What are composites? A short guide to fibre reinforced polymer composites, why they are useful and how they are made COMPOSITES Composites LEADERSHIP Trade Association FORUM Who are we? What is a composite? Composites UK is the trade association for the A composite material is composed of at least two materials, which combine UK composites industry. It acts to encourage to give properties superior to those of the individual constituents. Composites continuous growth and development of the Trade Association industry, promoting good practice. Its role is to This guide refers to fibre reinforced polymer (FRP) composites, usually with bring companies throughout the supply chain carbon, glass, aramid, polymer or natural fibres embedded in a polymer together, creating partnerships, as well as being a unified voice to drive the matrix. Other matrix materials can be used and composites may also industry forward. contain fillers or nano-materials such as graphene. compositesuk.co.uk The many component materials and different processes that can be used make composites extremely versatile and efficient. They typically result in The National Composites Centre (NCC) is a lighter, stronger, more durable solutions compared to traditional materials. research and development centre and is part of the High Value Manufacturing Catapult. The NCC mission is to accelerate the growth of UK industrial output by enabling design and manufacturing Growth in the composites industry enterprises to deliver winning solutions in the application of composites. nccuk.com The composites industry is an exciting industry to work in because new materials, processes and applications are being developed all the time – The Composites Leadership Forum is working like using hybrid virgin and recycled fibres, faster and more automated to influence the government and other bodies COMPOSITES manufacturing. The global composites materials market is growing at (including industry, research centres, academia, LEADERSHIP about 5% per year, with carbon fibre demand growing at 12% per year. skills providers) to bring together support for FORUM With around 1500 British companies involved, the UK composites product composites and ensure growth and industrial market was estimated at £2.3bn in 2015, and could grow to £12bn by 2030i. success for the UK. Fully supported by UK government, the CLF is chaired by industry with members drawn from industry sector groups, government, funding bodies and delivery partners. compositesleadershipforum.com PAGE What is a composite? 3 Growth in the composites industry 3 Why use composites? 4 A short history 6 Materials 7 Manufacturing processes 10 Design, data and automation 15 What about fire? 16 Buildings and rides in the new Ferrari Land theme park near Barcelona use FRP composites cladding and Can composites be recycled? 17 roofing. The FRP parts were moulded using Scott Bader’s ATH filled Crestapol® 1212 resin to meet stringent Do we know how to repair composites? 18 Euroclass fire performance ratings with excellent mechanical performance. Courtesy of Scott Bader Glossary 19 2 3 Why use composites? Weight reduction Added functionality The primary reason composites are Composites are thermal insulators chosen is improved specifi c strength which is good for fi re and blast / stiffness (strength / stiffness protection or cryogenic applications. specifi c per unit weight). Electrical insulation is useful for This helps to reduce fuel use, or railway lineside structures and radar increase acceleration or range in transparency. A conductive mesh transport. or coating can be integrated if needed, e.g. to refl ect radar or divert It allows for easier, faster installation lightning. or faster movement of robot arms and reduces supporting structures Sensors, electronics and cabling can A Ferrari Copper mesh or foil is integrated into the CFRP wing or foundations. be embedded. structure to protect from lightning It improves topside stability in vessels and offshore structures and buoyancy for deep sea applications. Design freedom Composites design allows for freedom of architectural form. Durability and maintenance Many parts can be consolidated into Composites don’t rust, which is one, and stiffeners, inserts, etc. can crucial, especially in marine and be integrated in-mould. chemical environments. The need for maintenance and painting is Composites can be tailored to reduced or eliminated. suit the application by choosing the constituent materials and Composite bearings for marine embedding extra functionality. engines and bridges need no Chanel Pavilion designed by Zaha Hadid lubrication and don’t corrode. comprising of 400 complex curved FRP façade panels. Courtesy of Arup Combine the excellent fatigue resistance, and composites can increase product lifespan by several A FRP walkway on an oil rig after 35 years of being in-situ. Fire resistant and durable, made with “Some things, such as the longest wind turbine blades, the times in many applications. phenolic resin. Courtesy of Pipex px deepest oil risers and the fastest racing cars simply can’t be made without composites.” 4 5 A short history Materials We have been using nature’s The constituent materials, along with the processes by which they are extraordinary FRP composites (such combined, determine the properties of a finished composite part. The most as wood) for many thousands of commonly used raw materials are described here. years. Robert Kemp’s patent filed in 1916, covered “light, strong and Fibres durable” materials for flying machines made from fibrous materials with E-glass is the most widely used binders such as Bakelite. Composites reinforcing fibre. Silica sand, as we know them now began in the limestone and other minerals are 1930s when Owens Corning started melted in a furnace and allowed to to produce glass fibres (‘fiberglas’) fall through tiny holes in a platinum Trabant P50, Dresden 1961. Photo by Richard Peter, and DuPont made a resin to combine Deutsche Fotothek plate to create fibres around 5-24μm with the fibres to make a composite. diameter. As they emerge they are Through the 1940s and ‘50s ‘sized’ (coated to enable handling applications developed for structural and bonding to the matrix), bundled aircraft parts, boat hulls and fishing together to form a ‘roving’, and ii rods . wound directly onto a bobbin. Carbon fibre fabric manufacture. Courtesy of Other types of reinforcing glass Sigmatex In 1941 Henry Ford unveiled his exist for higher strength or chemical plastic car, with panels reportedly resistance. made from soybean and possibly hemp fibres and phenolic resin. It was Carbon fibre is made from a precursor very resilient and a third lighter than fibre, usually polyacrylonitrile (PAN). its steel equivalentiii . A 12ft dinghy This is pyrolysed and converted at produced in 1951 by W&J Tod at high temperature into a graphite Weymouth was probably the first (carbon) fibre about 6-7μm diameter. production boat in Europe, using an Carbon fibres make the stiffest and early Crystic® polyester resin from strongest composites. Scott Baderiv. From 1955 body panels Glass fibre fabric manufacture at Scott and Fyfe for the East German Trabant were Aramid (aromatic polyamide) fibres made from compression moulded An early 1950’s Tod’s dinghy. Courtesy of National such as Kevlar® and Twaron® are Duroplast, a composite of cotton Maritime Museum Cornwall noted for their excellent impact resistance, as well as other properties, and fibres and phenol resins, all from waste materials. are widely used in armour applications. There are other high performance polymer fibres such as UHMWPE (ultra high molecular weight polyethylene) Carbon fibres were developed concurrently in the USA, UK (at Farnborough) and HMPP (high modulus polypropylene). and Japan in the early 1960s. Boeing and Airbus both introduced structural composites in commercial aircraft in the early 1970s. As the global polymer Natural fibres such as flax and hemp are often used in automotive interiors industry matured, it surpassed steel in terms of world production volumes and have good damping properties, which can work well hybridised with in the 1970s. FRP composites have grown alongside this and continue to carbon. Basalt fibres are increasingly used, especially where alkali resistance grow and find new applications. is important. 6 7 Materials continued... Resins Intermediate materials The resins used in composites are Fibres can be incorporated directly in polymers – made of long, chain- some processes, but more often are like molecules. These may be converted into fabrics which may be thermoplastic or thermoset. uni-/ bi-/ multi-axial, woven, knitted, braided, needle-punched or simply Thermoplastics melt when heated chopped and bound into a random- and solidify when cooled. Commonly oriented fabric. Textile engineering used thermoplastics include PP, is an important aspect of optimising PET, nylon, or, for high performance composite manufacture, and 3D applications, PEI or PEEK. preforms are increasingly being used, to align fibres exactly where they will Thermosets are cured by a chemical provide the best properties. reaction when resin and hardener or catalyst are mixed, causing cross-links Composite Integration Ltd supplies resin injection Some fabrics, especially carbon fibre, Shape Machining manufacture 2D and 3D between the polymer chains. They equipment and processing technology for wind are pre-impregnated with resin to preforms in carbon fibre, such as this bike seat, turbine blades. Courtesy of Composite