Automated Sweeping and Vacuum Forming for Composite Stiffeners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of composite laminate structural stiffeners with complex contours is challenging due to bridging and wrinkling issues, which require labor-intensive hand layup and rework, leading to inefficiencies in production and increased costs.
Innovation Solution
A method and apparatus using mechanical sweeping and vacuum forming to form composite prepreg plies onto complex contours of a mandrel, reducing bridging and wrinkling through a combination of a ply sweeper and a presser with a powered actuator, allowing for partial automation and increased production throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hand layup techniques are used to form contoured composite stiffeners, then bridging and wrinkling are minimized, but labor intensity and production time increase significantly
Solution Approach 1:
The patent replaces manual hand layup operations with an automated forming apparatus that uses a combination of mechanical sweeping and vacuum forming. The apparatus includes a forming head with sweeping elements that mechanically guide the prepreg material over contoured mandrels, eliminating the need for manual manipulation while maintaining surface quality by preventing bridging and wrinkling through controlled material flow.
Solution Approach 2:
The forming apparatus enables the composite material to self-form onto the contoured mandrel through the combined action of mechanical sweeping and vacuum pressure. The system allows the material to conform to the desired shape automatically through the forming process, reducing the need for subsequent hand rework and patches that would otherwise be required to correct surface defects.
2Productivity
If automated forming methods are used to increase production throughput, then labor requirements decrease, but bridging and wrinkling issues worsen
Solution Approach 1:
The forming process is divided into two distinct functional stages: mechanical sweeping to guide and distribute the prepreg material evenly over the mandrel contours, and vacuum forming to apply uniform pressure that eliminates air pockets and ensures complete conforming. This segmentation of functions allows automated high-speed forming while maintaining surface quality by addressing different aspects of material formation separately.
Solution Approach 2:
The patent merges two previously separate processes—mechanical sweeping and vacuum forming—into a single integrated forming head assembly. This combination allows both actions to occur simultaneously during automated operation, enabling high production throughput while the sweeping action prevents material bridging and the vacuum action prevents wrinkling by ensuring complete material-to-mandrel contact.
3Productivity
If mechanical sweeping and vacuum forming are combined, then production efficiency increases, but device complexity increases
Solution Approach 1:
The forming head assembly is designed as a multi-functional device that performs both mechanical sweeping and vacuum forming operations through a single integrated structure. The sweeping elements and vacuum sealing components are combined in one assembly that can be positioned and operated as a single unit, reducing the need for multiple separate devices and simplifying the overall system architecture despite the complexity of the combined functions.
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 significantly reduces nonconformities and rework, decreases labor requirements, and enhances factory throughput by effectively forming contoured composite stiffeners with reduced bridging and wrinkling, improving the efficiency of the manufacturing process.
Implementation Method 1
a vacuum source adapted to draw the at least one ply down onto the mandrel
Data Source
AI summary
A composite laminate such as a hat-type stringer is formed on a contoured mandrel using a combination of mechanical sweeping and vacuum forming.