ORNL is managed by UT-Battelle for the US Department of Energy

Additively Manufactured Blade Mold Demonstration Project

Lonnie Love and Brian PostOak Ridge National Laboratory

Jim Hannan and Stephen NoletTPI Composites

Joshua PaquetteSandia National Laboratory

Megan McCluer, Blake MarshallU.S. Department of Energy

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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

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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…

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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…)

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Partnership withCRADA

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 polymer AM system delivered to MDF, April 2014• Interest from multiple automotive, aerospace and tooling industries• Stretch form and hydroform tools demonstrated

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High profile demonstrations

Local Motors Strati –first 3D printed car

(Sept 2014)

ORNL AMIE – 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)

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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

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Parameter Target (this project) Stretch (low volume) Production

Substrate bondinterface 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)

DemoWindMoldFabrication:DesignRequirements

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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)

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Conventional layup

Mold Fabrication:Coatingsandsurfacefinish3D 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

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Mold Fabrication: HeatingIntegral 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.

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• Utilized14thermocouples(baselinemeasurements),thermalimagingandlaserscannertomeasuretemperatureandsurfacevariationsduringheating

• Experimentalvalidation• Thermocouple data

• Laserprofilometry data

• Thermalcyclingtrials

Experimental setup Laser tracker in foreground Thermal imaging on mold surface

MoldFabrication:Heatingtests

Surface temp Profile data

Results from all tests meet design requirements

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Mold Fabrication:Assembly

• Sectionsjoinedtogetherandsurfacefinished.• Bondflangesattached.• Moldsattachedtosupportscaffold“egg-crate”.• Electricalsystemsconnected.

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TPI Wind Turbine MoldsTraditional 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 the BAAM-CI from 20% CF-

ABS pellets

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SummaryofRiskReductionActivities

• Demonstratedprintedmoldsectionthatmet,orexceeded,targets• Temperaturevariationsexceedtargetof+/-5C(+/-3C)• Vacuumdropexceedstarget(2.6mbar, target15mbar)• Geometricvariationexceedtarget(0.1mmto0.2mm)

• Excellentadhesionbetweenfiberglasscoatingandprintedmaterial• Sixsuccessfultemperaturecycles• Useofstandardmaterial(fiberglass/epoxy) formold interface

• Printingenablesintegrationof• Ductedheating(reuseonmultiplemolds)• Designed flangesintostructureforeasyintegration intometaltruss(easeof

reuseandtransportation)

• Constructionofdemomoldsectionsandbladesectionwillprovideinsightshelpfulforfinalmolddesign,assembly,andbladeconstruction

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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).