Material Jetting 3D Printing: How It Works

Drop-on-demand · Liquid photopolymer jetted and UV cured · Full color, multi-material

Material jetting is a 3D printing process that sprays tiny droplets of liquid photopolymer from inkjet-style print heads and cures each layer instantly with UV light. It makes very smooth, accurate, full-color and multi-material parts, but the printers and resins are expensive and parts can be brittle, so it is mostly used for professional prototypes. It is one of the six main types of 3D printing.

What is Material Jetting?

Material jetting is a 3D printing technique that utilizes a liquid photopolymer and UV light. Learn everything there is to know about this cutting-edge technology, including how it operates, its benefits and drawbacks, and the best applications for it. Material jetting (MJ) is one of the most efficient and precise 3D printing methods. It constructs parts from liquid photopolymer droplets that are cured (solidified) using UV light.

MJ is often compared to the 2D inkjet process because the photopolymer resin is sprayed in droplets until it solidifies. MJ, on the other hand, builds layer upon layer until the part is complete, while inkjet printers only deposit a single layer of ink droplets.

Since it uses a UV light source to cure the resin, MJ is similar to SLA. The difference is that MJ 3D printers spray hundreds of tiny droplets at a time, while SLA 3D printers retain an entire vat of resin that is selectively cured by a laser (point-wise).

Material Jetting 3D Printers

Material Jetting 3D printers come in a number of sizes, varying from medium (380 x 250 x 200 mm) to massive (1000 x 800 x 500 mm), and can be configured to suit individual demands without losing the precision of 3D printed components. Content Jetting 3D printers are currently manufactured by Stratasys and 3D Systems. For example, 3D Systems' ProJet MJP 5600 3D printer creates multi-material colorful parts for prototyping and fast tooling fabrication using its patented MultiJet Printing technology.

The machine works with VisiJet components, which are exclusive to the brand. The machine's printing volume is 518 x 381 x 300 mm, making it suitable for medium-sized parts. Stratasys' J750 3D printer is the company's most recent Content Jetting machine. The PolyJet process used in the J750 is proprietary. The computer has a design volume of 490 x 390 x 200 mm and can print multicolor and multi-material 3D models simultaneously using six different materials.

Line-wise Deposition

Another attribute that separates MJ is the way material is deposited (and therefore cured). MJ printers use several print heads to jet resin along an X-axis carrier that runs back and forth over a changing print. Consider the light source of a 2D scanner or a car's windshield wiper to better visualize the movement of the apparatus. The three most popular 3D printing technology, FDM, SLA, and SLS, on the other hand, deposit, cure, and sinter content in a pointwise manner. As a result, MJ is regarded as one of the most rapid and precise 3D printing technologies.

What is the Process?

Print heads, UV light sources, a construction frame, and a content container are the key components of a MJ 3D printer. The print heads and light sources share the same X-axis carriage. Pouring the resin into the content tub is the first step in the printing process. MJ, like SLA, uses thermoset photopolymer resin, which means it must be heated (to between 30 and 60 °C) to achieve the desired viscosity.

The print heads start selectively jetting hundreds of tiny resin droplets as the X-axis carriage slides around the build platform. The UV light sources accompany the print heads, curing the sprayed resin instantly. The create platform lowers one layer in height after each layer is finished, and the process is repeated until the component is complete.

Pros & Cons of Material Jetting

Applications

Material Jetting's advantages make it an excellent technology for prototyping and tooling. Material Jetting's multi-material features, for example, can be used by artists to create incredibly realistic, full-color digital designs. The Audi Pre-Series Center is a clear example of this: the carmaker was able to build fully usable, multi-material designs using Stratasys' material jetting technology to speed up its product verification process. MJ is mainly used to build stunning, realistic-looking designs, as you might have guessed.

Material Jetting is widely being used in the medical industry to create practical anatomical templates for instructional purposes as well as pre-surgical preparation and training. Doctors and students, for example, may be interested in MJ's realistic models of body parts. Similarly, the accuracy and artistic consistency of content jetted models will help architects, designers, and artists greatly. Because of its high degree of detail and temperature tolerance, MJ can also be used to produce low-volume injection molds. In any case, the expense of 3D printing parts with MJ restricts the technology's use to technical uses in the vast majority of cases. And if you can't afford a MJ printer, you can still have your designs printed in high-resolution resin using a 3D printing service.

Material Jetting can be used to 3D print full-color anatomy images that look like actual body parts in medical colleges and hospitals. Such models not only aid medical students in their learning, but also enable surgeons to schedule and practice for surgery more effectively than a 2D image would allow. Furthermore, Material Jetting is well-suited for low-volume mold and casting pattern processing. Tooling for injection molding and investment casting can be made much quicker and cheaper using this 3D printing process, allowing for higher degrees of sophistication not available with conventional tooling manufacturing. Material jetting can also be used to print electronic devices in three dimensions. The DragonFly 2020 Pro 3D printer from Nano Dimension, for example, uses conductive silver inks to build multilayer electronic circuits, PCB prototypes, and antennas.

Materials Used in Material Jetting

Photopolymers (in liquid form) and casting wax are the two most widely used materials for Material Jetting today.

Stratasys and 3D Systems are two of the most well-known Material Jetting companies on the market, with a wide variety of photo-curable plastics and composites to choose from. For example, Stratasys has recently created "digital materials" for use with its patented PolyJet technology. These compounds are made up of two or more photopolymers, resulting in a composite substance (e.g. combining rigidity with flexibility). While such artifacts are fragile and brittle, there are materials that are better suited to particular applications such as tooling and investment casting.

Metals, ceramics, and silicones have also begun to enter the industry as a result of intensive studies into extending the variety of materials that can be used for material jetting. For example, the Israeli company Xjet has developed NanoParticle Jetting technology for metals and ceramics. Ceramic or metal particles are suspended in a liquid formulation using this technology, which is then separated at the sintering stage.

Silicone 3D printing, developed by ACEO, a subsidiary of the German chemical giant Wacker Chemie AG, has set a new benchmark in materials for Material Jetting. The ACEO process, which was first introduced in 2016, uses a "drop-on-demand" method to produce 100% silicone parts as well as multi-material parts of differing colors and hardness.

At the End of the Day

Material jetting is a great way to make practical prototypes and tooling because it produces full-color, multi-material components with a high degree of dimensional precision.

Material Jetting, on the other hand, has the potential to bring creative solutions to end-part manufacturing, especially in the realm of 3D printed electronics, thanks to ongoing research into photopolymer and other materials. Material Jetting also shows promise for bioprinting, with the potential to revolutionize regenerative medicine and tissue engineering thanks to its drop-on-demand process.

Compare With Other 3D Printing Technologies

Material jetting is one of several types of 3D printing. See how it compares: