Bonded Patches With Perforations And Spacers For Controlled Adhesive Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bonding processes face challenges in achieving consistent bond line thickness and reducing porosity in adhesive bonds, especially in field applications where specialized equipment and skilled technicians are not available, leading to inconsistent results.
Innovation Solution
A method using spacers to control adhesive thickness and limit compaction, combined with perforations in the patch to allow air and excess adhesive escape, enabling uniform adhesive application and curing without requiring high installer skill.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pressure is applied to control bond line thickness, then adhesive thickness can be controlled to some degree, but determining and applying the exact pressure uniformly across the patch is difficult
Solution Approach 1:
A compressible layer is introduced as an intermediary between the patch and the structure. This layer acts as a mediator that automatically controls the bond line thickness through its compression characteristics, eliminating the need for complex pressure control systems while achieving uniform adhesive thickness across the entire patch area.
Solution Approach 2:
The solution changes the approach from controlling pressure to controlling the compression of the intermediate layer. By selecting an intermediate layer with appropriate compression characteristics (compressibility, thickness, material properties), the bond line thickness is controlled through material parameter selection rather than complex pressure regulation.
2Manufacturing precision
If pressure is applied during bonding, then adhesive thickness can be controlled, but porosity and voids in the bond are not eliminated
Solution Approach 1:
The compressible intermediate layer serves as a mediator that uniformly distributes compression forces across the patch area. This uniform compression eliminates air pockets and voids while maintaining consistent adhesive thickness, thereby reducing porosity without compromising thickness control.
Solution Approach 2:
The compressible layer is placed beforehand between the patch and structure to cushion and distribute the bonding pressure uniformly. This pre-positioned cushioning element prevents the formation of voids and ensures even adhesive distribution before the bonding process completes.
3Manufacturing precision
If film type adhesives of constant thickness are used, then bond line thickness is controlled, but special handling is required such as refrigeration
Solution Approach 1:
Instead of using expensive film adhesives that require refrigeration and special handling, the solution employs a simple compressible intermediate layer that can be readily disposed of or reused. This eliminates the need for complex storage and handling requirements while achieving the same bond line thickness control.
Solution Approach 2:
The solution changes from using pre-formed constant thickness film adhesives to using a compressible layer whose thickness is controlled through compression. This parameter change eliminates the need for refrigerated storage and special handling while maintaining precise bond line thickness control.
4Adaptability or versatility
If bonding is performed in the field without specialized equipment, then mobility is improved, but consistent and repeatable results are difficult to achieve
Solution Approach 1:
The solution employs simple, inexpensive components including a compressible intermediate layer and basic bonding equipment that can be easily transported and used in field conditions. These disposable or reusable simple components eliminate the need for specialized laboratory equipment while maintaining consistent bonding results through the self-regulating compression mechanism.
Solution Approach 2:
The compressible intermediate layer provides self-regulating compression during bonding, automatically controlling adhesive thickness and uniformity without requiring skilled operators or complex equipment. This self-service mechanism ensures consistent and repeatable bonding results even when performed by less experienced technicians in field conditions.
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 approach allows for consistent, repeatable bonding results with controlled bond line thickness and reduced porosity, facilitating quick and effective patch installation in field conditions.
Implementation Method 1
pressing the patch against the tank
Implementation Method 2
adhesives may be used to bond patches to a structure
Implementation Method 3
pressure along with heat is applied to the patch in order to cure the adhesive
Data Source
Figure 1~2A
Figure 3
Figure 4~6
AI summary
A patch is used to rework an area of a structure. The patch is bonded to the structure by a layer of adhesive and may have perforations to allow escape of air and/or excess adhesive. A spacer placed between the patch and the structure is used to control the thickness of the adhesive and/or a bondline.