Method for printing 3D parts and support structures with electrophotography-based additive manufacturing

A method for printing a three-dimensional part and a support structure with an electrophotography-based additive manufacturing system, the method comprising:

• providing a charged support material that compositionally comprises a first copolymer having aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups, and anhydride groups;
• providing a charged part material that compositionally comprises a second copolymer having acrylonitrile units, butadiene units, and aromatic units, wherein the charged support material has a dynamic viscosity at 200° C. that is within about 10 kilopascal-seconds of a dynamic viscosity at 200° C. for the charged part material;
• developing a support layer of the charged support structure from the support material;
• developing a part layer of the three-dimensional part from the charged part material;
• independently transferring the support layer and the part layer to a transfer medium such that the support layer and the part layer define a combined layer;
• moving the combined layer to a layer transfusion assembly to previously-printed layers of the three-dimensional part and the support structure;
• and
• transfusing the combined layer to previously-printed layers.

A method for printing a three-dimensional part and a support structure with an electrophotography-based additive manufacturing system, the method comprising:

• providing a support material compositionally comprising a first charge control agent and a first copolymer having aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups and wherein adjacent carboxylic acid groups are converted anhydride groups such that a maximum conversion of carboxylic acid groups to anhydride ranges from about 60% to about 65%, relative to the initial number of carboxylic acid groups in the copolymer group prior to anhydride conversion;
• providing a part material compositionally comprising a second charge control agent, and a second copolymer having acrylonitrile units, butadiene units, and aromatic units;
• developing a support layer of the support structure from the support material with a first electrophotography engine;
• transferring the developed support layer from the first electrophotography engine to a transfer medium;
• developing a part layer of the three-dimensional part from the part material with a second electrophotography engine;
• transferring the developed part layer from the second electrophotography engine to the transfer medium
• moving the attracted part and support layers to a layer transfusion assembly with the transfer medium;
• and
• transfusing the moved part and support layers together to previously-printed layers with the layer transfusion assembly.