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TCA and Contributions Made to Improve SMC Paintability. Mike Siwajek ThyssenKrupp Budd Company Society of Plastics Engineers Automotive Composites Conference September 9-10, 2003 Troy, MI. Goals and Objectives. Defect Root Cause Analysis. 500+ defects from 10 assembly plants catalogued
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TCA and Contributions Made to Improve SMC Paintability Mike Siwajek ThyssenKrupp Budd Company Society of Plastics Engineers Automotive Composites Conference September 9-10, 2003 Troy, MI
Defect Root Cause Analysis • 500+ defects from 10 assembly plants catalogued • Large percentage of defects due to microcracks from handling • Majority of “handling” defects occurred after primer application
Root Cause Breakdown Cracks & damage
Toughening the Matrix • Targeting edge defects • Evaluate all components • resins • fillers • LPA’s • additives • catalysts / inhibitors • glass
Improved Toughness TCA Control
Paint Pop Flex Test • 2 x 18 x 0.1 test strips • 8.25 diameter cylindrical mandrel • designed for 125% of ultimate stress • deformation creates micro-cracks on SMC surface • Paint with conventional Primer-sealers using E-coat bake simulation (380F for 30 min.) • count “paint pops” on surface of SMC
PP Flex Test Panels Control Tough Class ‘A’
Verifying TCA’s Effectiveness • Multiple DOEs performed • Ford Paint on Plastics Team / 6-sigma black belts • AOC • Red Spot • Studied effects of • SMC type • Humidity • E-coat • Stress after molding (molding plant damage) • Stress after priming (body shop handling damage) • Type of primer (standard 2K and UV Thermal)
TCA DOE Results Sample Paint Pop Test Results • TCA less affected than control • humidity • temperature • handling extremes • 90+% improvement in pop resistance over control Desired
TCA Implementation • TCA has afforded: • Conversion from double layer of primer to single layer of primer without degradation in quality • Up to 98% reduction in paint defects • Currently less than 10 defects submitted for microscope analysis (since May 2002) - Zero Microcracks
Ford Sport Trac • Process DOE completed in May 2002 (defect rate reduced to ~60) • Full conversion to TCA in June 2002 • Defect rate has dropped from ~60 to below 10
Ford T-Bird • Defect rate includes all parts • fender converted July 2002 • decklid 07/29/02 • hood 09/2002 • Level defect rate for TCA 1X primed vs standard SMC 2X
Ford Ranger Hood • Full conversion to TCA 08/13/02 • Defect rate dropped from ~200 to nearly 0 • Pop rate data collection suspended by assembly plant Conversion to TCA
Lincoln Navigator Hood • Converted hood to TCA on 06/17/02 • Level defect rate for TCA 1X primed vs. standard SMC 2X
Lincoln Navigator Fenders • Converted fenders to TCA August / September ‘02 • Level defect rate for TCA 1X primed vs. standard SMC 2X
Ford Mustang Hood • Terminator, GT Hoods and Decklid converted to TCA • Defect rate reduced to 0-20 • Mach 1 launched with TCA Paint pop Data Collection Suspended by Assembly Plant
Ford Mustang Decklid Paint pop Data collection suspended by assembly plant
Ford Econoline Hood • Converted to TCA February 2003 Conversion to TCA
What next??? • Remove the Class ‘A’ SMC Stigma at OEMs • Tough Class ‘A’ • UV Thermal Primer • New primer-sealer technologies • SMC Consistency Program • Best practices (compounding and molding) • Defect traceability • Eliminate variability
SMC Consistency Improvement Plan • Target programs for improvement • Identify Key Performance Criteria (KPCs) • as defined by customer (molding plant or OEM) • Target broad cross-section of causes for inconsistencies (Control Factors / CFs) • Form cross-functional teams to focus on this effort • Stepwise regression of defects vs. CFs • Develop a sound engineering basis for the effort
SMC Consistency Roadmap Data Analysis - identify Data Gathering possible CF's Brainstorm - understand failure mode failure mode identified ? no yes Conduct experiments to Implement in production verify failure mode Establish CF statistical Data Gathering to verify capability improvement
Acknowledgements • SPE • Ford GPE • AOC • Red Spot • TK-Budd Team