Screw extrusion based 3D printing, a novel additive manufacturing technology

Extrusion based 3D printing is a popular additive manufacturing process for the production of plastic prototypes and single- or small series of functional products. The most common known extrusion based technique is Fused Deposition Modeling® , based on filament deposition. Although this is a popular 3D printing technique, there are some disadvantages which imposes some limitations for the end-users. Primarily the limited range of commercially available materials. Secondly the feed material needs to be a filament. In addition the diameter of the filament needs to be produced with a narrow tolerance with respect to the nozzle diameter, in order to prevent blocking of the nozzle. Especially the limited range of materials discourages a lot of end users to produce parts by means of extrusion based 3D printing. This resulted in the development of an alternative extrusion based additive manufacturing process. A good processing technique was found in the conventional plastic extrusion process in which granulate is fed into a plastic processing screw. The paper describes the comparing research between the extrusion based processes such as filament, syringe and screw extrusion, resulting in the choice for the screw extrusion based process. A concept for this process has been worked out and a functional screw extrusion based additive manufacturing process has been developed that complies with the objectives.