innovations in extrusion based additive manufacturing ... · extrusion based additive manufacturing...
TRANSCRIPT
Innovations in extrusion based additive
manufacturing technologies
Prof. Ludwig Cardon
Ghent, in the cultural and economical heart of Europe …
Mission statement
Ghent University wants to be a creative
community of staff, students and alumni,
connected by the values the university carries
out: engagement, openness and pluralism.
Our motto is Dare to Think: we encourage
students and staff members to adopt a critical
approach. Rector:
Professor Anne De Paepe
Established in 1817
Research: input
(Numbers: 2014)
Research expenditures 2014: € 265 million
0,00
50,00
100,00
150,00
200,00
250,00
300,00
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2 013 2014
m€
Public Research Funding - Regional and National Public Research Funding - EU and International Private Research Funding
Research lines
Prof. Ludwig Cardon
Prof. Kim Ragaert
Sustainableuse &
recycling
Post-industrial& post-
consumer
Mixed polymerstreams
Design for/fromrecycling
Advanced polymer
processing
Micro FibrillarComposites
Mould Engineering
Advanced extrusion
Additive Manufacturing
Polymers & composites
Extrusionbased
Fablab UGent
Known as FDM - Fused Deposition Modelling (Stratasys)
3D Plotter & BioScaffolder
Several types of low cost printers
Polymers
Composites
Ceramic and metal slurries
Extrusion based Additive Manufacturing
8
Extrusion based Additive Manufacturing
Towards 3D Printing of composites
and new materials?
“Nasa’s next Rover
has 3D-printed parts”
Resin infusion
Spray-up
Filament winding
To understand the process it may be useful to study a traditional
screw-fed extrusion process
Viscosity =
Share rate (speed) =
Shear stress =
Processing methodology
Processing methodology
Shear stress
.D / 4L
shear stress in N/mm²
pressure drop in N/mm²
D diameter of tube in mm
L length of tube in mm
Shear rate (speed)
=32Q / D³
average shear rate in s-1
Q output in mm³ s-1
D diameter of the tube in mm
Anisotropy between « layers and filaments»
Intermediate mechanical properties
Limited dimensional accuracy (stair-step effect)
Available materials
Poor interlayer bonding
Warpage and thermal stresses
Solidification process and shrinckage
Processing limitations
Processing limitations
Extrusion based Additive Manufacturing
Ongoing research
New printing heads and build strategies
for extrusion based AM technologies
Technical applications
Medical applications
Composite applications
Materials
New compounds and fillers
Improving the mechanical properties of AM composite materials
(bonding matrix and particles/fibres)
Dimensional accuracy (shrinkage)
Use “anisotropy as an advantage”
Composite materials for AM
Particle filled polymers for
enhanced stiffness, wear
resistance, thermal and
electric properties.
[1]: Nikzad, M., S. H. Masood, and I. Sbarski, 2011, Thermo-mechanical properties of a highly
filled polymeric composites for Fused Deposition Modeling, Materials & Design, v. 32, p. 3448-
3456
[2]: Ozkoc, G., G. Bayram, and E. Bayramli, 2005, Short glass fiber reinforced ABS and
ABS/PA6 composites: Processing and characterization: Polymer Composites, v. 26, p. 745-755
[3]: Markforg3D, Mark One, carbon fibre sample
Short fibre filled
polymers for higher
stiffness and wear
resistance.
Continuous fibre
composite for higher
stiffness, tensile and
impact strength.
Extrusion based Additive Manufacturing
High-end short fibre filled materials
Arevo labs
PEEK, PAEK, PPSU + short carbon - glass fiber fibre - CNT
(ArevoLabs, 2016)
Extrusion based Additive Manufacturing
Short fibre thermoset 3D Printing
Extrusion of short fibres containing epoxy
Syringe based, high accuracy
UV-curing after deposition
Printing of open structures
(Harvard, 2014)
Extrusion based Additive Manufacturing
Discontinuous fibre filled materials
ORNL labs (Oak Ridge National Laboratory,
Cincinnati Incorporated)
3D Printing of large volume parts with
discontinuous carbon fibre filled ABS
Carbon particles of 6-7 µm diameter
The parts have an improved stiffness of
5/6 times compared with unfilled polymers.
(Strati, ORNL, 2014)
M., R., Talagani, et al., 2016, Numerical
Simulation of Big Area Additive
Manufacturing (3D Printing) of a Full Size
Car , SAMPE 51 No.4
Extrusion based Additive Manufacturing
Coated filament materials
Texas Tech University
Carbon NanoTubes coated filaments
Improving the adhesion between layers
due to local heating of the layers via microwave heating
Extrusion based Additive Manufacturing
Continuous fibre filled materials
2,5D deposition of glass, carbon or aramid continuous fibre prepreg in a polyamide matrix
First continuous fibre “printed” part, “tailoring” fibre direction possible
Enhanced stiffness and strength compared to unfilled polymer
Curved Layer AM @UGent
Deposition normal to a surface
Better surface quality
Anisotropy can be used as an advantage
Faster printing of curved surfaces
Printing on existing objects
Van De Steen W., Ragaert K., Degrieck J., Cardon L.; Ghent University (2014)
The slicer creates a generic 5-axis
tool path which has to be followed
by the printhead to print the object.
This 5-axis tool path is modified
through a coordinate transformation
to compensate for the kinematic
properties of the specific 3D-printer
used. Lengths of the tool path
sections are calculated in order to
determine the necessary polymer
flow at each location on the tool
path.
Subsequently, the 3D-printer’s firmware
translates the 5-axis tool path
commands to actual signals to control
the motors that enable the print head to
make the corresponding movements.
This firmware is an advanced version of
an existing, open source firmware.
Unlike 3-axis 3D-printers, 5-axis
printers are able to print normally on a
complex surface on condition that the
print head does not collide with the
already printed part.
In future research, the development of
a custom made printing head will be
necessary for processing and
analysing new (composite) materials
for additive manufacturing. Existing
printing machines will have to be
adapted to give the printhead the
desired degrees of freedom.
(UGent, W. Van De Steene, S. Roegiers. L. Cardon, 2015)
Curved Layer AM – 5-axis 3D Printing @UGent
Advantages of a 5-axis 3D Printer:
More accurate and smoother surfaces
Better mechanical properties
Faster printing process
Less or no support structures required
Other – 5-axis 3D Printing
University of Oslo, Øyvind
Kallevik Grutle
(Øyvind Kallevik Grutle, 2015)
Parallel research at
Auckland University of Technology
Micro extruder AM technology @UGent
Additive manufacturing with a
microextruder
Increased production rates
compared to filament extrusion
Makes the extra step of filament
extrusion process obsolete
(UGent, M. Moerman, W. Van De Steene, L. Cardon, 2014)
Continuous Fibre AM technology @ UGent
Melt impregnation of continuous
glass fibres suitable for additive
manufacturing
This thermoplastic prepreg
production process is faster and
more efficient than powder
impregnation
Accurate pressure control is
necessary to guarantee complete
impregnation of the fibre bundle
(UGent, W. Van De Steene, L. Cardon et al, 2015)
26
The future?
Towards 3D Printing in space environment…
Spray-up
Contact information
Technologiepark 915
9052 Zwijnaarde
+32 9 331 03 91
Part of
Member of
Prof. dr. Ludwig Cardon
Head of CPMT
Characterization and 3D
Processing of Polymers
Additive Manufacturing of Polymers
0478/224 335
Prof. dr. Kim Ragaert
Sustainable Use and Recycling of
Polymers & Composites
0476/322 700
Questions?