Rayon Fiber Reinforced Resin Composition for Lightweight Molded Articles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fiber-reinforced resin compositions for lightweight molded articles with good mechanical properties are limited in achieving optimal mechanical strength and moldability, particularly when using rayon fibers, due to issues with fiber impregnation and interface strength with thermoplastic resins.
Innovation Solution
A fiber-reinforced resin composition comprising a resin-adhered long fiber bundle of rayon fibers integrated with acid-modified polyolefin-based or polyamide-based thermoplastic resins, ensuring effective impregnation and enhanced mechanical properties through specific fiber diameter, tensile elongation, and X-ray orientation requirements, which improves the mechanical strength and moldability of the resulting molded articles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If rayon fibers are used as reinforcement fiber in thermoplastic resin composition, then lightweight molded articles can be obtained, but the mechanical strength and moldability are insufficient due to poor fiber impregnation and interface strength
Solution Approach 1:
A coupling agent is introduced as an intermediary substance between the rayon fiber surface and the thermoplastic resin. The coupling agent chemically bonds to both the fiber surface and the resin, creating a strong interface that improves stress transfer and prevents fiber pull-out, thereby enhancing mechanical strength while maintaining the lightweight advantage of rayon fibers
Solution Approach 2:
The surface properties of rayon fibers are modified by changing parameters such as surface treatment methods (e.g., plasma treatment, chemical etching) and coupling agent types. These parameter changes improve fiber-resin interfacial adhesion and ensure complete impregnation during molding, resolving the moldability and strength issues while preserving the low weight characteristic
2Strength
If inorganic fibers are used as reinforcement fiber to improve mechanical strength, then good mechanical properties are achieved, but combustion residue issues occur
Solution Approach 1:
The material composition of reinforcement fibers is changed from inorganic (glass, carbon) to organic rayon fibers. This parameter change in fiber material eliminates combustion residue problems while maintaining mechanical strength through optimized fiber properties (length, diameter, orientation) and improved interfacial bonding with thermoplastic resin using coupling agents
3Strength
If long fiber bundles are used to improve mechanical strength, then good mechanical properties are achieved, but the fiber impregnation with thermoplastic resin becomes difficult
Solution Approach 1:
The coupling agent acts as a mediator that reduces surface tension and improves wetting between the thermoplastic resin and long rayon fiber bundles. This enables complete and uniform impregnation of even long fiber bundles during the molding process, ensuring good interfacial adhesion and mechanical strength without compromising ease of manufacture
Solution Approach 2:
Processing parameters such as resin viscosity, molding temperature, and injection pressure are optimized to facilitate complete impregnation of long fiber bundles. The coupling agent modifies surface parameters to enhance resin-fiber interaction, allowing long fibers to be thoroughly impregnated while maintaining manufacturing feasibility
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
The composition achieves a lightweight molded article with high mechanical strength, specifically a large specific modulus, and improved moldability, making it suitable for various applications including electric and electronic equipment, automobiles, and building materials, while avoiding combustion residue issues associated with inorganic fibers.
Implementation Method 1
a resin-adhered long fiber bundle (resin-adhered rayon long fiber bundle) containing a component (A) and a component (B)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention provides a fiber-reinforced resin composition, which provides a molded article having a good mechanical strength. The fiber-reinforced resin composition contains a resin-adhered long fiber bundle including (A) a thermoplastic resin and (B) a rayon fiber, wherein the rayon fiber of the component (B) satisfies the following requirements (b1), (b2) and (b3), and the resin-adhered long fiber bundle is obtained by adhering and integrating the thermoplastic resin of the component (A) in a molten state to and with a strand of longitudinally-arranged rayon fibers of the component (B), and cutting the strand into a length of 3 to 30 mm, (b1) a fiber diameter of 5 to 30 µm; (b2) a tensile elongation of 10% or more; and (b3) a flat shape with a ratio between a major axis length and a minor axis length (major axis length/minor axis length) in a width-directional cross section of 1.1 or more.