Developments in thermoplastic composites for automotive applications

Transcription

1 Developments in thermoplastic composites for automotive applications Thierry Renault Franco-British Symposium on Composite Materials, London - April 28, 2015

2 Faurecia - Leader in automotive equipement 34 countries 505 patents filed in billion of total sales* 6,000 engineers and technicians 99,500 employees 30 R&D centers 330 sites 515 programs in development * of which 14.1 billion of product sales 2

3 Faurecia Automotive Composites Presence on 9 Composite Market Segments 3

4 Faurecia Automotive Composites Strategy from low volume to mass market Low Volume Market Sport & Luxury, Trucks Mass Production Large vehicle platforms Semi-Structural parts & Exposed Carbon Technologies (SMC, RTM, BMC), Glass or Carbon Structural Composite Chassis Substitution of metal to achieve weight saving Technologies (T-RTM, Thermo-stamping), Glass or Carbon 4

5 Targets for CO 2 emissions in cars CO 2 emissions regulation (g/km) EU 103 China Japan US Europe Time (year) Power train - 10% fuel consumption = -13 g CO 2 Aerodynamics : - 5 dm 2 SCx = - 2 g CO 2 Road Resistance : -10% = - 2 g CO 2 Source : PSA 5 Weight : -110 kg = -10 g CO 2

6 What are the challenges? Cost efficiency Maximum cost : 4 to 5 premium /kg saved vs steel Composite GF-PA66 : From 7 to target 3.5 /kg Carbon fibers : From 15 /kg to target 8 /kg Industrialisation, short cycle time and compatibility with existing technologies Mass production : parts/year 500 parts/day => 2 cycle time Mass production : parts/year 1000 parts/day => 1 cycle time Hybrid metal-composites assembly Predictivity and numerical simulation No more prototype - Respect of the car development time Numerical validation expected according to specifications (crash) Recycling and sustainability End of life 2015 = recycling 85 % and valorization 95% 6

7 Why are CFRT of interest? CFRT = Continuous Fiber Reinforced Thermoplastics 7

8 Processes : compromise b/n fiber length, cycle time, and part complexity Fiber length Endless Thermo-stamping T-RTM RTM Autoclave Part complexity HP-RTM 10 to 50 mm Compression Molding GMT SMC 0.5 to 5 mm Injection Molding BMC Thermosets Thermoplastics For high volume automotive, thermoplastic composites are preferred and a combination of thermo-stamping and injection has the highest potential Cycle time (minutes) 8

9 Faurecia Composite - Technology Roadmap Structural semi structural From semi-structural products to more structural products SMC Chopped fibers SMC RTM THERMO STAMPING SMC High perf. RTM T-RTM Thermo Stamping Organo TP INJECTION TP Injection TP Injection Organo Weight saving Improved mechanical performance Cost saving 9

10 Material choice for high volume crash relevant automotive parts Thermoplastics are preferred to thermosets Lower cycle time (around 1 minute vs. 2 minutes or more) Better impact resistance Better process control (no chemical reaction) Better recyclability Less problems with VOC emissions and odor Easier assembly (welding, overmolding..) Main focus is on polyamide (PA6 and PA66) or polypropylene with glass fibers Interest for local reinforcement with carbon fibers 10

11 CFRT alternatives Organic sheets (woven fabrics in thermoplastic resin) Dry fabrics are impregnated by a thermoplastic resin to create a sheet of semiproduct Typical thickness of consolidated sheet is 0.5 to 4 mm Tapes (unidirectional fibers in thermoplastic resin) Thin (0.25 mm) unidirectional fibers BUT! 1. Organic sheets are currently too expansive for high volume applications 2. Processes to use tapes still have to be developed 11

12 Standard molding process for CFRT organic sheets Thermo-stamping process Organic sheet Infra red heating Positioning (blank holder) Forming bars Trim Finished Part Benefits of thermo-stamping High and controlled mechanical properties Low pressure process : low investments Short cycle time Limits of thermo-stamping No flow of materials : Trimming part edge is needed and loss of materials (25% mini) Only simple parts can be molded 12

13 Heating Forming Trimming Heating Injection Molding Heating Forming Trimming Heating Injection Molding Avoid Thermo-stamping? One shot injection process Two steps process : 1. thermo-stamping and 2. injection overmolding Organic sheet Formed Continuous fiber reinforcement Finished Part + : known process, inserts can be transverse to injection mold closing direction - : cost of thermo-stamping One shot process (thermostamping + injection overmolding + : cost optimization (no thermo-stamping step) Organic sheet Flat Continuous fiber reinforcement Finished Part - : only simple shapes for CFRT and CFRT only in injection mold closing direction 13

14 Potential Automotive Applications 14

15 Composite Back Global Partnership with BASF CFRT Tapes Composite back - key value drivers Slim Attractive perceived quality (PA6 + glass fibers) Tape-laying Kit Thermo-stamping CFRT Insert Steel bracket Injection molding PA6GF30 Actual Test Luggage Retention * Rear Crash * IIHS Rear Impact Lateral Fatigue Recliner Durability Chuck and Satiability Modal Analysis (< 18 hz) Abusive rearward load Torsional rigidity Results Pass (ECE-17) Pass (24 G Pulse) (Over all rating) Pass Pass Pass Pass (frequency= 33 hrz) Pass Pass Ready for production 15 * tests ok at -35 C and +80 C

16 Composite Back Crash Performance Rear Crash at 80 C 16

17 Seat Cushion Side Member LYCOS project One shot thermostamping + backinjection with PAGF30 17

18 Liftgate inner structure Thermoplastic concept Hybrid Steel / PP-GF structure Steel reinforcements PP-GF30 Thermoplastic structure CFRT 18

19 Composite structural floor thermostamping school mold Small radius possible Poor design with this draft angle Good design with this draft angle One shot solution for stamping and trimming 19

20 From learning mold to Rear Floor Assembly Static Load Rear Impact Draping Lateral impact 20

21 Composite structural floor Eolab concept Trunk Floor Rear passenger floor Front passenger floor - 5 kg - 11,5 kg 21

22 Conclusions Fierce competition between materials and processes to reduce the weight of cars at an affordable price Steel with advanced high strength steels Light alloys (mainly aluminum but also magnesium) Composites (thermosets but also thermoplastics) Current automotive market for CFRT is still very small but growth potential is high if Material price goes down Automated processes are developed Joining solutions are found 22

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