Weight reduction in the wind industry
The main element of a wind turbine is the blade, which, thanks to its design, is able to rotate under the action of the wind and generate clean, renewable energy. Over the years, wind turbine blades have grown in length in order to generate more energy, and their design has had to be adapted to adjust their weight and optimise their operation. The characteristics of the epoxy resins used in the manufacture of wind turbine blades have evolved towards systems with very low viscosity and long curing times, which allow the manufacturing process to be optimised with the most advanced vacuum infusion techniques.
Blades and nacelles
Epoxy resins for infusion
GAIRESA has managed to develop a whole range of epoxy resins adapted to each production process, with very low processing viscosities and high thermal and mechanical performance: BEPOX® 2086, BEPOX® 2182, among other references.
Structural adhesives for blades
Structural adhesives are a fundamental part in the construction of wind turbine blades, as the different elements that make up the blade must be joined efficiently and durably so that they function as a single body once they are in service.
GAIRESA has developed several ranges of composite adhesives based on 3 chemistries: methacrylate, polyurethane and epoxy.
- The LARBOND® 3001 MMA series is composed of methacrylate adhesives with excellent adhesion and fast curing (from 10 to 60 minutes), effective for bonding metals, plastics, foams, wood and composites.
- The LARBOND® 4001/4003 PU series consists of polyurethane adhesives with high tenacity and adhesion, with adjustable curing speed and functional in extreme climates, due to their good performance in service at both low and high temperatures.
- The LARBOND® 5000 EP series consists of a range of epoxy adhesives covering a wide range of thermal and mechanical properties, including wet or underwater bonding adhesives (LARBOND® 5011 EP), low density machinable fillers (LARBOND® 5014 EP), high tenacity reactive rubber modified adhesives (LARBOND® TI 5003 EP), among others.
Bepox Product features| Epoxy infusion resins
|
|
Viscosity (mPa-s, 20ºC) |
Pot-life (min) |
Tg (ºC) |
Tensile Strength (MPa) |
Elastic Modulus (MPa) |
Compressive Strength (MPa) |
Flexure Strength (MPa) |
|
BEPOX 2193 |
250 |
212* |
80 |
58,5 |
2600 |
85 |
112 |
|
BEPOX 2182 |
340 |
81* |
77 |
62 |
2900 |
82 |
78 |
|
BEPOX 2086 |
320 |
140* |
76 |
55 |
2000 |
70 |
96 |
LarbondProduct features | Structural adhesives for blades (methacrylate, polyurethane, epoxy)
| Pot-life (min) | Tg∞ (ºC) | Tensile Strength (MPa) | Elastic Modulus (MPa) | Tensile Energy to Break (kJ/m3) | Adhesion to steel (MPa) | Adhesion to epoxy (MPa) | Adhesion to polyester (MPa) | |
| LARBOND S 3001 MMA | 60 | 70 | 25 | 1100 | 700 | 19 | 10 | 15 |
| LARBOND M 3001 MMA | 30 | 70 | 21 | 920 | 675 | 19 | 10 | 15 |
| LARBOND 4003 PU | 50 | 50 | 28 | 2000 | 3500 | 11 | 6.5 | |
| LARBOND 5000 EP | 60 | 70 | 31 | 1515 | 7 | 16 | ||
| LARBOND HI 5003 EP | 180 | 70 | 31 | 1820 | 635 | 18.5 | 10.2 | 13.7 |
Protective coating for blades
The blades and other elements of the wind turbine need to be protected from the elements and from particles carried by the wind. For this purpose, high performance coatings must be used, capable of resisting the impact of solid particles and water droplets at high speed, of withstanding solar radiation and the salty environment in coastal areas, which accelerates the corrosion of metals. Innovation in this type of coatings is essential, as the existing solutions on the market do not always meet the expectations generated, mainly in critical areas such as the leading edge of the blades. GAIRESA is aware of this and has therefore developed systems based on aliphatic polyurethanes, with high impact resistance and excellent stability and resistance to ageing in environments with extreme radiation and salinity. GAIDUR® P is a solvent-based protective coating and GAIDUR® NANOCLEAR COATING is a 100% solid coating of high thickness, specially developed to meet the most demanding requirements.
GAIRESA’s range of products for the wind energy sector is completed with our GAIBRIDGE® bonding bridges, to ensure adhesion between resin layers when working with parts that have been manufactured for a long time, for example, in a reparation.
Gaidur Product Features | Blade Protection
|
|
|
Impact Resistance |
Wear Resistance |
|
GAIDUR P COMPOSITES |
2K Polyurethane solvent-borne |
> 29,4 N·m |
11,8 mg |
|
GAIDUR NANOCLEAR COATING |
2K Polyurethane high thickness (no solvent) |
14,7 N·m |
8,3 mg |
Towers and foundations
The blades and rotor are the most complex parts of a wind turbine, but both the tower and the foundations are also structural elements that have to withstand high mechanical stresses and harsh weather conditions. Therefore, these elements must be adequately protected with high performance coatings that extend their durability, avoiding the need for frequent maintenance operations.
Epoxy chemical anchoring for concrete tower segments
Many of these concrete towers are built with prefabricated pieces called dowels, which are fitted one on top of the other, anchoring them with special mortars and adhesives: GAIRESA has developed, in collaboration with one of the largest manufacturers of wind turbines in the world, an epoxy adhesive capable of reaching seismic level resistance after only 90 minutes after its application. This structural adhesive, certified with the CE Mark EN 15274, is called BEPOX® 2226 (in two versions, one very fast and the other ultra fast).
Epoxy resin injection to repair cracks in foundations.
Finally, the wind energy industry frequently suffers from the problem of cracks in foundations, which appear due to the enormous stresses that the foundations have to withstand when the wind turbine is rotating. To restore structural continuity to the foundations, low-viscosity epoxy resin must be injected, such as BEPOX® 626, a product that GAIRESA has been producing for more than 30 years with great success in the repair of large structures all over the world and which is certified with the CE mark for concrete injection (EN 1504-5).. In the last decade, hundreds of tonnes of BEPOX® 626 have been successfully injected into wind farms around the world.
Waterproof coating
GAIRESA has 100% waterproof coatings for concrete towers and foundations, such as BEPOX® ELASTIC and BEPOX® 3rd PHASE, both certified with the CE mark for concrete protection (EN 1504-2).
Anti-corrosion coating on metal towers
In the case of metal towers, GAIRESA’s anti-corrosion coatings comply with the most demanding standards: BEPOX® TP/Zn and GAIDUR® P form a tandem that is hard to outperform.
Bepox product features | Waterproof and elastic coating
- Waterproof and elastic coating
| Elongation to Break | Impact Resistance | ||
| BEPOX ELASTIC
|
Water based waterproofing coating | 960 % | > 20 N·m |
| Bepox 3rdPhase
|
Water based acrylic elastic paint | 430 % | > 20 N·m |
- Epoxy chemical anchoring for concrete tower segments
| Pot-life (min) | Tg∞ (ºC) | Tensile Strength (MPa) | Elastic Modulus (MPa) | Compressive Strength (MPa) | Flexure Strength (MPa) | |
| BEPOX 2226-10C | 10 | 67 | 42 | 4100 | 85 | 81 |
| BEPOX 2226-20C | 12 | 67 | 42 | 4000 | 86 | 78 |
- Anti-corrosion coating on metal towers
| Gaibridge 11 |
Water-based bonding bridge Protects the metal against corrosion and multiplies the adhesion of coatings from our BEPOX, GAIPOX and GAIDUR resin ranges. |
| Bepox TP ZINC | Passivating epoxy primer For corrosion protection of metal structures. One-component zinc-rich epoxy resin |
- Epoxy resin injection to repair cracks in foundations.
BEPOX 626
