Design of Energy-Friendly Glass Fibers

The Liquidus Temperature; Its Critical Role in Glass Manufacturing

“…To understand the implications of the liquidus temperature, a practical understanding of the phase diagram is required 2,9 . Although the following discussion is based on fiberglass compositions in the ternary SiO 2 –Al 2 O 3 –CaO phase diagram, 2 it is universally applicable to fiberglass compositions in the quaternary SiO 2 –Al 2 O 3 –CaO–B 2 O 3 phase diagram and in the quaternary SiO 2 –Al 2 O 3 –CaO–MgO phase diagram, and also to fiber, flat and container glass compositions in the SiO 2 –CaO–Na 2 O phase diagram.…”

“…The liquidus temperature of E‐glass 1 rose by 110°C from 1064°C to 1174°C. Design of energy‐saving compositions after 1998 2–9 therefore required close attention to the increasingly critical role of the liquidus temperature. The EPA ruling did not affect the glass industry because its key compositions were B 2 O 3 ‐ and F 2 ‐free.…”

“…Important viscosity–temperature standards (Table II) have been specified by industry to serve as benchmarks. The specific reference 8,9 is a generic soda–lime–silica glass and fiberglass (A‐glass) composition that is also the first example in Table VII and in Fig. 1.…”

“… Forming Temperature and Liquidus Temperature Trend Lines for A‐Glass Compositions 8,9 . A‐Glass Trend Lines.…”

“…New energy‐saving E‐glass compositions were designed since 1997 1–9 . Some have already been commercialized.…”