Flexible sealing assembly for optical fiber draw furnace and optical fiber

An optical fiber draw furnace (500), comprising:

• a vertical hollow body (506) having a top end (508) and a bottom end (510), wherein a glass preform (504) is hung near the top end (508), wherein the glass preform (504) is melted to form an optical fiber (502), wherein the optical fiber (502) exits the vertical hollow body (506) from the bottom end (510);
• and
• a flexible sealing assembly (100) placed near the top end (508), the flexible sealing assembly (100) comprising:
• a first plurality of curved ring sections (110) arranged in a circular arrangement, wherein each curved ring section is defined by a same radius of curvature;
• a plurality of flexible dielectric ring sections (120) attached to the first plurality of curved ring sections (110) such that the plurality of flexible dielectric ring sections (120) presses against the glass preform (504) for sealing;
• and
• a plurality of tension loaders (114) exerting continuous radially inward force on at least one curved ring section, wherein each curved ring section of the first plurality of curved ring sections (110) is separated from each other,
• wherein the first plurality of curved ring sections (110) is radially movable such that the first plurality of curved ring sections (110) creates a seal between the glass preform (504) and the vertical hollow body (506) while axial movement of the glass preform (504), where diameter of the glass preform (504) varies.