The Role of Recycled Carbon Fibres in Cost Effective Lightweight Structures SPE Automotive Composites Conference & Exhibition Novi, 2016
Overview of ELG Carbon Fibre Established in 2011 when ELG Haniel acquired the operations of Recycled Carbon Fibre Ltd. Patented process for recovery of carbon fibre from manufacturing waste and end-of-life products, using a modified pyrolysis process. Recovered and converted more than 1000 tonnes of carbon fibre in 2015. R&D programmes have led to the development of recycled carbon fibre products for the compounding and composites industries. Goal: to provide affordable, high performance materials to enable weight reduction in the transportation market. ELG Carbon Fibre Ltd. - Confidential 1
What We Do Carbon Fibre Reclaiming Metal removal and cutting of large composite structures to sizes suitable for downstream processing. Shredding of laminates and prepreg to enable efficient and consistent processing. Fibre recovery via a modified pyrolysis process. Carbon Fibre Conversion Milling. Nonwoven mat production. Pellet production. Product Research and Development Aligned fibre materials. Intermediate materials (e.g. SMC) ELG Carbon Fibre Ltd. - Confidential 2
Meeting The Industry s Needs Automotive Industry Needs Carbon fibre at $5-$7/lb Low cost conversion techniques to intermediate products. Recycled Carbon Fibre Delivers Carbon fibre at less than $5-$7/lb Potentially low cost conversion techniques to products suitable for use in injection moulding and composites manufacturing. Stable supply chain. Low carbon footprint. 24,000 tonnes of carbon fibre from manufacturing waste, much of this coming from long term programmes using high quality fibres. Less than 10% of the global warming potential of virgin carbon fibre. The key challenge in delivering the potential benefits is development of usable products ELG Carbon Fibre Ltd. - Confidential 3
Tensile Strength MPa Tensile Modulus GPa Recycled Carbon Fibre Properties 5000 4500 Difference in test method 4% reduction in tensile strength after pyrolysis 300 2% reduction in tensile modulus after pyrolysis 4000 250 3500 3000 200 2500 2000 150 1500 100 1000 500 50 0 Impregnated Strand Tensile Strength Pre-furnace Single Filament Tensile Strength Post-furnace Single Filament Tensile Strength 0 Impregnated Strand Tensile Modulus Pre-furnace Single Filament Tensile Modulus Post-furnace Single Filament Tensile Modulus Similar mechanical properties to the original fibre ELG Carbon Fibre Ltd. - Confidential 4
Recycled Carbon Fibre Challenges Low bulk density = difficult handling Variable fibre lengths Variable nature of material fibre clumps, single filaments ELG Carbon Fibre Ltd. - Confidential 5
Conversion Routes Pellets for thermoplastic compounding. Nonwoven mats for composite manufacturing. ELG Carbon Fibre Ltd. - Confidential 6
Pellets Designed for use in reinforcing thermoplastic compounds. Intended as a low weight replacement for glass fibres or a low cost replacement for virgin carbon fibres. Challenges: Achieving sufficient fibre length to provide the same mechanical properties as 6mm chopped virgin carbon fibre. Achieving a sufficiently high fibre loading to make the product viable as a base for further compounding. Ensuring a dust-free product. ELG Carbon Fibre Ltd. - Confidential 7
Manufacturing Routes Diced Fibreboard 100% carbon fibre. 6mm fibre length. Not dust free. Multiple processing steps. Lack of consistency. Energy intensive. Ring Die Pellet Mill High carbon fibre content. Not dust free unless large amounts of binder are used. Multiple processing steps fibre damage. Lack of consistency. Energy intensive drying. Extrusion Dust free. Polymer compatibility ensured. Low number of processing steps. Limitations of carbon fibre content. Feeding of recycled carbon fibres. ELG Carbon Fibre Ltd. - Confidential 8
Fibre Length Critical fibre length dependent on the shear strength of the fibre/resin interface. Once targets has been established based on testing, these were verified by comparing mechanical properties with compounds made using 6mm chopped virgin carbon fibre. ELG Carbon Fibre Ltd. - Confidential 9
Tensile Strength - MPa Tensile Strength Comparison 60 50 40 30 20 10 Tensile Strength of PP Recycled carbon fibre products provide at least the same performance as virgin carbon fibre products 0 0% 5% 10% 15% 20% 25% 30% 35% Reinforcement Content Milled carbon 6mm chopped virgin tow Extruded pellet ELG Carbon Fibre Ltd. - Confidential 10
Influence of Processing Parameters Processing parameters for compounding and injection moulding being investigated in a project being carried out with the University of Warwick. Investigating the effects of changing processing parameters on mechanical properties and fibre length. ELG Carbon Fibre Ltd. - Confidential 11
Quantity of Fibres (%) Influence of Processing Parameters 40 Significantly shorter fibre length in pressed fibre pellets 35 30 25 20 15 Mean fibre length in part 0.48mm 2.6% of fibres longer than 1.5mm Mean fibre length in pellet 0.67mm 6.4% of fibres longer than 1.5mm 10 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 Fibre Length Extruded RCF Pellet Pressed RCF Pellet Part From Extruded RCF Pellet ELG Carbon Fibre Ltd. - Confidential 12
Flexural Strength MPa Tensile Modulus GPa Mechanical Properties of rcf Compounds Flexural Strength of PA66 450 400 350 300 250 200 150 100 50 0 0% 5% 10% 15% 20% 25% 30% 35% Reinforcement Content Glass Recycled Carbon Virgin Carbon Tensile Modulus of PA66 30 25 20 15 10 5 0 0% 5% 10% 15% 20% 25% 30% 35% Reinforcement Content Glass Recycled Carbon Virgin Carbon Recycled carbon fibres give the same mechanical property enhancement as virgin carbon fibres. 10% loading of recycled carbon fibre provides the same mechanical properties as 30% loading of glass fibres. 23% density reduction. 4% material cost increase. 30% to 45% loadings of recycled carbon fibre provide mechanical properties comparable to magnesium castings and aluminium castings. ELG Carbon Fibre Ltd. - Confidential 13
Performance comparison 15% weight reduction 30% glass fibre reinforced PA66 56.9g 10% rcf reinforced PA66 48.7g Higher mechanical properties 15% weight reduction can be achieved whilst providing the same mechanical performance without any change to the design. Higher weight savings achievable with product optimization. Part cost increase to achieve this weight saving ~2%. Over 750,000 tonnes of 30% glass reinforced PA66 compounds used for air inlet manifolds and cam covers each year by the automotive industry potential for over 110,000 tonnes of low cost weight saving! ELG Carbon Fibre Ltd. - Confidential 14
Recycled Carbon Fibre in Composites Nonwoven mats are the basis of the products for composites manufacturing. These can be either 100% carbon fibre or blends of carbon fibre with thermoplastic fibres. Carbon fibre products can be used in liquid, prepreg and SMC applications. Hybrid products can be used in compression moulding applications. ELG Carbon Fibre Ltd. - Confidential 15
Consolidation Pressure (bar) Influence of Processing Parameters 10.0 9.0 8.0 7.0 6.0 5.0 4.0 Processing Characteristics-Fibre Volume Fraction Autoclave Prepreg RTM/LCM and Compression moulded prepreg/smc Carbon fibre nonwovens have different processing characteristics and mechanical properties compared to conventional composite materials. With proper design, they can be used to manufacture low cost, lightweight structures using most high volume manufacturing processes. 3.0 2.0 1.0 Resin Infusion 0.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 Fibre Volume Fraction % ELG Carbon Fibre Ltd. - Confidential 16
Fabic Cost /kg Fibre Cost /kg Affordability 60 50 Fibre cost $5-$7/lb. 40 Reinforcement products cost $8-$12/lb. 30 20 10 0 Virgin Fibre Recycled Fibre Weight savings depend on design criteria, but typically the weight of a recycled carbon fibre part is within 5%- 10% of the weight of a virgin carbon fibre part. 70 60 50 40 30 20 Hybrid designs comprising approximately 10% virgin carbon fibre and 90% recycled carbon fibre, typically show no weight disadvantage but have a significantly lower cost. 10 0 Virgin Fibre Fabric Recycled Fibre Fabric ELG Carbon Fibre Ltd. - Confidential 17
Tensile Strength MPa Tensile Modulus GPa Mechanical Properties of Nonwovens 500.0 450.0 400.0 350.0 300.0 250.0 200.0 150.0 100.0 50.0 Tensile Strength 0.0 20.0% 22.0% 24.0% 26.0% 28.0% 30.0% 32.0% 34.0% Fibre Volume Fraction Tensile Modulus 40 35 30 25 20 15 10 5 0 20.0% 22.0% 24.0% 26.0% 28.0% 30.0% 32.0% 34.0% Fibre Volume Fraction Fibre volume fraction typically in the range of 27% to 40% for compression moulding processes. Properties dependent on type of feedstock, structure of the nonwoven mat and processing conditions. ELG Carbon Fibre Ltd. - Confidential 18
Case Study istream Carbon Conventional stamped steel chassis: Typically hundreds of stamped metal panels. istream hybrid structural composite chassis: Simple, low cost steel tubular members. 14 composite panels. istream photos and information courtesy of Gordon Murray Design Ltd. ELG Carbon Fibre Ltd. - Confidential 19
Environmental Benefits The use of recycled carbon fibre significantly reduces the global warming footprint and improved the life cycle analysis for lightweight structures. Global warming potential comparison prepared by Fraunhofer UMSICHT based on ELG CF 2014 operational data. Further 36% reduction in energy consumption per kg achieved in 2015. ELG Carbon Fibre Ltd. - Confidential 20
Summary Carbon fibre recycling has been established at an industrial scale. Products for the plastics compounding and composites industries offer the potential for cost effective weight saving in the automotive industry. The use of recycled carbon fibre products also offers significant environmental benefits and an improved life cycle analysis where carbon fibre structures and components are used. ELG Carbon Fibre Ltd. - Confidential 21