Flexible Mold Element for Composite Wheel Vacuum Infusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for molding fibre-reinforced composite wheels, such as compression molding with prepreg sheets, face challenges including high costs, limited shelf life, difficulty in conforming to complex shapes, and the need for high-pressure autoclave curing.
Innovation Solution
A method using a mold assembly with a flexible polymer mold element that allows for the formation of a fibre-reinforced composite wheel by locating reinforcement fabric within the mold, sealing with a flexible mold element, introducing resin through vacuum infusion, and curing to create an integral wheel, which reduces tooling costs and facilitates molding of undercut areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a rigid mold element is used for molding, then manufacturing precision can be maintained, but the ability to mold undercut areas and complex shapes is limited
Solution Approach 1:
The patent employs a flexible mold element made of elastomeric material that can be deformed and flexed during the molding process. This flexibility enables the mold to conform to complex shapes and undercut areas that rigid molds cannot access, while still producing precise composite wheel components through the adaptive conforming capability of the flexible material.
2Ease of manufacture
If matched solid molds are used, then manufacturing precision is maintained, but tooling costs increase due to high tolerance machining requirements
Solution Approach 1:
The flexible elastomeric mold element eliminates the need for precision-machined matched solid molds. The flexibility of the material allows for simpler, less expensive mold construction while maintaining adequate dimensional control through the elastomeric properties, thereby reducing tooling costs without completely sacrificing manufacturing precision.
Solution Approach 2:
The flexible mold element can be designed as a cost-effective, potentially disposable or limited-life component that does not require the high initial investment in precision machining of permanent solid molds. This approach trades long-term durability for reduced upfront tooling costs and simplified manufacturing.
3Strength
If prepreg sheets are used, then fiber reinforcement is achieved, but storage and handling become difficult due to low temperature requirements
Solution Approach 1:
Instead of pre-impregnating fibers with resin in a controlled low-temperature environment (which creates storage and handling issues), the patent applies the resin during the molding process itself. The dry fiber reinforcement materials can be stored and handled at ambient conditions, then impregnated with resin just before forming, eliminating the need for cold chain logistics while maintaining fiber reinforcement strength.
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 lowers equipment and infrastructure costs, enables easier molding of complex shapes, and allows for cost-effective tooling with reduced labor requirements, while improving storage and handling of reinforcement fabrics.
Implementation Method 1
introducing a resin into the mold cavity by withdrawing air from the mold cavity through an inlet at a convenient location on the mold assembly
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method of molding a fibre-reinforced composite wheel using a mold assembly. The mold assembly includes an annular rim mold portion for defining an outer surface of a rim of the wheel and a disc mold portion for defining a front surface of a disc portion of the wheel. The method comprises the steps of : locating at a first part of reinforcement fabric within the mold assembly around the rim mold portion; locating at a second part of reinforcement fabric within the mold assembly over the disc mold portion; sealing the mold assembly with a flexible mold element to form a substantially fluid tight mold cavity, the flexible mold element comprising a flexible polymer component for defining an inner surface of the rim of the wheel and a rear surface of the disc portion of the wheel; introducing a resin into the mold cavity by withdrawing air from the mold cavity through an inlet at a convenient location on the mold assembly; and curing the resin to form an integral fibre-reinforced composite wheel.