The purpose of this study is to develop automotive frictional parts, especially continuously variable transmission (CVT) blocks using a composite material made of thermoplastic resin and fiber. CVT blocks were used at about 100ºC under high pressure and friction conditions; nylon 9T, otherwise named PA9T, was used. PA9T has a high melting point which is higher than the maximum temperature at the state of slip. To apply composite materials to the manufacture of CVT blocks, material properties such as high strength, modulus of elasticity and fatigue strength are important. Therefore, the aim of this study is improvements in mechanical properties by adding fillers to PA9T under various compounding and molding conditions. PA9T and carbon fibers were mixed using a twin screw extruder. After compounding, dumbbell specimens were made using an injection molding machine. Bending, fatigue and abrasion tests were conducted. Moreover, the transmission capacity of CVT belt made of PA9T composites was evaluated and slip tests were conducted. According to the results of tests, PA9T with CF38.8 vol% achieved desired values for CVT application. The CVT belt has a torque capacity of 40 Nm under an axle load of 2.0 kN.

The purpose of this study is to develop automotive frictional parts, especially continuously variable transmission (CVT) blocks by using a composite material made of thermoplastics resin and fiber. CVT blocks are used at about 100ºC under high pressure and friction condition. So, we have used nylon 9T, PA9T. PA9T has high a melting point that is higher than maximum temperature of the state of slip. To apply composite materials to CVT blocks, the material properties such as high strength, modulus of elasticity and fatigue strength are important. Therefore, a purpose of this study is improvements of mechanical properties by adding fillers to PA9T with various compounding and molding condition. PA9T and CF were mixed by using twin screw extruder. After compounding, dumbbell specimens were made by using injection molding machine. Bending, fatigue and abrasion tests were conducted. Moreover, we evaluated the transmission capacity of CVT belt made of PA9T composites and conducted slip test. According to results of tests, PA9T with CF38.8 vol% achieved desired values of CVT. The CVT belt has 40 Nm of torque under 2.0 kN of axle load.