TECHNOLOGY
Test facility for 90 m blades
FORMAX gears up for growth UK MULTIAXIAL reinforcements producer FORMAX is investing in new equipment to meet growing demand for its products. 2010 was a difficult year for many composite companies, but FORMAX saw its sales grow 20%. The company manufactured over 6 million m2 of material for customers serving the wind energy, marine, automotive, sports and industrial markets worldwide. As a result of this growth, FORMAX will invest £1.5 million in new machinery during 2011.
A NEW facility capable of testing wind turbine blades up to 90 m in length will be inaugurated at the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) in Germany this June. The central feature of the test facility will be a tiltable 1000 tonne steel and reinforced concrete mounting block. Hydraulic cylinders used to tilt the block, and additional cylinders to load the blade, will allow the IWES engineers to bend the blade tip of 90 m blades through a distance of 25 m. A test facility for rotor blades up to 70 m long was opened at IWES in Bremerhaven in 2009, but it is not equipped with a tiltable mounting block. “The big advantage of the hydraulic tiltable mounting block is that it allows us to set up the ideal configuration
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for conducting tests with high precision in a minimum amount of time,” says Falko Bürkner, leader of the rotor blade testing team at IWES. The new test facility will also be able to simulate the cyclic forces acting on the blades as they rotate due to the force of the wind. This fatigue loading is simulated in the new facility by a hydraulic cylinder which alternately pushes and pulls on the blade, causing it to vibrate at its horizontal and/or vertical resonant frequencies.
An important part of this year’s investment is the installation of the latest Karl Mayer carbon multiaxial machine – the Carbon Malitronic®. This is the only machine of its type in the world. It has a variable width from 1000 mm to 1600 mm. As FORMAX’s managing director Oliver Wessely points out, given the cost of carbon fibre, the ability to produce fabrics to the exact size required results in huge material cost savings. FORMAX is also investing in a laminating line that combines surface veils with existing fabrics for applications that require high quality surface finishes, such as Class A automotive panels. Wessely points out the diverse range of applications the company has been involved in. These range
from developing quadraxial fabrics for use in Lamborghini’s new carbon composite supercar, to supplying materials for the Dokaae Tower in Mecca – the work’s largest clock tower. On the Dokaae Tower project FORMAX worked with Premier Composite Technologies (PCT) of Dubai to produce the clock hands using carbon prepreg. The clock hands had to be hollow to allow access to the 2000 LEDS embedded into their surface. They were therefore designed as sandwich structures, featuring an outer layer of prepregged glass cloth, a structural laminate of unidirectional (UD) carbon prepreg and secondary reinforcements using FORMAX carbon biaxial fabrics. FORMAX materials will also be used in the tower’s hilal (crescent moon) structure which will measure 23 m. Working with PCT and Gurit UK, FORMAX developed a custom hybrid quadraxial fabric for this, which uses a blend of carbon and glass fibres. Wessely explains that although FORMAX’s business is growing, he wants it to remain a “small company in mindset,” with the flexibility to offer innovative, bespoke materials with quick turnaround times and low minimum order quantities. FORMAX; www.formax.co.uk
A full series of extreme load and endurance tests takes around four months to complete. During this time, the blade is subjected to the same loads that it would normally have to withstand in 20 years of operation. IWES; www-cwmt.cwmt.fraunhofer.de
MAY/JUNE 2011
FORMAX worked with Premier Composite Technologies to create the hands for the clock of the Dokaae Tower in Mecca, the world’s largest clock tower. The clock hands are 22 m and 17 m in length and are made out of carbon prepreg. They weigh 6 tonnes each.
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