Fiberglass recovery method

An apparatus for removing char from glass fibers and for increasing a tensile strength of the glass fibers, the apparatus comprising:

• a molten salt bath provided with molten salt configured to remove char from the glass fibers and to increase a tensile strength of the glass fibers by forming a temperature gradient for gradually and continuously heating the glass fibers, the molten salt bath having:
• a first stage configured to heat glass fibers to within a second temperature range;
• a second stage configured to heat glass fibers to within a third temperature range such that a temperature gradient is formed in the molten salt bath;
• a movable separator provided between the first stage and the second stage and configured to provide thermal separation between the first stage and the second stage of the molten salt bath, wherein the separator is moveable to allow the glass fibers to pass from the first stage into the second stage while still being located within the molten salt bath and remaining continuously heated to at least within the second temperature range;
• and
• transport means for transporting the glass fibers through the molten salt bath, including from the first stage, past the movable separator, and to the second stage.