Near-Net Thermoplastic Composite Forming via Co-Spraying
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Solution Overview
Problem
Compression molding processes for thermoplastic composite parts result in significant scrap material, uneven polymer distribution, fiber concentration issues, and limited customization due to the use of pre-consolidated blank sheets, which are difficult to recycle and require complex end-of-arm tooling for complex part designs.
Innovation Solution
A method involving co-spraying or spray chopping a mixture of thermoplastic polymer material and chopped reinforcing material onto a tool with controlled temperature and pressure, allowing for near-net component formation with improved polymer distribution and fiber orientation, eliminating the need for pre-consolidated blanks and complex tooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pre-consolidated blank sheets are used as feedstock, then the manufacturing process is simplified, but significant scrap material is generated and material utilization is poor
Solution Approach 1:
The patent changes the physical state and form of the feedstock from pre-consolidated blank sheets to loose fiber mats with thermoplastic binder. This parameter change enables direct molding without blanking operations, eliminating scrap material while maintaining ease of manufacture through a streamlined process.
Solution Approach 2:
The patent applies local quality by allowing different regions of the fiber mat to have different fiber orientations and concentrations before molding. This enables optimized material distribution in different part regions, reducing waste while maintaining manufacturing simplicity.
2Loss of substance
If blank sheets are cut to part shape before molding, then material is wasted through trimming, but the process requires additional cutting operations
Solution Approach 1:
The patent performs preliminary action by pre-orienting fibers and distributing binder throughout the fiber mat before molding. This preliminary preparation eliminates the need for post-molding trimming operations, reducing both material waste and process complexity.
Solution Approach 2:
The patent extracts the cutting/trimming operation from the manufacturing process entirely. By using loose fiber mats that can be directly molded to near-net shape, the unnecessary trimming step is removed, eliminating both waste and associated equipment complexity.
3Manufacturing precision
If compression molding with blanks is used, then part formation is achieved, but polymer distribution around reinforcement fibers is uneven
Solution Approach 1:
The patent segments the composite material into discrete fibers with binder material distributed throughout. This segmentation allows for more uniform polymer distribution around reinforcement fibers during molding, improving manufacturing precision without significantly increasing process complexity.
Solution Approach 2:
The patent changes the parameter of material form from consolidated blank to loose fiber mat with distributed binder. This parameter change enables better polymer distribution around fibers during the molding process, achieving improved uniformity while maintaining ease of manufacture.
4Shape
If end-of-arm tooling is used for complex part shapes, then complex geometries are achieved, but device complexity increases
Solution Approach 1:
The patent performs preliminary action by pre-orienting fibers and preparing the fiber mat structure before molding. This preliminary preparation enables complex part geometries to be achieved through the molding process itself, eliminating the need for complex end-of-arm tooling.
Solution Approach 2:
The patent inverts the conventional approach by using loose fiber mats instead of pre-consolidated blanks. This inversion allows the material to be more easily conformable to complex tool surfaces during molding, achieving complex geometries with simpler tooling.
5Adaptability or versatility
If a single uniform blank is used, then manufacturing is simplified, but material customization in different regions is not permitted
Solution Approach 1:
The patent applies local quality by enabling different fiber orientations, concentrations, and types in different regions of the fiber mat before molding. This allows material customization for specific regional requirements while maintaining relatively simple manufacturing processes.
Solution Approach 2:
The patent segments the material composition to allow regional customization. By using loose fiber mats with distributed binder rather than uniform blanks, different material properties can be implemented in different regions without significantly complicating the manufacturing process.
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 reduces material waste, achieves uniform polymer distribution, allows for customized material properties in different regions, and enhances ultraviolet radiation stability by minimizing exposure to oxygen during the melting process, resulting in high-quality near-net thermoplastic composite components.
Implementation Method 1
The mixture is heated to a second temperature while the mixture is on the tool. The first temperature is below the solidification temperature of the thermoplastic polymer material and the second temperature is above a solidification temperature of the thermoplastic polymer material, so that the thermoplastic polymer material flows.
Implementation Method 2
The mixture on the tool is exposed to a negative pressure to promote removal of gases from the mixture.
Implementation Method 3
Compressive force is then applied to the mixture.
Data Source
AI summary
A method is provided for forming a near-net thermoplastic composite component includes co-spraying a mixture comprising a thermoplastic polymer material and a chopped reinforcing material deposited onto at least one region associated with a tool having a first temperature and defining a near-net component shape. The mixture and adjacent tool is heated to a second temperature while the mixture is on the tool. The first temperature is below the solidification temperature of the thermoplastic polymer material and the second temperature is above the solidification temperature. Then, the mixture is exposed to a negative pressure to promote removal of gases from the mixture and put under compressive force to densify the mixture. The thermoplastic polymer material melts and flows. The tool is cooled to the first temperature and removing the mixture to form the near-net thermoplastic composite component having randomly oriented chopped reinforcement material distributed within a thermoplastic polymer matrix.