A needled blanket is provided comprising melt-formed inorganic fibres having an overall composition in weight percent SiO.sub.2: 47 to 65% Al.sub.2O.sub.3: 35 to 53%the blanket having a shot content, of shot >45 .Math.m, of less than 51 wt%, a specific surface area (BET) > 0.25 m.sup.2.g.sup.-1.also disclosed are fibres for producing such blankets, and self-supporting products made from such fibres.

A glass composition includes 59.00 to 65.00% by mass of SiO.sub.2, 16.00 to 26.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, 0 to 6.00% by mass of SrO, 0.10 to 5.00% by mass of TiO.sub.2, 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, less than 0.20% by mass of P.sub.2O.sub.5, and less than 1.00% by mass of Na.sub.2O, K.sub.2O and Li.sub.2O in total, wherein the ratio of TiO.sub.2 to the total content of CaO, MgO, and SrO (TiO.sub.2/(CaO+MgO+SrO)) is from 0.66 to 4.00, and the content SI of SiO.sub.2 and the content A of Al.sub.2O.sub.3 satisfy the following formula (1): 1.00≤1000×A/SI.sup.2≤4.65 (1).

A glass composition includes 59.00 to 65.00% by mass of SiO.sub.2, 16.00 to 26.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, 0 to 6.00% by mass of SrO, 0.10 to 5.00% by mass of TiO.sub.2, 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, less than 0.20% by mass of P.sub.2O.sub.5, and less than 1.00% by mass of Na.sub.2O, K.sub.2O and Li.sub.2O in total, wherein the ratio of TiO.sub.2 to the total content of CaO, MgO, and SrO (TiO.sub.2/(CaO+MgO+SrO)) is from 0.66 to 4.00, and the content SI of SiO.sub.2 and the content A of Al.sub.2O.sub.3 satisfy the following formula (1): 1.00≤1000×A/SI.sup.2≤4.65 (1).

A glass composition for glass fiber includes 50.00 to 61.00% by mass of SiO.sub.2, 16.00 to 27.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0.20 to 4.00% by mass of P.sub.2O.sub.5, 0.50 to 5.00% by mass of TiO.sub.2, 0.10 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, and 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, with respect to the total amount of the glass composition for glass fiber, and the content S of SiO.sub.2, the content A of Al.sub.2O.sub.3, the content P of P.sub.2O.sub.5, the content T of TiO.sub.2, the content C of CaO, and the content M of MgO satisfy the following formula (1):

3.65≤(S/A).sup.2×(P×T).sup.1/2/(C+M).sup.3≤8.25  (1).

A glass composition for glass fiber includes 50.00 to 61.00% by mass of SiO.sub.2, 16.00 to 27.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0.20 to 4.00% by mass of P.sub.2O.sub.5, 0.50 to 5.00% by mass of TiO.sub.2, 0.10 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, and 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, with respect to the total amount of the glass composition for glass fiber, and the content S of SiO.sub.2, the content A of Al.sub.2O.sub.3, the content P of P.sub.2O.sub.5, the content T of TiO.sub.2, the content C of CaO, and the content M of MgO satisfy the following formula (1):

3.65≤(S/A).sup.2×(P×T).sup.1/2/(C+M).sup.3≤8.25  (1).

A glass material with a low dielectric constant and a low fiberizing temperature includes silicon dioxide, boron trioxide, aluminum oxide, calcium oxide, phosphorus pentoxide and zinc oxide. The silicon dioxide makes up 45%-52% by weight of the glass material. The boron trioxide makes up 25%-30% by weight of the glass material. The aluminum oxide makes up 10%-14% by weight of the glass material. The calcium oxide makes up 1%-4% by weight of the glass material. The phosphorus pentoxide makes up 0-3% by weight of the glass material. The zinc oxide makes up 1%-5% by weight of the glass material. The reduced silicon dioxide content and calcium oxide content and addition of phosphorus pentoxide and zinc oxide in the glass material lower the dielectric constant and fiberizing temperature of the glass material.

A glass composition for glass fiber includes SiO.sub.2 in the range of 52.0% by mass or more and 56.0% by mass or less; B.sub.2O.sub.3 in the range of 21.0% by mass or more and 24.5% by mass or less; Al.sub.2O.sub.3 in the range of 9.5% by mass or more and 13.0% by mass or less; MgO in the range of 0% by mass or more and less than 1.0% by mass; CaO in the range of 0.5% by mass or more and 5.5% by mass or less; SrO in the range of 0.5% by mass or more and 6.0% by mass or less; and TiO.sub.2 in the range of 0.1% by mass or more and 3.0% by mass or less; and includes F.sub.2 and Cl.sub.2 in the range of 0.1% by mass or more and 2.0% by mass or less in total, with respect to the total amount.

A glass composition for glass fiber includes SiO.sub.2 in the range of 52.0% by mass or more and 56.0% by mass or less; B.sub.2O.sub.3 in the range of 21.0% by mass or more and 24.5% by mass or less; Al.sub.2O.sub.3 in the range of 9.5% by mass or more and 13.0% by mass or less; MgO in the range of 0% by mass or more and less than 1.0% by mass; CaO in the range of 0.5% by mass or more and 5.5% by mass or less; SrO in the range of 0.5% by mass or more and 6.0% by mass or less; and TiO.sub.2 in the range of 0.1% by mass or more and 3.0% by mass or less; and includes F.sub.2 and Cl.sub.2 in the range of 0.1% by mass or more and 2.0% by mass or less in total, with respect to the total amount.

Methods of making a bioactive glass fiber include forming a melt of a 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 glass composition. The melt has a viscosity of from 200 Poise to 2,000 Poise. Methods include drawing the melt into a drawn glass fiber. Bioactive glass compositions include: 60 to 70% SiO.sub.2; 15 to 30% Na.sub.2O, 5 to 15% K.sub.2O, 1 to 10% CaO, and 5 to 10% P.sub.2O.sub.5, based on a 100 wt % of the glass composition.

Methods of making a bioactive glass fiber include forming a melt of a 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 glass composition. The melt has a viscosity of from 200 Poise to 2,000 Poise. Methods include drawing the melt into a drawn glass fiber. Bioactive glass compositions include: 60 to 70% SiO.sub.2; 15 to 30% Na.sub.2O, 5 to 15% K.sub.2O, 1 to 10% CaO, and 5 to 10% P.sub.2O.sub.5, based on a 100 wt % of the glass composition.