Soluble support material for electrophotography-based additive manufacturing
AssigneeStratasys, Inc.
InventorTrevor I. Martin
Life of this patent
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Abstract
A support material for printing a support structure with an electrophotography-based additive manufacturing system, the support material including a composition having a charge control agent and a thermoplastic copolymer having aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups, and anhydride groups, with a high anhydride conversion. The composition is provided in a powder form having a controlled particle size, and the support material is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the support structure in a layer-by-layer manner, and is at least partially soluble in an aqueous solution.
Claims20
A support material for printing a support structure with an electrophotography-based additive manufacturing system, the support material comprising:
- a composition comprising:
- a thermoplastic copolymer comprising aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups, and anhydride groups, wherein the copolymer has an anhydride conversion that is at least 90% of a maximum anhydride conversion for the thermoplastic copolymer;
- and
- a charge control agent;
- wherein the composition is provided in a powder form having a D50 particle size ranging from about 5 micrometers to about 30 micrometers;
- wherein the support material is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the support structure in a layer-by-layer manner in coordination with printing a three-dimensional part;
- and
- wherein the composition is at least partially soluble in an aqueous solution.
A method for manufacturing a support material for use in an electrophotography-based additive manufacturing system, the method comprising:
- polymerizing monomers comprising one or more ethylenically-unsaturated aromatic monomers, one or more alkyl(meth)acrylate monomers, and one or more (meth)acrylic acid monomers, to produce a thermoplastic copolymer in acid form, which comprises aromatic groups, (meth)acrylate-based ester groups, and carboxylic acid groups;
- heating the thermoplastic copolymer in acid form to convert a portion of the carboxylic acid groups to anhydride groups with an anhydride conversion that is at least 90% of a maximum anhydride conversion for the thermoplastic copolymer, thereby producing a thermoplastic copolymer in anhydride form;
- blending a charge control agent to the thermoplastic copolymer in anhydride form;
- and
- forming the blend into a powder form having a D50 particle size ranging from about 5 micrometers to about 30 micrometers.
A method for printing a support structure with an electrophotography-based additive manufacturing system having an electrophotography engine, a transfer medium, and a layer transfusion assembly, the method comprising:
- providing a support material to the electrophotography-based additive manufacturing system, the support material compositionally comprising a charge control agent and a thermoplastic copolymer having aromatic groups, (meth)acrylate-based ester groups, carboxylic acid groups, and anhydride groups, wherein the thermoplastic copolymer an anhydride conversion that is at least 90% of a maximum anhydride conversion for the thermoplastic copolymer, and wherein the composition is provided in a powder form;
- triboelectrically charging the support material to a Q/M ratio having a negative charge or a positive charge, and a magnitude ranging from about 5 micro-Coulombs/gram to about 50 micro-Coulombs/gram;
- developing layers of the support structure from the charged support material with the electrophotography engine;
- electrostatically attracting the developed layers from the electrophotography engine to the transfer medium;
- moving the attracted layers to the layer transfusion assembly with the transfer medium;
- and
- transfusing the moved layers to previously-printed layers of the support structure with the layer transfusion assembly.
Dependencies are inferred from the claim text.