Thermoplastic Forming with Rotating Mandrel and Rollers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming thermoplastic structures, such as those used in aerospace components like fan cowl outer skins, are time-consuming and prone to wrinkling, especially when forming complex geometries like semi-cylindrical shapes with non-linear contours.
Innovation Solution
A system comprising a rotating mandrel, series of rollers, and heating/cooling elements, along with a tensioning assembly, is used to heat, compress, and cool thermoplastic charges to a hardened state, minimizing wrinkling and enabling quick formation of complex geometries by applying radially inward pressure and controlled tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional carbon fiber layup process is used to form fan cowl outer skins, then complex geometries can be formed, but the manufacturing time takes many hours to complete
Solution Approach 1:
The patent changes the material state parameter by heating the thermoplastic charge to a forming temperature, transforming it from a rigid state to a pliable state that can be rapidly formed into complex geometries. This parameter change enables the material to be shaped quickly without requiring multiple stacking and curing steps, thereby reducing manufacturing time while maintaining geometric complexity
Solution Approach 2:
The patent utilizes phase transition of the thermoplastic material by heating it above its melting point to create a pliable state for forming, then cooling it to solidify the formed geometry. This phase transition approach replaces the traditional multi-step layup and curing process with a single rapid forming operation, significantly reducing manufacturing time while achieving complex shapes
2Manufacturing precision
If thermoplastic charge is compressed between mandrel and rollers, then wrinkling is minimized, but the system complexity increases
Solution Approach 1:
The patent divides the compression function into multiple segments by using a series of rollers distributed along the mandrel circumference rather than a single compression device. Each roller applies localized pressure to specific portions of the thermoplastic charge, ensuring uniform compression and wrinkling prevention across the entire surface while keeping each individual roller component simple
Solution Approach 2:
The mandrel serves multiple functions: it provides the forming geometry, acts as a support structure during compression, and enables rotation to facilitate uniform pressure distribution. The rollers simultaneously apply compression force and can be positioned at different circumferential locations to address different areas of the workpiece. This multi-functionality reduces the need for additional specialized components, managing system complexity
3Ease of manufacture
If heating element is located upstream of rollers, then the thermoplastic charge becomes pliable for forming, but energy consumption increases
Solution Approach 1:
The heating element is positioned upstream of the rollers to pre-heat the thermoplastic charge before it reaches the compression zone. This preliminary heating action ensures the material is already pliable when it enters the forming area, eliminating the need for additional heating during compression and optimizing energy efficiency by heating only the necessary portion of the material at the right time
Solution Approach 2:
The heating element applies thermal energy locally to the thermoplastic charge in the upstream region rather than heating the entire workpiece uniformly. This localized heating approach provides sufficient pliability only where and when needed for forming, reducing overall energy consumption compared to full-piece heating methods
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 method significantly reduces the manufacturing time for thermoplastic components with complex geometries, minimizing or eliminating wrinkling and allowing for the production of smooth, aerodynamic surfaces like fan cowl outer skins with improved efficiency.
Implementation Method 1
heating a thermoplastic charge to a forming temperature
Implementation Method 2
cooling the thermoplastic charge to a hardened temperature
Data Source
AI summary
A system for forming a thermoplastic may comprise a mandrel configured to receive a thermoplastic charge. The mandrel may rotate about a mandrel axis. A series of rollers may be located circumferentially about the mandrel and configured to apply radially inward pressure. A heating element may be located upstream of the series of rollers.