Binder Jetting

Process description

Binder jetting's process is very similar to that of powder bed fusion. it involves placing down a layer of a powder material onto the whole print bed, but instead of melting the powder together with a heat source a print head deposits a liquid binder the sections of the layer that will be in the final part. after the process is complete the part is normally left in the powder bed to let the binder fully cure, and is then cleaned of excess powder.

strengths

• low energy: since it requires no melting of materials binder jetting is a very low energy printing technique
• material flexibility: binder jetting can be printed with any powder material that can be held together with a liquid binder
• scalable: because the print heads needs to deliver very little binder in relation to the volume of the final part
• no need for supports: very similar to powder bed fusion the excess powder acts as natural supports

weaknesses

• material properties: straight out of the printer binder jetting parts tend to be weaker then other am types
• surface finish: the surface finish is entirely dependent on the powder material used
• post processing: in order to increase the material properties extensive post processing is sometimes needed such as injecting extra binder, more cure time, or metal sintering.

Technologies

There are a number of specific technologies that can vastly change to capabilities of a printer.

• multi color printing using a powder of a neutral color allows the binder to both fuse and dye the colors of prints. this makes binder jetting one of the easiest technologies to create multi color printers for.
• metal sintering: using a temporary binder to hold metal powder together for a further sintering to fuse the powder. this allows binder jetting printers to create metal parts, but this requires heavy post processing and parts must be printed at a larger scale to account for shrinking