Screw-based MEX (SB) High quality metal filament and bar feedstocks are still very limited in alloy selection. Hence, screw-based MEX is currently the most versatile material extrusion system in term of material selection. Screw-based MEX uses the granulated feedstock in a similar form as MIM, hence all alloys for MIM feedstocks are applicable. The feedstock will be transported by screw rotation [132] and simultaneously heated by heating elements to a temperature above the glass transition temperature of the polymer binder. The softened material will be deposited through the nozzle in a pattern that follows the CAD design, as presented in Figure 3a. The advantages of this type over the latter two processes, which are plunger- (Figure 3b) and filament- (Figure 3c) based types are high productivity due to a continuous filling system and no requirement for an additional processing step for bar or filament preparation. In addition, high solid loading equivalent to that employed in MIM can be used. This process provides the best available feedstock filling system, which can continFigure 3. Types of material extrusion additive manufacturing classified by feeding system:(a) screw-based, (b) plunger-based and (c) filament-based types.• Screw-based MEX (SB)High quality metal filament and bar feedstocks are still very limited in alloy selection.Hence, screw-based MEX is currently the most versatile material extrusion system interm of material selection. Screw-based MEX uses the granulated feedstock in a similarform as MIM, hence all alloys for MIM feedstocks are applicable. The feedstock will betransported by screw rotation [132] and simultaneously heated by heating elements to atemperature above the glass transition temperature of the polymer binder. The softenedmaterial will be deposited through the nozzle in a pattern that follows the CAD design, aspresented in Figure 3a. The advantages of this type over the latter two processes, whichare plunger- (Figure 3b) and filament- (Figure 3c) based types are high productivity dueto a continuous filling system and no requirement for an additional processing step forbar or filament preparation. In addition, high solid loading equivalent to that employedin MIM can be used. This process provides the best available feedstock filling system,which can continuously feed without interruption during printing, as the feedstock in the