Piston metering systems are less subject to wear, but single-piston metering systems have a serious disadvantage in that the material flow is not constant. On the other hand, constant flow is often essential for high productivity in applications requiring protracted shot times, or to supply several mixing heads. This metering machine provides a system where the abrasive component is fed by two pistons operating in tandem. The pistons move anti cyclically example while one is discharging the other is filling. A sophisticated control system ensures that material flow remains constant even during piston switchover. The pistons are actuated by servomotor spindle drives. Electric drives have several advantages compared with hydraulic drives. System start-up is very much simpler. The spindle drive supports high-precision piston movements. As a result, the filled component is fed at highly uniform rate to the mixing head, maintaining a constant mixing ratio. The end result is consistently high product quality. This piston metering machine is the right solution for many different application areas from processing glass fiber and abrasive flame inhibitors to fillers and reinforcing materials, such as wollastonite, barite or chalk. In some of the metering machine, two pistons feed the abrasive component to the mixing head. The alternating action of the two pistons results in a continuous flow of material. Each of the two pistons is actuated by servomotor spindle drives, which guarantees very precise piston movement.