Three-dimensional printing

Abstract

Methods and compositions of three-dimensional printing are described herein. In an example, a method for three-dimensional printing can comprise: (i) a powder bed material being deposited, wherein the powder bed material comprises a polyimide-11 powder having an average particle size of from about 20 μm to about 120 μm, wherein the polyamide-11 powder has a solution viscosity of from about 1.75 to about 1.9 at 25° C. based on ASTM using m-cresol as solvent; (ii) a fusing agent being selectively applied on a first portion of the powder bed material, wherein the fusing agent comprises an energy absorber to absorb electromagnetic radiation (IR) to melt or fuse at least a portion of the polyamide-11 powder in areas covered by the fusing agent, and (iii) (i) and (ii) repeated at least once.

What is claimed is: 
     
         1 . A method for three-dimensional printing comprising:
 (i) depositing a powder bed material,   wherein the powder bed material comprises a polyimide-11 powder having an average particle size of from about 20 μm to about 120 μm,   wherein the polyimide-11 powder has a solution viscosity of from about 1.75 to about 1.9 at about 25° C. based on ASTM using m-cresol as solvent;   (ii) selectively applying a fusing agent on a first portion of the powder bed material,   wherein the fusing agent comprises an energy absorber to absorb electromagnetic radiation (IR) to melt or fuse at least a portion of the polyamide-11 powder in areas covered by the fusing agent, and   (iii) repeating (i) and (ii) at least once.   
     
     
         2 . The method of  claim 1 , wherein the polyamide-11 powder has a solution viscosity of from about 1.75 to about 1.85 at about 25° C. 
     
     
         3 . The method of  claim 1 , wherein the polyamide-11 powder has a solution viscosity of from about 1.8 to about 2.2 when heated to about 180° C. for up to about 72 hours in air. 
     
     
         4 . The method of  claim 3 , wherein the polyamide-11 powder has a solution viscosity of from about 1.9 to about 2.1 when heated to about 180° C. for up to about 72 hours in air. 
     
     
         5 . The method of  claim 1 , wherein the polyamide-11 powder bed material has a yellow index value of less than about 10 as a virgin powder, and the yellow index value increases to no greater than about 40 when exposed to about 180° C. for about 72 hours in air. 
     
     
         6 . The method of  claim 1  further comprising:
 (ii)-(a) applying a detailing agent on a second portion of the powder bed material. 
 
     
     
         7 . The method of  claim 1 , wherein the energy absorber comprises a carbon black pigment, a near-infrared absorbing dye, a near-infrared absorbing pigment, a tungsten bronze, a molybdenum bronze, metal nanoparticles, a conjugated polymer, or a combination thereof. 
     
     
         8 . The method of  claim 1 , wherein the powder bed material further includes an anti-oxidant powder admixed with the polyamide-11 powder. 
     
     
         9 . A three-dimensional printing composition comprising:
 a powder bed material,
 wherein the powder bed material comprises a polyamide-11 powder having an average particle size of from about 20 μm to about 120 μm, 
 wherein the polyamide-11 powder has a solution viscosity of from about 1.75 to about 1.9 at about 25° C.; and 
   a fusing agent comprising an energy absorber to absorb electromagnetic radiation (IR) to melt or fuse at least a portion of the polyimide-11 powder in areas covered by the fusing agent.   
     
     
         10 . The composition of  claim 9 , wherein the polyamide-11 powder has a solution viscosity of from about 1.75 to about 1.85 at about 25° C. 
     
     
         11 . The composition of  claim 9 , wherein the polyamide-11 powder has a solution viscosity of from about 1.8 to about 2.2 when heated to about 180° C. for up to about 72 hours in air. 
     
     
         12 . The composition of  claim 11 , wherein the polyamide-11 powder has a solution viscosity of from about 1.9 to about 2.1 when heated to about 180° C. for up to about 72 hours in air. 
     
     
         13 . The composition of  claim 9 , wherein the volume weighed particle size distribution of the polyamide-11 powder is as follows:
 D10 is from about 15 μm to about 35 μm,   D50 is from about 35 μm to about 65 μm, and   D90 is from about 65 μm to about 95 μm.   
     
     
         14 . The composition of  claim 9 , wherein the powder bed material further includes an anti-oxidant powder admixed with the polyamide-11 powder. 
     
     
         15 . The composition of  claim 9 , wherein the energy absorber comprises a carbon black, a near-infrared absorbing dye, a near-infrared absorbing pigment, a tungsten bronze, a molybdenum bronze, metal nanoparticles, or a conjugated polymer, or a combination thereof.