IDTechEx – April 2018
Digital Printing Technologies
Inkjet printer’s data path challenges in emerging
printing applications
© 2018 Meteor Inkjet Ltd.

Inkjet printing circa 2040 …
Three-dimensional printing of biological matters
© 2018 Meteor Inkjet Ltd.

 Inkjet printing is fundamentally a 2D process
 Inkjet printers have been designed to print on flat surfaces
 Printheads are designed to increase throughput in 2D
printing
 The existing inkjet technology has been optimized to support
2D printing processes
 The physics of drop jetting and formation limit the range
of usable fluid viscosities
 The main use of inkjet printing in 3D are in binder jetting
and direct material deposition
Inkjet in 3D printing - background
© 2018 Meteor Inkjet Ltd.

 Inkjet in 3D printing is being used as a multi-layered 2D process
 In binder jetting the 3rd dimension is added by stepping in height and adding a new layer of powdered
base material
Inkjet in 3D printing – how is being used
Yang L. et al. (2017) Introduction to Additive Manufacturing. In: Additive Manufacturing of
Metals: The Technology, Materials, Design and Production. Springer Series in Advanced
Manufacturing. Springer, Cham
© 2018 Meteor Inkjet Ltd.

 Inkjet in 3D printing is being used as a multi-layered 2D process
 In direct material deposition the height is built by overlapping 2D layers on top of each other
Inkjet in 3D printing – how is being used
© 2018 Meteor Inkjet Ltd.

 Inkjet file formats are in essence 2D arrays covering the complete span of the printable image
 A 3D object has to be represented as a collection of 2D arrays (monochrome images)
 This is not the most efficient way to represent 3D objects
 Example: 3D object embedded in a 10 cm side cube with 800 dpi resolution (voxel side 3 um)
• Cube volume: 1012 um3
• Voxel volume: 33 103 um3
• Number of voxels: 300 M
• Information per voxel: 3 dim x 2 Bytes
• Files size: ~225 MBytes
~300 files x 750 KByte
Inkjet file formats
© 2018 Meteor Inkjet Ltd.

 A number of file formats are used in 3D printing, most of them describe the surfaces of the 3D
object
 Triangular tessellation based: e.g. STL
• Add curvature: e.g. AMF, 3MF
 Encoded geometry: e.g. OBJ
 An many others, none of them ideally suited for direct inkjet printing
3D file formats
https://all3dp.com/3d-printing-file-formats/
© 2018 Meteor Inkjet Ltd.

 A translator is needed, commonly called a slicer
 Literally, they cut a 3D model into 2D slices
 Mostly intended to use with extruder 3D printers
• 2D slices + G codes for CNC machines
 Not aware of a suitable solution for inkjet printing
• If you know of one, I want to talk to you!
3D file to 2D inkjet
“An Optimal Algorithm for 3D Triangle Mesh Slicing”
Rodrigo Minetto1, Neri Volpato2, Jorge Stolfi3,
Rodrigo M. M. H. Gregori1 and Murilo V. G. da Silva1
© 2018 Meteor Inkjet Ltd.

 Inkjet allows for highly parallelized 3D manufacturing:
 N x M object array
 Following our previous example:
 10 x 10 object in parallel
• Files size: ~22.5 GBytes
~300 files x 75 Mbytes
 High laydown
 Resonant waveforms
 Controllable laydown
 Variable drop volumes
 Adaptive slicing, more detailed features
High productivity
© 2018 Meteor Inkjet Ltd.

 Inkjet scanning configurations:
 XY table + ΔZ
 X scan + Y print bar + ΔZ
 X scan + Y print bar + Δφ + ΔZ
 Cartesian XYZ tables + rotation
 Good mechanical stability
 High precision
 Easy to invert kinematics
• Slicer can generate the motion sequences
 More complex robots
 Position accuracy augmentation by visual means
 Complex real-time inversion kinematics, variable
printing data
Inkjet scanning machine topologies
http://www.robotbasics.com/robot-arm-configurations
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An inkjet printer data path
Print Controller
Head Driver
Printhead
© 2018 Meteor Inkjet Ltd.
 Distributed memory approach to handle
large size images [pre-load mode]
 PC memory: Buffer architecture to ensure
continuous supply of data
 Print controller memory
• Printing from DDRAM memory: enables
multiple image repeats with minimal
data transfer
• Printing from SD card: large image
library availability with minimal data
transfer
 Fast data download [variable data mode]
 Dynamic adjustment to printed image
 Scalable networked architecture
 Gb Ethernet TCP

 Material deposition
 Drop formation
• Nozzle pressure waveform profile
 Ejection
• Nozzle to nozzle variability
• Printhead to printhead variability
 Drop-substrate interactions
• Drop to drop coalescence
• Coffee ring effect
 Nozzle failure
 Material compatibility between
printhead and ink
 Big topic, we will not cover it here
Inkjet technology: challenges for material deposition
© 2018 Meteor Inkjet Ltd.

 Software screening algorithms
 Can minimize the effect of:
• Nozzle to nozzle variability
• Printhead to printhead variability
• Drop to drop coalescence
• Coffee ring effect
• Nozzle failure
 It will not solve all problems
• In functional printing, the creation of structures by inkjet printing relies on drop coalescence or coffee
ring effect
• Screening algorithms have been design to produce an average image impression on a human eye
Minimising variability: screening
© 2018 Meteor Inkjet Ltd.

Compensation for printhead to printhead variability
Fundamental problems in inkjet Solutions using advanced screening
Nozzle to nozzle variability
Drop to drop coalescence
Printhead to printhead variability
Highly parallelized
3D manufacturing
Adaptive slicing,
more detailed
features
© 2018 Meteor Inkjet Ltd.

 Mature industrial technology
 Can handle image sizes and productivity data rates required for 3D printing
 Scalable architecture
 Screening algorithms to minimize component variability
Inkjet 3D printing: existing data path
© 2018 Meteor Inkjet Ltd.

Inkjet 3D printing: open opportunities data path flows
 Slicing algorithms better suited for inkjet printing
 Integration of differentiated tasks with unique workflows into one digital thread:
 Physical based design
 Scanning based design
 Planar deposition (binder jetting)
 Line formation (drop coalescence)
 Process monitoring
 Product validation
 End product management
© 2018 Meteor Inkjet Ltd.

 Extended workflows:
 Integration of differentiated tasks:
• Physical based modelling leading to a 3D printing structure
Inkjet 3D printing: open opportunities data path flows
© 2018 Meteor Inkjet Ltd.

Inkjet 3D printing: digital thread
© 2018 Meteor Inkjet Ltd.

enquiries@meteorinkjet.com
talk with Meteor technical sales support in
Hong Kong, Germany, Shanghai, UK (Cambridge HQ), USA, Japan
© 2018 Meteor Inkjet Ltd.