Enhanced glass reinforcements for wind turbine blade manufacture

Reinforced Plastics asked Onur Tokgoz, Wind Energy Global Business Leader at 3B-the fibreglass company, about the company’s activities in the wind energy market and its new glass reinforcement for wind turbine blade manufacture, Advantex® SE2020.

Typical SE2020 relative properties vs. current sizing in unidirectional (UD) epoxy laminate. (Source: 3B.)
Typical SE2020 relative properties vs. current sizing in unidirectional (UD) epoxy laminate. (Source: 3B.)

Reinforced Plastics: How does 3B determine the needs of wind turbine blade manufacturers, and what are these needs today?

3B: One of the pillars of 3B’s strategy is to be a key wind energy solution provider. Since 3B was formed, we have been investing heavily in R&D and resources to better understand the wind energy market.

To determine the needs and the challenges that wind blade manufacturers are confronting, 3B has been focusing on the entire value chain by creating a loop between the raw material manufacturers and the OEMs (wind turbine manufacturers in this case). We are in very close contact with all upstream parties linked to the wind turbine manufacturer, including the blade manufacturers and designers (vertically integrated or independent), weavers and resin manufacturers.

In recent years, the wind energy market has been facing several challenges, one of them being bigger turbines. Multi-megawatt (MW) and therefore bigger turbines are almost a standard design nowadays due to the rapid growth of the offshore wind power market. The need for bigger turbines brings the need for longer blades. Since blade lengths have been significantly increasing the challenges for designers have become more significant as well such as blade weight, stiffness and performance. These challenges have triggered designers to search for better performing and enhanced raw materials to respond to their needs for the reinforcement of longer blades.

Reinforced Plastics: How is 3B answering these needs?

3B: By combining state-of-the-art Advantex glass fibre technology together with an expert understanding and a very competitive savoir-faire of sizing technology 3B is able to offer enhanced material solutions which respond to the needs of wind blade manufacturers.

Furthermore, by working hand in hand with the entire value chain of the wind energy market, 3B has been able to identify and resolve the need for improving the existing sizing technology for epoxy resin systems.

At 3B, we strongly believe wind energy will play a key role in the need for efficient power generation that is clean, reliable and cost effective, especially in light of the recent announcements concerning the reduction and eventual elimination of our dependence on nuclear power. To meet future needs and help reduce the cost per kWh, larger multi-MW turbines will become the norm, but these will require improved blade designs with enhanced materials to ensure their efficiency and productivity.

Reinforced Plastics: How was the Advantex SE2020 roving developed, and what are its benefits over other products?

3B: Advantex SE2020 is a new single-end roving specifically engineered for epoxy polymer systems utilised in resin infusion or prepreg processes.

At present multi-compatible reinforcements are commonly used with different resin systems such as epoxy, unsaturated polyester, vinyl ester, etc. However by developing innovative and proprietary sizing technology focused on a specific resin family (epoxy), 3B is changing the rules of the game. By optimising the coupling of the reinforcement uniquely for epoxy resin systems 3B thereby achieves best-in-class composite properties.

Compared to conventional materials in the market place (see chart), 3B’s new Advantex SE2020 roving for epoxy resin systems offers better wet out, therefore providing a more consistent laminate quality, a significantly improved resin matrix adhesion which delivers higher shear strength, and substantially greater interfibre strength. This, together with the resulting enhanced fatigue performance, makes the SE2020 roving the solution that designers need to greatly improve existing blades and, more importantly, to create the next generation of epoxy turbine blades.

Advantex SE2020 roving has been designed specifically for epoxy resin applications in the wind energy market. However, its attractive properties and superior mechanical performances together with very good hydrolysis resistance and inherent corrosion resistance will be of interest to many other epoxy resin composite structural applications such as pressure vessels, pipes, leaf springs, tidal turbine blades, etc.

Reinforced Plastics: What other resin-specific reinforcements will 3B be introducing?

3B: Aligned with our strategy to be a key wind energy solution provider, 3B is pursuing efforts to bring to market additional new and enhanced reinforcement materials for wind turbine blades. These new developments to be introduced during the first half of 2012 will include both resin specific and high-performance properties such as high modulus glass for longer, lighter and stiffer blades especially designed for multi-MW offshore turbines.

Reinforced Plastics: How does 3B see the processes used in wind blade manufacture changing over the coming years?

3B: Due to the ever-evolving needs of the wind energy market, primarily driven by the growth in the offshore wind market, the technologies used will also need to evolve.

Glass fibre is and will remain essential for the wind power industry going forward.
Onur Tokgoz, Wind Energy Global Business Leader, 3B

The production of bigger components is leading to developments in processes and automation.

However, glass fibre is and will remain essential for the wind power industry going forward. Today, glass fibre represents a significant portion of the raw material making up a wind turbine blade with up to 70% of blade weight. Even in the case of carbon spar-cap blades, this ratio will not be lower than 45-50%.

Finally, due to the cost-performance ratio, glass fibre is the preferred option for the longer blades needed for offshore turbines and for multi-MW onshore turbines. ♦  

 This interview is part of the feature Wind turbine blade production – new products keep pace as scale increases, which was published in the January/February 2012 issue of Reinforced Plastics magazine.