Material jetting is one of the seven standard categories of additive manufacturing: droplets of build material are selectively deposited and then solidified, usually by ultraviolet cure or by cooling. It is the family that includes photopolymer jetting and wax jetting, and it is defined by depositing the build material itself rather than a binder or a beam of energy.
How it differs from the neighbouring families
Vat photopolymerisation cures liquid held in a tank, so the build material fills the whole volume. Binder jetting deposits a binder into a powder bed, so the build material is the powder. Material jetting deposits the build material itself, droplet by droplet, which is why it can place different materials at different points in the same layer and why it needs a separate support material.
What the family includes
Photopolymer jetting, where ultraviolet light cures droplets as they land, is the largest branch and covers the multi material and full colour machines. Wax jetting produces patterns for investment casting with excellent detail and clean burnout. Metal droplet jetting exists in a research and early commercial form, depositing molten metal droplets directly.
Strengths
The finest layer thicknesses in general use, so surfaces are smooth and detail is fine. Multiple materials and colours in one part. Very accurate small features. And a clean digital workflow, since a full colour appearance model can be produced from a rendered file with no interpretation step.
Limits to plan around
The materials are photopolymers or waxes rather than engineering thermoplastics or metals, so functional durability is limited. Support material must be removed from every overhang and internal channel. Build volumes are modest and machine and material costs are high. And parts are sensitive to ultraviolet light and heat in storage.
Questions people ask about material jetting
What is material jetting?
An additive process category in which droplets of the build material are selectively deposited and then solidified, usually by ultraviolet cure or by cooling.
How does it differ from binder jetting?
Binder jetting deposits an adhesive into a bed of powder. Material jetting deposits the build material itself, which is why it can place several materials in one layer.
What is it best at?
Fine detail, smooth surfaces, multi material parts and full colour models, plus wax patterns for investment casting.
Why is it not used for end use parts?
Because the materials are photopolymers or waxes rather than engineering thermoplastics, so toughness, creep and ultraviolet stability all limit service life.