Method for building three-dimensional models in extrusion-based additive manufacturing systems using core-shell semi-crystalline consumable filaments

A method for building a three-dimensional object with an additive manufacturing system having a heated build chamber and an extrusion head, the method comprising:

• feeding a consumable filament to the extrusion head, the consumable filament comprising:
• a longitudinal length;
• a core portion extending along the longitudinal length, wherein the core portion compositionally comprises a first semi-crystalline polymeric material having a first peak crystallization temperature;
• and
• a shell portion extending along the longitudinal length and substantially encasing the core portion, wherein the shell portion compositionally comprises a second semi-crystalline polymeric material having a second peak crystallization temperature that is different from the first peak crystallization temperature of the first semi-crystalline polymeric material;
• melting the fed consumable filament in the extrusion head to form a molten material;
• depositing the molten material in the heated build chamber as an extruded road of a layer of the three-dimensional object, wherein the extruded road comprises a core region of the first semi-crystalline polymeric material, and a shell region of the second semi-crystalline polymeric material;
• and
• begin crystallizing the first semi-crystalline polymeric material of the core region and the second semi-crystalline polymeric material of the shell region at different times.

A method for building a three-dimensional object with an additive manufacturing system having a heated build chamber and an extrusion head, the method comprising:

• feeding a consumable filament to the extrusion head, the consumable filament comprising:
• a longitudinal length;
• a core portion extending along the longitudinal length, wherein the core portion compositionally comprises a first polyamide material having a first peak crystallization temperature;
• and
• a shell portion extending along the longitudinal length and substantially encasing the core portion, wherein the shell portion compositionally comprises a second polyamide material having a second peak crystallization temperature that is greater than the first peak crystallization temperature of the first polyamide material by at least about 10° C.;
• melting the fed consumable filament in the extrusion head to form a molten material;
• depositing the molten material in the heated build chamber to form a series of extruded roads for a layer of the three-dimensional object, wherein at least a portion of the extruded roads each comprise a core region of the first polyamide material and a shell region of the second polyamide material;
• and
• maintaining an environment within the heated build chamber at one or more temperatures that are about equal to, or are within a range of about 20° C. above or below, the second peak crystallization temperature of the second polyamide material.