Pultrusion Process for Preparing Composites Having Low Percentage of Fibers and Articles Made from Same

• US 20130204368A1
• Filed: 02/06/2012
• Published: 08/08/2013
• Est. Priority Date: 02/06/2012
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Prevost, Julien J.
• Granted Patent: US 9,090,029 B2
• Time in Patent Office: Days
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2002/3093 for promoting ingrowth of bone tissue
• CPC Class Codes: A61F 2002/4495 having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00161 Carbon; Graphite
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00329 Glasses, e.g. bioglass
• CPC Class Codes: A61F 2310/0097 Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61F 2310/00976 Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/44 having a macromolecular matrix
• CPC Class Codes: B29C 70/506 and impregnating by melting a solid material, e.g. sheet, powder, fibres B29C70/508 takes precedence
• CPC Class Codes: B29C 70/523 and impregnating the reinforcement in the die
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix

Abstract

An improved pultrusion process for preparing composite materials having about 10 percent to about 45 percent by volume of reinforcing fibers so as to produce a composite material having enhanced flexibility as compared with composite materials having a higher percent of reinforcing fibers by volume. Articles of manufacture made from composite material produced by the improved pultrusion process, specifically spinal implants, are also provided.

Claims

1. A pultrusion process for-preparing a low percent of continuous reinforcing fibers composite material comprising the steps of:

(a) providing continuous reinforcing fibers wrapped with strands of matrix material having a lower melting point than a melting point of the continuous reinforcing fibers;

(b) directing the wrapped continuous reinforcing fibers through a heated curing die to melt the matrix material about the reinforcing fibers so as to produce a solid fiber reinforced composite; and

(c) withdrawing the solid fiber reinforced composite from the curing die wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 10 percent by volume and about 45 percent by volume.

2. A pultrusion process according to claim 1, further comprising continuously pulling the reinforcing fibers through an impregnation chamber comprising a mixture containing precursors and initiators that polymerize when heated above a reaction temperature to produce impregnated continuous reinforcing fibers that are then wrapped in step (a).

3. A pultrusion process according to claim 1, wherein the continuous reinforcing fibers are wrapped with braided strands of matrix material having a lower melting point than a melting point of the continuous reinforcing fibers.

4. A pultrusion process according to claim 2, wherein the temperature of the impregnation chamber is below the polymerization temperature of the precursors and initiators in the impregnation chamber.

5. A pultrusion process according to claim 2, wherein the polymer produced from the precursor and initiator is selected from the group consisting of thermoplastic, Nylon, a polyurethane, an epoxy, a polyacrylate, a polymethacrylate, and a thermoset.

6. A pultrusion process according to claim 1, wherein the continuous reinforcing fibers are selected from the group consisting of metallic wire, glass fibers, carbon fibers, polyolefin fibers, polyester fibers, and aromatic polyamide fibers.

7. A pultrusion process according to claim 1, wherein the wrapped continuous reinforcing fibers are positioned in predetermined positions so as to produce a solid fiber reinforced composite having reinforcing fibers positioned in predetermined configurations so as to provide predetermined mechanical properties.

8. A pultrusion process according to claim 1, wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 15% to about 40% by volume.

9. A pultrusion process according to claim 1, wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 25% to about 35% by volume.

10. A pultrusion process according to claim 2, wherein the impregnation chamber mixture further comprises at least one additive.

11. A pultrusion process according to claim 10, wherein the additive is a catalytically effective amount of a catalyst selected from the group consisting of organobismuth catalysts and combinations thereof.

12. A pultrusion process according to claim 2, wherein the mixture in the impregnation chamber further comprises short pieces of reinforcement fibers that are configured to contact the continuous reinforcement fibers as it is passed through the impregnation chamber and attach to the continuous reinforcement fibers so as to become trapped between the reinforcing fibers and the wrapped continuous reinforcing fibers so that the solid fiber reinforced composite withdrawn from the curing die contains fragments of reinforcement fibers as well as continuous reinforcement fibers.

17. An article manufactured from a solid fiber reinforced composite produced from a pultrusion process according to claim 1.

19. An article according to claim 17 in the form of a spinal implant.

13. An article manufactured from a solid fiber reinforced composite produced from a pultrusion process comprising the steps of:

(a) continuously pulling reinforcing fibers through an impregnation chamber comprising a mixture containing precursors and initiators that polymerize when heated above a reaction temperature to produce impregnated continuous reinforcing fibers;

(b) wrapping the impregnated continuous reinforcing fibers with strands of matrix material having a lower melting point than a melting point of the continuous reinforcing fibers to produce wrapped impregnated continuous reinforced fibers;

(c) directing the wrapped impregnated continuous reinforcing fibers of step (b) through a heated curing die to melt the matrix material about the reinforcing fibers so as to produce a solid fiber reinforced composite; and

(d) withdrawing the solid fiber reinforced composite from the curing die wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 10 percent to about 45 percent by volume.

14. A pultrusion process according to claim 13, wherein the wrapped impregnated continuous reinforcing fibers are wrapped with braided strands of matrix material having a lower melting point than a melting point of the continuous reinforcing fibers.

15. A pultrusion process according to claim 13, wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 15 to about 40 percent by volume.

16. A pultrusion process according to claim 13, wherein the percentage of continuous fibers in the solid fiber reinforced composite is between about 25 to about 35 percent by volume.

18. An article manufactured from a solid fiber reinforced composite produced from a pultrusion process according to claim 13.

20. An article according to claim 18 in the form of a spinal implant.