Method of grinding polyaryletherketones
An improved method of grinding polyaryletherketones, providing very good yields and the production of powders of polyaryletherketones with an average diameter below 100 μm having a narrow size distribution with few fine particles (Dv10>15 μm). Method of grinding polyaryletherketones of apparent density below 0.9 carried out in a temperature range between 0° C. and the glass transition temperature of the polymer measured by DSC, in order to obtain powders having a particle size distribution (diameters by volume) of d10>15 μm, 50<d50<70 μm, 120<d90<180 μm.
1. A method of obtaining a powder of a polyaryletherketone, comprising carrying out grinding of a polyaryletherketone of tapped apparent density, measured on a STAV 2003 jolting volumeter equipped with a 250 ml test specimen after 2500 impulses, below 0.4 kg/I to a powder, wherein the grinding is carried out at a temperature above 0° C., with a yield of at least 48%, wherein the powder obtained from said grinding has a particle size distribution (diameters by volume) with d10>15 μm and 50<d50≤81 μm.
2. The method according to claim 1 , in which the polyaryletherketone is a polyetherketoneketone.
3. The method according to claim 1 , in which an impact mill is used for grinding.
4. The method according to claim 1 , in which an air jet mill is used for grinding.
5. The method according to claim 1 , in which a combination of impact mill and air jet mill is used for grinding.
6. The method according to claim 1 , wherein the polyaryletherketone has a porosity above 2 m 2 /g, measured by adsorption of nitrogen at 105° C.
7. The method according to claim 1 , wherein the grinding is carried out in a temperature range between 0° C. and the glass transition temperature of the polyaryletherketone as measured by DSC.
8. The method according to claim 1 , wherein the grinding is carried out in a temperature range between 0° C. and 50° C.
9. The method according to claim 1 , wherein the grinding is carried out with a yield approaching 100%.
10. The method according to claim 1 , wherein the grinding is carried out with a yield around 98%.
11. The method according to claim 1 , further comprising a selection which only allows particles that have been ground sufficiently to pass through.
12. The method according to claim 1 , wherein the polyaryletherketone used in the method is in the form of scales or powders.
13. The method according to claim 1 , which is accomplished without additional sieving.
14. The method according to claim 1 , wherein grinding is carried out at a temperature of between 10° C. and 30° C.
15. The method according to claim 1 , further comprising an additional step of adding a filler to the powder.
16. The method according to claim 1 , wherein the powder obtained from said grinding has a particle size distribution (diameters by volume) with d90≤184 μm.
17. The method according to claim 1 , wherein the powder obtained from said grinding has a particle size distribution (diameters by volume) of d10>15 μm, 50<d50<80 μm and 120<d90<180 μm.
18. A method for coating an article, comprising coating the article with a powder obtained in accordance with claim 1 .
19. A method for manufacturing a component, comprising laser sintering a powder obtained in accordance with claim 1 .
20. The powder obtained by the method according to claim 1 .