What is Binder Jetting? Process, Benefits, and Applications

Binder jetting (BJ) is a versatile additive manufacturing technology that is used to print polymer, metal, ceramic and sand parts. The Binder jetting 3d printing technology uses powdered materials upon which the print head selectively deposits a liquid binding agent (binder) to fuse adjacent powdered particles together to form a bond. It can be understood better by considering it a mix of powder bed fusion and material jetting technologies in a way that it uses powdered material and also uses a binder to fuse particles.

(source: Protolabs Network)

Since the Binder jetting 3d printing technology uses powdered material, the parts do not require support structures and thus enable the printing of complex geometries. This BJ technology is ideal for batch manufacturing of parts and is one of the only 3D printing technologies that achieves significantly faster build rates and lower operational costs compared to other laser-based 3D printing processes.

What is Binder Jetting? Understanding 3D Printing's Original Technology

The binder jetting technology emerged from the popular 2D inkjet printers which everyone uses regularly. Binder Jetting also works on a similar principle, just that this technology also prints in Z-direction.

The binder jetting technology was developed at the Massachusetts Institute of Technology and patented in 1993. Its fundamental mechanism resembles the popular 2D inkjet printing technology, where ink is deposited onto a paper but in binder jetting the binding agent is deposited on powder material and it can print in all three directions thus making solid three dimensional parts.

Key differentiators of the Binder jetting additive manufacturing process:

Printing at Room Temperature: Binder jetting prints parts at room temperature thus avoids commonly found warping and stress issues in 3D printing.

Wide range of materials: It can print with a wide range of materials and grades from metals to polymers and from composites and to sand.

Self-supporting builds: As the bed is full of powder, the printed parts support themselves and so it does not require support structures saving significant material, cost and post-processing time as well.

Blazing fast speeds: This is the fastest metal 3D printing technology and therefore can print parts in low-volume batches.

Massive build volumes: Binder jet machines are quite big too. They largely start have a bed of 300 x 250 x 250 mm and can go higher up to or sometimes even more than 2200 x 1000 x 800 mm.

How Does Binder Jetting (BJ) Work? Breaking Down the BJ Process

(Binder Jetting process/Dassault Systems)

Let us break down the binder jetting workflow which will also help you understand why certain applications are a perfect fit for this technology.

The Five-Stage Binder Jet 3D Printing Workflow

1. File Preparation and Slicing

The 3D printing process, irrespective of the technology, always starts with a CAD file. Ideally use a STEP file format and upload it to a slicing software. The slicing software will slice your model into thousands of thin layers and also generate instructions in the form of a Gcode for the binder jet printer to understand.

2. Powder Spreading

Once this file is connected with the printer and the print is started, a recoater steps in and spreads a thin layer of powdered material across the printer bed or build platform. This is the first layer and its thickness is equal to the layer thickness set through the slicing software.

3. Selective Binder Deposition

After the first layer is ready, the print head moves around the bed and deposits the liquid binding agent (binder) on top of the powder at exactly the points where it is needed so that the adjacent powder particles fuse together. The individual layer printing works similar to an inkjet printing. Some advanced systems can pump out 670 million drops per second.

4. Layer Completion and Lowering

Once the binder is deposited for the first layer, the print head goes to its home location, the bed as a whole moves down by a distance equal to one layer thickness. The recoater is activated and it spreads a new layer of powder on top of the previous layer. From this layer onwards, the process just keeps on repeating till the time the entire part is printed.

5. Part Extraction

Finally, once the part is printed, the part is still inside the mound of powder material. We have to remove the part from inside the loose sand and so it goes for post-processing where the loose powder is removed and sent for reuse and the part is cleaned of any excess powder. After the cleaning process the part is ready for further post-processing.

Post-Processing Requirements

Once the part is cleaned of excess powder, it is still not ready. These parts are not strong enough yet and thus are called “Green” parts. Additional steps are required to make them strong for use.

For Metal Parts:

Curing – A low-temperature oven strengthens the binder bonds

Sintering – High heat burns off the binder and fuses metal particles together

Infiltration – Sometimes you'll fill remaining pores with bronze or other materials

Ready to see how fast binder jetting 3d printing can accelerate your timeline? Get an instant quote on your binder jeting 3D printing project and discover the speed advantage first-hand.

What Are the Advantages and Disadvantages of Binder Jetting 3D Printing？

As with any technology, binder jetting also has its own set of advantages and limitations. We will explain them so you are able to make informed decisions about when to use and when to not use the binder jetting process in additive manufacturing.

(The M5 screws 3D printed using Digital Metal’s system/AMFG)

Binder Jet 3D Printing Advantages

Speed and Throughput

Binder jet technology is ideal for manufacturing functional industrial parts at volume. In the 3D printing universe, this is one technology that thrives on having some volume. And so it offers speed for batch sizes where other technologies might feel slow.

Cost Effectiveness

Binder jetting is one of the costliest types of 3D printer but this is half the story. If you consider its price and the amount of parts it can print at a time with other metal 3D printing technologies, metal binder jetting typically costs 10 times less than DMSL/SLM processes for comparable parts. It might seem we are mistaken, but we are not.

Stainless steel MIM powder costs just €5–10 per kilogram versus €50-100 for powders required for other metal systems. This itself can give you an 80–90% material cost reduction. For a manufacturer producing thousands of brackets or housings annually, this translates to hundreds of thousands of dollars in savings. Companies like GE Additive have reported that switching appropriate parts to binder jetting cut their per-part costs by over 70%.

Recently, BMW revealed that it prints close to 4,000 sand cores per day in large-scale series production on 17 printers.

Design Freedom

Binder jetting process does not need support structures as the part is supported by the powdered material itself. And this opens up a multitude of opportunities for creating freeform geometries, undercuts, interlocking assemblies-designs that would give traditional manufacturing engineers nightmares.

Large Build Volumes

Binder jetting systems can be very big. Sand printing systems can handle volumes up to 2200 x 1200 x 600 mm. Build multiple parts at once or go big with single components.

Material Efficiency

Almost 95%+ of unbonded powder material is reusable and goes right back into your material supply. It is a super low-waste technology which also means cost savings and giving some amount of economies of scale to bring down per-part costs across your entire production run.

Binder Jet 3D Printing Disadvantages

Surface Finish and Porosity

The surface finish in most 3D printing technologies is rough and the same is the case with binder jetting. Since this is a powder-based technology, the powder imprints a texture on the surfaces of the printed part. So, every binder jet part has to be surface finished for attaining smooth surfaces.

Anisotropy

The material properties can exhibit anisotropy (meaning that the properties vary with the direction of measurement), with elongation showing a significant directional dependence.  

Post-Processing Requirements

Post-processing is extra important in Binder jetting and sometimes curing and sintering can take longer than the printing itself. Impacts the speed you gained in printing.

Binder Jetting Materials: From Metals to Sand

(TriTech Binder Jetted Titanium parts/TriTech)

Binder jetting technology processes a diverse range of materials, with material selection significantly influencing both processing parameters and final part characteristics.

Metal Materials

a. Stainless Steels

SS 17-4PH: This material delivers high strength through precipitation hardening for demanding engineering applications.

SS 316L: This is a 96%+ dense material that provides excellent corrosion resistance and is ideal for medical devices and food processing equipment.

Tool Steels

M2: This is a high-speed steel suitable for cutting tools and wear-resistant components.

H13: This hot work steel is optimized for injection molding and die casting applications.

b. Sand and Foundry Materials

Sand binder jetting eliminates traditional pattern requirements in metal casting operations. Through the technology sand moulds and cores can be 3D printed and then literally any metal can be casted as it happens in traditional sand moulds. For this the binder jetting machine uses sand like:

Silica sand: This is a commonly used sand that is ideal for standard casting applications

Chromite sand: This is a medium costly sand and generally used for high-temperature casting requirements

Zircon sand: This sand is the costliest and only used for highly precision casting with stringent dimensional tolerances

c. Ceramic and Specialty Materials

Silicon carbide (SiC) and oxide-based ceramics process successfully with appropriate binder systems. The technology also enables processing of metal-polymer composites and wood-based composites for sustainable manufacturing applications.

Explore material options and processing capabilities for your specific application requirements.

Practical Applications: What is Binder Jetting Used For?

There are some of the practical real-world applications of binder jet technology.

Metal Casting and Foundry Applications

Sand Molds and Cores

Sand casting is an age-old metal part manufacturing technology but it has not changed since its discovery in ancient times. With binder jetting, this technology is seeing a much needed innovation. To create sand moulds and cores is a tedious job. It also requires care and has a high possibility of breakage.

Binder jetting is now completely taking over prototype and small batch manufacturing by offering pattern-less manufacturing. We can directly create sand moulds and cores and with some post-processing, the desired metal can be poured and parts can be manufactured.

Investment Casting Patterns

Complex parts like aerospace turbine blades with impossible-to-machine cooling passages, medical implants with patient-specific geometries, precision components that would cost a fortune to tool traditionally, can now be casted with relative ease all the while saving time, effort and cost.

Production Manufacturing

Automotive Industry

Car manufacturers run binder jetting machines around the clock for manufacturing Jigs and fixtures that speed assembly, prototype components for testing, production brackets and housings, injection molding inserts and more. As we shared earlier, BMW runs around 17 binder jet machines to print sand moulds and cores.

Medical and Dental Applications

The medical field embraces customization by building prosthetics tailored to individual anatomy, surgical guides for precise procedures, controlled-release pharmaceutical tablets, dental crowns produced while you wait.

Prototyping and New Product Development

Heavy engineering applications in aerospace, aviation, and defence often face a lot of challenges in getting complex parts manufactured. These are sectors that are constantly innovating and iterating and for them, prototyping and new product development is commonplace. Binder jetting fits perfectly in this system and can quickly churn out prototypes which can lead to faster new product development cycles.

Binder Jetting vs. Other Technologies: A Comparative Analysis

How does binder jetting stack up against the competition? Let's compare apples to apples.

Binder Jetting vs. Powder Bed Fusion (PBF)

Speed and Productivity

Powder Bed Fusion (PBF) uses CO2 or fibre lasers to melt powder during printing-that creates residual stress and demands support structures. Binder jetting's cold process eliminates both issues entirely.

Cost Considerations

If you want to print high-mix low-volume parts, then binder jetting is the ideal technology to choose. PBF will make sense when you need intricate, high-performance parts in very low quantities.

Binder Jetting vs. Material Jetting

Material jetting uses UV-cured photopolymer which is great for transparent parts and fine details, but is brittle. Binder jetting offers true functional materials and end-use parts after proper post-processing.

For a deeper dive into the distinctions between these two methods, delve into our head-to-head comparison: Binder Jetting vs. Material Jetting.

The Binder Jetting Ecosystem: Machines, Companies, and Services

(HP Metal Jetting systems/HP)

Let us take a look at the market leaders from the industry.

Leading Equipment Manufacturers

ExOne (Part of Desktop Metal)

For two decades, ExOne led the binder jetting charge. Desktop Metal saw the potential and acquired them for $575 million in 2021.

Their product lineup includes:

 Innovent+ – The research workhorse everyone starts with

 X1 Series – Large-format systems for serious production

 S-Series – Sand printing monsters for foundry work

Other Notable Players

 Voxeljet, a German OEM that also builds industrial binder jetting systems.

 FZHL, a leading Chinese 3D printer manufacturer, offers a wide set of binder jetting 3D printers in various sizes.

 HP has developed its proprietary Multi Jet Fusion technology.

 Digital Metal also offers high-precision binder jet 3D printers used for various applications.

Conclusion: The Future of Binder Jetting 3D PrintingTechnology

Binder jetting was one of the earliest technologies to be developed and today it is impacting some core areas like aviation, marine, space, defence, and more. Its biggest advantage is that it can cost effectively manufacture complex parts that are otherwise hard or costly to produce, even in other 3D printing technologies.

As the technology further evolves and becomes cheaper and its materials library grows, the use cases will also grow and the adoption will spread.

For customers who are looking to manufacture complex metal parts at speed and reduce new product development costs, then binder jetting is the technology of choice.

Contact us to explore how binder jetting can transform your manufacturing. Start your evaluation today by talking to our experts and know how you can leverage this technology.