Thin-Wall Molded Article Resolving Clogging and Strength Trade-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Small-sized molded articles with thin wall parts, such as camera module components, face issues with deformation due to dimensional changes from molding shrinkage, overheating, and water absorption, leading to inadequate mechanical strength and dimensional stability, and the use of fillers like glass flakes can cause clogging and affect moldability.
Innovation Solution
A thermoplastic resin composition containing a semi-aromatic polyamide and an inorganic filler with a specific aspect ratio and thickness, which enhances tensile characteristics, mechanical strength, and dimensional stability, while preventing clogging and improving moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If glass flakes are used as filler to improve dimensional stability and mechanical strength, then the mechanical properties and dimensional accuracy are improved, but clogging occurs in the gate part and moldability deteriorates
Solution Approach 1:
The invention changes the aspect ratio parameter of the glass flake filler from conventional values to a specific range (length 10-50 μm, thickness 2-8 μm, aspect ratio 1.25-2.5). This parameter optimization allows the filler to provide sufficient mechanical reinforcement while reducing clogging in the gate part, thereby improving both strength and moldability simultaneously
Solution Approach 2:
The invention uses a composite filler system combining glass flake and mica in specific weight ratios (glass flake 30-70 wt%, mica 30-70 wt%). This composite approach creates synergistic effects where glass flake provides structural strength and mica improves flow characteristics, resolving the contradiction between mechanical strength and moldability
2Stability of the object's composition
If glass flakes are used as filler to control warp and improve dimensional stability, then the dimensional stability is improved, but clogging is generated in the gate part
Solution Approach 1:
The invention optimizes the thickness parameter of glass flake to a specific range (2-8 μm) which prevents excessive accumulation and clogging in the gate part while maintaining sufficient dimensional stability. This parameter control eliminates the harmful clogging effect while preserving the beneficial dimensional stability
Solution Approach 2:
The invention introduces mica as an intermediary filler material that acts as a flow promoter and clogging prevention agent. Mica particles fill the spaces between glass flake particles and improve the overall flow characteristics of the resin composition, preventing clogging while allowing glass flake to provide dimensional stability
3Strength
If conventional fillers are used to improve mechanical properties, then the mechanical strength is improved, but the focus is not right due to slight dimensional changes in small-sized thin wall parts
Solution Approach 1:
The invention uses a composite filler system of glass flake and mica in specific ratios that work synergistically to provide both mechanical strength and dimensional accuracy. The combination creates a balanced reinforcement system that prevents warping and maintains focus in small-sized thin wall parts while achieving the required mechanical strength
Solution Approach 2:
The invention optimizes the aspect ratio parameter of the filler to a specific range (1.25-2.5) which provides sufficient mechanical reinforcement without causing excessive stiffness that would lead to warping. This parameter optimization achieves the right balance between strength and dimensional accuracy for small precision parts
Data Source
Figure 1~2
Figure 3~4
AI summary
Disclosed is a molded article obtained by molding a thermoplastic resin composition, wherein the thermoplastic resin composition contains a thermoplastic resin (A) and an inorganic filler (B); the content of the inorganic filler (B) is 60 to 150 parts by mass based on 100 parts by mass of the thermoplastic resin (A); the content of a plate-shaped inorganic filler (b1) having an average thickness of 4.0 µm or less and an aspect ratio of 130 or more in the inorganic filler (B) is 35 to 100% by mass; and a thickness of the thinnest part thereof is 2.0 mm or less.