Rounded-Particle Plastic Powder in Particular for Application in Laser Sintering, Method for Production of Such a Powder and Laser Sintering Process Using Such a Powder

Abstract

In a laser sintering method for producing a three-dimensional object wherein subsequent layers of the object to be formed are subsequently solidified on positions corresponding to the object, as a build-up material, a powder is used wherein the upper grain limit of the powder particles is below 100 μm, the D 0.5 -value is below 55 μm, the BET-surface is smaller than 5 m 2 /g and the grains of the powder basically have a spherical shape.

1 . A polymer powder produced by a process of milling or precipitating comprising a surface which is compact and not jagged. 
   
   
       2 . (canceled) 
   
   
       3 . A polymer powder according to  claim 1  for producing a three-dimensional object by means of laser sintering, wherein the powder comprises a BET-surface which is smaller than 5 m 2 /g and at the same time the upper grain limit is below 100 μm, the D 0.9 -value is below 80 μm, and the D 0.5 -value is below 55 μm and the particles comprise a basically spherical shape. 
   
   
       4 . A powder according to  claim 1 , wherein the powder has a BET-surface having a value smaller than or equal to 4 m 2 /g. 
   
   
       5 . A powder according to  claim 1 , wherein the powder has a BET-surface having a value smaller than or equal to 3 m 2 /g. 
   
   
       6 . A powder according to  claim 1 , wherein the powder has a BET-surface having a value smaller than or equal to 2 m 2 /g. 
   
   
       7 . A powder for manufacturing a three-dimensional object by means of laser sintering  claim 1 , wherein a laser sintering refreshing factor is less than 50 percent. 
   
   
       8 . A powder according to  claim 7 , wherein the refreshing factor is less than 30 percent. 
   
   
       9 . A powder according to  claim 1 , wherein the powder is a polyamide powder. 
   
   
       10 . A powder according to  claim 1 , wherein the powder consists of polyamide 11 or polyamide 12. 
   
   
       11 . A powder according to  claim 9 , wherein the powder is a precipitated PA12 powder. 
   
   
       12 - 17 . (canceled) 
   
   
       18 - 26 . (canceled) 
   
   
       27 . A method for producing a powder according to  claim 1 , wherein as a base material a plastic powder attained by means of precipitation or milling is used which is mechanically or mechanically-thermally mixed for at least one minute in an appropriate aggregate. 
   
   
       28 . A method according to  claim 27  wherein the base material has at least one further powder component. 
   
   
       29 . A method according to  claim 28  wherein a further powder component is a polymer powder or an additive. 
   
   
       30 . A method for manufacturing a three-dimensional object by means of laser sintering wherein subsequent layers of the object to be formed are subsequently solidified from solidifiable powder material in positions corresponding to the object and a powder according to  claim 1  is used as powder material. 
   
   
       31 . A method according to  claim 30  wherein the powder base material has at least one further powder component. 
   
   
       32 . A method according to  claim 31  wherein a further powder component is a polymer powder or an additive.