ガラス短繊維強化LCP薄肉射出成形品の諸特性に及ぼすリブ形状とガラス繊維充填率の影響 [in Japanese] Effects of Rib Shape and Glass Fiber Content on Mechanical and Thermal Properties of an Injection Molded Thin Short-GF/LCP Part [in Japanese]
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LCP (Liquid Crystalline Polymer) is widely used for the injection molded parts of small, thin-walled, and fine shapes. However, strong anisotropy appears in thermal and mechanical properties (ex. coefficient of thermal expansion, bending rigidity) of the parts for molecular orientation by shearing in a flow-solidification process. Therefore, LCP is generally used with the short fiber of glass or carbon for the anisotropic relaxation and reinforcement. In this paper, we discussed the changes of thermal and mechanical properties of parts with thin-walled rib by the dimensional factor (thickness of the rib and base plate) and the material factor (glass fiber content) as parameters. To evaluate anisotropy of the rib, TD (Transverse Direction) was evaluated by the coefficient of thermal expansion measured with TMA. Moreover, MD (Machine Direction) was evaluated with the bending rigidity by measuring deflection of rib.<BR>As a result, in the part with the thin-wall which is relatively thin compared with the length of glass fiber, the following points were obtained;<BR>(1) Cause-specific trends in the anisotropy of coefficient of thermal expansion of the rib in the case that glass fiber content is high and the thickness of the rib and base plate are thin.<BR>(2) Bending rigidity of the rib is higher when the thickness of the rib is thin, and less susceptible to the thickness of the base plate or glass fiber content when the rib is thick.<BR>(3) Aggregation of glass fiber occurs near the entrance of the rib in the case that glass fiber content is high and the thickness of rib and base plate are thin.
Seikei-Kakou 22(9), 512-518, 2010
The Japan Society of Polymer Processing