Processes - Additive Manufacturing
Material Jetting (MJT)
Material jetting is an additive manufacturing technique inspired by traditional 2D inkjet printing, where tiny droplets of material are selectively deposited layer by layer to build a 3D object. Instead of ink, these systems use materials such as UV-curable photopolymers, thermoplastics, or wax, depending on the specific technology. Once deposited, the material solidifies either through UV curing (as in PolyJet and MultiJet systems) or by thermal phase change (as in Solidscape printers), forming a precise and thin layer.
This process offers exceptional accuracy and high-resolution surface finishes, making it ideal for prototypes requiring fine detail, such as those used in form and fit testing, as well as for producing jewelry, dental models, and medical components. However, drawbacks include relatively slow build speeds, limited material diversity, and lower mechanical strength of printed parts.
One notable implementation of thermal-based material jetting is by Solidscape Inc. Their printers, such as the ModelMaker, utilize separate jets for the build material (thermoplastic) and the support material (wax). Both materials are stored in a melted state and jetted onto the build area in precise locations via a print head moving in the X-Y plane. After each layer is printed, a milling head smooths the surface, and residual particles are vacuumed away. The build platform is then lowered to allow for the next layer. Upon completion, the wax support structures are easily removed by melting.
3D Systems also employs material jetting in their MultiJet Modeling (MJM) technology, which uses arrays of hundreds of nozzles to increase printing speed and throughput. These systems primarily use photopolymers cured by UV light, providing a different material and curing mechanism compared to Solidscape's thermal approach.
Advantages
Cost-Effective for High Precision Applications
Material Jetting offers exceptional droplet accuracy, which minimizes material waste and contributes to cost efficiency. Additionally, the ability to print with multiple materials, colors, and varying mechanical properties in a single build enhances process efficiency and reduces both production time and costs.
High Precision and Detail Resolution
This technology excels in producing complex geometries and fine details that may be challenging for other additive manufacturing methods. It is particularly well-suited for applications requiring intricate features and tight tolerances.
Superior Aesthetic Quality
Material Jetting delivers excellent surface finishes and full-color capabilities, making it ideal for prototypes and end-use parts where visual appearance is critical. The ability to simulate textures, gradients, and realistic color schemes further enhances its appeal in design-driven applications.
Integrated Curing Process
Unlike stereolithography (SLA), which often requires post-processing, Material Jetting typically incorporates built-in UV curing, allowing parts to solidify immediately during printing. This reduces the need for additional curing steps and simplifies the workflow.
Disadvantages
Limited Material Selection
Although a range of photopolymers and wax-like materials are available, Material Jetting is restricted to a narrow selection compared to other 3D printing methods, particularly when it comes to high-strength or functional engineering materials.
Higher Equipment and Operating Costs
The machines and materials used in Material Jetting tend to be more expensive than those used in other additive processes such as Binder Jetting. Additionally, the technology often requires more frequent maintenance and calibration to maintain optimal performance.
Smaller Build Volume
Material Jetting systems are generally not designed for large-format printing. They are better suited for producing small to medium-sized components, which may limit their utility in certain industrial applications.
Lower Mechanical Strength
Due to the nature of the photopolymers and waxes typically used, parts produced via Material Jetting often exhibit lower structural integrity compared to those printed with thermoplastics or metals. As a result, the technology is primarily used for early-stage prototypes, visual models, or non-functional parts.
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.