a compounder feeder for mixing and then injecting materials such as polymers and glass fibers into a female die mold includes first and second parallel screws which have interengaging spur gears and external mixing discs , the mixing discs of one screw not engaging the mixing discs of the second screw , a drive motor for rotating the first screw and a drive cylinder for moving the second screw axially toward and away from the female die mold to inject mixed material directly therein .