaimer: All process specifications reflect the approximate range of a process's capabilities and should be viewed only as a guide. Actual capabilities are dependent upon the manufacturer, equipment, material, and part requirements.