Fiber Orientation control for improve mechanical properties and design method for weight reduction of injection molded parts

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04201
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Kanazawa Institute of Technology
• Principal Investigator: SETO MASAHIRO 金沢工業大学, 工学部, 教授 (90367459)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 射出成形 / 繊維配向 / 可視化観察 / 配向制御 / 製品設計

Outline of Final Research Achievements

Fiber reinforced plastics injection molded products are widely used because high strength and good moldability. However, resin flow can cause fiber orientation, resulting in defects such as warpage deformation and shrinkage anisotropy. In this study, a method to actively control the orientation of reinforcing fibers in injection molding was investigated. Visualization of resin flow behavior revealed that fiber orientation behavior is affected by shear stress and its time variation caused by the resin flow velocity distribution in the cavity thickness direction. The shear stress is highest at the solid-liquid boundary layer, indicating that fiber orientation can be controlled by controlling the solidification layer during molding and that the mechanical properties of the molded product can also be arbitrarily controlled by orientation control.

Free Research Field

プラスチック成形加工

Academic Significance and Societal Importance of the Research Achievements

地球環境問題を背景に，輸送機器分野において部品の軽量化対策が積極的に行われている．プラスチック部品の軽量化手法の一つとして，ガラス繊維や炭素繊維を含有した繊維強化樹脂射出成形品が用いられている．この繊維強化樹脂射出成形品は，繊維の配向によって力学特性が変化することから，本研究で検討した繊維配向メカニズムおよび配向制御手法によって，任意の方向に力学的特性を発現させること可能となる．このことは設計した部品の力学的な使用環境を事前に把握することができれば，その使用環境に応じた部品設計が可能となることを示唆しており，プラスチック部品のさらなる軽量化が期待できる．