Cold Press Molding of Fiber-Reinforced Resin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in cold press molding of fiber-reinforced resin materials is to achieve thin-walled, high-strength molded articles with excellent appearance, as existing methods lack clear specifications for mold cooling and heating parameters, leading to inefficient moldability and limited wall-thinning capabilities.
Innovation Solution
A method involving specific temperature and time parameters for heating, cooling, and pressing, including a calculated moldable time, to ensure compatibility of moldable temperature and pressure conditions, utilizing a fiber-reinforced resin material with thermoplastic resin and reinforcing fibers, where the heating temperature is set above the melting or glass transition point, and controlled cooling and pressing rates are applied to achieve optimal moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the mold temperature is increased to improve moldability, then the molded article can be further thin-walled, but the molding cycle time increases and productivity decreases
Solution Approach 1:
The patent applies periodic temperature control to the mold, alternating between high temperature (for improved moldability and thin-walled formation) and low temperature (for rapid cooling and short cycle time). The mold temperature is dynamically adjusted during the molding process rather than maintaining a constant temperature, enabling both thin-walled precision and high productivity
Solution Approach 2:
The mold temperature is made dynamic rather than static. The patent specifies that the mold temperature should be changed according to the molding stage: initially high to allow resin flow and wall-thinning, then rapidly lowered to freeze the structure and enable quick ejection. This dynamic temperature control resolves the contradiction between needing high temperature for moldability and low temperature for productivity
2Shape
If the mold temperature is decreased to improve appearance, then the surface quality improves, but the moldability decreases and wall-thinning capability is limited
Solution Approach 1:
The patent applies preliminary heating to the mold before molding to ensure the resin has sufficient fluidity for wall-thinning and complex shape formation. Only after the molding process begins does the temperature decrease to improve surface appearance. This preliminary high-temperature action enables both good appearance and wall-thinning capability
3Weight of moving object
If the fiber-reinforced resin material is made thinner to meet customer demands, then the molded article becomes lighter and more compact, but the moldability deteriorates and manufacturing becomes difficult
Solution Approach 1:
The patent changes the temperature parameter dynamically during the molding process to enable thin-walled manufacturing. By initially raising the mold temperature, the resin viscosity decreases and flowability increases, making it possible to successfully mold thin-walled structures that would otherwise be difficult to manufacture
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 further thin-walled fiber-reinforced resin molded articles with enhanced bending strength per unit weight and improved appearance, by precisely managing the molding process parameters to extend wall-thinning capabilities.
Implementation Method 1
The internal temperature of the fiber-reinforced resin material immediately after heating before molding is in a temperature range higher than the melting point of the crystalline resin by 50 to 100°C
Implementation Method 2
the heating temperature is in a temperature range higher than a glass transition temperature of an amorphous resin by 125 to 175°C
Implementation Method 3
A cooling rate of the fiber-reinforced resin material from when the upper mold is brought into contact with the fiber-reinforced resin material to when a temperature of the fiber-reinforced resin material becomes the flow stop temperature
Data Source
AI summary
Provided is a method for manufacturing a fiber-reinforced resin molded article by cold press molding a fiber-reinforced resin material including reinforcing fibers and a thermoplastic resin using molds containing an upper mold and a lower mold. In the method, the respective parameters for: heating temperature; charge time; air-cooling rate; pressurization time; flow-stopping temperature; and a moldable time satisfies specified numerical ranges simultaneously.