Development of Preforming Process in PCM* Technology · 2012-09-02 · PCM Technology High cycle...
Transcript of Development of Preforming Process in PCM* Technology · 2012-09-02 · PCM Technology High cycle...
DevelopmentDevelopment of Preforming Process of Preforming Process in PCM*in PCM* TechnologyTechnology
Koichi AkiyamaToyohashi Research LaboratoriesComposite Material Development Center
* Prepreg Compression Molding
PCM TechnologyPCM Technology
High cycle process based on compression molding Rapid cure prepreg
2 minutes cure at 150 ℃ (302°F)Carbon Fiber SMCDeveloped for high volume Carbon Fiber Reinforced Plastic (CFRP) applications
PCM (Prepreg Compression Molding)Newly developed rapid curing prepreg is preformed, and then cured in heated steel tool.Short mold cycle times.
Laminate Heat Preforming Charge Compression De-molding
Prepreg for PCMPrepreg for PCMResin Properties
Resin type Gel time @ 140 C min.
Minimum cure time @140 C min.G'-Tg ℃
tanδ ℃
Notes
Prepreg Properties
CF reinforcement1)
FAW g/㎡ Resin Content wt%
CF Vf vol% Specific Gravity
1) TR50S carbon fiber from Mitsubishi Rayon Co., Ltd. is used for all prepregs Tensile strength; 4900 MPa, Modulus; 240 GPa, Elongation; 2.0%2) Plain, twill and Satin fabric can be used.
1.54 1.47
30.0 40.059 49
UD Fabric2)
250 or 125 200.0
Properties Ttypical grade
167
Good SurfaceHigh Tg
High TgGood Surface154 186 190
R 05
Bisphenol A typeEpoxy resin
2.75.05.0 3.0
Resin Formulation R 02 R 03
Bisphenol A typeEpoxy resin
Bisphenol A typeEpoxy resin
2.0 1.3
125 165
Compression Molding ProcessCompression Molding Process
By Courtesy of
Automotive Body PanelsAutomotive Body Panels
Class A surface is achievable with UD prepregBody panels can be produced by bonding PCM outer panel and CF-SMC inner panel
Outer Panel PCM
Part size; 600X600X1.1mm
UD prepreg with body color paint
CF-SMC
Part size; 600X600X1.5mm
Inner Panel Fabric prepreg with clear coat
By Courtesy of
Automotive Structural PartsAutomotive Structural Parts
PCM process application on floor partMolded parts have high mechanical properties due to continuous fiber materialCo-molding of prepreg and CF-SMC allows complex three dimensional shapes
Rapid Curing MaterialRapid Curing Material
Prepreg compression molding significantly reduces time to convert PREPREG to COMPOSITE
Traditional ProcessCycle time; 240 minutes
AutoclaveAutoclave PressPress
High Cycle ProcessCycle time; 5 Minutes
Rapid Preforming ProcessRapid Preforming ProcessConventional preforming process is inefficient compared to high-cycle PCM process
Manual lay-upVery slow
Large variationHuman error
Conventional Preforming
Conventional Preforming
Advanced Preforming Process
Advanced Preforming Process
Fast enough for PCMConsistent
Less manual laborAutomated
Preforming process for PCM must be…
Preforming process for PCM must be…
RapidRapid Preforming ProcessPreforming Process
Pattern cutting, preforming and compression molding are consecutive processes.Cycle times of each process must match for high capacity production.
5minutes5minutes5minutes
Heating PreformingLaminating
Net shapepreform
CuttingPatterns
Prepreg
CompressionMolding
Composite
Development of Development of RRapid apid PPreforming reforming PProcessrocess
Preforming large and complex shapesDeep drawn shapesShapes that cannot be preformed by stretching materialThree dimensional shapes such as ribs and bosses
Optimization of preforming parametersHeating temperature and time, press pressure, etc.
Automated process for rapid preforming system
Prepreg Curing AnalysisPrepreg Curing AnalysisTemperature of prepreg quickly rises after charged on heated steel toolCuring reaction starts immediately after prepreg is heated to tool temperature.
Preforming cannot be done with compression molding tool.Preforming cannot be done with compression molding tool.
Curing property of Prepreg
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0 50 100 150 200 250 300
Time (second)
Tem
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C)
Cure time
Gel time
Temperature at the center of prepreg was measured by a thermocouple.(Measuring Condition)Material; R05 UD prepreg, cross plyThickness of prepreg; 4mm (2mmX2sets)Tool temperature; 140 ℃
Magnified chartExothermal behavior of prepreg
Preforming with PressPreforming with Press
Heating temperature must be below 80 ℃during press-preforming process.
Resin viscosity decreases by heating and prepreg becomes flexible and drapableCuring occurs when temperature is over 80 ℃
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
0 1 1 2 2time (min)
55℃
60℃
65℃70℃
80℃90℃
90 1206030
Vis
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ndex
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0 50 100 150Temperature(℃)
Vis
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ndex
Stability of Resin at Elevated TemperatureTemperature Dependence of Resin Viscosity
Resin formulation; R02Measured by TA Instruments AR-G2 RheometerTemperature ramp up rate; 2℃/min
Resin formulation; R02Measured by TA Instruments AR-G2 Rheometer
Preforming with PressPreforming with PressThicker laminates need longer heating time.
Longer time is needed for inside to reach to appropriate temperature (50-75℃)Low heater output allows longestworking time.
IR Heater output; Low (11mA)Material; R05 (Thickness of Laminate; 1, 2, 3mm)
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Thickness 3mm
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Thickness 2mm
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Thickness 1mm
TopMiddleBottom
Good temperature rangeWorking rang (Preform is possible)
BottomMiddleTop
IR Heater
About 15cm
Thermocouple
Preforming with PressPreforming with Press
Higher heater output shortens heating time, but working time is shorter.
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60 1200 60 1200 60 1200Hea
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Thickness; 1mm Thickness; 2mm Thickness; 3mmMaterial; R05 (Thickness of Laminate; 1, 2, 3mm)
Typical Preforming ProcessTypical Preforming ProcessNear net shape preform can be produced at low temperature and low pressure.
Low cost equipment can be used (chemical wood tool, air cylinder driven press, IR heater, etc.)
1) Heat laminate to 70 ℃ex) 30 seconds by IR heater for 1mm thick
2) Press for 1 minute to cool downTypical pressure is lower than 0.1 MPa (1 bar)
3) Debulk for 1 minute by vacuum(if necessary)
1) Lay up several prepreg sheets2) Debulk for 2 minutes by vacuum3) Cut patterns
Heat PreformLaminate
Net shapepreform
CutPatterns
Prepreg
Preforming Demonstration UnitPreforming Demonstration Unit
Preforming demonstration unit was builtPressing by tool stretches prepreg like manual lay-up in few minutes.
Press unitHeating unit
Preforming ProcessPreforming Process
Preforming of Complex ShapePreforming of Complex Shape
Advanced procedures to produce near net shape preform for complex shape
Apply tension to stretch laminate.Optimal for forming round or deep drawn shape
Divide into smaller sections.Preform each section with press.Sections are combined into an integrated near net shape preformOverall short process time.
Combine prepreg and CF-SMC for three dimensional complex shape.
Prepreg based design for mechanical properties with CF-SMC only for three dimensional complex shape.CF-SMC based design for design flexibility with prepreg as local reinforcement.
1/2 Scale Seat Back Demonstration1/2 Scale Seat Back Demonstration
Complex deep drawn shapeNormally preformed manually by skilled operator
By Courtesy of
400mm(15.7”)
300mm(11.8”)
85mm(3.3”)
Preform Capability AnalysisPreform Capability Analysis
Fiber distortion was observed in simple press-preforming by matched tool.
By Courtesy ofAnalysis by FiberSimAnalysis by FiberSim
Fiber Direction; 0/90
Fiber distortion
Fiber Direction; 45/-45
Actual Preforming ResultsActual Preforming Results
3K Plain Fabric PP ; 0/90
Shear deformation angleB; 0-15° PossibleY; 15-30° DifficultR; over 30°impossible
3K Plain Fabric PP ; 45/-45
Shear deformation angleB; 0-15° PossibleY; 15-30° DifficultR; over 30°impossible
Fiber distortion
Preforming Deep Drawn ShapesPreforming Deep Drawn Shapes
Apply tension to stretch material and fit on tool surface without fiber distortion.
Jigs are used to simulate manual lay-up
Jigs for press preforming- Apply tension during preforming- 10 minutes
Traditional Manual Preforming- Heat and stretch by hand- 60 minutes
By Courtesy of
Tension ApplicationTension Application
Automatic chucking unit applies tension and stretches prepreg during preforming
By Courtesy ofPreforming Unit
Chucking unit Heating unit
Press unit
Trim
Automatic System for Complex ShapeAutomatic System for Complex Shape
By Courtesy of
Sectional Preforming ProcessSectional Preforming Process
Divide large complex shape to smaller sections.
Each section can be preformed by press in only a few minutes.
Layer A
Section #1
Layer B
Section #3
Section #2 Section #4
Sectional Preforming ProcessSectional Preforming Process
Design sections so their edges are not at same position and do not overlap.
Section edges must not be where significant load is applied, as mechanical strength is lower
Layer B
Section #1
Layer A
Section #2 Section #3 Section #4
Sectional Preforming ProcessSectional Preforming Process
Preformed sections are merged into a net shape preform.
Each section is stacked, layer by layerSection #1
Section #2 Section #4
Section #3
Sectional Preforming ProcessSectional Preforming Process
A near net shape preform is debulked by vacuum.
Debulking is completed in a few minutesReady to mold by compression molding
Two each of Layer A and B are stacked alternately
Debulk by vacuum for 3minutes
Three dimensional net Shape preform
Sectional Preforming ProcessSectional Preforming ProcessHigh cycle preforming is also possible for large complex shaped part by automated process.
Combined Unit
Near Net Shape Preform
Compression Molding Press
Prforming Line C
Prforming Line A
Prforming Line B
Prforming Line D
Hybrid Hybrid Molding of Prepreg and CFMolding of Prepreg and CF--SMCSMCPrepreg for mechanical properties and CF-SMC for complex shapes
Curing properties of both materials were matched for co-moldingCF-SMC flows in the tool cavity and molds into complex structures
PrepregSMC Compressionmolding
PCM/SMCHybrid Part
Tool
CF-SMC was charged onthe net shape preform
Molded part
SummarySummaryAutomated preforming process for PCM technology has been developed.
Short preforming process by press matches compression molding of rapid cure prepreg.
Large complex shape also can be preformed quickly by using following procedures.
Apply tension to stretch prepreg and fit to parts shape.Divide part to several smaller sections.
Sections can be preformed by pressThey are consolidated and form a near net shape preform ready for compression molding.
PCM/CF-SMC hybrid moldingCo-molding of prepreg and CF-SMC can provide high mechanical properties with three dimensional complex shape
Thank youThank you
AcknowledgmentAcknowledgment
Special Thanks to; Yajima Industry Co., Ltd.
Cooperation on the quarter engine hood development.
Challenge Co., Ltd.Cooperation on devide-preforming process development.
The other authorsY. Kazehaya, Y. Kakimoto, Y. Fukuharaand T. TakanoComposite Material Development CenterMitsubishi Rayon Co., Ltd.