Tensioning Material Reduces Ply Wrinkling in Composite Hot Drape Forming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hot drape forming of composite laminate parts with radius features often results in ply material wrinkling, leading to increased labor and material costs due to the need for reworking or scrapping of parts.
Innovation Solution
A method and apparatus that uses a tensioning material to maintain compressive force on plies closest to the forming tool during hot drape forming, preventing bunching and gathering by placing the tensioning material over the laminate charge and applying weights to retain it in place, thereby reducing ply wrinkling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If hot drape forming is used to form composite laminate parts with radius features, then the parts can be manufactured with complex geometries, but ply material wrinkling occurs leading to increased labor and material costs
Solution Approach 1:
The tensioning material is applied to the laminate charge before the forming process begins. This preliminary action pre-positions the tensioning material to apply compressive force on the plies during forming, preventing wrinkling before it can occur. The tensioning material is stretched and secured to the forming tool in advance, so that when forming starts, the compressive force is already in place on the radius features.
Solution Approach 2:
The tensioning material acts as an intermediary between the forming tool and the laminate charge. It transfers and distributes compressive force uniformly across the plies during forming, particularly on radius features. This intermediary material prevents direct contact between the forming tool and laminate, allowing controlled compression that eliminates ply bunching and wrinkling.
2Ease of manufacture
If conventional hot drape forming is used without additional measures, then the process remains simple and cost-effective, but ply material bunching and creasing occur on radius features
Solution Approach 1:
The tensioning material used is a low-cost, disposable material that is applied to the laminate charge and then removed after forming. Examples include release film, parchment paper, or similar inexpensive materials that serve their purpose during forming and are discarded afterward. This approach maintains process simplicity while significantly improving part quality, as the cheap material prevents wrinkling without requiring complex or expensive equipment modifications.
3Manufacturing precision
If ply material is compressed during forming to prevent wrinkling, then manufacturing precision improves, but additional tooling or complex apparatus may be required
Solution Approach 1:
The tensioning material serves multiple functions simultaneously: it applies compressive force to prevent wrinkling, acts as a release layer to facilitate forming, and distributes pressure uniformly across the laminate. This multi-functional approach achieves improved manufacturing precision without requiring complex or specialized tooling, as the tensioning material itself performs the compression function that would otherwise require additional mechanical systems.
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 solution effectively reduces or eliminates ply wrinkling, lowering labor and material costs by minimizing the need for reworking and part scrap, and can be easily implemented without additional tooling using low-cost materials.
Implementation Method 1
drawing a vacuum between the forming membrane and the tool
Implementation Method 2
maintaining tension on the tensioning material as the radius features being formed. The tensioning material applies a compressive force to the plies
Implementation Method 3
heating it until soft enough to form
Data Source
AI summary
Ply wrinkling during hot drape forming of a composite laminate is reduced at corner radii. A tensioning material placed over an uncured composite laminate charge maintains a compressive force on the laminate charge as the charge is formed over a tool.