Sunday, November 28, 2010

Prepregs: Oppourtunites Ahead

Prepregs are ready to use material to produce composite parts wherein matrix resin is impregnated into the reinforcing fibre along with the curing agent and additives; impregnated reinforcements mainly make three forms : unidirectional tape (0o orientation), woven fabrics, and roving.Prepregs are classified as thermoset prepregs and thermoplastic prepregs,but thermosets are the most prevalent,with the epoxy, phenolic, Vinyl ester,bismaleimide, and cynate ester resins while high-performance thermoplastics such as polyether ether ketone (PEEK) and polysulfone (PS) are also used to produce prepregs. Further it is classified by aerial weight as grammes per square metre (g/m2) or ounces per square yard (oz/yd2). The materials are also grouped by c u r e temper a t u r e : room temperature, 250°C and 350° C. Prepregs generally comes in a rolled and flat sheet form in a thickness range of 0.127 mm (0.005”) to 0.50 mm (0.02”) from var ious combinat ions of reinforcement fibres and matrices in a partially cured (B-stage) form. This difference is based on type of resins used. Reinforcements in prepreg can be glass, graphite, carbon, and aramid, and are used in filament or woven fabric form in either of these prepregs. 
Prepregs are used in a wide range of applications such as aerospace, defense and military, railway, marine, wind energy, printed circuit boards, sporting good items, medical components and industrial products. The advantages of prepreg materials over metals and conventional materials are higher specific strength, higher specific stiffness, longer shelf life, low requirements of refrigeration for storage, excellent corrosion resistance, lower fabrication cost and faster production  rate . The major disadvantage of prepregs material is initial higher cost and moderate volatile organic compounds (VOCs) emission. The Products made with prepreg materials cure at lower temperatures without the need for autoclave techniques and autoclave, layup, vacuum bag, and pressure bag processing techniques are used to consolidate and cure prepreg materials after placement in a tool or onto a mandrel which leads to higher fiber volume fraction. The choice of processing method is determined by the cost, quality and type of component being manufactured.Vacuum bag processing is suited to components with thin sections and large sandwich structures while autoclave processing is used for the manufacture of superior quality structural components containing high fibre volume and low void contents.
The prepregs are used in multiple applications but the majority of uses come from aerospace (63%), industrial market (25%), sporting goods & leisure (12%). The phenolic prepreg is used for aerospace, marine and mass transit interior applications while epoxy is predominantly used in printed circuit board industry where flame/ smoke/ toxicity (FST) performance required. Epoxy and polyester prepregs are suitable for radome and antenna applications due to excellent dielectric performance. Carbon, epoxy, phenolic, BMI, PEEK, PS, and cynate ester prepregs are used for the aerospace's primary structures such as empennage, vertical tail, radome, antenna, horizontal stabilizer, fuselage including aft, middle and centre, skins, stringers, stiffeners, spars for the main wings and wing boxes, wing tips, cargo and access doors. Prepregs provide good structural properties, excellent dimensional stability, low coefficient of thermal expansion (CTE), net shape molding, better fatigue performance than most metals, with lower weight and no need for fiberglass galvanic corrosion barrier plies. Cytec and Hexcel are the largest carbon prepreg suppliers to the aerospace industry as carbon prepreg is being used for the parts fabrication of Boeing 787 Dreamliner. In FY 2009, Hexcel is awarded a contract worth about US$4 billion through 2025 to supply primary structure prepreg for the Airbus A350 XWB aircraft. Carbon fiber prepreg is being used in sporting goods & leisure items such as motorcycle wheels, rim, integral spokes and structural components which represent a typical weight saving of 40 to 50 percent over their conventional aluminium counterparts, with no decrease in strength as well as stimulates lighter bike, reduce fatigue, and lower moment of inertia. Prepregs application in wind energy sector is started foothold due to production of longer rotor blades that demand lighter weight. For thick laminate sections in the production of spar caps of wind turbine blades, prepreg is used. The other use of prepreg is in composite tooling for the construction of lightweight tools for fabrication of smaller and midsized components due to theirs heavy aerial weight properties, excellent dimensional stability and upto 1000 cycle tool production. Norplex-Micarta manufactures ballistic prepreg for ballistic applications to achieve five levels of bullet resistance range from ¼ to 1-3/16 inches (6.35-31.2 mm). The use of prepregs is also growing for automotive applications for body parts and interior components.
Market Analysis
Global prepregs industry has been growing at a rate of around 12% annual average growth rate (AAGR) since 2004 while robust demand has fueled prepreggers to increase production capacity. The leading prepregs suppliers are Hexcel, Advanced Composites Group (ACG), Toray, Cytec, Gurit, and TenCate Advanced Composites, among them Hexcel, Toray, and Gurit are building new capacity to meet the increased demand. The key drivers for the growth trend are aerospace, military and defense, wind energy, ocean, automotive, and emerging industrial end use applications. In fact, 50% composite material is used in the production of the Boeing 787 primary structure by weight primarily made of prepreg that tells itself growth story. In the prepreg industry, Hexcel has largest market share just before Cytec whereas Toray is preceded by Gurit. The top 3 suppliers are having 70% market share of the total prepreg market. The wind energy market fuels prepregs growth as in FY 2009 prepreg market grew in double digits for wind energy.Gurit has largest market share in the wind energy prepreg while in the aerospace market, Hexcel retains number one podium. Toray is the number one supplier of prepreg to the sporting goods and industrial market and sells significant amounts of prepregs to various sub sectors such as golf shafts, bicycles, fishing rods, and rollers. ACG has a limited product range mainly suitable for the industrial market. Examples of such niche markets are race cars, tooling prepreg, and automotive. ACG dominates in these three markets and captures maximum market share in these markets.
The prepregs demand will higher peak due to strong demand continuing from aerospace, defense & military and wind energy sector. The critical success factor for prepreg producers will application specific products, and customer focused solutions. Over the next decade prepregs application will secure a good position in alternative energy, high performance automobiles, construction and infrastructure end use applications.