ORNL is partnering with TPI Composites, Sandia National Laboratory, and the Department of Energy to demonstrate the feasibility of additively manufacturing wind turbine blade molds using Big Area Additive Manufacturing (BAAM). The project aims to 3D print mold sections for a 13m wind turbine blade and evaluate the mold against design requirements for temperature consistency, vacuum stability, dimensional accuracy, and lifespan. Successful demonstration of a printed mold section meeting or exceeding targets would indicate the potential for the technology to significantly reduce the cost and time of manufacturing wind turbine molds.

1. ORNL is managed by UT-Battelle
for the US Department of Energy
Additively Manufactured
Blade Mold
Demonstration Project
Lonnie Love and Brian Post
Oak Ridge National Laboratory
Jim Hannan and Stephen Nolet
TPI Composites
Joshua Paquette
Sandia National Laboratory
Megan McCluer, Blake Marshall
U.S. Department of Energy

2. 2
Project Objective
• Explore impact Additive Manufacturing can have on
wind turbine mold manufacturing
• Teaming with
– Sandia on wind turbine design (13 m blade)
– Wetzel on structural analysis
– TPI on mold design and blade manufacturing
– ORNL on additive manufacture of mold
• Supported by DOE Wind and Water Power Program
(WWPP) and Advanced Manufacturing Office (AMO)
– Demonstration of teaming between offices, labs and
industry

3. 3
Motivation and Challenge
• Additive Manufacturing’s Strengths
– Excellent for low volume, complex structures
– Direct CAD to Part process
– Enables integration of multiple components into
one printed system
– Current ‘killer application’ is tooling
– Additive Manufacturing’s
Weaknesses
– Expensive feedstocks (> $100/lb)
– Limited to small components (< 1 ft3)
– Extremely slow (< 1 in3/hr)
– Concept of Additively Manufacturing
tooling for wind turbine industry with
current technologies is not practical.
However…

4. 4
Big Area Additive Manufacturing (BAAM)
Big Area Additive Manufacturing
• Targeting disruption in AM
• Large (> 1000 cubic ft)
• Fast (>2500 ci/hr)
• Cheap (<$5/lb)
• Low energy intensity (1 kW-hr/kg)
• Composite materials (carbon fiber, glass fiber…)

5. 5
Partnership with
CRADA
ORNL and Cincinnati
Incorporated collaborate
to create commercial
large-scale system
Partnership to establish US-based large-scale AM equipment manufacturer
• Targets tooling lead time and cost reduction
• Based on existing ORNL gantry system
• Cincinnati providing >$1M in cost share year one
– First large-scale polymerAM system delivered to MDF,April 2014
• Interest from multiple automotive, aerospace and tooling industries
• Stretch form and hydroform tools demonstrated

6. 6
High profile
demonstrations
Local Motors Strati –
first 3D printed car
(Sept 2014)
ORNLAMIE – scaling up
printed car and house (Sept
2015)
Printed Cobra – first finished parts
(Jan 2015)
Printed Jeep – Fast
application coatings
(Nov 2015)
Printed Trim Tool –
Guinness Largest
Printed Object
(Aug. 2016)
Composite tooling with
Boeing– (March 2016)

7. 7
Demo wind turbine mold project
• Objective – Team approached by DOE to demonstrate feasibility of using
BAAM to manufacture wind turbine mold.
– Quantify costs and explore potential for significant manufacturing cost reduction
• Mold is one component of a large program exploring variable blade designs
to increase efficiency in field due to eddy currents (led by Sandia)
• Project will result in manufacture of ~12 13 m blades to be installed and
tested in Swift facility

8. 8
Parameter Target (this project) Stretch (low volume) Production
Substrate bond
interface and
coatings
Short beam shear test
with no failure of
interface at ambient
Short beam shear test
with no failure of
interface at 40 C
Short beam shear test
with no failure of
interface at 70 C
Mold temp
(+/-5 C)
Ambient (need oven) 40 C (resin flows) 70 C (fast cure) with
100 C peak
Mold distortion Match HP to LP at
ambient less than 1%
of chord
Match HP to LP at 40
C less than 1% of
chord
Match HP to LP at 70
C less than 1% of
chord
Vacuum drop 30 mbar over 30
minutes
15 mbar over 60
minutes
15 mbar over 60
minutes
Assembly of
mold pieces
Meet gap tolerance
(defined next page) at
Room temp
Meet gap tolerance at
40 C
Meet gap tolerance at
70 C
Life 4 blades 12 blades 1000 (production)
Demo Wind Mold Fabrication: Design Requirements

9. 9
Mold Requirements: Printed in 6 foot
sections
• Mold designed and printed in 6 ft sections.
• Tooling balls inserted inside machine to
calibrate part to original geometry.
• Enables rapid calibration of printed part
between machines (BAAM and router)
and parts to system (integrating
sections)

10. 10
Conventional layup
Mold Fabrication: Coatings and surface finish
3D printed mold form with fiber glass
layup machined down to mold line
• ORNL/TPI design mold and use
Additive Manufacturing to make
near net shape mold using CF/ABS.
• Mold printed 4 mm below mold
surface.
• TPI uses conventional layup of
fiberglass (8 mm).
• ORNL machined 4 mm off to
get final mold surface.
• Integrate ducted heating for final
mold
3D printed mold form
Conventional frame/scaffolding
Mold surface with 8mm of
conventional layup/coating

11. 11
Mold Fabrication: Heating
Integral air heating
• Ducts designed into support structure
for mold form
• Eliminates embedded wiring and
electronics
• One printed piece has structure,
ducting and interfaces to truss
structure
• Integral commercial inline
blowers/heaters complete the system
• Flexible, reusable - blowers and
heaters can be transferred from
mold to mold as opposed to
embedded into each mold
permanently
• Confident strategy applicable for full
mold.

12. 12
• Utilized 14 thermocouples (baseline measurements), thermal imaging and laser
scanner to measure temperature and surface variations during heating
• Experimental validation
• Thermocouple data
• Laser profilometry data
• Thermal cycling trials
Experimental setup Laser tracker in foreground Thermal imaging on mold surface
Mold Fabrication: Heating tests
Surface temp Profile data
Results from all tests meet
design requirements

13. 13
Mold Fabrication: Assembly
• Sections joined together and surface finished.
• Bond flanges attached.
• Molds attached to support scaffold “egg-crate”.
• Electrical systems connected.

14. 14
TPI Wind Turbine Molds
Traditional 50 m Mold 3D Printed Mold
Fabrication takes a total of 27 weeks
•12 weeks: fabricate plug
•3 weeks: setup and inspect
•6 weeks: layup shell, attach frame demold
•6 weeks: electrical connections, QA, ship
Based on 13 m mold results, 50 m mold
can be printed and finished in 20 weeks
•12 weeks: print mold sections
•4 weeks: glass and finish sections
•4 weeks: attach frame, install heaters, QA.
1 pair of main plugs – reliable for 6 to 10
molds. One pair of molds reliable to 1,000
blades
No plugs are needed. Direct CAD to part
Wires are embedded into the fiberglass
surface by hand during mold fabrication to
heat the surface
Air passages are incorporated into the
design of the mold to accommodate heated
air which is cycled throughout the mold
One section of the wind turbine blade mold
manufactured on theBAAM-CI from 20% CF-
ABS pellets

15. 15
Summary of Risk Reduction Activities
• Demonstrated printed mold section that met, or exceeded, targets
• Temperature variations exceed target of +/-5 C (+/-3C)
• Vacuum drop exceeds target (2.6 mbar, target 15 mbar)
• Geometric variation exceed target (0.1 mm to 0.2 mm)
• Excellent adhesion between fiberglass coating and printed material
• Six successful temperature cycles
• Use of standard material (fiberglass/epoxy) for mold interface
• Printing enables integration of
• Ducted heating (reuse on multiple molds)
• Designed flanges into structure for easy integration into metal truss (ease of
reuse and transportation)
• Construction of demo mold sections and blade section will provide
insights helpful for final mold design, assembly, and blade
construction

16. 16
What’s next
• Bigger, faster and cheaper
– Bigger: CRADA with Ingersoll on development of WHAM
– Faster: from 100 lb/hr to over 1000 lb/hr
– Cheaper: Exploring glass filled material rather than carbon
fiber ($2/lb vs $5/lb).