3D Printing (3DP) provides a wide range of possibilities for the realization of freeform 3D structures. Recent develop-ments allow for a wide range of materials to be processed, from pure polymers to polymer-based highly filled composites for creating functionality enhanced 3D parts. In the FFF process, the material of choice is provided as a filament that is melted in a hot chamber, extruded through a nozzle and selectively deposited on the building platform layer by layer. In inkjet printing, on-demand small and uniform droplets of different UV curable ink are precisely ejected onto a wide range of substrates to produce multi-material functional components with intricate features of micro-scale resolution.

Equipment

FFF-Printers

• Leapfrog Xeed
• Leapfrog Bolt
• zMorph 2.0 SX
• Builder Extreme 2000
• Prusa MK3S with MMU2s

Inkjet Printers

• Notion System n.jet 3D functional/high laydown
• Notion Systems n.jet 3D

3D Scanning

• Einscan Pro (Accuracy up to 0.05 mm)

Filament fabrication

• Filafab Extruder & Winding

 
Key Features

• FFF-Resolution: 50 µm (z-axis), 200 µm (x/y-axis)
• Inkjet-Resolution: 10 µm (z-axis)
• FFF: Printhead temperature up to 250 °C
• FFF: Graded structures possible (see Samples)
• Multi-Material prints for both FFF and Inkjet possible

Materials

• ABS, PLA, PVA, Nylon
• Filled materials (optical effects, magnetic, electrically conductive)
• Custom materials
• Inkjet: Depending on material availability

Data

• STL format
• Various CAD files can be exported to STL format
• Wall thicknesses should be multiples of x/y resolution for better accuracy
• Use correct units during designing the structures
• Avoid duplexes (use snaps)
• Overhangs with degrees >30° need support
• Models must be solid bodies, not surfaces. No open faces, models must be watertight
• In case of periodic structures a single unit cell is sufficient

Limitations/constraints

• Depending on object size & geometry: long build time
• Currently no materials with melting temperature >250 °C possible

 
Samples (FFF)

Samples (Inkjet)

(LCM will soon be available as a standalone technology in the KNMFi proposal system. Until then, please use the 3DP technology to submit proposals.)

Lithography-based Ceramic Manufacturing (LCM) is a method for rapid prototyping with ceramic materials. A UV-curable resin or slurry, containing ceramic particles, is polymerized layer by layer into the desired geometry. The printed parts are then cleaned with special cleaning fluids and thermally postprocessed. This last step consists of debinding, in which the polymer is burned off, and sintering, in which a dense ceramic part is obtained. The principle of this method allows the fabrication of complex geometries, which is hard to achieve with other methods when working with ceramic materials.

Equipment

• CeraFab S25 from Lithoz GmbH

Features

• Printing resolution: 25 um (x/y-axis), 10 to 100 um (z-axis)
• Printing volume: 64 x 40 x 320 mm

Materials

• Aluminium oxide (Al2O3)
• Yttrium-stabilized zirconium oxide (ZrO2)
• Hydroxylapatit (medical grade possible after prior agreement)
• Tricalcium phosphate (medical grade possible after prior agreement)

Limitations/constraints

• Cavities must have at least an inlet, so that remaining slurry can come out during cleaning
• Cavities are possible depending on the aspect ratio. At high aspect ratios, cleaning of the cavities may not be successful
• Realizable wall thickness depends on the design and geometry stability
• Depending on the design size and needed resolution, the printing time might be very long

Data

• STL-format
• Use correct units in CAD model for exporting to STL file