Processing Carbon Epoxy materials for meeting the lighter car challenges. D. Granger, 10 December 2015

Transcription

1 Processing Carbon Epoxy materials for meeting the lighter car challenges D. Granger, 10 December 2015

2 Company Overview all businesses Burlington, WA Kent, WA SLC, UT Dublin, CA Casa Grande, AZ Seguin, TX Decatur, AL Windsor, CO Stamford, CT Nantes, France Parla, Spain Pottsville, PA Illescas, Spain Duxford, U.K. Dagneux, France Welkenraedt, Belgium Stade, Germany Neumarkt, Austria Les Avenières, France Tianjin, China Leading advanced composites company with 65 years of experience Headquarters in Stamford, CT, USA 20 manufacturing sites (including 2 JV) 5,700 employees worldwide Listed on NY and Paris Stock Exchanges Hexcel 2014 Total Sales of $1.85 Billion Markets Products Regions 14% 20% 66% Industrial Space & Defense Commercial Aerospace 24% 76% Engineered Products Composite Materials Carbon Fiber Reinforcements Prepregs Honeycomb 16% 39% 45% Middle East, Asia, Africa Europe Americas 1

3 CFRP- Epoxy for light weighting cars PC : P LVC : X PC : P LVC : P Material Designer Cost, per Kg saved Logistic Chain PC : P LVC :? Fc2 PC : LVC : P Fc3 Fc1 Preforming Processing Health, social acceptation Material proposals for structural parts Fc4 Assembling, joining, bonding, co-molding Less CO 2 emission Fp 1 : high relative strength & Modulus Part recycling Re-use For Premium cars, PC, 50K cars/year, > 70 K Criteria are partially reached, according BMW i3, i8, BMW 7 Series, Corvette Next cars generations developments might create cost reduction ideas (eco-conception ) Diesel concerns might reinforce the light weighting axis for CO 2 emissions reduction For Large Volumes cars, LVC, the economic expectations are not reached Cost is the unreached goal, might change fundamental approaches Fc5 PC : P Parts Recycling currently is expensive, down cycling, with low benefit for the environment Fc6 Fc7 PC : P LVC :? PC : LVC : P Continued success with PC is a learning stage for LVC PC : X LVC : X 2

4 Raw materials ~ Hexcel approach (1/2) Matrix for pre impregnation process (pre-preg) rather than in mold impregnation (RTM) Mismatch for, maintaining the low viscosity while infusing, and having the fast effects of hardeners HSE constrains, transferring the liquid resins and Amine (hardeners) from mixer to mold Scrap level Hexcel M77 Hot melt Epoxy system for pre-preg : Reach conform, free of styrene 2 min curing time (at 150 C) High Tg 125 C GIC (Toughness) : 530 J/M 2 Long shelf life: 6 weeks at RT Low tack adapted to automated handling Hexcel s epoxy core technology enlarged for automotive 3

5 Fibers pre-selection Fiber (s) selection Raw materials ~ Hexcel approach (2/2) Fibers differentiations, example (*) Tensile Strength, MPa (3) T700S Toray, 12K IMS60, Toho Tenax, 12K AS7 Hexcel, 12K TRH50, MRC, 60K Toho Tenax, 48K (3) Fiber choice process : IM10, Hexcel 12K HM63, Hexcel, 12K Zoltek PX 35, 48K (2) Tensile Modulus, GPa (2) (2) Fiber pre-selection o Performances, cost o Sourcing Commitment Fiber evaluation o Core targets : spreading, impregnation o Mechanical evaluation (translation) (1) (1) : High K Tow : Small K Tow (*) non exhaustive list, built from main producers list communicated in CCev 2015 market report (1) Fiber process influencing performance and cost (2) High K Tow levels, lower performance, lower cost, easier handling (kg/min) (3) Small K Tow with middle performances for thinner plies and stronger parts - Spreading evaluation - Wettability evaluation - UD&Fabrics processing - impregnation - Flow test (HexMC) - Mechanical evaluation Select the Fibres according to Targets and Processing 4

6 From Pre-preg rolls to automated preforming 1. Pre-preg Handling Flexibility 2. Lay-up process Preform cutting Low viscosity and tack matrices allowing poly-free handling High frequency preform cutting in net shape geometry (contour accuracy ±0,4mm, Cut speed up to 120m/min) Through-put Process reproducibility Quality Part weight Cold Tg Up to 3kg/min to prevent preforming as cycle time bottleneck Narrow dimension, weight ( ) capability Process keeping matrix stability Automated and fully integrated quality controls SPC follow up A game changer for large volumes and cost efficiency 5

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9 Cut-off Reuse, efficiency of material management Anticipate a material efficiency strategy with the part Designer Maximum CF ADDED VALUE (2) (1) : For complex geometry parts, CF (Continuous Fibers) layers are partially used in the part, the overall down cycling and the cut-off level (ex. 60% ) are liaised. Optimum Downcycled (1) (3) (2): The optimum added value and efficiency are obtained by reducing the numbers of CF layers, which are combined with a material made from the cut-offs (ex. inertia compensated by ribs). Ex. 60% 100% MATERIAL RESSOURCE EFFICIENCY (3) : Keeping the part design with only CF Layers, the way to reach a good material efficiency is to generate a C-SMC for another part (2) : M77 Multi- layers cut off transformed in C-SMC for an hybrid construction UD layers C-SMC filling ribs Hybrid construction, ~ 100% material efficiency Cut-Offs C-SMC Stacks and re-use combination for an efficient technology 8

10 Cold Tg [ C] Resin flow [g] [ C] Logistic chain challenges Frozen goods Climate control <23 C (Shelf-life: 6 weeks) Warehouse Transport to Warehouse Shop Customer XYZ Tack level at 35 C (cold Tg acc. to ISO ) Shelf-life [days] Limit Tack level M Resin flow at 35 C (acc. to wind energy standard) Shelf-life [days] Resin flow Shop-floor out-life: 5days at 35 C Reactivity at 35 C (Peak/Tg Onset acc. to ISO ) Shelf-life [days] Peak Tg onset Resin formulation answering to logistic constrains 9

11 Carbon SMC for B.I.W applications? C SMC, a diversifier for Thermo-sets? Merits : o isotropic material with insensitiveness to notches o Preforming much easier than with UD s o No waste Needs to be competitive against aluminum > 300 MPa, 40 Gpa? o Fiber length > 25mm? o High FVC > 45%? Needs flow for complex geometry Epoxy in a standard C-SMC process, Equation impregnation + snap curing Merits of Epoxy vs Vinyl Esther: styrene VOC free Viscosity profile should near a VE profile for maximum flow (it s a given) during SMC process, challenging in : o V1 : enough viscosity for low tack for pre-forming o V2 : enough viscosity for avoiding the separation of matrix from fiber while pressing o T1 : snap cure <2 min Viscosity (Pa.s) HSE, Performance, Cycle time, challenging C-SMC V1 V Ultimate Tensile Strength (MPa) Specific UTS (MPa) Al 530 * 342 QI Carb.UD C-SMC? (* : 25% Fibers in 0 ) : SMC process : Impregnation at ~70 : Curing at ~150 C, Part process T1 Time (min) 10

12 High K Tow C-SMC Epoxy based, Hexcel approach Impregnation before chopping for Epoxy : Enables Hot Melt Epoxy with relative high viscosity + for Mechanical performances : o Impregnation o Fiber VC 52% Tensile : 300 MPa and 40 Gpa OK Industrial production concept, for a competitive price, related to volumes Automotive application Constrains for Parts manufacturing : Ribs filling, in an industrial process, and without waste : o Solved by the Pre-forming, ~ 60% coverage P Reduces Parts surface preparation for bonding with other Epoxy parts : o Step of Sand abrasion unnecessary P Part release : o Enhance the material Release properties P o Work closely with the part and tool designer (-) Kunststoff Wagner Peel test, Cohesive failure Release force measurement HexMC - i, a technology for Epoxy C- SMC 11

13 Future targets And continuous improvement on : TS/TP combination to integrate functionalities Bruckbauer P. Morphology Development and mechanical Properties of Interfaces between Epoxy Resin and Thermoplastics Films. Garching; 2014 Carbon and Glass combination Fast cure epoxy system Hybrid CFRP (UD and HexMC -i) Technology development will drive future CFRP applications 12

14 Thank You for your attention! More questions : Denis.granger@hexcel.com 13

15 Disclaimer This document and all information contained herein is the sole property of HEXCEL CORPORATION. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of HEXCEL. This document and its content shall not be used for any purpose other than that for which it is supplied. The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, HEXCEL will be pleased to explain the basis thereof. 14