Profile-extruded poly(vinyl chloride) articles and method of making same

• US 20040166301A1
• Filed: 02/04/2004
• Published: 08/26/2004
• Est. Priority Date: 02/25/2003
• Status: Active Grant

• Current Assignee: Geon Performance Solutions LLC
• Original Assignee: Polyone Corporation (Avient Corp.)
• Inventors: Lee, Sang H., Hooks, Robert B.
• Granted Patent: US 7,198,840 B2
• Time in Patent Office: Days
• US Class Current: 428/297.4
• CPC Class Codes: C08J 2327/06 Homopolymers or copolymers of vinyl chloride
• CPC Class Codes: C08J 5/04 Reinforcing macromolecular compounds with loose or coherent fibrous material
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/249946 Glass fiber

Abstract

A profile-extruded article is disclosed, made of a fiber-reinforced polymer of vinyl-chloride monomer, wherein the article has a ratio of actual specific gravity to theoretical specific gravity of nearly unity. A method of making the article is also disclosed.

Claims

1. A profile-extruded article of a fiber-reinforced polymer of vinyl-chloride monomer, wherein the article has a ratio of actual specific gravity to theoretical specific gravity of nearly unity.

2. The article of claim 1, the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.90 to about 0.99.

3. The article of claim 1, the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.95 to about 0.99.

4. The article of claim 1, the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.97 to about 0.99.

5. The article of claim 1, wherein the polymer of vinyl chloride monomer has a weight average molecular weight ranging from about 30×

10³ to about 168×

10³.

6. The article of claim 1, wherein the fiber is selected from the group consisting of glass, nylon, graphite, wood, and combinations thereof.

7. The article of claim 6, wherein the article has glass fibers.

8. The article of claim 1, wherein the fibers have a length ranging from about 500 μ

m to about 1 mm.

9. The article of claim 1, wherein the fibers are present in the polymer up to about 40 percent by weight.

10. A method of making a fiber-reinforced poly(vinyl chloride)-containing article, comprising the steps of:

(a) feeding granules of poly(vinyl chloride) reinforced with fibers into a two-stage, single-screw extrusion apparatus that has a vent at the beginning of the second stage for devolatilization of outgasses during extrusion; and

(b) extruding fiber-reinforced poly(vinyl chloride) through a profile extrusion die.

11. The method of claim 10, wherein between step (a) and step (b) the following steps occur:

(1) compression of the fed granules in a transition zone of the screw along with melting of the compressed material at a barrel/material interface,

(2) continued melting along with dispersive mixing in a metering/mixing zone of the screw,

(3) decompression of compressed and melted/partially melted material at a start of a second zone of the screw,

(4) devolatilization of the decompressed material to remove volatiles including moisture, and

(5) build-up of melt pressure and conveying of the devolatilized melt to the die.

12. The method of claim 11, wherein the extrusion apparatus has a L/D ratio ranging from 20:

1 to 40;

1.

13. The method of claim 12, wherein screw configurations are selected from the group consisting of increasing pitch, standard, decreasing pitch, double flighted, two stage vented, and combinations thereof.

14. The method of claim 13, wherein the screw includes mixing pins, slotted disks, or both.

15. The method of claim 11, wherein the decompression is in the range of from 2 to 95 kilopascals.

16. The method of claim 10, wherein the fiber-reinforced poly(vinyl chloride) extruded through the profile extrusion die has a ratio of actual specific gravity to theoretical specific gravity of nearly unity.

17. The method of claim 16, wherein the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.90 to about 0.99.

18. The method of claim 16, wherein the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.95 to about 0.99.

19. The method of claim 16, wherein the ratio of actual specific gravity to theoretical specific gravity ranges from about 0.97 to about 0.99.

20. The method of claim 11 wherein the granules contain fibers in an amount up to about 40 percent by weight.