BICOMPONENT FIBER WITH SYSTEMS AND PROCESSES FOR MAKING

1 . A bicomponent fiber comprising:

a glass core; and

a polytetrafluoroethylene (PTFE) sheath circumferentially enclosing the glass core;

wherein the bicomponent fiber has a diameter between approximately five micrometers and approximately twenty micrometers.

2 . The bicomponent fiber of claim 1 , wherein the bicomponent fiber has a diameter between approximately five micrometers and approximately ten micrometers.

3 . The bicomponent fiber of claim 1 , wherein the bicomponent fiber is laminated to an expanded PTFE membrane, and the expanded PTFE membrane comprises a laminate.

4 . The bicomponent fiber of claim 3 , wherein the laminate comprises a portion of one of a filter bag and a pleated filter element.

5 . The bicomponent fiber of claim 1 , wherein the bicomponent fiber comprises a portion of one of a woven fabric and a needle felt fabric.

6 . The bicomponent fiber of claim 1 , wherein the bicomponent fiber remains stable in an environment having a temperature of at least approximately 250° C.

7 . The bicomponent fiber of claim 1 , wherein the bicomponent fiber remains stable in an environment having a pH of at most approximately 2.0.

8 . A system for making a bicomponent fiber, the system comprising:

a container having an inlet and an outlet;

an aqueous dispersion within the container, wherein the aqueous dispersion includes polytetrafluoroethylene (PTFE); and

a heated surface configured to receive a core fiber coated with the aqueous dispersion from the outlet of the container, wherein the heated surface sinters the coated aqueous dispersion into a sheath.

9 . The system of claim 8 , further comprising a roller configured to direct the core fiber into the inlet of the container.

10 . The system of claim 8 , wherein the system is configured to yield a bicomponent fiber comprising:

a glass core; and

a PTFE sheath circumferentially enclosing the glass core;

wherein the bicomponent fiber has a diameter between approximately five micrometers and approximately twenty micrometers.

11 . A process of making a bicomponent fiber, the process comprising:

passing a glass fiber through an aqeuous dispersion including polytetrafluoroethylene (PTFE) to coat the glass fiber with the aqueous dispersion, thereby yielding a PTFE coat of the glass fiber; and

contacting the PTFE coat of the glass fiber with a heated surface to form a PTFE sheath, wherein the PTFE sheath circumferentially encloses the glass fiber, thereby yielding the bicomponent fiber.

12 . The process of claim 11 , further comprising:

chopping the bicomponent fiber into staple fibers; and

forming a felted fabric from the staple fibers.

13 . The process of claim 11 , further comprising:

weaving the bicomponent fiber into a woven fabric.

14 . The process of claim 13 , further comprising:

laminating the woven fabric to an expanded PTFE membrane to form a laminate.

15 . The process of claim 11 , wherein the aqueous dispersion of PTFE includes approximately 60% PTFE.

16 . The process of claim 11 , wherein the PTFE coat of the glass fiber comprises approximately 20% by weight of the glass fiber.

17 . The process of claim 11 , further comprising:

adding a PTFE powder to a liquid to form the aqueous dispersion.

18 . The process of claim 11 , wherein the bicomponent fiber has a diameter between approximately five micrometers and approximately twenty micrometers.

19 . The process of claim 11 , further comprising:

forming a fabric from the bicomponent fiber;

laminating the fabric onto an expanded PTFE membrane to form a laminate structure; and

forming one of a filter bag and a pleated filter element from the laminate structure.

20 . The process of claim 11 , wherein the glass fiber comprises a texturized glass filament.