An apparatus for injection molding two compatible polymeric materials, in which two substantially coaxial extrusion screws are used to plasticize the two materials into a common accumulation space. The apparatus includes various sensors, control schemes and thermal models, to control pump flow rates and fan flow rates to minimize power consumption, fan noise, and noise transients. In various embodiments, the method may further include the steps of forming a first pattern in a first photo-resist, forming a second pattern in a second photo-resist, and transferring the first and second patterns to a target layer. Mixing of the mortar materials is achieved by agitating the same in an agitator until agitating load rapidly decreases.