The system consists of five major components: wind turbine blades, hub assemblies, nacelle (gearbox/generator), tower structure and foundation, and electronic pitch control system. It employs five distinct adhesive categories—structural bonding, sealing protection, potting thermal insulation, threaded fastening, and repair adhesives—to withstand harsh operating conditions including land-based wind-sand exposure, offshore salt spray, temperature cycling, and prolonged vibration fatigue.

1. Fan Blade System (the component requiring the largest amount of adhesive for wind power applications)

The blade body is constructed from fiberglass/carbon fiber composite material, designed to withstand year-round exposure to strong winds, bending forces, ultraviolet radiation, rain, salt spray, and lightning strikes. Key requirements include high fatigue resistance, low shrinkage, UV resistance, resistance to sagging, and excellent toughness.

Select all adhesive application points and the appropriate adhesive type.

table

Use glue point position	Adhesion Position	Glue Type	key role	Hard Requirements for Performance	Recommended gel system (imported + domestic)
1 Main housing mold bonding	The upper and lower half of the blade housing are joined together.	Two-component toughening epoxy structural adhesive (specifically designed for wind power applications)	Responsible for overall load-bearing and transmitting wind loads; serves as the core safety component of the entire structure.	Shear strength ≥22 MPa; resistance to thermal cycling (-40°C to 85°C); fatigue resistance of millions of cycles; thixotropic properties with anti-sag behavior.	Imported: Araldite 2031; Domestic: Zhijiang ZJ-EP821, Xinai HNEP6220G
2 Main beam + web plate bonding	The internal main beam, web plate, and outer shell are bonded together.	High-toughness epoxy structural adhesive	Internal load-bearing framework bonded to distribute bending stresses	High fracture elongation, low internal stress	Wind-resistant, toughened epoxy resin suitable for filling thick adhesive joints
3 Leaf segmentation adhesive	The ultra-long blades, each exceeding 90 meters in length, are assembled on-site in segments.	Epoxy joint adhesive that can cure at room temperature	Long-distance transportation is divided into separate segments, with on-site assembly carried out in an integrated manner.	Long operational lifespan, resistance to seawater salt spray, and low water absorption rate	Specialized segmented bonding epoxy adhesive
4 Filling of luminal spaces	Internal cavities and corner gaps within the housing	Epoxy filling putty / Epoxy potting compound	Eliminate cavities, prevent water accumulation, and avoid vibration-related abnormal noises.	Low shrinkage, self-leveling/tixotropic optional	Epoxy filling paste
5 Rear Edge / Front Edge Protection	Wing edge facing the wind, tail edge	Polyurethane elastic sealant	Resistant to wind-sand erosion, UV radiation, and impact buffering	High elasticity, wear-resistant, weather-resistant, and UV-resistant	Polyurethane weather-resistant sealant HNPU7003
6 Bonding of metal pre-embedded components	Flange at the root of the leaf; pre-installed metal bolts	Epoxy structural adhesive + Anaerobic retention adhesive	The metal is firmly bonded to the glass fiber, preventing loosening of the embedded component.	Heterogeneous materials exhibit high bonding strength.	Epoxy resin + threaded locking adhesive combination
7 Leaf repair locations	Surface cracks, dents, and layered repairs	Oxygen Repair Adhesive (Two-Component)	On-site repair and reinforcement of damaged areas during operation and maintenance	Quick-curing, suitable for outdoor application, water-resistant	Specialized repair epoxy: ZJ-EP821R
8. Bonding of lightning protection diversion strips	Copper lightning protection strip on the surface of the blade	Weather-resistant epoxy/organosilicone rubber	Fixed lightning protection components with insulating and weather-resistant properties	Insulation, lightning resistance, high-temperature tolerance, and outdoor aging resistance	Insulating epoxy; transparent silicone

II. Hub and Pitch Bearing Assembly (Blade-Cabin Connection)

Operating conditions: continuous alternating vibrations, significant diurnal temperature variations, and high salt spray exposure at sea, making fasteners highly susceptible to vibration-induced loosening.

1. Blade – Hub flange bolt: Adhesive used – High-strength anaerobic thread locking adhesive (red high-strength). Functions – Prevent loosening due to prolonged vibration, provide rust-proof sealing; serves as a anti-clogging agent for marine applications to avoid bolt seizure in later stages.
2. Sealing compound for the outer ring of the pitch control bearing: Polyurethane elastic sealing compound / Oil-resistant silicone sealing compound. Function: Seals bearing gaps and prevents leakage of rainwater, salt mist, and lubricating oil.
3. Sealant for wheel hub end cover: RTV silicone flat sealant; replaces traditional rubber gaskets.
4. Gel used for securing sensors and wiring harnesses inside the wheel hub: room-temperature curing epoxy or flexible silicone adhesive.

III. Nacelle Assembly (gearbox + generator + nacelle cover – the most adhesive-intensive area for wind turbines)

3.1 Gearbox (high load, exposure to lubricating oil, high temperature)

1. Flanges on the upper and lower housing bodies of the gearbox, as well as maintenance cover plates: polysulfide sealant / oil-resistant polyurethane sealant / liquid anaerobic gasket adhesive. Advantages: resistant to prolonged exposure to gear oil and withstands oil temperatures up to 120°C; replaces rubber gaskets to eliminate oil leakage.
2. For gear bearings, bushings, and shaft mating surfaces: use anaerobic adhesive (specifically designed for bearings) to fill metal clearance gaps, prevent displacement of inner or outer rings during vibration, and enhance load-bearing capacity.
3. YouTube hydraulic joint thread: PTFE threaded sealant/gas-tightening adhesive for preventing hydraulic oil leakage.

3.2 Generator (Permanent Magnet Direct Drive/Dual-Feeding, with insulation, thermal conductivity, and moisture resistance as core features)

1. Rotor permanent magnet bonding: Acrylic structural adhesive / High-temperature resistant epoxy adhesive for permanent fixation of magnetic steel, capable of withstanding motor operating temperatures and resisting centrifugal detachment.
2. Stator winding slot filling: thermal conductive epoxy encapsulant or flame-retardant silicone encapsulant; provides insulation, moisture resistance, heat dissipation, and corona protection; flame-retardant silicone is preferred for offshore models.
3. Seam joint of the generator housing: weather-resistant neutral silicone sealant provides all-weather waterproofing and dustproofing for outdoor use.
4. Thermal conductive filling for the heat dissipation surface: thermal gel or thermal epoxy (TIM thermal adhesive) to eliminate heat dissipation gaps between metal components.

3.3 Engine compartment enclosure (FRP engine compartment shell)

1. Fiberglass reinforced plastic splicing for cabin cover: modified epoxy structural adhesive; polyurethane structural adhesive used in lightweight sections.
2. Cabin doors, ventilation openings, and observation windows: weather-resistant silicone sealant with tolerance to extreme temperatures ranging from-50°C to 180°C.
3. Cabin bracket and metal components bonding: methyl methacrylate (MMA) adhesive for rapid bonding of metal and fiberglass reinforced plastic.

IV. Tower cylinder, tower base, and foundation (steel cylindrical structure, fully exposed outdoors, subjected to salt spray, freeze-thaw cycles, and strong winds)

4.1 Tower Section Flanges (End-to-end flanges between upper and lower sections of the steel tower cylinder)

1. Flange surface sealing: Polyurethane flange sealant and silicone weather-resistant sealant, designed to accommodate minor flange deformation while providing waterproofing, rust prevention, and protection against seawater salt mist penetration into bolt holes.
2. Main tower connection bolts: medium-to-high-strength threaded locking adhesive + rust-resistant lubricating anti-clogging grease; for onshore applications, medium-strength detachable type; for offshore applications, high-strength permanent locking type.
3. For tower cylinder manholes and pipeline openings: use one-component polyurethane sealant.

4.2 Tower Base (Concrete Foundation)

1. Ground bolt sleeve grouting: using epoxy grout material with high strength and no shrinkage to secure the pre-installed anchor bolts in the tower cylinder.
2. Gap between the concrete at the tower base and the steel foundation: filled with epoxy sealant or polyurea sealant to prevent groundwater infiltration.
3. Cable tray fixation on the inner wall of the tower tube: epoxy structural adhesive used to bond the cable tray to the metal support structure with concrete.

4.3 Anti-corrosion gaps inside the tower cylinder

All weld seams and cable pass-through holes shall be sealed with three-way polyurethane sealant providing protection against moisture, mold, and salt spray.

V. Electronic Control System (Control Cabinet, Converter, Sliding Rings; Insulation with moisture-proof and flame-retardant properties; Encapsulation)

1. Power module and IGBT heat dissipation: thermal conductive epoxy and thermal conductive silicone gel, providing both insulation and heat dissipation.
2. Circuit board and sensor encapsulation: flame-retardant silicone encapsulant (two-component addition-curing silicone rubber) resistant to extreme temperatures, providing insulation and shock resistance, as well as protection against condensation and salt spray corrosion in marine environments.
3. Seam between the control cabinet door and the cabinet body: weather-resistant silicone sealant.
4. Waterproofing of wiring harness joints: polyurethane potting compound, silicone sealant.
5. Internal seal of the slip ring: low-friction silicone sealing grease combined with elastic sealing compound, providing wear-resistant and waterproof performance during rotation.

VI. Comprehensive Performance Comparison and Selection Table for the Four Main Types of Adhesives Used in Wind Power Applications

table

Seedling root	Key Advantages	short slab	The precise locations for installing wind power systems
Two-component toughening epoxy	High strength, fatigue resistance, chemical resistance, and low creep	Hard in texture; prone to cracking due to excessive deformation	Bleed body bonding, embedded components, tower foundation grouting, metal repair
Polyurethane (PU) adhesive	Excellently elastic, impact-resistant, UV-resistant, and seawater-resistant.	The intensity is lower than that of epoxy.	Blade leading-edge protection, dynamic flange sealing, cabin elastic joint
Silicone	Resistant to extreme temperatures; features optimal insulation properties; suitable for use on weather-resistant ceilings.	The adhesive strength is average; it bonds well to mortar.	Engine compartment sealing, motor potting, electrical control insulation, outdoor static sealing
Anaerobic adhesive (for threads/holds)	Metal缝隙 sealing, oil-resistant, shockproof and anti-loosening	Adhesive only for metal; not suitable for plastic or fiberglass.	All cabin bolts, bearings, and hydraulic pipelines have been securely fastened and sealed.
MMA methyl acrylate	Extraneously rapid curing; suitable for both metals and glass fibers; water-resistant.	The odor is quite strong.	Quick assembly of cabin hardware components and fiberglass-based small parts

VII. Different Requirements for Adhesive Materials Between Onshore Wind Power and Offshore Wind Power

1. Onshore wind power (subject to wind-blown sand and significant temperature fluctuations): Priority requirements include UV resistance and resistance to sand erosion; blade edges require PU adhesive, while tower bodies require weather-resistant silicone; standard epoxy resin is sufficient.
2. All offshore wind power installations (characterized by high salt mist, high humidity, and significant day-night temperature variations) have been upgraded:
3. Use a seawater-resistant modified epoxy formulation to reduce water absorption.
4. All seals are upgraded to salt spray-resistant polyurethane or marine-grade silicone.
5. All bolts come standard with locking mechanisms and corrosion protection.
6. The motor and electronic control components must be sealed with flame-retardant, hydrolysis-resistant silicone compound.
7. The long-term marine use of conventional polysulfides is prohibited due to their susceptibility to hydrolysis.