長繊維強化複合材の成形と特性の評価
A Study on How Injection Molding Conditions Affect Mold Properties of Long-fibre Reinforced Thermoplastics
土倉克彦・児矢野富士雄・鴨下隆志
Tsuchikura, Katsuhiko / Koyano, Fujio / Kamoshita, Takashi
Injection-moldable long-fibre reinforced compounds produced by a thermoplastic pultrusion technique have 10-15 times long fibres compared with conventional short-fibre compounds. These materials offer property benefits conferred by the longer fibres. In order to achieve maximum property benefits from long-fibre reinforced compounds, it must be processed in such a way as to minimize the amount of fibre damage during injection molding. The purpose of this work is to clarify the processing-property relationships for dimensional accuracy, flexural strength and Izod impact strength for long-fibre reinforced compounds. The conventional short-fibre compounds were assigned to an orthogonal array L18 as major control factors to compare with long-fibre compounds. Both gate configurations and configurations of test plaque were assigned to the outer array as error factors. The results showed that both dimensional accuracy and the Izod impact strengths were improved by optimizing the process conditions. In particular, the Izod impact strengths of long-fibre compounds was 5dB higher than their short-fibre analogues. However, there was no improvement in the flexural strengths.
Key words: Long-fibre reinforced compound / Taguchi methods / Injection molding / Glass-fibre reinforced / Orthogonal L18 / Nylon 66