Wind Turbine Blade Spar Cap Bonding With Heat-Activated Silane Primer

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Solution Overview

Problem

Existing methods for bonding wind turbine blade components, particularly the spar cap with the shell, face challenges such as reduced adhesion strength due to moisture-reactive primers, high flammability, dusty work environments, and health risks, necessitating improved methods for stronger and safer adhesion at reduced costs.

Innovation Solution

A method involving a silane-containing primer composition is applied to the spar cap surface, followed by heat activation, and then co-infused with resin to form a spar-cap reinforced wind turbine shell member, enhancing bond strength and eliminating the need for surface grinding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If known isocyanate-based primers are used to improve adhesion, then adhesion strength increases, but the primer reacts with moisture in the air reducing efficacy over time and requiring critical time control

Engineering Contradiction:

Improveadhesion strengthVSAvoidprimer efficacy stability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the primer from isocyanate-based to silane-based chemistry. This fundamental parameter change allows the primer to maintain stability in humid conditions while still achieving strong adhesion to the spar cap surface, eliminating the time-critical window problem associated with isocyanate primers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite primer system combining silane compounds with specific resins (polyester, vinyl ester, or epoxy). This composite approach creates a primer that simultaneously provides moisture resistance, adhesion promotion, and extended pot life, resolving the contradiction between strength and reliability.

Inventive Principle:

Principle #40Composite materials

2Strength

If known primers are used, then adhesion is improved, but the flash point is low implying high flammability and work hazards

Engineering Contradiction:

ImproveadhesionVSAvoidflammability

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition of the primer system to silane-based chemistry, which inherently has a higher flash point than isocyanate-based primers. This parameter change reduces flammability and associated work hazards while maintaining adhesion performance.

Inventive Principle:

Principle #35Parameter changes

3Strength

If prior grinding of spar cap surfaces is performed, then adhesion is improved, but the work environment becomes dusty and noisy with associated health risks

Engineering Contradiction:

ImproveadhesionVSAvoiddust and noise

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical grinding process with a chemical treatment approach using silane-based primer. Instead of mechanically abrading the spar cap surface to improve adhesion, the silane primer chemically bonds to the surface, achieving strong adhesion without generating dust or noise.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Quantity of substance

If polyester resin is used for spar cap bonding, then cost is reduced, but adhesion properties are low compared to vinyl ester and epoxy resin

Engineering Contradiction:

ImprovecostVSAvoidadhesion properties

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The patent introduces a silane-based primer as an intermediary layer between the polyester resin and the spar cap surface. This primer acts as a bridge that enhances the bonding interface, allowing cost-effective polyester resin to achieve adhesion properties previously only attainable with more expensive vinyl ester or epoxy resins.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method achieves up to five times higher bond strength and improved fracture toughness between the spar cap and shell, providing a safer, more efficient, and environmentally friendly manufacturing process.

Implementation Method 1

the primer composition comprises a silane compound

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

applying heat to the primer-treated surface of the spar cap member to provide an activated surface

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

The method achieves up to five times higher bond strength and improved fracture toughness between the spar cap and shell

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS20250319673A1Method of improving the adhesive bonding of wind turbine blade components

Publication Date: 2025.10.16 LM WIND POWER AS

AI summary

A method is provided of manufacturing a wind turbine blade shell member (36, 38), the method comprising the steps of providing a blade mould (96) for the blade shell member, arranging one or more layers of fibre material in the moulding cavity to provide a fibre layup (97), and providing a pre-manufactured spar cap member (62). The surface of the spar cap member is treated with a primer composition to provide a primer-treated surface. Heat is then applied to the primer-treated surface of the spar cap member to provide an activated surface, for improving the bonding in a subsequent resin co-infusion of the spar cap member and the fibre layup.