Fiber-Reinforced Plastic Molded Article Production via Compression
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Solution Overview
Problem
The production of fiber-reinforced plastic (FRP) molded articles with a sandwich structure using the RTM method often results in defective portions due to low fiber volume content in the surface components, leading to reduced flexural properties and decreased production efficiency when attempting to increase fiber volume content to prevent these defects.
Innovation Solution
A method involving the stacking of continuous fiber components with a non-woven fabric in between, creating a fiber base material that is initially placed in an enclosed space with a larger volume than the product cavity, allowing for impregnation with liquid matrix resin before applying a pressing load to increase apparent fiber volume content and enhance flexural properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the fiber volume content of the surface component is increased to prevent defective portions, then the flexural properties are improved, but it becomes difficult to impregnate the fiber base material with liquid matrix resin, leading to unimpregnated areas and lowered production efficiency
Solution Approach 1:
The non-woven fabric is placed between the first and second continuous fiber components before impregnation to preliminarily establish a structure that enables subsequent compression. This preliminary arrangement allows the fiber base material to be compressed to high fiber volume content after impregnation, resolving the contradiction between achieving high flexural properties and maintaining production efficiency
Solution Approach 2:
The apparent fiber volume content is changed by applying compression to the fiber base material after impregnation with liquid matrix resin. This parameter change allows the surface components to achieve high fiber volume content (improving flexural properties) while the impregnation process occurs under more favorable conditions (maintaining production efficiency)
2Reliability
If the fiber volume content of the surface component is increased to prevent meandering portions and non-uniform density distribution, then the generation of defective portions is prevented, but the impregnation of liquid matrix resin becomes difficult, leading to unimpregnated areas
Solution Approach 1:
The non-woven fabric is preliminarily positioned between the surface components to create a compressible structure before impregnation. This preliminary action ensures that the fiber base material can be properly compressed after impregnation, preventing meandering portions and non-uniform density distribution while not interfering with the impregnation process itself
Solution Approach 2:
Instead of compressing the fiber base material before impregnation (which would make impregnation difficult), the invention inverts the sequence by impregnating first and then compressing. This inversion resolves the contradiction by allowing easy impregnation of the uncompressed fiber base material while still achieving high fiber volume content and preventing defective portions after compression
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 effectively prevents unimpregnated areas, improves flexural strength and rigidity, and maintains production efficiency by increasing fiber volume content in the surface components, making the FRP molded articles suitable for applications like car body components.
Implementation Method 1
the fiber base material is impregnated with a liquid matrix resin
Implementation Method 2
hardening the liquid matrix resin with which the fiber base material has been impregnated
Data Source
AI summary
A first continuous fiber component and a second continuous fiber component are stacked with a non-woven fabric interposed therebetween to thereby prepare a fiber base material. The fiber base material is placed between an upper mold and a lower mold. The upper mold and the lower mold are brought close to each other to thereby form an enclosed space therebetween. The enclosed space is larger in volume than a product cavity. A liquid matrix resin is supplied to the enclosed space. The upper mold and the lower mold are brought closer to each other to thereby form the product cavity in a manner that a pressing load is applied to the fiber base material. Then, the liquid matrix resin with which the fiber base material has been impregnated is hardened in the product cavity, whereby a fiber-reinforced plastic molded article is produced.