VaRTM Mold Fixing Member for Thermal Expansion Positioning
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Solution Overview
Problem
In integral molding methods like VaRTM, accurate positioning of fiber-reinforced plastic members is challenging due to thermal expansion of mold materials like steel or aluminum, which affects the precise alignment of reinforced fabrics during the heating process.
Innovation Solution
A device and method that utilize a fixing member or bladder with positioning portions to accurately position the fabric relative to a cured fiber-reinforced composite member, independent of the mold, thereby avoiding thermal expansion issues. This includes a first mold for the composite member, a second mold for the fabric, and a fixing member or bladder with positioning features that align the fabric directly with the composite member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If generic materials such as steel or aluminum are used for the lower mold jig, then the costs are low and cutting is simple, but the lower mold jig experiences thermal expansion during the heating process, causing the reinforced fabric to be inaccurately mounted on the cFRP
Solution Approach 1:
The system is divided into two independent positioning subsystems: (1) the first mold jig positions the cured cFRP member, and (2) the fixing member positions the fabric relative to the cFRP member. This segmentation allows each subsystem to perform its positioning function independently, preventing thermal expansion of the first mold jig from affecting fabric positioning accuracy.
Solution Approach 2:
The fixing member acts as an intermediary between the first mold jig and the fabric. Instead of directly positioning the fabric on the first mold jig (which undergoes thermal expansion), the fixing member provides a stable reference frame that mediates the positioning process, ensuring accurate fabric placement relative to the cFRP member despite thermal effects on the first mold jig.
2Manufacturing precision
If the lower mold jig is made from materials with low thermal expansion, then thermal expansion effects are reduced, but the costs increase and cutting becomes more difficult
Solution Approach 1:
The positioning function is extracted from the first mold jig and transferred to the fixing member. By taking out the positioning responsibility from the thermally affected first mold jig and assigning it to the fixing member (which can be made from generic materials), the system achieves high positioning accuracy without requiring expensive low thermal expansion materials for the entire mold jig assembly.
Solution Approach 2:
Instead of requiring the entire first mold jig to be made from expensive low thermal expansion materials, the invention applies local quality by using generic materials for the first mold jig while employing the fixing member (which can be precisely manufactured) for the critical positioning function. This localized approach to quality ensures accuracy where needed without incurring unnecessary costs elsewhere.
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
Ensures accurate positioning of the fabric relative to the fiber-reinforced composite member, enhancing the precision and reliability of the integral molding process by isolating the fabric from thermal expansion effects of the mold materials.
Implementation Method 1
vacuum assisted resin transfer molding (VaRTM) in which the difference in pressure between a vacuum and the atmosphere is used to facilitate impregnation of resin in a fabric
Implementation Method 2
the inside of which reduced in pressure and heated
Data Source
AI summary
An object is to provide a device and method for manufacturing a fiber-reinforced plastic molded article, whereby two members can be accurately positioned with respect to each other upon integral molding of the members via a VaRTM method. A device for manufacturing a fiber-reinforced plastic molded article includes a skin mold in which a skin, which is a cured fiber-reinforced composite member, is mounted; a stringer mold that is configured to accommodate a stringer, which is a fabric to be joined to the skin; and a folded plate that is configured to accommodate the stringer mold and includes a positioning portion for positioning with respect to a positioning portion provided on the skin.