RTM Molding with Chain-Curing Resin for High Fiber Volume
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional resin transfer molding (RTM) methods face challenges in achieving high fiber volume content (Vf) in fiber-reinforced plastics (FRP), particularly in CFRP, due to limitations in energy ray-curable resins, such as surface curing and incompatibility with energy ray-blocking substances, leading to reduced strength and increased processing costs.
Innovation Solution
An RTM molding method using a chain-curing resin composition with a temperature increase of 50°C or more within 10 seconds after curing initiation, facilitated by a resin reservoir and energy ray irradiation, allowing for efficient impregnation and curing of reinforcing fibers, even with high Vf content, such as carbon fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional light-curable resins are used for thick-walled FRP molding, then the resin can be applied to various fields, but the deep portion of the resin remains uncured due to energy ray attenuation
Solution Approach 1:
The patent changes the curing mechanism from purely photochemical (energy ray-dependent) to thermal-driven by utilizing the exothermic heat generated during the initial photo-curing phase to propagate curing through the entire resin thickness, including deep portions that would otherwise remain uncured
Solution Approach 2:
The patent converts the harmful effect of energy ray attenuation (which limits curing depth) into a beneficial self-heating mechanism, where the initial photo-curing reaction generates heat that compensates for the attenuation and enables complete curing throughout the resin thickness
2Adaptability or versatility
If light-curable resins contain energy ray blocking substances such as fillers, then the resin composition can be tailored for specific applications, but curing failure occurs due to absorption of radiation
Solution Approach 1:
The patent converts the harmful absorption of energy rays by fillers (which blocks curing) into a beneficial thermal initiation mechanism, where the initial photo-curing reaction generates heat that propagates curing through the entire resin matrix, including regions blocked from direct energy ray exposure
Solution Approach 2:
The patent introduces thermal energy as an intermediary that mediates between the initial photo-curing reaction and the complete curing process, allowing curing to proceed in regions where energy rays are blocked by fillers
3Reliability
If heat curing is used for thick-wall FRP, then complete curing can be achieved, but the processing cost increases and curing time becomes excessively long
Solution Approach 1:
The patent performs preliminary photo-curing to initiate the curing reaction and generate heat in the resin, which then propagates through the entire resin thickness without requiring prolonged external heating, thus achieving complete curing much faster than conventional heat-curing methods
Solution Approach 2:
The patent maintains continuous curing action through the self-propagating exothermic reaction, where the heat generated in one region continuously initiates curing in adjacent regions, eliminating the need for intermittent or prolonged external heating cycles
4Ease of manufacture
If conventional RTM methods are used to achieve high fiber volume content, then the molding process can be simplified, but the resin cannot be properly impregnated due to viscosity changes during curing
Solution Approach 1:
The patent performs resin impregnation and initial photo-curing before the exothermic reaction fully propagates, ensuring that the resin is properly impregnated into the fiber structure while the viscosity is still manageable, and then the self-propagating heat completes the curing process without requiring re-impregnation
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 enables the production of FRP molded bodies with increased fiber volume content, enhancing their strength and lightweightness while reducing processing costs and curing time, and enabling the use of energy ray-curable resins in thicker materials.
Implementation Method 1
after the initiation of the curing of the resin composition, the highest temperature at the curing head of the resin composition, undergoing chain curing, within 10 seconds after the initiation of the curing is increased to be higher by 50° C. or more than the temperature of the resin composition at after the impregnation and before the curing
Implementation Method 2
a chain-curing resin composition which undergoes chain curing upon irradiation with energy ray, and by which the highest temperature at the curing head within 10 seconds after the initiation of the curing is increased to be higher by 50° C. or more than the temperature of the resin composition at after the impregnation and before the curing
Data Source
AI summary
Provided is an RTM molding method enabling to yield an FRP molded body formed so as to be increased in the fiber volume content and to thereby be made more excellent in strength and lightweightness. The resin composition is a chain-curing resin composition, and after the initiation of the curing of the resin composition, the highest temperature at the curing head of the resin composition, undergoing chain curing, within 10 seconds after the initiation of the curing is increased to be higher by 50° C. or more than the temperature of the resin composition at after the impregnation and before the curing, and thus, the resin composition is chain-cured with a Vf of 41% or more.