Abstract: The air eliminator valve helps to eliminate air in the plastic resin used for composite products manufacturing. During operation, it continuously eliminates the air bubbles in the plastic resin running through the valve, and then transfers the filtered plastic resin into the mold. The design of the air eliminator valve consists of: inlet, inlet lock, air vent, upper cover, main body, ultrasonic generator, outlet lock and outlet. In which, the ultrasonic generator plays a role in generating ultrasonic waves to the plastic resin in the valve body that allows speeding up the air releasing process out the plastic resin. The air content in the valve could go out through the air vent on the upper cover, its status “open/close” is controlled by airlock with automatic response mechanism.