Binder Jetting

Binder Jetting technology is one of the most relevant technology for medium-high quantity production. The technology was developed by Ely Sachs and Mike Cima at the Massachusetts Institute of Technology in 1993.

Binder jetting is an additive manufacturing (AM) technology that involves using a binder material to selectively bond layers of powder material to form a three-dimensional (3D) object. Binder jetting technology has been around for a few decades, but recent advances in hardware and software have made it more practical and affordable for industrial and commercial applications.

Binder jetting is used in a variety of industries, including aerospace, automotive, medical, and consumer goods. It is particularly useful for producing medium-volume, high-value parts, as well as prototypes and molds.

The process typically involves spreading a thin layer of powdered material (such as metal, ceramic, or plastic) onto a build platform. The binder is then selectively applied to the powder layer using inkjet printheads, which bind the powder particles together in the desired shape. The process is repeated layer-by-layer until the final 3D object is formed.

The binder jetting process typically follows a loop that includes the following steps:

• Design: The first step in the process is to design the 3D model using computer-aided design (CAD) software. The model is then exported as a digital file that can be read by the binder jetting machine.
• Preparation: The next step is to prepare the build platform by spreading a thin layer of powdered material onto it. The thickness of the powder layer can vary depending on the application and the material being used.
• Binder deposition: The binder is then selectively deposited onto the powder layer using inkjet printheads. The printheads apply the binder in a precise pattern, bonding the powder particles together to form the first layer of the 3D object.
• Powder deposition: Once the binder has been applied, another layer of powder is spread over the top of the first layer, and the process is repeated. This continues until the 3D object is complete.
• Post-processing: After the printing is complete, the part is removed from the build platform and any excess powder is removed. The part is then cured, often in an oven or furnace, to strengthen the bonds between the powder particles. Post-processing may also include additional steps such as surface finishing, polishing, or coating.
• Inspection: Finally, the printed part is inspected to ensure that it meets the required specifications and tolerances. Any defects or issues are identified and addressed before the part is used in the desired application.
• Once the inspection is complete, the process starts over again with the design of the next 3D model, and the loop continues.

The working cycle of the Binder Jetting technology can be resumed in four main steps:

• A thin layer of powder is released on  the printing plane
• The inkjet print head deposits the liquid binder agent which bonds the powder particles together
• When the layer is complete, the build platform is lowered and a new layer of powder is spread over the previous layer
• When the process is completed, parts are left to solidify and cool.
• After cooling, the parts are removed and the excess powder is cleaned off.

Binder jetting technology can be used to print a wide range of materials, including metals, ceramics, and polymers. Some of the most common materials used in binder jetting include:

• Metals: Binder jetting can be used to print metal powders such as stainless steel, aluminum, titanium, copper, and bronze. These materials are often used in aerospace, automotive, and medical applications.

• Ceramics: Binder jetting is also used to print ceramic materials such as zirconia, alumina, and silica. These materials have high strength, durability, and are often used in dental and biomedical applications.

• Polymers: Binder jetting can be used to print polymer materials such as nylon, polypropylene, and polycarbonate. These materials are commonly used in consumer goods and packaging applications.

• Composites: Binder jetting can be used to print composite materials, which are made up of a combination of two or more materials. For example, binder jetting can be used to print metal matrix composites, which are used in aerospace and automotive applications.

The choice of material for binder jetting depends on the specific application and the required properties of the printed part, such as strength, durability, and thermal resistance.

One of the key benefits of binder jetting technology is its ability to produce complex geometries and intricate shapes without the need for support structures. It is also a relatively fast process compared to other AM technologies, as multiple layers can be printed simultaneously.

However, it should be noted that parts produced using binder jetting may have lower mechanical properties compared to parts produced using other AM technologies like selective laser sintering (SLS) or fused deposition modeling (FDM). Nevertheless, ongoing research and development in the field are constantly improving the strength and durability of binder jetted parts.

There are several companies that produce binder jetting 3D printers, including:

ExOne

ExOne is a leading manufacturer of binder jetting 3D printers for metal, ceramic, and composite materials. Their machines are used in a variety of industries, including aerospace, automotive, and medical.

HP

HP produces the Multi Jet Fusion (MJF) 3D printer, which uses a binder jetting process to print parts using polymer materials. Their machines are used in industries such as automotive, consumer goods, and healthcare.

Desktop Metal

Desktop Metal produces the Shop System, a binder jetting 3D printer designed for use in machine shops and small-scale production facilities. Their machines can print metal parts using a variety of materials, including stainless steel and copper.

Voxeljet

Voxeljet produces a range of binder jetting 3D printers for industrial applications, including printing large-scale parts and molds. Their machines can print with a variety of materials, including sand, ceramics, and metals.

Digital Metal

Digital Metal produces high-precision binder jetting 3D printers for metal materials. Their machines are used in industries such as aerospace, automotive, and medical, and can print complex geometries with high accuracy and resolution.

These are just a few examples of companies that produce binder jetting 3D printers. As the technology continues to advance, we can expect to see more companies enter the market with new and innovative machines.