Low Cost, High Quality Composite Tooling Utilizing Additive Manufacturing Processes Bill Macy, Stratasys SME Tooling for Composites Charleston, SC Oct 24 th 2011
My Apologies for the bait and switch Depot Repair Project Postponed Funds & resources diverted to higher priority repairs Project Plan 180 C cure, 1.2m x 0.5m x 15cm thick tool Track cost metrics for FDM vs. traditional Low Cost Assessment Digitize tools and parts throughout process High Quality Assessment Stay Tuned We will bring you these results in a future presentation
Overview Study to expand FDM Core to 180 C Parts Utilize flexible cure resins/prepreg Two stage cure Core provides form during first stage cure Core is non structural during post cure Identify and characterize FMD material options Testing Oven testing Material behavior @ 180 C Layup cure tests
180 C Cure FDM Cores Question If a flexible cure epoxy resin was used Lower initial cure temperatures netting self supporting composite part Followed by 180 C secondary post cure How could FDM cores be utilized? Opportunities Lower initial cure temperatures Minimize FDM CTE compensation factors Maximize core strength Post cure temperature Can we take advantage of FDM Tg to melt out core with secondary post cure?
Prepreg UMECO MTM 45-1 Initial Cure: Three OoA cure cycle options @ >28inHg vacuum pressure Option 1: 20 Hours @ 80 C Option 2: 4 Hours @ 120 C Option 3: 2 Hours @ 130 C Post Cure: 2 Hours @ 180 C
Composite Tooling Application FDM Composite Applications Patterns Lay Up / Cure Tools Consumable Cores Digitally Coordinated Tool Families Masters Pre Layup Consolidation Tools Low Temp High Temp Bonding Fixtures Intensifiers Caul Plates Soluble Cores Net Shaped Cores Integrated Interfaces Trim Tool Drill Tool Check Fixture
Composite Tooling Application FDM Composite Applications Patterns Lay Up / Cure Tools Consumable Cores Digitally Coordinated Tool Families Masters Pre Layup Consolidation Tools Low Temp High Temp Bonding Fixtures Intensifiers Caul Plates Soluble Cores Net Shaped Cores Integrated Interfaces Trim Tool Drill Tool Check Fixture
FDM Tool Material Selection Service FDM Temp Materials ABS AMB 80 C 120 C 175 C AMB 180 F 250 F 350 F Low Temp Tools Low Temp Consumable Cores Master Patterns SR30/SR100 SR30 Soluble Cores SR100 Soluble Cores PC ULTEM Low Temp Cure Tools & Consumable Cores Master Patterns Trim & Drill Tools Med Temp Cure Tools & Consumable Cores High Strength Trim & Drill Tools With Caution PPSF High Temp Tools & Consumable Cores ABS Master & Tooling Composites High Temp CTE Matched Tools 200 C (400 F) Max ABS Master & Nevada Composites High Temp CTE Matched Tools High Temp CTE Matched Soluble Cores +300 C (600 F)
FDM Tool Material Selection Service FDM Temp Materials ABS AMB 80 C 120 C 175 C AMB 180 F 250 F 350 F Low Temp Tools Low Temp Consumable Cores Master Patterns SR30/SR100 SR30 Soluble Cores SR100 Soluble Cores PC ULTEM Low Temp Cure Tools & Consumable Cores Master Patterns Trim & Drill Tools Med Temp Cure Tools & Consumable Cores High Strength Trim & Drill Tools With Caution PPSF High Temp Tools & Consumable Cores ABS Master & Tooling Composites High Temp CTE Matched Tools 200 C (400 F) Max ABS Master & Nevada Composites High Temp CTE Matched Tools High Temp CTE Matched Soluble Cores +300 C (600 F)
FDM Tool Material Selection Service FDM Temp Materials ABS AMB 80 C 120 C 175 C AMB 180 F 250 F 350 F Low Temp Tools Low Temp Consumable Cores Master Patterns SR30/SR100 SR30 Soluble Cores SR100 Soluble Cores PC ULTEM Low Temp Cure Tools & Consumable Cores Master Patterns Trim & Drill Tools Med Temp Cure Tools & Consumable Cores High Strength Trim & Drill Tools With Caution PPSF High Temp Tools & Consumable Cores ABS Master & Tooling Composites High Temp CTE Matched Tools 200 C (400 F) Max ABS Master & Nevada Composites High Temp CTE Matched Tools High Temp CTE Matched Soluble Cores +300 C (600 F)
Application Trade Offs Cycle Time Savings Trade cure time vs. initial cure temp Accuracy CTE growth vs. initial cure temp Cost Savings Lower cost materials vs. higher performance materials Cure Cycle Cure Temp ( C) Cure Time (hrs) Compatible FDM Material FDM Service Temp ( C) FDM Material Tg ( C) Option 1 80 20 SR30/ABS 80 108 Option 2 120 4 SR100/PC 120 161 Option 3 130 2 ULTEM Support 150 186 Post Cure 180 2
180 C Behavior Test Materials tested: Ultem Support 1 Polycarbonate ABS M30 SR100 soluble support SR30 soluble support Test part Geometry: 3 diameter cylinder 4 tall 0.250 wall thickness All parts utilized Insight sparse double dense build style PC SR30 Ultem S1 ABSM30 SR100
Test Setup
Results Following 2 hour exposure at 180 C Simulating resin post cure cycle
Results continued ABSM30 PC Ultem S1 SR30 SR100
Results Summary Cure Temperatures ULTEM Support PC & SR100 ABS & SR30 80 C Structural Structural Structural 120 C Structural Structural 130 C 180 C 2 Hour Exposure Structural Did not melt still breaks down with acetone Melted Melted
ULTEM Support Breakdown Part must be at room temperature or cooler Part is then wet with acetone Note: Spray or misting of acetone will not work Acetone will then embrittled the support structure enabling crushing/breaking of the support structure by hand
Layup Test Samples PC SR100 ULTEM S1
Sample Prep Surface Prep Sanded PC ULTEM Support Left SR100 as is Release Treatment Frekote Layup 10 plies MTM45 5mm (.200 ) thick
First Stage Cure Test PC & SR100 4 hours @ 120 C, 1-3 ramp rate Parts maintained shape PC SR100
Post Cure Test PC & SR100 2 hrs @ 180 C, 1-3 ramp rate SR100 PC
Observations PC Melted 50% of the way out Was fully released Part could easily come free if PC had melted in its entirety Consider fixturing or bagging strategy to promote better melt flow out of part Part maintained shape
Observations SR100 Delaminated from itself Did not release from the part SR100 cracking occurred Part is not usable but maintained shape
Cure Test ULTEM Support First stage 2 hrs @ 130 C, 1-3 ramp rate Post cure 2 hrs @ 180 C, 1-3 ramp rate
Observations ULTEM Support Maintained shape Readily released from part Was easily removed with typical composite scraper Only 3oz of acetone was needed
Summary/Conclusion ABS/SR30 Could be used but significantly extends cure time, 22 hrs PC Limited value do to melt flow constraints SR100 Can be used, but would still require tank washout Total cure time would be 6 hrs ULTEM Support Supports minimum cure time of 4 hrs Was surprisingly easy to remove Would be geometry limited Requires acetone for removal Using two stage process reduces CTE compensation issues by 30% (delta temp of 50-60 C)
Next Steps Large scale core test in work 1m x 0.5m x 1m tall Material: ULTEM Support Gather mechanical properties for ULTEM Support CTE Dynamic Flex Tensile, Compression
Questions?
Thank you! Bill Macy, Stratasys