成形温度におけるCF/PA6の引張特性評価

抄録

Carbon Fiber Reinforced Thermoplastics (CFRTP), which have high specific strength and specific rigidity, superior productivity and recyclability, have been expected to reduce the weight of cars. Since the thermoplastics resin has higher viscosity than thermosetting resin during molding process, the deformation characteristic of CFRTP in the molten state depends on the material properties of the resin. It is necessary to clarify the mechanical properties of CFRTP under high temperature that is higher than melting point of the matrix resin. While bias-extension test using temperature controlled chamber has been applied for the evaluation of mechanical properties of CFRTP under high temperature, strain measurement is one of the important issues to be overcome. In this study, tensile test of FRTP under high temperature over melting point of the matrix resin by using far infrared ray heaters to heat only the gauge of specimen has been developed. This method allows us to observe the specimen surface and to measure strain of the specimen. Mechanical properties of CF/PA6 have been evaluated under high temperature by this method. The tensile strength and tensile modulus of CF/PA6 decreased as the temperature increased, and even under the high temperature, which is higher than the melting point of the matrix resin, the effect of the viscosity of the matrix resin should be taken into account. Under the relatively higher temperature condition (e. g. 280°C), smaller shear deformation occurred and larger shear locking angle of CF/PA6 was obtained due to lower viscosity of matrix resin. On the other hand, under the relatively lower temperature condition (e. g. 240°C) shear locking angle of CF/PA6 became smaller, i. e. larger shear deformation after the stretching between fiber bundles occurred due to higher viscosity of the matrix resin.