Multijet technology (MJM), also know as polyjet, is very similar to desktop inkjet printer, however rather than dispensing ink, the machine dispenses a single layer of photopolymer material. This sliding printer head is then followed by an ultraviolet light to cure the resin.
What is Polyjet?
PolyJet 3D printing is similar to inkjet document printing, but instead of jetting drops of ink onto paper, PolyJet 3D Printers jet layers of liquid photopolymer onto a build tray and instantly cure them with UV light. The layers build up to create a precise 3D model or prototype. Along with the selected model materials, the 3D printer also jets a gel-like support material specially designed to uphold overhangs and complicated geometries. It is easily removed by hand or water.
The most advanced PolyJet systems, Objet Connex 3D Printers, combine diverse 3D printing materials in one model by jetting multiple materials simultaneously. This means the user can selectively position multiple materials in one printed prototype and even combine two or three materials to create composite models with distinct, predictable properties. The most complex models can combine up to half a dozen different materials to accurately replicate structures like a rubber wheel positioned on a rigid hub, or a solid figurine with bendable joints and rigid skeletal structures. Furthermore, different materials can be jetted together at the same time to produce unique composite materials with varying properties and colors - often well beyond the range of the basic materials themselves.
Capable of impressive detail and multi-material printing, PolyJet printers are some of the most expensive printers in the world, with even rudimentary machines costing tens or hundreds of thousands of USD. A single polyjet prototype can cost anywhere from a few dollars to many hundreds of USD depending on size.
Examples of polyjet materials include: digital ABS, transparent high-strength materials that mimic glass or crystal, rigid opaque photopolymers, rubber-like flexible material, simulated polypropylene, biocompatible polymers used for medical or surgical prototypes, and even mouth-safe dental material for molding and orthodontic work. For additional information, see the materials section.
- VeroWhite offers production-like parts.
- Transparent is best for clear parts.
- Rubber-like has great flexible material properties.
- ABS-like is similar to ABS material, but uses Polyjet.
- Accuracy: Offers 16 micron layer heights; the best of any technology.
- Surface finish: Great looking smooth surfaces.
- Details: Able to print small, delicate features.
- Cost: Use for late-stage development prototyping.
- Support material: Depending on the required amount of support material, costs can be higher.