Fiber-Reinforced Resin Surface Grains for Appearance Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber-reinforced thermoplastic resin products exhibit variations in appearance due to differences in fiber orientation between flowing and non-flowing portions during compression molding, leading to inconsistent surface finishes and potential weathering deterioration.
Innovation Solution
Incorporating grains with specific dimensions and resin proportions on the surface of the product to uniform fiber orientation and reduce resin content, thereby minimizing appearance differences and enhancing weather resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If compression molding is performed on fiber-reinforced thermoplastic resin material, then productivity is improved and desired shape is achieved, but appearance consistency deteriorates due to fiber orientation differences between flowing and non-flowing portions
Solution Approach 1:
The invention applies different surface treatments to different regions of the molded product. Specifically, a grain pattern is applied only to the non-flowing portion (such as the gate area) where fiber orientation causes appearance issues, while leaving the flowing portion with a smooth finish. This local differentiation resolves the appearance consistency problem without affecting the overall productivity of the compression molding process.
Solution Approach 2:
The grain pattern is pre-formed on the mold surface before the molding process begins. During compression molding, this pre-formed grain pattern is transferred to the non-flowing portion of the product, preventing the appearance defect from occurring in the first place rather than requiring post-processing corrections.
2Strength
If long fiber-reinforced thermoplastic resin is used to maintain strength, then tensile strength is improved, but surface appearance deteriorates due to fiber orientation variations
Solution Approach 1:
The grain pattern is selectively applied only to the non-flowing portion where long fibers cause orientation-related appearance defects, while the flowing portion maintains its smooth surface. This allows the use of long fibers for strength without compromising overall surface appearance uniformity.
3Manufacturing precision
If grain pattern is applied to suppress appearance differences, then surface appearance is improved, but manufacturing complexity increases
Solution Approach 1:
The grain pattern is pre-formed directly on the mold cavity surface during mold manufacturing. This eliminates the need for complex post-processing equipment or additional manufacturing steps, as the grain pattern is automatically transferred to the product during the standard compression molding process.
Solution Approach 2:
The mold serves multiple functions: it forms the basic product shape, controls fiber orientation, and simultaneously transfers the grain pattern to the non-flowing portion. This multi-functionality avoids the need for separate grain application equipment, maintaining manufacturing simplicity.
4Reliability
If resin content is reduced in projection portions to improve weather resistance, then weather resistance is improved, but manufacturing precision becomes more difficult to control
Solution Approach 1:
The grain pattern creates local variation in resin distribution, with projection portions having lower resin content and recess portions having higher resin content. This local differentiation is achieved through the molding process itself rather than requiring precise external control, improving weather resistance while maintaining manufacturability.
Data Source
Figure 1~5
Figure 6~7
AI summary
A fiber-reinforced resin molding that comprises a reinforcing fiber having a weight-average fiber length of 100 mm or less and a thermoplastic resin, said fiber-reinforced resin molding being characterized by having embosses at least on a part of the surface thereof, the maximum height (Rz) of the embosses is 100-200 µm, and the average pitch (Rsm) between embosses adjacent to each other is 1100 µm or less.