The first photopolymer jetting 3D printer was developed in 2000 by Objet Geometries (now acquired by Stratasys). The printer was called Quadra.
Polyjet printers usually have two or more jetting heads. One head is for jetting the build material, and the other heads are for jetting the support material. Printers with multiple print heads are capable of printing multi-material and multi-color objects.
The print heads move in the X-Y directions above the build plate. When printing, they jet tiny drops of UV reactive photopolymer onto the build plate. These drops are instantly solidified by a UV lamp located next to the print head. The build plate moves down by an increment for the next layer to be printed. The thickness of a single layer is usually between 14 microns to 28 microns, achieving a fine level of detail.
With Polyjet printers, there are usually two types of support settings available – matte and glossy. Matte supports completely cover the printed object in the support material. These are used on most prints and are recommended when you aim for the best dimensional accuracy.
Glossy setting generates supports only under overhangs and “floating” parts. In the areas without supports, the printed model ends up with a shiny surface. Glossy supports can dramatically reduce the print time and support material consumption (on some prints). Usually, there will be noticeable differences between areas printed with and without supports; the areas covered with supports will be matte.
The support material typically used in 3D Systems printers (MultiJet) is wax. These supports are melted away by placing the 3D printed model into a small oven or a hot oil bath.
Stratasys (PolyJet) use water soluble supports in most of their new machines. The 3D printed model is placed in a water bath where the soap-like supports dissolve. In older machines, a gelatin-like material is used to print the supports, and it has to be removed by water blasting or manually.
XJET – works similarly like the Polyjet printer, but prints from metal materials
Complicated prints with detailed features
Multi-material prototypes of products
Clear transparent prints (even parts that look like colored glass, but they all have to be polished manually)
Master models for vacuum casting or metal casting