繊維強化ポリアミドサンドイッチ射出成形品の力学的特性
Mechanical Properties of Fiber Reinforced Polyamide Injection Moldings with Sandwich Structure
藤田章洋・馬場文明・_田泰以
Fujita, Akihiro / Baba, Fumiaki / Hamada, Hiroyuki
The sandwich injection molding technique can be used to wide ranges of engineering applications. 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. The products with special characteristics can be obtained by the sandwich injection molding process.
In this study, the sandwich injection moldings which consisted of polyamide 66 and the fiber reinforced polyamides 66 were molded by using SCI. molding process. The bending properties of the sandwich injection moldings were evaluated by comparing with those of the moldings with single materials. Consequently, the bending properties of the sandwich moldings were more than 80% those of the single moldings in spite of lower fiber contents of the sandwich moldings. It was also clear that the adhesive properties of the interface greatly contributed to the bending properties, in particular, bending strength. The sandwich molding with short glass fiber which had more superior interfacial adhesion, exhibited more superior bending properties as compared with those with the long glass and carbon fibers. Moreover, the bending properties obtained by the composite beam theory were compared with the experimental result. This calculation method using the sandwich beam theory was valid to predict the bending properties of the sandwich moldings.
Key words: Sandwich structure / Injection molding / Fiber reinforced polyamide