ExOne uses Binder Jetting technology to 3D print complex parts in industrial-grade materials.
Binder Jetting is an additive manufacturing process in which a liquid binding agent is selectively deposited to join powder particles. Layers of material are then bonded to form an object. The printhead strategically drops binder into the powder. The job box lowers and another layer of powder is then spread and binder is added. Over time, the part develops through the layering of powder and binder.
Binder Jetting is capable of printing a variety of materials including metals, sands and ceramics. Some materials, like sand, require no additional processing. Other materials are typically cured and sintered and sometimes infiltrated with another material, depending on the application. Hot isostatic pressing may be employed to achieve high densities in solid metals.
Binder Jetting is similar to traditional paper printing. The binder functions like the ink as it moves across the layers of powder, which like paper, forms the final product. Due to its ability to produce solid layers, Binder Jetting is often considered the best option for 3D printing. Binder Jetting also has the ability to print very large objects. Room sized architectural structures have been printed with Binder Jetting.
How does Binder Jetting differ from other additive techniques?
There are various methods of 3D printing in existence, and there is often confusion amongst the many offerings. Many of these techniques center around building parts through a melting or welding process - using lasers or melted material - to fuse each layer together. These processes typically require a build plate to be added to the part for part stability throughout the build process. Such processes require significantly more material. The build process itself is also time-intensive.
Binder Jetting is unique in that it does not employ heat during the build process. Other additive techniques utilize a heat source which can create residual stresses in the parts. These stresses must be relieved in a secondary post-processing operation. Additionally with Binder Jetting, the parts are supported by the loose powder in the job box, thus eliminating the need for a build plate. Spreading speeds for Binder Jetting continue to significantly outperform other processes. Binder Jetting has the ability to print large parts and is often more cost-effective than other additive manufacturing methods.