Composite Layup Forming With Vacuum Control for Wrinkle Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods of forming composite materials, such as dry carbon fabrics and non-crimped fabrics, often result in inconsistencies like wrinkles due to the bulk of the materials and limitations in tooling options.
Innovation Solution
A method involving a composite layup sealed in a vacuum envelope, formed onto a tool under vacuum, with controlled vacuum levels and heating to reduce wrinkles, using sweepers like inflatable bladders or compliant wipers to apply pressure and maintain shape, followed by resin infusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry composite fabrics are formed into a part shape before infusion and cure, then the composite structure can be manufactured, but wrinkles and inconsistencies are generated during forming
Solution Approach 1:
The composite layup is debulked in advance within the vacuum envelope before forming, removing excess bulk and potential wrinkle sources prior to the shaping operation. This preliminary debulking action prevents wrinkles from forming during the subsequent forming process.
Solution Approach 2:
Vacuum pressure is applied through the vacuum envelope during forming to hold the composite layup against the tool. The controlled vacuum pressure ensures uniform contact and prevents wrinkle formation while maintaining the ability to form complex shapes.
2Manufacturing precision
If the bulk of dry composite fabrics is reduced, then forming quality improves, but the complexity of the forming process increases
Solution Approach 1:
The vacuum envelope serves multiple functions simultaneously: it debulks the composite layup, applies vacuum pressure during forming, and maintains the formed shape. By combining these operations in a single apparatus, the process complexity is reduced despite the multiple functions performed.
Solution Approach 2:
The vacuum level within the envelope is dynamically adjusted during the process - initially lower vacuum for debulking, then increased vacuum for forming and shape maintenance. This parameter change allows optimization of each process stage without requiring separate equipment.
3Manufacturing precision
If composite layup is held under vacuum during forming, then wrinkles are reduced, but the control of vacuum levels becomes more complex
Solution Approach 1:
The vacuum level is dynamically adjusted during the forming process - starting with lower vacuum for debulking, then increasing to higher vacuum for forming and shape maintenance. This dynamic adjustment optimizes wrinkle reduction while managing system complexity through a single controllable parameter.
4Manufacturing precision
If composite layup is debulked before forming, then forming precision improves, but the forming time increases
Solution Approach 1:
Debulking is performed as a preliminary action within the vacuum envelope before the main forming operation. By completing the debulking step in advance, the subsequent forming process proceeds more efficiently with reduced risk of wrinkles, overall optimizing the balance between precision and time.
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 effectively reduces wrinkles and bulk in composite layups by controlling vacuum and applying pressure, ensuring precise shaping and consistent material integrity.
Implementation Method 1
A composite layup is sealed in a vacuum envelope... the composite layup is formed onto a tool while the composite layup is held under vacuum in the vacuum envelope
Implementation Method 2
Heating the composite layup may comprise melting at least one of a thermoplastic veil or thermoplastic stitching in the composite layup
Implementation Method 3
The composite layup may be heated while under vacuum to maintain the formed shape in the composite layup by tacking the composite layup
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods of creating a formed shape into composite layups with reduced wrinkling. A composite layup is sealed in a vacuum envelope, the composite layup comprising at least one of a resin or a thermoplastic material. The composite layup is formed onto a tool while the composite layup is held under vacuum in the vacuum envelope to create a formed shape in the composite layup.