IP Library Granted Patent US 10,926,432
Granted Patent B2
US 10,926,432 · App. 15/872,478 · Granted Feb 23, 2021

Polymer powder and method of using the same

Inventors: Scott DeFelice (Holyoke, MA); Anthony DeCarmine (Lebanon, CT)
Assignee: Hexcel Corporation
B29B9/16B02C23/10B29C64/153B33Y10/00B33Y70/00C08G65/4012C08G65/46C08J3/12C08J5/042C08L71/12B29B2009/168B29K2071/00C08G2650/40C08J2371/10
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Quick Facts
Patent No.
US 10,926,432
App. No.
15/872,478
Granted
Feb 23, 2021
Kind
B2
Abstract

A method for preparing a PEKK powder for use in SLS includes the steps of: providing a raw, non-powder PEKK material; heat treating the raw PEKK to evaporate at least substantially all of a liquid solvent in the raw PEKK, causing at least substantially all of the raw PEKK to be in the form of irregularly-shaped particles; cooling the raw PEKK; and grinding the raw PEKK to form a PEKK powder.

Claims (37)

1. A method for preparing a PEKK powder for use in SLS, the method comprising:

providing a raw, non-powder PEKK material;

after the providing step, heat treating the raw PEKK to evaporate a liquid solvent in the raw PEKK, wherein during the heating step the raw PEKK remains below a temperature at which raw PEKK begins to melt;

after the heat treating step, cooling the raw PEKK; and

after the cooling step, grinding the raw PEKK to form a PEKK powder;

wherein after the heating step the raw PEKK has a purity greater than 99.75% as determined by the ASTM E1868 loss-on-drying test method.

2. The method of claim 1 , further comprising sieving the PEKK powder to eliminate particles having sizes outside a range of 30-150 μm.

3. The method of claim 1 , wherein before the heat treating step, the raw PEKK is of a gel form.

4. The method of claim 1 , wherein the temperature of the raw PEKK does not exceed 250° C. during the heat treating step.

5. The method of claim 1 , wherein the heat treating step includes:

(i) a first heating period during which the temperature of the raw PEKK is ramped up from room temperature to approximately 200° C.;

(ii) a second heating period during which the temperature of the raw PEKK is held at a temperature of approximately 200° C.

6. The method of claim 5 , wherein the heat treating step further includes:

(iii) a third heating period during which the temperature of the raw PEKK is ramped up from approximately 200° C. to approximately 225° C.;

(iv) a fourth heating period having a duration of at least one hour, during which the temperature of the raw PEKK is held at a temperature of approximately 225° C.

7. The method of claim 6 , wherein the heat treating step further includes:

(v) a fifth heating period during which the temperature of the raw PEKK is ramped up from approximately 225° C. to approximately 250° C.;

(vi) a sixth heating period having a duration of at least one hour, during which the temperature of the raw PEKK is held at a temperature of approximately 250° C.

8. The method of claim 7 , wherein the first heating period has a duration of one hour, the second heating period has a duration of seven (7) hours—the third heating period has a duration of 0.5 hours, the fourth heating period has a duration of 1.5 hours the fifth heating period has a duration of 0.5 hours and the sixth heating period has a duration of two (2) hours.

9. The method of claim 7 , wherein the first heating period has a duration of 0.5 hours, the second heating period has a duration of four (4) hours, the third heating period has a duration of 0.5 hours, the fourth heating period has a duration of 4 hours, the fifth heating period has a duration of 0.5 hours and the sixth heating period has a duration of five (5) hours.

10. The method of claim 1 , wherein the heat treating step involves placing the raw PEKK into a pan and heating both the raw PEKK and the pan within a convection oven.

11. The method of claim 1 , wherein the cooling step is performed by allowing the raw PEKK to cool only naturally.

12. The method of claim 1 , wherein the heating step causes coalescence of the particles of the raw PEKK.

13. A PEKK powder manufactured according to a method comprising:

providing a raw, non-powder PEKK material;

after the providing step, heat treating the raw PEKK to evaporate at least substantially all of a liquid solvent in the raw PEKK, causing at least substantially all of the raw PEKK to be in the form of irregularly-shaped particles;

after the heat treating step, cooling the raw PEKK; and

after the cooling step, grinding the raw PEKK to form a PEKK powder.

14. A method for preparing a PAEK powder for use in LS, the method comprising:

providing a raw, non-powder PAEK material;

after the providing step, heat treating the raw PAEK to evaporate a liquid solvent in the raw PAEK wherein during the heating step the raw PEKK remains below a temperature at which raw PEKK begins to melt;

after the heat treating step, cooling the raw PAEK; and

after the cooling step, grinding the raw PAEK to form a PAEK powder,

wherein after the heating step the raw PEKK has a purity greater than 99.75% as determined by the ASTM E1868 loss-on-drying test method.

15. The method of claim 1 , wherein the heat treating step includes:

(i) a first heating period during which the temperature of the raw PEKK is held at a temperature between approximately 200° C. and approximately 250° C.

16. The method of claim 15 , where the first heating period has a duration of at least ten hours.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 19, 2018
From: DEFELICE, SCOTT; DECARMINE, ANTHONY
To: HEXCEL CORPORATION
Reel/Frame 044666/0415 →
Continuity (5)
Provisional Application 62446460 · Jan 15, 2017
Provisional Application 62446470 · Jan 15, 2017
Provisional Application 62446462 · Jan 15, 2017
Provisional Application 62446464 · Jan 15, 2017
Related Publication 20180200922A1 · Jul 19, 2018