Compression Molded Composite Parts with Integrated Voids
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Solution Overview
Problem
Current methods for manufacturing motor vehicle parts with composite materials, such as fiber-reinforced plastics, require secondary processing steps to create voids, which increase manufacturing costs, waste, and the risk of defects, as well as generate environmental hazards like dust and water treatment issues.
Innovation Solution
A method of forming motor vehicle parts with voids directly in a compression mold by allowing melted resin to flow around restrictions within the mold, ensuring sufficient reinforcing fibers are present at the void borders, eliminating the need for secondary cutting processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If secondary processing steps are used to create voids in molded parts, then the parts can have desired void configurations, but manufacturing costs increase and waste is generated
Solution Approach 1:
The patent combines the molding process and void formation into a single integrated operation. Restrictions are built directly into the mold cavity, allowing voids to form automatically during compression molding as resin flows around the restrictions. This eliminates the need for separate secondary cutting or machining operations to create voids, thereby reducing manufacturing costs and eliminating waste generation from material removal.
Solution Approach 2:
The restrictions that define void boundaries are pre-installed in the mold cavity before the molding process begins. This preliminary positioning of restrictions ensures that voids form with the correct configuration during the initial molding operation, eliminating the need for subsequent processing steps to create or modify void shapes.
2Shape
If secondary processing steps are used to create voids, then voids can be formed, but additional tooling and equipment are required
Solution Approach 1:
The patent integrates void formation capabilities directly into the compression mold cavity by incorporating restrictions as integral mold features. This merging of void formation functionality into the existing mold eliminates the need for separate cutting tools, water jet equipment, or other secondary processing machinery, thereby reducing device complexity.
3Shape
If material is removed to create voids, then voids are formed, but waste material is generated that cannot be easily recycled
Solution Approach 1:
The restrictions are pre-positioned in the mold to define void boundaries before molding begins. This preliminary action ensures that voids form through resin flow patterns during molding, eliminating the need for subsequent material removal operations that would generate waste material requiring disposal or recycling.
Solution Approach 2:
The patent converts what would traditionally be waste material (excess resin and fibers) into a beneficial outcome by directing the resin flow around restrictions to form voids with proper fiber reinforcement. The material that would have been removed as waste in secondary processing instead becomes part of the void structure, eliminating waste generation.
4Shape
If resin flows around restrictions to form voids, then voids are created, but knit lines with insufficient fibers may form
Solution Approach 1:
The patent applies local quality control by strategically designing restriction geometry and positioning to manage resin flow patterns. The restrictions are configured to guide resin and fiber flow in a way that ensures adequate fiber reinforcement at critical locations while still forming the desired void shapes, thereby maintaining local strength requirements.
Solution Approach 2:
The patent optimizes flow path parameters including restriction geometry, size, and positioning to control resin and fiber flow dynamics. By adjusting these parameters, the design ensures that fibers are properly distributed and reinforced at void boundaries during the molding process, preventing weak knit lines while maintaining void formation.
5Shape
If multiple processing steps are used, then parts can be made with voids, but handling and transit increase risk of damage and error
Solution Approach 1:
The patent merges void formation into the primary molding operation, creating a single-step process that produces finished parts with voids directly from the mold. This eliminates multiple handling and transit steps between molding and secondary processing, thereby reducing the risk of part damage and human error associated with repeated handling.
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 reduces material usage, waste production, and labor costs while ensuring the parts can support heavy loads without weak points, as the voids are formed with sufficient fiber reinforcement during the molding process.
Implementation Method 1
Heat and pressure are applied to the closed mold to melt the charge of resin to form resinous material
Implementation Method 2
a charge of the composite material is placed into one of the mold portions, such as in a reservoir. The mold portions close to form the mold
Implementation Method 3
Heat and pressure are applied to the closed mold to melt the charge of resin
Data Source
AI summary
The invention is a method to make compression molded motor vehicle parts from a charge of composite material with resin and fibers, such as sheet molded compound. The parts have voids, such as holes and gaps, that form in the compression mold under heat and pressure and not in secondary processing steps. The resin in the charge is melts in a reservoir in the mold to form resinous material from the charge. A flow front of resinous material is allowed to flow into a flow path around a restriction corresponding to the shape of the void from the reservoir. The flow front carries sufficient reinforcing fibers into the flow path. At least part of a border for the void forms in the flow path. The configuration is allowed to at least partially set.