A bioactive glass composition including: 50 to 70% SiO.sub.2; 0.1 to 10% Al.sub.2O.sub.3, 5 to 30% Na.sub.2O, 0.1 to 15% K.sub.2O, 0.1 to 15% MgO, 0.1 to 20% CaO, and 5 to 10% P.sub.2O.sub.5, based on a 100 wt % of the composition. Also disclosed is a method of making the bioactive glass composition.

The methods disclosed herein include forming an expanded core in an optical fiber with a glass core having a core dopant and a core outer surface, and a glass cladding immediately surrounding the core and having a flat glass-portion surface closest to the core outer surface at a first core spacing S1. The methods include applying heat to a section of the optical fiber to cause the glass core to expand toward the flat glass-portion surface due to thermal diffusion of the core dopant. The methods also include terminating the application of heat to define the expanded core in the heated section of the optical fiber. The expanded core defines an evanescent coupling region having a second core spacing 0≤S2<S1 and an adiabatic transition region between the core and the evanescent coupling region of the expanded core.

The methods disclosed herein include forming an expanded core in an optical fiber with a glass core having a core dopant and a core outer surface, and a glass cladding immediately surrounding the core and having a flat glass-portion surface closest to the core outer surface at a first core spacing S1. The methods include applying heat to a section of the optical fiber to cause the glass core to expand toward the flat glass-portion surface due to thermal diffusion of the core dopant. The methods also include terminating the application of heat to define the expanded core in the heated section of the optical fiber. The expanded core defines an evanescent coupling region having a second core spacing 0≤S2<S1 and an adiabatic transition region between the core and the evanescent coupling region of the expanded core.

A system for spraying products onto glass fibers, designed to spray at least one sizing composition and an anti-dust agent onto the glass fibers includes two separate annular spraying elements which are successively arranged on the path of the glass fibers, the two spraying elements including a first annular element for spraying the sizing composition and a second annular element for spraying the anti-dust agent, each one embodied by at least one specific annular crown surrounding the glass fibers. The second annular element for spraying the anti-dust agent is arranged downstream of the first annular element for spraying the sizing composition in relation to the path of the glass fibers.

A system for spraying products onto glass fibers, designed to spray at least one sizing composition and an anti-dust agent onto the glass fibers includes two separate annular spraying elements which are successively arranged on the path of the glass fibers, the two spraying elements including a first annular element for spraying the sizing composition and a second annular element for spraying the anti-dust agent, each one embodied by at least one specific annular crown surrounding the glass fibers. The second annular element for spraying the anti-dust agent is arranged downstream of the first annular element for spraying the sizing composition in relation to the path of the glass fibers.

A composition for producing a glass fiber, including the following components with corresponding percentage amounts by weight: 54.2-64% SiO.sub.2, 11-18% Al.sub.2O.sub.3, 20-25.5% CaO, 0.3-3.9% MgO, 0.1-2% of Na.sub.2O+K.sub.2O, 0.1-1.5% TiO.sub.2, and 0.1-1% total iron oxides including ferrous oxide (calculated as FeO). The weight percentage ratio C1=FeO/(iron oxides−FeO) is greater than or equal to 0.53. The total content of the above components in the composition is greater than 97%. The invention also provides a glass fiber produced using the composition and a composite material including the glass fiber.

Described herein is a method of forming a smelting byproduct that can be formed into an inorganic fiber, the method comprising: a) introducing silicomanganese slag and a smelting additive into a submerged arc furnace comprising a collection zone; b) smelting the silicomanganese slag into a silicomanganese metal and a smelting byproduct, whereby the silicomanganese metal settles to a lower portion of the collection zone and the smelting byproduct gathers in an upper portion of the collection zone due to density differential between the silicomanganese metal and the smelting byproduct; c) flowing the smelting byproduct from the collection zone from a first outlet; and d) flowing the silicomanganese metal from the collection zone from a second outlet.

Described herein is a method of forming a smelting byproduct that can be formed into an inorganic fiber, the method comprising: a) introducing silicomanganese slag and a smelting additive into a submerged arc furnace comprising a collection zone; b) smelting the silicomanganese slag into a silicomanganese metal and a smelting byproduct, whereby the silicomanganese metal settles to a lower portion of the collection zone and the smelting byproduct gathers in an upper portion of the collection zone due to density differential between the silicomanganese metal and the smelting byproduct; c) flowing the smelting byproduct from the collection zone from a first outlet; and d) flowing the silicomanganese metal from the collection zone from a second outlet.

Provided is a glass strand that, when mixed with mortar, is less likely to decrease the fluidity of the mortar and can 5 effectively increase the mechanical strength of a cementitious material. A glass strand includes: a plurality of glass filaments containing 12% by mass or more ZrO.sub.2 and 10% by mass or more R.sub.2O (where R represents at least one selected from Li, Na, and K); and a coating covering surfaces of the glass filaments, 10 wherein the coating contains polyvinyl acetate resin and polyether-based urethane resin, and wherein a content of the polyether-based urethane resin in the coating is, in solid content ratio, not less than 10% by mass and not more than 90% by mass.

Provided is a glass strand that, when mixed with mortar, is less likely to decrease the fluidity of the mortar and can 5 effectively increase the mechanical strength of a cementitious material. A glass strand includes: a plurality of glass filaments containing 12% by mass or more ZrO.sub.2 and 10% by mass or more R.sub.2O (where R represents at least one selected from Li, Na, and K); and a coating covering surfaces of the glass filaments, 10 wherein the coating contains polyvinyl acetate resin and polyether-based urethane resin, and wherein a content of the polyether-based urethane resin in the coating is, in solid content ratio, not less than 10% by mass and not more than 90% by mass.