Process for producing a fiber-reinforced molded product
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional RTM methods often result in surface defects like pinholes and voids due to poor resin flow and impregnation, requiring additional processing steps and increasing production time and cost.
Innovation Solution
Incorporating a specified interlayer with a high cover factor and a resin distribution medium with a specific impregnation coefficient, positioned between the skin layer forming substrate and the reinforcing fiber substrate, to enhance resin flowability and prevent bubble exposure on the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional RTM method is used, then production efficiency is maintained, but surface defects such as pinholes and voids occur requiring additional processing steps
Solution Approach 1:
The patent applies preliminary action by incorporating a resin distribution medium and interlayer with high cover factor into the laminate structure before resin injection. The resin distribution medium (with coefficient of impregnation ≥1×10^-10 m²) is positioned to guide resin flow and distribute it uniformly, while the interlayer (with cover factor ≥90%) is placed to prevent bubble exposure on the surface. These structural elements are prepared in advance to proactively prevent surface defects during molding, eliminating the need for post-processing repairs and maintaining production efficiency.
2Manufacturing precision
If foamable particles are used to improve surface quality, then surface defects are reduced, but device complexity and molding cycle time increase
Solution Approach 1:
The patent extracts the surface quality improvement function from the foamable particle mechanism and implements it through a passive structural approach. Instead of using foamable particles that require heating and expansion mechanisms, the invention uses a resin distribution medium with high impregnation coefficient and an interlayer with high cover factor. These components naturally guide resin flow and block bubble exposure without requiring active foam generation, thereby simplifying the mold structure and reducing device complexity while maintaining surface quality.
3Productivity
If random mat layer is added to extract bubbles, then resin impregnation is accelerated, but through pinholes are generated in the upper surface substrate
Solution Approach 1:
The patent applies local quality by assigning different functional characteristics to different layers of the laminate structure. The resin distribution medium (with coefficient of impregnation ≥1×10^-10 m²) is positioned at the resin injection side to accelerate impregnation locally, while the interlayer (with cover factor ≥90%) is positioned at the surface side to locally prevent bubble exposure. This spatial differentiation of functions allows rapid resin impregnation in the bulk while maintaining surface quality, avoiding the through pinholes problem caused by uniform random mat placement.
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 significantly reduces the occurrence of surface defects, allowing for efficient and stable production of high-quality fiber-reinforced molded products with reduced need for post-processing repairs and lower production costs.
Implementation Method 1
a resin distribution medium, which is located between the skin layer forming substrate and the reinforcing fiber substrate
Implementation Method 2
the interlayer has a cover factor of 90%-100% and comprises at least one woven fabric
Implementation Method 3
coefficients of impregnation and the cover factor are determined as disclosed in the description
Data Source
Figure 1~3
Figure 4~7
Figure 8
AI summary
A process for producing a fiber reinforced resin which comprises placing at least a reinforcing fiber substrate in a cavity of a mold, injecting a resin into the cavity, and curing the resin, characterized in that a substrate for forming a skin layer, and a resin distribution medium, which is located between the substrate for forming the skin layer and the reinforcing fiber substrate and in which the ratio of the coefficient of impregnation thereof to that of the substrate for forming the skin layer is 1.5-10, are disposed on at least one surface of the reinforcing fiber substrate via an interlayer having a cover factor of 90%-100% and comprising at least one woven fabric. The process diminishes pinhole generation in the skin layer in RTM, and can reduce the necessity of a repair step in, e.g., a painting step as a later step, thereby improving productivity .