Process and apparatus for heat treatment of a polymer powder

Patent metadata

Field	Value
Publication number	US-11858173-B2
Application number	US-201917258464-A
Country	US
Kind code	B2
Filing date	Jul 9, 2019
Priority date	Jul 11, 2018
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A method and apparatus for heat treating powders of semi-crystalline or crystallizable polymers. The apparatus includes a heating device for heating the powder to a temperature that is less than the melting temperature of a highest melting crystalline form of the powder, a vessel containing the powder that is exposed to heat produced by the heating device, and a mechanism for moving the vessel to cause the powder within the vessel to move with respect to the vessel.

First claim

What is claimed is:

1. A method for heat treating a powder of a semi-crystalline or crystallizable polymer comprising polyaryletherketone (PAEK), the method comprising:
heating untreated powder of said semi-crystalline or crystallizable polymer comprising PAEK contained within an interior region of a vessel to a temperature that is less than the melting temperature of a highest melting crystalline form of the polymer; and
simultaneously for at least a first period of time during the heating step, moving the vessel to cause the untreated powder of said semi-crystalline or crystallizable polymer comprising PAEK within the vessel to move with respect to the vessel,
optionally heating and moving the vessel for a second period of time,
to produce a heat-treated powder comprising PAEK.

2. The method of claim 1 , wherein the powder comprises polyetherketoneketone (PEKK) and the heating step comprises heating the powder to a temperature of 230 degrees Celsius to 295 degrees Celsius or 260 degrees Celsius to 290 degrees Celsius.

3. The method of claim 1 , wherein the heating step comprises heating the powder to a temperature above a glass transition temperature (Tg) of the polymer.

4. The method of claim 1 further comprising either moving the powder through a mixing element or moving mixing elements having a compact shape through the powder.

5. The method of claim 1 further comprising moving the powder through a mixing element and rotating a sieve along with the vessel.

6. The method of claim 1 further comprising rotating the vessel in a single rotational direction about a first axis of the vessel.

7. The method of claim 1 further comprising rotating the vessel in two different rotational directions about the first axis of the vessel.

8. The method of claim 1 further comprising rotating the vessel in a first rotational direction about the first axis of the vessel, and before reaching one revolution of the vessel, rotating the vessel in a second rotational direction that is opposite to the first rotational direction.

9. The method of claim 1 further comprising rotating the vessel about a second axis of the vessel that is normal to the first axis.

10. The method of claim 9 further comprising simultaneously rotating the vessel about the first and second axes.

11. The method of claim 1 further comprising positioning the vessel within an oven.

12. The method of claim 1 wherein the vessel forms part of a roto-molding unit.

13. The method of claim 1 further comprising removing agglomerations from an interior surface of the vessel during movement of the vessel.

Assignees

• Arkema Inc

Inventors

• Huze Denis
• Brule Benoit
• Decraemer Nadine
• Pascal Jerome
• Clay Bruce

Classifications

• B29B13/021 Primary

  Heat treatment of powders · CPC title

• B29C41/04

  Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould · CPC title

• B29K2071/00

  Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material · CPC title

• B29B13/10

  by grinding, e.g. by triturating; by sieving; by filtering · CPC title

• B29B15/00

  Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00 · CPC title