Method of fabricating a polymer part with a negative thermal expansion coefficient and a polymer part obtained by the method

• US 20030227097A1
• Filed: 06/02/2003
• Published: 12/11/2003
• Est. Priority Date: 06/10/2002
• Status: Abandoned Application

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Girardon, Valerie, Loury, Herve
• Application Number:
  US10/449,672
• Publication Number:
  US 20030227097A1
• Time in Patent Office: Days
• US Class Current: 264/1.24
• CPC Class Codes: B29C 45/0001 characterised by the choice of material
• CPC Class Codes: B29C 45/2669 with means for removing excess material, e.g. with overflow cavities B29C45/1711 takes precedence
• CPC Class Codes: B29K 2105/0079 Liquid crystals

Abstract

A method of fabricating a polymer part having a negative thermal expansion coefficient includes injecting a thermotropic polymer under controlled temperature and pressure conditions into a mold having an injection inlet substantially equal to the thickness of the part and a length that causes elongation of the polymer.

Claims

1. A method of fabricating a polymer part having a negative thermal expansion coefficient, said method including a step of injecting a thermotropic polymer under controlled temperature and pressure conditions into a mold having an injection inlet substantially equal to the thickness of said part and a length adapted to cause elongation of said polymer.

2. The method claimed in claim 1 wherein said polymer is injected at a temperature from 290°

C. to 360°

C. and at a pressure from 200 Bar to 1 500 bar and a maintenance pressure of said polymer in said mold is from 200 bar to 1 500 bar.

3. The method claimed in claim 2 wherein said polymer is injected at a pressure less than or equal to said maintenance pressure.

4. The method claimed in claim 1 wherein said mold includes a reservoir for collecting injection surplus.

5. The method claimed in claim 1 further including a step of cutting the injected part transversely.

6. A solid polymer part having a negative thermal expansion coefficient from −

4.10<sup>−

6</sup> to −

10.10<sup>−

6</sup> obtained by a fabricating method including a step of injecting a thermotropic polymer under controlled temperature and pressure conditions into a mold having an injection inlet substantially equal to the thickness of said part and a length adapted to cause elongation of said polymer.

7. The polymer part claimed in claim 6 having a thickness greater than 2 mm.

8. An optical component support comprising a solid polymer part having a thickness greater than 2 mm and a negative thermal expansion coefficient from −

4.10<sup>−

6</sup> to −

10.10<sup>−

6</sup>.