Dry Thermoplastic Prepreg for Automated CMC Thermoforming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The preforming process for ceramic matrix composites (CMCs) is costly due to high touch labor requirements, and there is a need for materials that enable automated preforming and thermoforming processes.
Innovation Solution
A fibrous textile impregnated with a thermoplastic resin mixture, primarily polyvinyl butyral, with controlled solvent content, allowing for the production of dry prepregs that are rigid and robotically handleable, enabling automated thermoforming into desired molds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional wet prepreg materials are used, then the material has good drape and conformability, but the material lacks rigidity for automated robotic handling
Solution Approach 1:
The patent changes the physical state of the prepreg from wet to dry by removing solvent, transforming the material from flexible and drapable to rigid and handleable. This parameter change enables automated robotic pick-and-place operations while maintaining the ability to conform to molds during thermoforming through controlled heating.
Solution Approach 2:
The prepreg material exhibits dynamic properties that change with temperature: rigid at room temperature for automated handling, and flexible when heated for mold conformability. This dynamic behavior allows the same material to satisfy contradictory requirements at different stages of the manufacturing process.
2Manufacturing precision
If high solvent content is used in the thermoplastic resin mixture, then the prepreg remains flexible and processable, but the final product exhibits fiber distortion and tow spreading
Solution Approach 1:
The patent extracts and removes the solvent from the thermoplastic resin mixture after impregnation, leaving a dry prepreg with minimal residual solvent (less than 5%). This extraction eliminates the harmful effects of solvent on fiber structure while maintaining the benefits of thermoplastic impregnation during processing.
Solution Approach 2:
The solvent removal is performed as a preliminary step before automated handling and molding. By removing solvent beforehand, the material is prepared in its optimal state for automated robotic operations, preventing fiber distortion before it can occur during subsequent processing steps.
3Productivity
If manual touch labor is used for preforming operations, then the process can handle complex materials, but the production cost increases significantly
Solution Approach 1:
The dry prepreg material is designed to be self-sufficient for automated handling, requiring no special handling procedures or manual intervention. The material's inherent rigidity and stability allow robotic systems to pick, place, and process it autonomously, enabling full automation of the preforming process and reducing labor costs.
4Manufacturing precision
If iterative debulking and solvent removal steps are used, then the prepreg quality is improved, but the process time and complexity increase
Solution Approach 1:
The solvent removal is performed as a preliminary step during prepreg fabrication, before the material reaches the customer or enters the molding process. This preliminary action eliminates the need for iterative debulking and solvent removal steps during production, reducing process time and complexity while maintaining prepreg quality.
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 process reduces costs and improves throughput by allowing fully or partially automated preforming, maintaining consistent microstructures, and producing high-quality CMCs with reduced fiber distortion and tow spreading.
Implementation Method 1
a thermoplastic resin mixture which impregnates the fibrous textile
Implementation Method 2
removing the solvent from the combined fibrous textile with a thermoplastic resin mixture wherein the remaining wt % of solvent is less than 5%
Implementation Method 3
The at least two dry prepreg plies are aligned within the mold form such that the pressure applied to the at least two dry prepreg plies presses the at least two dry prepreg plies into physical contact with each other
Data Source
AI summary
A dry prepreg of fibrous textile/thermoplastic with handling characteristics highly compatible with robotic handling and a method for making at least one dry prepreg and forming the at least one dry prepreg over a mold form. The method also includes using the at least one molded dry prepreg as at least one sub-laminate in a thermoforming process. The methods include CMC preforming processes which can be automated though the use of robotic handling devices.