同時複合射出成形法による繊維強化サンドイッチ構造物の成形と物性
Processing and Properties of Fiber Reinforced Article with Sandwich Structure in Simultaneous Composite Injection Molding
泊 清隆・早崎 進・高嶌弘樹・夏 明・_田泰以・前川善一郎
Tomari, Kiyotaka / Hayasaki, Susumu / Takashima, Hiroki / Ming, Xia / Hamada, Hiroyuki / Maekawa, Zenichiro
A simultaneous composite injection molding (SCI. molding) process is a new process of molding composite parts in which two different melts are injected into one mold cavity simultaneously through two channels. This molding process has the outstanding advantages of high resin/resin bonding strength and low production cost compared with the conventional two-color injection molding. The sandwich injection molding process as well as two-color injection molding uses two injection units. However, since they use one common nozzle, some problems remain such as the limitation in the selection of materials. The SCI. molding process can solve these problems with the conventional sandwich injection molding.
In this study, we fabricated fiber reinforced thermoplastics articles with sandwich structures using the SCI. molding process. The effect of molding conditions on the sandwich structure was discussed. Two different materials with large differences in melting temperature can be fabricated. Bending tests were carried out, and composite beam theory and laminated beam theory were applied to predict the bending modulus. It was confirmed that sandwich composite injection molding has various unique properties i.e. high strength, low cost, low weight etc. The bending modulus of the sandwich beam showed good agreement with the theoretical value obtained by composite beam theory. This result suggested that a very strong interface could be formed between two different materials.
Key words: Sandwich structure / Co-injection molding / Fiber reinforced thermoplastics