Binder jetting is an additive manufacturing process that uses a liquid binding agent to selectively join powder material layer-by-layer to produce 3D parts. This innovative technology offers significant benefits over traditional manufacturing methods and other 3D printing processes for industrial applications.
In this comprehensive guide, we will cover everything you need to know about binder jetting technology, including:
- How Binder Jetting Works
- Materials Used in Binder Jetting
- Key Benefits and Advantages
- Applications and Suitable Industries
- Comparison to Other 3D Printing Processes
- Current Technology Leaders
- Future Outlook
Understanding the binder jetting process, its capabilities, and advantages allows you to determine if it is the right additive manufacturing method for your specific needs.
How Does Binder Jetting Work?
The binder jetting process starts with a thin layer of powder material spread evenly across the build platform using a roller or blade. Common materials include metals, sand, ceramics and polymers.
An inkjet print head selectively deposits microscopic droplets of a liquid binding agent onto the powder bed. The binder acts to join particles of powder together in the printed areas.
The build platform then lowers, and a new layer of powder is spread over the previous layer. The print head deposits binder again to print each layer one at a time.
Once printing is finished, excess powder is removed, leaving the 3D printed part surrounded by unbound powder. The part then undergoes post-processing which typically involves drying and curing the binder to further strengthen the part.
Binder jetting does not involve heating or melting the material during printing. This allows a wide range of materials to be used including temperature-sensitive polymers and metals.
Materials for Binder Jetting
The two main components required for binder jetting are the powder material and the liquid binding agent.
Powder Materials Some of the common materials used include:
- Metals – stainless steel, tool steel, titanium, inconel, copper
- Sand – silica sand, ceramics, foundry sand
- Polymers – nylon, polystyrene
- Plaster
The powder particulates are usually 20-100 microns in diameter. Finer powders improve resolution while coarser powders improve build speed. Most systems use single material powders but some also support composite blends.
Binding Agents The binder is a liquid that is printed selectively to join the powder particles together. Requirements for the binder include:
- Adheres strongly to the powder material
- Cures rapidly to full strength
- Does not expand excessively during curing to avoid distortion
- Does not alter properties of the printed part significantly
Common binders include furan resins, phenol formaldehyde, epoxy resins. Water-based binders are used for metals and inorganic powders.
Key Benefits of Binder Jetting Technology
There are several important advantages that make binder jetting an appealing production method:
High build speeds – Print heads can deposit binder rapidly, so layers can be printed in just seconds. This enables some of the fastest build rates of any 3D printing process.
- Print heads can deposit binder rapidly, so layers can be printed in just seconds. This enables some of the fastest build rates of any 3D printing process. Low costs – No lasers or high heat required results in lower operating costs compared to powder bed fusion processes. Minimal material waste also improves cost efficiency.
- No lasers or high heat required results in lower operating costs compared to powder bed fusion processes. Minimal material waste also improves cost efficiency. Material versatility – A wide range of metals, polymers, ceramics and composites can be printed without melting or heat, enabling more applications.
- A wide range of metals, polymers, ceramics and composites can be printed without melting or heat, enabling more applications. Less residual stress – Absence of heating during printing minimizes residual stresses in the printed parts.
- Absence of heating during printing minimizes residual stresses in the printed parts. High resolution – Print heads can produce very small, accurate binder droplets allowing intricate designs and details.
- Print heads can produce very small, accurate binder droplets allowing intricate designs and details. Minimal post-processing – binder jetted parts require less support removal and surface finishing compared to other AM processes.
Together these advantages make binder jetting suitable for efficient, cost-effective production of complex metal and sand parts for industrial applications.
Applications of Binder Jetting
Here are some of the most common applications and uses for binder jetting in various industries:
Metal casting and foundries
Binder jetting is revolutionizing sand casting patterns and cores for investment casting. It eliminates the need for tooling while bringing 3D design capabilities. High resolution and accuracy of printed sand molds and cores allow complex casted metal parts to be produced.
Automotive
Binder jetting is used in automotive manufacturing to print metal prototypes, jigs and fixtures, and sand casting molds rapidly without hard tooling. It enables on-demand customization and parts consolidation.
Aerospace
Lightweight aerospace components made from titanium and other alloys are printed using binder jetting. It allows complex optimized geometries not possible with casting or machining.
Medical and Dental
Customized medical implants, surgical guides and dental copings are efficiently produced using binder jetting technology. Biocompatible metals and polymers can be printed.
Tooling
Durable tooling for injection molding, thermoforming and other production processes can be 3D printed in high-strength metals by binder jetting. This avoids the lead time and costs of CNC machining.
Jewelry
Intricate jewelry pieces, settings and molds for jewelry casting are created with high precision and fine details using binder jetting. A variety of precious metals like gold and silver are supported.
Compare Binder Jetting vs. Other 3D Printing Processes
Binder jetting has some distinct differences when compared to other popular additive manufacturing technologies:
Powder Bed Fusion (SLS/SLM)
- Uses a laser or electron beam to selectively melt powder. Binder jetting does not melt or sinter material.
- Limited mostly to polymers and metals. Binder jetting supports more material options like sand.
- Higher residual stresses. Binder jetting has lower stresses.
- Higher operating costs due to energy required. Binder jetting is more economical.
Material Jetting
- Uses liquid photopolymers jetted out and cured with UV light. Binder jetting utilizes powder materials.
- Produces highly detailed and smooth surface finishes. Binder jetting has lower resolution.
- Only prints polymers and waxes. Binder jetting allows metals, sand, ceramics.
- Very high operating costs. Binder jetting is more affordable.
Material Extrusion (FFF)
- Melts and extrudes thermoplastic filament. Binder jetting is powder-based.
- Limited mostly to low-temperature thermoplastics. Binder jetting offers more material capabilities.
- Slow build rates due to material limitations. Binder jetting enables faster printing.
- Lower costs for polymer printing. Binder jetting is more suitable for metals and sand.
Understanding these key differences allows selection of the best printing process based on application requirements, materials needed, accuracy and surface finish demands, production volumes and budgets.
Leading Companies in Binder Jetting Technology
Binder jetting was first patented by the Massachusetts Institute of Technology in 1993. Since then, companies have commercialized and advanced binder jetting systems for industrial production.
Here are some of the top companies to watch in binder jetting:
Desktop Metal is a pioneer in making binder jetting practical and cost-effective for manufacturing. They offer a range of systems from entry-level Studio System to high-volume Production System.
ExOne
ExOne was one of the first providers of binder jetting systems. They offer industrial metal, sand and ceramic 3D printers along with binders and powder materials.
HP
HP’s Metal Jet systems leverage binder jetting to print production-ready metal parts with excellent properties and accuracy. High throughput is enabled by their multi-agent printing process.
GE Additive
GE Additive offers the H2 Binder Jetting solution capable of high productivity and large metal parts up to 1 meter long. Their systems are used for aviation components and tooling applications.
Stronger Parts, Requires Less Support
With continual advances in print heads, binders, powder materials and software, binder jetting technology is poised for faster growth and adoption across industries. Already companies are using binder jetting to manufacture end-use metal and composite parts for aviation, automotive, medical and other critical applications.
As binder jetting capabilities continue to evolve, it will become viable for printing highly functional parts in a widening range of materials without the constraints of traditional processes. The future is bright for this innovative additive manufacturing method that empowers new design freedom and manufacturing flexibility.
