What is Binder Jetting?

Binder jetting is an innovative technique of additive manufacturing that was developed in 1993 Ely Sachs and Mike Cima at the Massachusetts Institute of Technology. This method makes use of 3D printing to create complex 3D objects with various types of materials using a technique that’s similar to inkjet printing. 

In recent years, many industries have been using binder jetting for manufacturing intricate metal parts, prototypes, and other components that wouldn’t be possible or be difficult to produce through traditional manufacturing. However, many product teams still aren’t aware of what is binder jetting and what it is used for. We’ll break it down for you in this post.

How Binder Jetting Works

Binder jetting is a powder bed fusion technology like many other additive manufacturing techniques that build objects layer by layer. But instead of using a nozzle or laser to melt and sinter these layers, binder jetting sprays a liquid binding agent onto the powder bed that binds the powder together. This happens in alternating steps of layering the powder and then the binding material on top until the object is completed. This is the gist of what binder jetting is. 

Powder, sand, and metal are the three broad categories of materials that can be used for binder jetting. Sand and silica are the preferred binder jetting materials for sand casting one-time use cores or molds. When creating full color models or prototypes, polymethyl methacrylate (PMMA) powders are typically used for time savings and cost efficiency.

Advantages of Binder Jetting

Metal powder is one of the most popular binder jetting materials because creating metal objects using the process is up to ten times more economical than other methods like selective laser sintering (SLS) or selective laser melting (SLM). 

Moreover, what binder jetting is used for is printing intricate objects. It allows the creation of parts with large build sizes with high dimensional accuracy that don’t require any support structures during the 3D printing process.

Here’s what binder jetting is known for:

• Allows the simultaneous production of several small parts or a large part with fast turnover times. It’s much faster than SLS and stereolithography since it doesn’t use a heat source.
• Offers more design freedom than direct metal laser sintering and selective laser melting because parts are not subjected to any thermal effects.
• It’s low wastage. 100% of the leftover materials can be recycled and reused in the next print, as opposed to SLS where only a certain amount of the material can be reused.

Limitations of Binder Jetting

Binder jetting is what’s used for manufacturing parts by large and small businesses alike due to its cost efficiency and speed. But despite these advantages, it also has several limitations that one should be aware of:

• The mechanical properties of parts produced using binder jetting are not as strong as the ones produced through traditional methods or laser sintering and melting. 
• They have a high porosity, so they need to undergo post-processing to improve their strength and mechanical properties. This may introduce inaccuracies and can lead to increased production times and energy costs.
• Compared to other 3D printing processes, the selection of materials is very limited in binder jetting, which can make it a less attractive production method.

Some post processing methods typically applied to binder jetting printed parts are:

• Debinding and infiltration — In the first step, the binding material from binder jetting is what’s removed from the finished part thermally through evaporation or by dissolving using a solvent. The voids are then filled with a metal alloy or ceramic depending on the application.
• Sintering — In sintering, the part is subjected to high temperatures for debinding and fusing the particles together. This increases grain growth, density, strength, and hardness. However, it also causes shrinkage and may lead to inaccuracies you couldn’t account for during the design stage.

Other methods that can help improve the mechanical properties of binder jetting printed parts are hot isostatic pressing (HIP), heat treatments like annealing, quenching, and tempering, machining and finishing treatments, and mechanical or thermal post-processing.

Applications of Binder Jetting

Binding jetting has found application in many industries such as aerospace, automotive, and architecture due to its unique capabilities. Here’s what binder jetting is often used for:

• Rapid prototyping for testing concepts.
• Tooling and fixtures used in the manufacturing processes.
• Detailed jewelry designs, art pieces, and sculptures.
• Surgical guides, dental implants and models.
• Architectural models.
• Creating lightweight parts and customized components in aerospace and automotive.
• Lightweight consumer goods like phone cases.
• Sand molds and cores using sand casting.

Binder Jetting Materials from KBM

Now you know what binder jetting is. It’s an ideal solution for businesses that require a fast and economical method for mass producing parts and colored prototypes that don’t require very high performance. If you feel like this is the right technology for your business and you’re ready to get started, we recommend browsing our collection of metal powder for binder jetting. 

If you need more information on this technology and how your business can benefit from it, or if you’re still confused about what is binder jetting, please contact the additive manufacturing experts at KBM.