Abstract: A method of printing a multi-material part in a layer-wise manner with an extrusion-based 3D printer includes providing a sliced digital model of a multi-material part and determining a number of materials in each of the slices of the digital mode. The method includes utilizing a digital model of a purge tower having N subdivisions having a closed geometry, wherein N is the number of print heads needed to print the part that is greater than or equal to three, each adjacent subdivision contact one another along an interface and assigning each print head to one subdivision and to tool paths forming the one subdivision in each layer. The method includes reassigning the assigned subdivision within the purge tower of an inactive print head in a layer to a print head that is active in the layer of the multi-material part.

Abstract: A method of printing a multi-material part in a layer-wise manner with an extrusion-based 3D printer includes providing a sliced digital model of a multi-material part and determining a number of materials in each of the slices of the digital mode. The method includes utilizing a digital model of a purge tower having N subdivisions having a closed geometry, wherein N is the number of print heads needed to print the part that is greater than or equal to three, each adjacent subdivision contact one another along an interface and assigning each print head to one subdivision and to tool paths forming the one subdivision in each layer. The method includes reassigning the assigned subdivision within the purge tower of an inactive print head in a layer to a print head that is active in the layer of the multi-material part.