All About PolyJet™ 3D Printing: Advantages, Materials, and Different Types
Learn more about this versatile process and its capabilities.
PolyJet™ 3D printing is a process used to create multi-color and multi-material components using a process similar to standard inkjet printers. An inkjet-type head deposits multiple droplets of a photopolymer onto a build plate. A UV light source immediately cures this layer, and the process is repeated until the part is complete.
The key advantage of PolyJet™ printing is its ability to create parts with multiple colors and materials in one go. This allows for the creation of prototypes that exactly match the color and physical feel of a final product. PolyJet can also create these multicolor parts much faster than most other 3D printing technologies. PolyJet™ 3D printing can use multiple materials that can be transparent and have rubber-like properties while also simulating the properties of common thermoplastics like ABS or polypropylene.
This article will review the PolyJet™ 3D printing process and discuss its advantages, applications, and how it differs from other 3D printing processes.
The PolyJet™ 3D printing process makes use of an inlet-style printing head that can deposit multiple different materials from independent nozzles onto the build platform; as such PolyJet™ is a subclass of inkjet printing. The materials used in PolyJet™ printers are exclusively photopolymers. These 3D printed polymers will solidify when exposed to UV light. PolyJet™ parts also require support materials for large overhangs and internal volumes, which means some post-processing may be required. A typical PolyJet™ printer is shown in Figure 1 below:
PolyJet™ 3D Printer.
Image Credit: Shutterstock.com/Moreno Soppelsa
The advantage of using PolyJet™ printers is that they can quickly manufacture “form, fit and functional” prototypes. These prototypes look and feel like the final product by making use of different colors and different materials. For example, a mock-up of a hand drill can be printed that has all the relevant colors and feel of the final part while also having a soft grip handle.
The different types of PolyJet™ 3D printers include:
- Objet30: Used for printing rubber-like materials all the way up to a high-production-volume J4100 machine.
- J5 Medijet: A purpose-built machine for the medical industry.
- J5 Dentajet: A purpose-built machine for the dental industry.
PolyJet™ is a Stratasys trademark for a material jetting type 3D printing process. The company offers a wide range of PolyJet™ printers.
PolyJet™ 3D printing is widely used in the dental industry for creating accurate molds and for surgical aids in the medical industry. The method can also print multi-color and multi-material components in one step. As such, it is widely used for rapid prototyping, with the added benefits of retaining the final product's colors. Functional prototypes are also possible with materials like simulated polypropylene and ABS.
PolyJet™ printers make use of one category of material: photopolymers. These materials are deposited in a liquid form and are cured using UV light. Listed below are the materials used in PolyJet™ printing:
- Digital Materials: These materials are created by depositing up to seven different resins at once to create an acutely optimized material. Their physical and visual properties depend on the concentration, material type, and location of these individual droplets.
- Digital ABS Plastic: Digital ABS is a collection of photopolymer resins that have been selected to simulate the properties of traditional thermoplastic ABS. Digital ABS has comparable properties to standard ABS.
- Rubber-Like Materials: These are materials that exhibit rubber-like properties. Material hardness can vary from 25 to 75 on the shore A hardness scale.
- High-Temperature Materials: These are materials with a relatively high heat deflection temperature of 80 °C (with an additional post-cure process). While this is relatively low compared to standard high-temperature engineering thermoplastics, it is still sufficient for many hot air and water prototyping applications.
- Transparent Materials: PolyJet™ offers a transparent photopolymer called VeroClear, which simulates the mechanical and visual properties of PMMA (Acrylic/Perspex). For improved optical clarity, some post-processing, like polishing, is required. Translucent materials are also available if complete optical clarity is not required.
- Rigid Opaque Materials: These materials have properties comparable to acrylic and, as such, are best suited to light-duty applications that are not exposed to shock or cyclic loads.
- Simulated Polypropylene Materials: These materials have almost double the impact resistance of other PolyJet™ materials, making them better suited to mechanical applications. They can also simulate the capacity of polypropylene for living hinges and snap-fit assemblies.
- Biocompatible Materials: These materials are suitable for long-term direct skin contact and short-term muscular membrane contact.
PolyJet™ is a trademark for an inkjet-style 3D printing technology developed by Stratasys. The multi-jet process was first developed in 1998 by Objet industries, which Stratasys later acquired in 2011. Since then, many PolyJet™ Stratasys 3D printers have been released into the market.
PolyJet™ printing works by depositing multiple drops of photopolymer on the build platform and immediately passing a UV light source over the layer. This solidifies the layer, after which the build platform moves down by one layer, and the next layer is deposited on top of the previous one. PolyJet™ printers have multiple independent printheads, which allow them to print multi-color and multi-material parts.
PolyJet™printers are among the fastest 3D printers. A PolyJet™ printer works much like an inkjet printer in the sense that it deposits a layer of photopolymer onto the building line as if it was printing an image of that layer of the part. PolyJet™ printers can print the fastest if only one resin is used for a part.
PolyJet™ printers can print with excellent accuracy, with layer heights ranging from 14 microns to 55 microns. The exact level of accuracy depends on the machine and the print speed. The highest levels of accuracy are achievable at the slowest print speeds. The dimensional accuracy of the part depends on the part size as listed below:
- Smaller than 100 mm: +- 100 microns
- Larger than 100 mmm: +- 200 microns or 0.06 % of the part length (whichever is larger)
PolyJet™ printers are some of the most advanced printers on the market and are regarded as industrial tools. As such, it should be no surprise that they are generally very costly when compared to other plastic 3D printers. A typical PolyJet™ printer can range anywhere from $6,000 to $75,000.
FDM (Fused Deposition Modeling) printing works by depositing a thermoplastic from a heated extruder nozzle one layer at a time. FDM is typically limited to one material at a time or uses two materials at most. PolyJet™, on the other hand, makes use of photopolymers and can print in many different materials and colors at a time. For more information, see our guide on FDM vs. PolyJet™3D Printing.
PolyJet™ and multijet make use of similar technology, i.e., both jet a photopolymer onto a build platform and make use of UV light to cure one layer at a time. Multijet cannot print in multiple materials. For more information, see our guide on PolyJet™vs. Multijet 3D Printing.
SLS (Selective Laser Sintering) is a process that makes use of a laser to melt a plastic powder, typically nylon, into the final part one layer at a time. SLS can only print one material at a time. PolyJet™ does not make use of a heat source to produce parts but rather a UV light to cure a photoreactive polymer. For more information, see our guide on PolyJet™ vs. SLS 3D Printing.
SLA (Stereolithography) printing also makes use of photopolymers. However, the build plate is lowered into a vat of photopolymer, and a layer is projected onto the build plate with a UV light source. This light source then cures the entire layer at once. The process repeats until the part is complete. PolyJet™ deposits the photopolymer onto the build plate using multiple independent nozzles, allowing for multicolor and multi-material parts. For more information, see our guide on PolyJet™ vs. SLA 3D Printing.
PolyJet™ 3D printing makes use of an inkjet-type process that deposits material using multiple independent nozzles. As such, inkjet printing is an umbrella term used to describe processes like PolyJet™ and similar.
This article discussed the PolyJet™ 3D printing technology, including what it is, how it works, its advantages, applications, and how it differs from other 3D printing processes. To learn more about PolyJet™ 3D printing and how it can be used to print high fidelity, full color, and multi-material prototypes, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities, including 3D printing and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
- PolyJet™ is a trademark of Stratasys, Prairie, MN.
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