Knowledge Transfer Network Materials TECHNOLOGY OVERVIEW BIOCOMPOSITES Knowledge Transfer Networks Accelerating business innovation: a Technology Strategy Board programme TECHNOLOGY OVERVIEW BIOCOMPOSITES FOREWORD EXECUTIVE SUMMARY The Technology Strategy Board’s Enabling Technologies Strategy 2012-2015[I] includes advanced materials as one Composite materials derived from natural, renewable A number of bio-based polymers are commercially of four technologies that “have a key role to play in helping business to develop high-value products and services sources have received significant interest in recent available including thermoplastics such as starch, to meet market needs across all economic sectors, and to generate significant growth in the UK”. At the heart of years, in particular due to the increased awareness of PLA and PHB, which are used in packaging, and this is a drive to produce advanced materials that are both lightweight and more sustainable whilst maintaining or and drive towards more environmentally sustainable thermosets from plant oils and sugars. In the short improving performance for an equivalent cost. In this regard, biocomposites have an integral role to play. technologies. In many cases bio-based materials term, blended resins containing both bio and synthetic constituents offer a good compromise The development and manufacture of advanced materials is also recognised as strategically important to the offer weight reduction, added functionality (e.g. of performance and environmental impact. growth of UK Manufacturing in the Technology Strategy Board’s High Value Manufacturing Strategy[II], and damping / impact absorption) and occupational health composite materials are included within this. benefits. A significant market driver for high volume In most cases, natural fibres have lower environmental applications is the potential to disassociate material impact than glass fibres due to reduced CO emissions Advanced biocomposite materials will enable solutions for a growing market and will help companies meet societal 2 costs from the fluctuating price of oil and energy. and energy consumption during production. During challenges. Exploitation of these materials, with improved properties, will open up new market opportunities, the use phase, natural fibres can have a positive particularly in applications where lightweighting and environmental performance are key considerations. This guide provides an overview of biocomposites, and environmental impact due to their low weight. At the the natural fibres, bio-based polymers and bio-based This joint report, commissioned by the Materials KTN and authored by NetComposites, describes current and end of life, natural fibre composites can be recycled, core materials used to produce them, and presents emerging biocomposites and demonstrates that these materials are now starting to find applications across a wide biodegraded (when used with biodegradable the current best practice in materials, processes and range of industry sectors. polymers), or can be incinerated for energy recovery. applications. Sources of information include technical papers, articles, online information and discussions A wide range of applications exist for natural composites, with experts. The term “biocomposite” is used here to most notably in the automotive, construction, consumer denote fibre-reinforced polymer composite materials and leisure markets. Commercial applications of where the fibres and/or matrix are bio-based. natural fibre-synthetic polymer composites include WPC decking and outdoor furniture and automotive Hemp, jute and flax are common natural fibre parts such as door liners and trim panels. The Dr Robert Quarshie Dr Joe Carruthers reinforcements in biocomposites and have good demand from designers, manufacturers and Director, Materials KTN Managing Director, NetComposites Ltd mechanical properties. Fibre quality is influenced consumers for environmentally friendly products significantly by the harvesting and processing steps will inevitably drive the rapid development of www.materialsktn.net www.netcomposites.com and there is a move to reduce the on-field processing other biocomposite materials and products. to improve consistency and reduce costs. Loose fibre, non-woven mats, aligned yarns and woven fabrics are possible forms of natural fibre for composites, March 2014 with aligned variants offering the best mechanical properties. Fibre treatments such as acetylation can be used to reduce moisture uptake and improve compatibility with polymers. Synthetic bio-based fibre reinforcements, such as regenerated cellulose, are also available and offer higher consistency. [I] Enabling Technologies Strategy 2012- Biocomposites: Technology Overview is a major 2015, Technology Strategy Board, revision of Best Practice Guide, Natural Fibre November 2012, www.innovateuk.org Composites, by Brendon Weager, NetComposites, commissioned by Materials KTN, issued March 2010. [II] High Value Manufacturing Strategy 2012-2015, Technology Strategy Board, May 2012, www.innovateuk.org This revision has been jointly undertaken by Materials KTN and NetComposites Ltd. TECHNOLOGY OVERVIEW TECHNOLOGY OVERVIEW BIOCOMPOSITES BIOCOMPOSITES CONTENTS 1 INTRODUCTION 1 3 BiO-BASED POlymers AND RESINS 17 5 NATURAL FIBRE-SYNTHETIC 7 ENVIRONMENTAL ISSUES 41 POLYMER COMPOSITES 28 2 NATURAL FIBRES 3 3.1 Thermoplastic Bio-based polymers 18 7.1 Life Cycle Assessment 43 5.1 Wood Plastic Composites 29 2.1 Types of Natural Fibres 4 3.1.1 Starch 18 7.1.1 Environmental Impact of Natural Fibres 44 5.2 Natural Fibre Injection 2.2 Growing and Harvesting 5 3.1.2 Cellulose 18 Moulding Compounds 30 7.1.2 Environmental Impact of Bio-based Polymers 45 2.3 Processing of bast fibres 6 3.1.3 Polyesters 18 5.3 Non-Woven Natural Fibre Mat Composites 32 7.1.3 Interdependency of Fibre, 2.3.1 Flax Processing 7 3.1.4 Lignin 19 Matrix and Process 46 5.4 Aligned Natural Fibre-Reinforced 2.3.2 Hemp Processing 9 3.2 Thermosetting Bioresins 20 Composites 33 7.2 Durability 47 2.3.3 Jute Processing 10 3.2.1 Plant oils 20 6 FULLY BIO-BASED COMPOSITES 34 7.3 End-of-Life Options 47 2.3.4 Further Processing to Optimise 3.2.2 Polyfurfuryl Alcohol 21 6.1 Natural Fibre-Bio-based Polymer 7.4 Sustainability 48 Properties 11 Injection Moulding Compounds 35 3.3 Synthetic-Bio-based Polymer Blends 22 8 CURRENT AND FUTURE 2.4 Fibre Properties 13 6.2 Non-Woven Natural Fibre-Bio-based APPLICATIONS 49 3.4 Properties 23 polymer Composites 36 2.5 Fibre Treatments 14 8.1 Automotive 50 4 BIO-BASED CORE MATERIALS 24 6.3 Aligned Natural Fibre-Bio-based 2.5.1 Physical treatments 14 Polymer Composites 37 8.2 Construction 51 4.1 Cores from Trees 25 Chemical treatments 15 2.5.2 6.4 Natural Fibre-Thermoset 8.3 Sports and Leisure 53 4.2 Bio-based polymer Honeycombs 25 Bioresin Composites 37 2.5.3 Additive treatments 15 8.4 Consumer Products 55 4.3 Bio-based polymer Foams 26 6.5 Future Developments 40 2.6 Other Natural Fibres 16 9 CONCLUSIONS 57 4.4 Nano Cellulose Foams 26 10 ACKNOWLEDGEMENTS 59 4.5 Properties 27 11 GLOSSARY 59 12 REFERENCES 63 TECHNOLOGY OVERVIEW TECHNOLOGY OVERVIEW BIOCOMPOSITES BIOCOMPOSITES LIST OF FIGURES LIST OF TABLES Figure 1: Types of natural fibre, from [3]. 4 Table 1: Typical properties of natural fibres and glass fibres, from [4-33]. 13 Figure 2: Pulling of flax crop (photo used with kind permission of Mr Marian Planik, WFB Baird Poland Sp. z o.o.). 5 Table 2: Properties of bio-based polymers. 23 Figure 3: Cross-section of a bast stem [8]. 6 Table 3: Mechanical properties of bio-based materials used as cores in composite panels. 27 Figure 4: Bale opening at the start of a flax processing line (photo used with kind permission Table 4: Typical properties of WPCs. 39 of Mr Marian Planik, WFB Baird Poland Sp. z o.o.). 7 Table 5: Typical properties of short natural fibre-thermoplastic composites. 30 Figure 5: Production of bio-based materials and products from flax plant. © British Standards Institution (BSI – www.bsigroup.com). Extract reproduced with permission. From [1]. 8 Table 6: Properties of non-woven natural fibre mat composites. 32 Figure 6: Proportions of different products obtained from processing flax (total 5,600 kg/hectare), data from [15]. 9 Table 7: Properties of aligned natural fibre composites. 33 Figure 7: Effect of yarn twist on dry yarn strength and impregnated yarn (composite) strength. Table 8: Properties of natural fibre-bio-based polymer compounds. 35 Minimum yarn strength is 200 MPa. Data from [23]. 11 Table 9: Typical properties of natural fibre-bio-based polymer non-woven mats. 36 Figure 8: A selection of flax reinforcement fabrics (courtesy of Composite Evolution Ltd). 12 Table 10: Typical properties for the EcoPreg material, courtesy of Composites Evolution Ltd. 38 Figure 9: BioMid reinforcement yarn and fabric. A ‘second generation’ bio-based fiber made from Table 11: Properties of natural fibre-bioresin composites. 39 by-products of the lumber industry. Photo by Linda Taylor. 16 Figure 10: Indicative prices of bio-based polymers compared to synthetic polymers, data from [54-57]. 19 Figure 11: Cashew nut shell liquid based Flax Coral Prepreg, produced by CTS, Ohio. Photo courtesy of Elmira Ltd, UK. 21 Figure 12: Granulated cork formed into a sheet, courtesy of Amorim Cork Composites. 25 Figure 13: Indicative prices of PP-NF granules and competing injection moulding materials. Data from [75]. 31 Figure 14: Automotive door panel made from non-woven natural fibre mat with furan bioresin (photo used with kind permission of TransFurans Chemicals). 37 Figure 15: Image of EcoPreg material. From left to right: the woven flax reinforcement, the PFA resin-infused prepreg and finally the finished consolidated material, courtesy of Composites Evolution Ltd. 38 Figure 16: Flax / bioresin / paper honeycomb sandwich by EcoTechnilin. Photo:Stella Job, Materials KTN 50 Figure 17: Pavilion at the Louisiana Museum of Modern Art, Denmark, made from sustainable materials including biocomposites (photo used with kind permission of 3XN, Denmark). 51 Figure 18: A bio-based façade made from hemp and part-bio resin (Gas receiving station clad in biocomposite panels.