MULTI JET FUSION (mjf)

About MJF 3D Printing

HP Multi Jet Fusion (MJF) is a powerful 3D printing technology that produces highly accurate and durable parts at fast speeds, especially compared to other powder bed fusion technologies like selective laser sintering (SLS) or direct metal laser sintering (DMLS). Due to their affordability, speed, and high resolution, HP Multi Jet Fusion can be used for end-use, low-volume production, rapid prototyping, or as a bridge process to injection molding. MJF allows engineers to get a feel for how parts will perform with minimal upfront costs.

Sinterize Advantage

At Sinterize, we have wide range of capabilities offerred through single, easy-to-use platform so you spend less time sourcing parts and more time on design innovation.

Overview

Fused Deposition Modeling (FDM), or Fused Filament Fabrication (FFF), is an additive manufacturing process that belongs to the material extrusion family. In FDM, an object is built by selectively depositing melted material in a pre-determined path layer-by-layer. The materials used are thermoplastic polymers and come in a filament form.

I. A spool of thermoplastic filament is first loaded into the printer. Once the nozzle has reached the desired temperature, the filament is fed to the extrusion head and in the nozzle where it melts.
II. The extrusion head is attached to a 3-axis system that allows it to move in the X, Y and Z directions. The melted material is extruded in thin strands and is deposited layer-by-layer in predetermined locations, where it cools and solidifies. Sometimes the cooling of the material is accelerated through the use of cooling fans attached on the extrusion head.
III. To fill an area, multiple passes are required (similar to coloring a rectangle with a marker). When a layer is finished, the build platform moves down (or in other machine setups, the extrusion head moves up) and a new layer is deposited. This process is repeated until the part is complete.

Support structure is essential for creating geomentries with overhangs in FDM because melted thermoplastic cannot be deposited on thin air. Surfaces printed on support will generally be of lower surface quality than the rest of the part. For this reason, it is recommended that the part is designed in such a way to minimize the need for support.

Support is usually printed in the same material as the part. Support materials that dissolve in liquid also exist, but they are used mainly in high-end desktop or industrial FDM 3D printers. Printing on dissolvable supports improves significantly the surface quality of the part, but increases the overall cost of a print.

FDM parts are usually not printed solid to reduce the print time and save material. Instead, the outer perimeter is traced using several passes, called the shell, and the interior is filled with an internal, low-density structure, called the infill. Infill and shell thickness affect greatly the strength of a part. For desktop FDM printers, the default setting is 25% infill density and 1 mm shell thickness, which is a good compromise between strength and speed for quick prints.