FRP Coating Adhesion via Pull-off Fabric Roughening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surface preparation methods for thermal spraying on fibre-reinforced plastic (FRP) components, such as sandblasting, induce strength-reducing damage and do not ensure adequate adhesion of the coating, while existing solutions like complete removal of the polymer matrix are not practical.
Innovation Solution
A method involving the use of a pull-off fabric, mesh, or gauze impregnated with a flowable polymeric matrix material to create a surface with increased roughness, allowing for thermal spraying without exposing the fibres, ensuring improved adhesion and mechanical interengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If sandblasting is used to roughen the surface for thermal spraying, then surface roughness is improved, but substrate strength is reduced due to induced damage
Solution Approach 1:
A mesh structure is placed on the surface before the final resin layer is applied, creating a predetermined roughness pattern that will remain after the mesh is removed. This preliminary action avoids the need for post-manufacturing surface treatment that could damage the substrate.
Solution Approach 2:
The mesh structure serves as a temporary element that is extracted (removed) after serving its purpose of creating surface roughness. The mesh is deliberately taken out after the coating is applied, leaving behind the desired rough surface pattern without the damaging effects of sandblasting.
2Manufacturing precision
If complete removal of the polymer matrix is performed to allow direct fibre-to-coating adhesion, then coating adhesion is improved, but structural integrity is compromised
Solution Approach 1:
The mesh structure acts as an intermediary element between the polymer matrix and the coating. It creates a rough surface that enhances mechanical interengagement while the polymer matrix remains intact, providing both adhesion and structural integrity.
Solution Approach 2:
Surface roughness is created locally at the interface between the mesh and the polymer matrix, rather than removing the matrix globally. This localized modification provides enhanced adhesion points for the coating while preserving the overall structural integrity of the composite material.
3Ease of manufacture
If conventional purchased pull-off fabrics are used, then ease of manufacture is improved, but coating adhesion is insufficient due to inadequate surface roughness
Solution Approach 1:
The mesh structure parameters (opening size, material, thickness) are specifically optimized to create the appropriate surface roughness for thermal spray coating adhesion. This tailored approach improves coating adhesion while maintaining ease of manufacture through a systematic design process.
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
This method enhances the adhesion and strength of the composite component by maintaining a sufficient thickness of the polymeric matrix material, preventing fibre exposure and damage, and allowing for localized surface roughening, thus achieving improved coating quality comparable to sandblasting without the drawbacks.
Implementation Method 1
A flowable polymeric matrix material ought in this case to have a viscosity enabling it to penetrate into interstices of fibres in the textile structure. This may be achieved with pressure assistance. In that case, for example, infiltration may be achieved by means of sub-atmospheric pressure.
Implementation Method 2
Thereafter the polymeric matrix material, more particularly a polymeric resin, is cured, and then the at least one ply of a pull-off fabric, a mesh or a gauze is removed by peeling.
Implementation Method 3
The coating of fibre-reinforced plastic (FRP) by means of thermal spraying is possible only with suitable surface preparation.
Data Source
AI summary
At least one surface of a FRP component is coated by impregnating a structure formed with textile fibres with a flowable polymeric matrix material so the fibres are completely covered to form the coating, a thickness of the flowable polymeric matrix material above the fibres of at least 100 μm and at least one ply of pull-off fabric, mesh or gauze is laid on and wetted or impregnated completely with the flowable polymeric matrix material. The polymeric matrix material is cured then the at least one ply of pull-off fabric, mesh or gauze is removed by peeling and in this region a surface of increased roughness is obtained so between the surface of increased roughness and fibres there is a layer formed with the cured polymeric matrix material, having a thickness of at least 100 μm. Coating the increased roughness surface with a thermal spraying process.