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Agenda

SGL at a Glance

Snap-cure Resins – The Motivation

Reclaimed Carbon Fiber – The Reality

SGL E420 Toolbox

Summary – The combination of reclaimed carbon fiber, snap-cure resins and prepreg for large scale production.

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Company profile SGL Group

§ One of the world’s largest manufacturers of carbon-based products

§ Comprehensive portfolio ranging from carbon and graphite products to carbon fibers and composites

§ 41 production sites worldwide

§ Service network covering more than100 countries

§ Sales of ~€ 1.3 bn in 2015

§ Head office in Wiesbaden/Germany

§ ~ 5,700 employees worldwide

§ Stock listed in Germany

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Markets

Acrylic Fibers

Automotive

Aerospace

Wind Energy

Industrial

Business Unit Composites – Fibers & MaterialsOur solutions serve key markets

Unique integrated value chain

Fibers

Materials

Components

Broad portfolio of high-performance products - Acrylic fibers - Stretch broken yarn- Oxidized fibers - Chopped & milled fibers- Carbon fibers

Production technologies along the fiber value chain - Woven fabrics - Preforms- Non crimp fabrics (NCF) - Prepregs & TowPregs- Non-wovens - Tapes & organo sheets- Braidings - Wet friction materials

Lightweight and Application Center (LAC) - In-house bridge between SGL products and customer applications

in the development of fiber reinforced composite components - Engineering solutions and manufacturing prototypes (e.g. CFRP parts)

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Snap-cure material toolbox – Motivation

Offer a complementary set of pre-impregnated materials based on one fast-curing (“snap-cure”) epoxy resin system

Benefits for the customer:

Ø Pick the right materials for the right application and use material combinations (e.g. local UD reinforcements of isotropic / planar materials) for maximum design freedom

Ø Ensured compatibility of the different materials (à all based on one resin system)

Ø Less qualification and testing effort (à only one type of resin and one type of fiber leads to standardization)

Ø Snap-cure resin system for short cycle times (≤ 3 min)

Ø Pre-impregnated materials offer high mechanical performance, reliable processing and eliminate the need for a resin infusion step and handling of resin components

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Carbon Fiber Waste Streams – The Reality

Dry Fiber Waste

Source: Carbon Fiber manufacturing waste• Use: Primary supply source for short fiber

production by carbon fiber manufacturers

Source: Fabric manufacturing wasteSource: Waste associated with fabric use§ Use: Feedstock for non-woven fabrics

§ Use: Feedstock for “long” short fibers used in unique compounding or direct processing.

Prepreg Waste and CFRP scrap

Source: Prepreg manufacturing waste• Use: Direct molding of low-end sport applications

Source: Waste associated with prepreg useSource: CFRP manufacturing wasteNote: resin removed prior to conversion

§ Use: Feedstock for short fiber compounding

§ Use: Direct processing (Vartega)

1/3 of waste volume – Est. = 6 k ton2/3 of waste volume – Est. = 12 k ton

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World Leader in Carbon Fiber Recycling

Advantages§ Typical carbon fiber properties§ Epoxy sizing on the fiber§ Excellent electrical conductivity§ Low density§ Light weight structural reinforcement

Sustainable production from the start

Cut Open Card Combine

Productionprocess ofnonwovencomplexes

Production Technologies§ RTM / SMC / BMC§ Compounding§ Compression molding§ PU spraying

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The next level of carbon fiber in automotiveNew BMW 7 series

Significant weight-savings through lightweight chassis

Source: BMW Group

New BMW

7 Series

Center Console Reinforcement Rocker Panel Lightweight Chassis

Side Roof frame C-Pillar Rear Shelf

Reclaimed CF Examples

SGL’s Snap-Cure Toolbox

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SGL Group’s carbon & glass fiber material tool box for high-volume automotive applications (resin E420)

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Snap-cure epoxy resin system E420 is the best choice for high-volume applications

§ Rapid build-up of properties like stiffness and Tg

§ Very short curing cycles possible, e.g. conversion of > 90 % in ~ 1.5 min at 160 °C§ High Tg of 140 - 150 °C allows for hot demolding at curing temperature§ Further resin variants tailored for specific processes available, e.g. adjusted tack or Tg

Typical mechanical properties @ FVC 55 %(cure: 3 min at 150 °C)

UD prepreg, SGL 50k carbon fiber,

FAW 300 g/m²

0° Tensile strength 1950 MPa

0° Tensile modulus 127 GPa

0° Compressive strength 1150 MPa

0° Compressive modulus 120 GPa

0° Flexural strength 1450 MPa

0° Flexural modulus 121 GPa

Interlaminar shear strength 83 MPa

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Mechanical properties are comparable to standard epoxy prepregs

E320: autoclave curingheating & cooling with 5 K/min100 min @ 130 °C, 6 bar

E420: hot press curing3 min @ 150 °C, 10 bar

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SGL Group offers a pre-impregnated composite material based on an isotropic carbon fiber nonwoven

§ Due to its randomized fiber structure the mechanical properties show almost isotropic in-plane behavior

§ For enabling of high-volume automotive applications a combination with snap-cure epoxy resin (curing time < 3 minutes) is most suitable

§ Unique visual appearance due to randomized carbon fiber distribution §

§ Usage in CFRP sandwich applications as filling material à same coefficient of thermal expansion as outer CFRP layers (UD, NCF or woven fabrics)

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Prepregs based on isotropic carbon nonwoven

§ Isotropic carbon nonwoven:- 50k CF, fiber length Ø 40 mm, FAW 450 g/m², dry thickness 8 mm

§ Available pre-impregnated with epoxy resins, such as:- Standard 120 °C systems (e.g. E500)

- Snap-cure systems (e.g. E420)

- High-Tg systems (e.g. E800)

§ Pros & cons:+ Comparably high, nearly isotropic mechanical properties

+ High drapability; unique visual appearance

+ Limited / no flow of fibers (depending on resin and molding conditions)à fibers stay “in place”, beneficial e.g. for combination with UD materials

− Limited / no flow of fibers (depending on resin and molding conditions)à no SMC-like flowing behavior

− Certain variation of properties (FAW) due to random fiber distribution

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Prepregs based on isotropic carbon nonwovenMechanical properties

Property Prepreg with resin system E420

Cure cycle (hot press) 3 min @ 150 °C,10 bar

Fiber volume content [%] 30

0° Tensile strength [MPa] 210

0° Tensile modulus [GPa] 23

90° Tensile strength [MPa] 280

90° Tensile modulus [GPa] 31

Apparent ILSS [MPa] 70

0° Flexural strength [MPa] 360

0° Flexural modulus [GPa] 22

90° Flexural strength [MPa] 400

90° Flexural modulus [GPa] 25

Prepreg with resin system E500

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Nonwoven prepreg with E420 and vinyl ester resinComparison of mechanical properties

Property E420, ICV, FAW 450 g/m²,resin content 62 %

Vinyl ester*, ICV, FAW 450 g/m²,resin content 64 %

Curing cycle (hot press) 3 min @ 150 °C, 10 bar 3 min @ 145 °C, 230 bar

Fiber volume content [%] 30 25

0° Tensile strength [MPa] 209 (± 16) N/A

0° Tensile modulus [GPa] 23.1 (± 1.8) N/A

90° Tensile strength [MPa] 285 (± 21) 209 (± 16)

90° Tensile modulus [GPa] 31.0 (± 1.8) 23.2 (± 0.7)

Apparent ILSS [MPa] 72.1 (± 4.0) 26.2 (± 2.5)

0° Flexural strength [MPa] 365 (± 11) 184 (± 57)

0° Flexural modulus [GPa] 22.0 (± 1.1) 19.6 (± 1.5)

90° Flexural strength [MPa] 398 (± 43) 273 (± 19)

90° Flexural modulus [GPa] 25.3 (± 2.4) 24.5 (± 1.4)

*not offered by SGL

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Nonwoven prepreg with snap-cure resin E420Press study

0° Tensile strength vs. molding time at 150 °C (10 bar) 90° Tensile strength vs. molding time at 150 °C (10 bar)

Fiber volume content ≈ 30 %

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0° Tensile modulus vs. molding time at 150 °C (10 bar) 90° Tensile modulus vs. molding time at 150 °C (10 bar)

Fiber volume content ≈ 30 %

Nonwoven prepreg with snap-cure resin E420Press study

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Interlaminar shear strength vs. molding time at 150 °C (10 bar)Conclusion:Ø Constant mechanical properties are

achieved already after 30 s molding time (closed mold) at 150 °C

Ø This is due to the high reactivity and exothermic reaction: laminate core temperatures of ~ 220 °C are reached with 4 - 5 mm laminate thickness and ~ 60 wt.% resin content

Fiber volume content ≈ 30 %

Nonwoven prepreg with snap-cure resin E420Press study

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Benefit Summary

E420 Snap-Cure Resin System• Key properties achieved after 30s – Expedited de-molding

• High Glass Transition temperature• 1 month non-refrigerated storage

Reinforcement Options Add Value and Provide Task Specific Part Construction§ UD Tape, Non-Crimped Fabric and even woven fabric can be utilized for strength, stiffness and visual

characteristics

§ Nonwoven prepreg can add some key properties while being utilized to build volume

High Volume Part Production custom tailored for the right properties is achievable utilizing prepreg compression molding technology whether single-sided tooling or classic double-sided tooling.

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