Thermoset or Thermoplastic - global-automotive-lightweight ...

Thermoset or Thermoplastic ?

The choice for automotive structural composite applications

Strictly Private & Confidential

Process Development of McLaren Road Cars

McLaren F1 2000
1992 ± 1998
McLaren-Mercedes
107 cars SLR, 2003 - 2009
1000hrs/tub
2114 cars
275hrs/tub

1990

McLaren MP4-1 2010
1981-1983
20 cars McLaren 12C
800hrs/tub 2011

1980 2000 cars this year
100hrs/tub
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Factors Affecting Choice of Matrix Resin (in no particular order)

‡ Raw material cost
‡ Temperature performance
‡ Environmental resistance
‡ Recyclability
‡ Production route
‡ Mechanical performance

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Raw Material Costs

‡ Typical prices (per square metre) for composite materials based
on standard (T300) carbon fibres :-

‡ RTM epoxy resin and NCF carbon fibre - $18m-2
‡ Thermoset resin pre-preg - $65m-2

‡ PEI thermoplastic pre-preg - $62m-2

‡ PPS thermoplastic pre-preg - $70m-2

‡ PEEK thermoplastic pre-preg - $92m-2

‡ Reduce manufacturing costs when using thermoplastics by :-

‡ Improved design and production efficiencies
‡ Reduction in assembly part count and secondary processing

‡ Reduced waste

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Composite Matrix ± Advantages and Disadvantages

Advantages Thermoset  Matrix   Advantages Thermoplastic  Matrix
Disadvantages Disadvantages

Proven  technology Cure  times  can  be  long Fast  manufacturing  routes  available Un-­‐proven  Technology

Adhesive  Properties Brittle/Lack  of  toughness  (RTM) Toughness/Impact  resistance Secondary  bonding  can  be  difficult
Recycleability
Mechanical  properties Difficult  to  recycle Semi-­‐crystalline  thermoplastics  require  
Can  be  reworked controlled  cooling
Secondary  Bonding  Capability Difficult  to  rework Joining  by  welding  techniques
High  temperature  processing
Processing  window  can  be  broad Very  low  water  absorption
Although  base  resin  costs  can  be  low,  processed  
Isothermal  tooling/curing  possible (eg  pre-­‐preg)  costs  are  high

Automated  lay-­‐down  rates  upto  4  times  slower  
than  for  epoxies

Matrix  Material Temp Pressure Processing Cycle Neat  Resin   Service  Temp   CTE  (x10-­‐6) Base   Matrix   Polymer  Structure
Route Tg (Composite) Resin   Density

Epoxy  Resin 80°C 15  -­‐  100  Bar RTM  &  High  Pressure  RTM 90mins 125°C 120°C 81 ΦϭϬ͘ϬϬ 1.12 Amorphous
Press  moulding,  ATL,  AFP,  RTM
Polyamide  12 230°C 10  Bar 10mins 55°C 70°C 130 Φϴ͘ϬϬ 1.02 Semi-­‐crystalline
T  -­‐  RTM
Anionic  Polyamide  6  (APA6) 150  -­‐  180°C Press  moulding*,  ATL,  AFP 15  -­‐  60mins 65°C 50°C 90 1.15 Semi-­‐Crystalline
Press  moulding*,  ATL,  AFP
Poly  Phenylene  Sulfide  (PPS) 330°C 10  -­‐  40  Bar Press  moulding*,  ATL,  AFP 10mins 90-­‐120°C 100°C 20  -­‐  60 Φϱ͘ϬϬ 1.35 Semi-­‐crystalline
Press  moulding*,  ATL,  AFP
Poly  Ether  Imide  (PEI) 300°C 10  Bar Press  moulding*,  ATL,  AFP 10mins 217°C 149°C 5  -­‐  120 Φϭϯ͘ϬϬ 1.27 Amorphous
Compression  Moulding,  VARTM
Poly  Ether  Ether  Ketone  (PEEK) 390°C 10  -­‐  40  Bar 10mins 143°C 120°C 11  -­‐  150 Φϰϴ͘ϬϬ 1.32 Semi-­‐crystalline

Poly  Ether  Ketone  Ketone  (PEKK) 370°C 10mins 156°C 121°C 21  -­‐  77 1.29 Semi-­‐crystalline

Polycarbonate  (PC) 270°C 10  Bar 10mins 143°C HDT  130°C 70 ΦϮ͘ϱϬ 1.2 Amorphous

Polyester  Polybutylene  Terephalate  (PBT) 170°C 1  Bar 40mins HDT  215°C 149°C 21  -­‐  130 1.6 Semi-­‐crystalline

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Matrix Resin Overview ‡ Polybutylene Terephthalate (PBT)

‡ Epoxy ‡ Advantages
‡ Low water absorption
‡ Advantages ‡ High strength
‡ Low, isothermal processing temperatures ‡ Mouldability (RTM)
‡ High strength and stiffness when reinforced ‡ Isothermal processing possible
‡ Dimensional stability
‡ Limitations
‡ Limitations ‡ Affected by boiling water
‡ Relative brittleness (RTM grades) ‡ Poor chemical resistance (except to hydrocarbons)
‡ Water Absorption
‡ Anionic Polyamide 6 (APA-6)
‡ Polyetherimide (PEI)
‡ Advantages
‡ Advantages ‡ Ease of processing (RTM)
‡ High strength ‡ Isothermal processing ± low temperature for a
‡ Continuous use temperature thermoplastic
‡ Inherently flame retardant ‡ Improved dry mechanical properties over melt
‡ Readily bonded with conventional adhesives processed PA-6

‡ Limitations ‡ Limitations
‡ Cost ‡ Affected by moisture
‡ High processing temperature
‡ Polyetheretherketone (PEEK)
‡ Polyphenylene Sulphide (PPS)
‡ Advantages
‡ Advantages ‡ High strength and toughness
‡ Excellent chemical resistance ‡ Outstanding chemical resistance
‡ High temperature performance ‡ Ease of processing
‡ High modulus when reinforced ‡ Wear resistance

‡ Limitations ‡ Limitations
‡ Brittleness ‡ Cost
‡ Cost ‡ High processing temperature
‡ Tendency to warp during processing

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Processing Costs ± Relative

Relative Component Cost v's Manufacturing Route/Matrix Material

1.0

0.9

0.8

0.7

Relative Cost 0.6

0.5

0.4

0.3

0.2

0.1

0.0

RTM ± TS Low Cost RTM Low Cost RTM Press Press DCFP - RTM DCFP - Press ATL/Press TS ATL/Press TP

TS TP Moulding - TS Moulding - TP TS TP

Manufacturing Route

Carbon Resin Pre-preg / laminate Other Materials Labour

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Composite Materials ± Available Forms

Thermoset Systems.

‡ Resin infused tapes/fabrics ± Pre-preg

‡ Dry fabrics (UD Tow, woven or NCF) for liquid resin infusion

Thermoplastic Systems

‡ Catalysed reactants as in the case of aPA-6 and Cyclic PBT for use
in thermoplastic resin infusion processes

‡ Co-mingled fibres ± polymer and carbon fibres woven to give a dry
fabric

‡ Thermoplastic pre-preg ± polymer infused into a ply of fibre/fabric
using polymer films or powder as the pre-cursor

‡ Tow-preg ± individual tows of reinforcing fibres coated with
thermoplastic.

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Processing Methods

Thermoset Systems.

‡ Autoclave moulding ± hand or automated (ATL/AFP) lay-up of pre-
preg

‡ Press moulding

‡ Diaphragm forming

‡ Resin infusion of dry fibres ± RTM, VARTM, Film Infusion
(includes variants such as filament winding, braiding etc)

Thermoplastic Systems

‡ Press forming from pre-preg or consolidated pre-heated blanks

‡ Automated Fibre Placement & Tape Laying (AFP/ATL) with
possibility of in-situ consolidation.

‡ Resin Infusion (RTM) using cPBT or aPA6/PA12 Strictly Private & Confidential

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Joining Processes

Thermoset Systems.
‡ Adhesive Bonding ± simple bond preparation
‡ Bolting/riveting
Thermoplastic Systems
‡ Adhesive bonding ± except for PEI, surface preparation can be

problematic ± plasma/corona discharge and/or etching
‡ Bolting/riveting
‡ Welding ± ultrasonic, hot plate, resistance, laser and eddy current

KVE developed eddy current
welding ± can use carbon fabric
reinforcement as the conductor.

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Mechanical Properties (Manufacturers Data)

                                                                                   

    Material       Toughened  Epoxy     PEI   PPS   PEEK   cPBT      

    Resin   Fibre   Weave   Resin   Fibre   Weave   Resin   Fibre   Weave   Resin   Fibre   Weave   Resin   Fibre   Weave      

                T300   UD       T300   Plain       T300   5HS   (UD  90°)   AS-­‐4   UD   UD/2       Panex   UD   UD/2      
21  

                                                                           

    Mechanical  Property  (@RT)   Unit                                                                          
                                                                       
   

                                                                                   

    0°  Tensile  Strength   MPa   52.4   2044   105   712   90.3   758   89.6   2280   1140       1565   783      

    0°  Tensile  Modulus   GPa   4   126   3.3   55   3.8   56   11   141   70.5       115   58      
    1100   550       827   414      
    0°  Compressive  Strength   MPa       1316   152   658   148   644  

    0°  Compressive  Modulus   GPa       113   3.3   51   3   51       122   61                  

    In-­‐Plane  Shear  Strength   MPa           103   125       119       83.4           64          
    In-­‐Plane  Shear  Modulus   GPa      
    n/a   3.4       4       7.1           3.8          

    Flexural  Strength   MPa       1478   138   820   125   1027   148               1310   655      

    Flexural  Modulus   GPa       112   3.5   46   3.7   60                              

    ILSS   MPa       92                       88.9           75          

    Bearing  Strength  (ultimate)   MPa                       844                              

    Bearing  Strength  (yield)   MPa                       454                              

    CAI   MPa                       215                              
       
    Open  Hole  Tensile  Strength   MPa       261       278       387   193.5                  
       
Open  Hole  Compressive   MPa       275       256       318   159                  
Strength  
   

                                                                                   

                                                                                   

Modulus  

    Fibre     (Gpa)   Strength  (Mpa)                                                              

    T300   235   3530                                                              

    AS-­‐4   235   3800                                                              

    Panex  21   N/A   N/A                                                              
       
                                                                           

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Other Considerations When Using Thermoplastics

‡ Creep?
‡ Spring-back

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Where Next ± The Future

BMW Megacity ± RTM
Thermosetting resin

Teijin demonstrator - Thermoplastic UD,
Isotropic and Injection Moulding Material

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Any Questions

Thank You

14 Strictly Private & Confidential