Composite particulate build materials

Abstract

The present disclosure is drawn to a composite particulate build material, including 92 wt % to 99.5 wt % polymeric particles having an average size from 10 μm to 150 μm and an average aspect ratio of less than 2:1. The composite particulate build material further includes from 0.5 wt % to 8 wt % reinforcing particles having an average size of 0.1 μm to 20 μm and an average aspect ratio of 3:1 to 100:1 applied to a surface of the polymeric particles.

What is claimed is: 
     
         1 . A composite particulate build material, comprising:
 92 wt % to 99.5 wt % polymeric particles having an average size from 10 μm to 150 μm and an average aspect ratio of less than 2:1; and   0.5 wt % to 8 wt % reinforcing particles having an average size of 0.1 μm to 20 μm and an average aspect ratio of 3:1 to 100:1 applied to a surface of the polymeric particles.   
     
     
         2 . The composite particulate build material of  claim 1 , wherein the polymeric particles include a nylon, a thermoplastic elastomer, a urethane, a polycarbonate, a polystyrene, a polyacetal, a polyproplylene, a polyester, a polyether ketone, a polyacrylate, a polyurethane, an engineered plastic, a polyethylene, a polyethylene terephthalate, an amorphous polymer thereof, a blend thereof, or a core-shell composite thereof. 
     
     
         3 . The composite particulate build material of  claim 1 , wherein the reinforcing particles include mica, talc, or glass. 
     
     
         4 . The composite particulate build material of  claim 1 , wherein the reinforcing particles have an elongated fiber structure. 
     
     
         5 . The composite particulate build material of  claim 1 , wherein the reinforcing particles have a flattened plate-like structure. 
     
     
         6 . The composite particulate build material of  claim 1 , wherein the reinforcing particles are substantially not present below the surface of the polymeric particles. 
     
     
         7 . The composite particulate build material of  claim 1 , wherein from 10% to 80% of the surfaces of the polymeric particles are covered by the reinforcing particles by total surface area. 
     
     
         8 . The composite particulate build material of  claim 1 , wherein the material is in the form of a free-flowing particulate suitable for use as a powder bed build material for 3D printing. 
     
     
         9 . A method of making a composite particulate build material, comprising:
 admixing polymeric particles having an average size from 10 μm to 150 μm and an average aspect ratio of less than 2:1 with reinforcing particles having an average size of 0.1 μm to 20 μm and an average aspect ratio of 3:1 to 100:1 in the presence of a polymer swelling solvent; and   allowing the polymeric particles to swell such that the reinforcing particles to is become applied to a surface of the polymeric particles to form the composite particulate build material.   
     
     
         10 . The method of  claim 9 , further comprising rinsing and drying the composite particulate build material to leave a particulate composition comprising 92 wt % to 99.5 wt % polymeric particles and 0.5 wt % to 8 wt % reinforcing particles embedded on the surface of the polymeric particles. 
     
     
         11 . The method of  claim 9 , wherein the step of admixing includes mixing the polymeric particles and the reinforcing particles first, followed by addition of the swelling solvent. 
     
     
         12 . The method of  claim 9 , wherein the step of admixing includes mixing the swelling solvent and the reinforcing particles first, followed by addition of the polymeric particles. 
     
     
         13 . The method of  claim 9 , wherein the step of admixing includes mixing the polymeric particles and the polymer swelling solvent first, followed by addition of the reinforcing particles. 
     
     
         14 . A material set for 3D printing, comprising:
 a composite particulate build material, including:
 92 wt % to 99.5 wt % polymeric particles having an average size from 10 μm to 150 μm and an average aspect ratio of less than 2:1, and 
 0.5 wt % to 8 wt % reinforcing particles having an average size of 0.1 μm to 20 μm and an average aspect ratio of 3:1 to 100:1 applied to surfaces of the polymeric particles; and 
   a fusible ink, including:
 a liquid vehicle; and 
 electromagnetic radiation absorbing solids dispersed in the liquid vehicle which are suitable for receiving electromagnetic energy from an energy source and fusing with the composite particulate build material when contacted with the composite particulate build material and irradiated by the electromagnetic energy. 
   
     
     
         15 . The material set of  claim 14 , wherein the reinforcing particles are substantially not present below the surfaces of the polymeric particles, and wherein from 10% to 80% of the surfaces of the polymeric particles are covered by the reinforcing particles by total surface area.