A glass composition includes from 55.0 mol % to 75.0 mol % SiO.sub.2; from 8.0 mol % to 20.0 mol % Al.sub.2O.sub.3; from 3.0 mol % to 15.0 mol % Li.sub.2O; from 5.0 mol % to 15.0 mol % Na.sub.2O; and less than or equal to 1.5 mol % K.sub.2O. The glass composition has the following relationships: Al.sub.2O.sub.3+Li.sub.2O is greater than 22.5 mol %, R.sub.2O+RO is greater than or equal to 18.0 mol %, R.sub.2O/Al.sub.2O.sub.3 is greater than or equal to 1.06, SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+P.sub.2O.sub.5 is greater than or equal to 78.0 mol %, and (SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+P.sub.2O.sub.5)/Li.sub.2O is greater than or equal to 8.0. The glass composition may be used in a glass article or a consumer electronic product.

A glass composition includes from 55.0 mol % to 75.0 mol % SiO.sub.2; from 8.0 mol % to 20.0 mol % Al.sub.2O.sub.3; from 3.0 mol % to 15.0 mol % Li.sub.2O; from 5.0 mol % to 15.0 mol % Na.sub.2O; and less than or equal to 1.5 mol % K.sub.2O. The glass composition has the following relationships: Al.sub.2O.sub.3+Li.sub.2O is greater than 22.5 mol %, R.sub.2O+RO is greater than or equal to 18.0 mol %, R.sub.2O/Al.sub.2O.sub.3 is greater than or equal to 1.06, SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+P.sub.2O.sub.5 is greater than or equal to 78.0 mol %, and (SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+P.sub.2O.sub.5)/Li.sub.2O is greater than or equal to 8.0. The glass composition may be used in a glass article or a consumer electronic product.

Provided is a glass fiber having a low spinning temperature and a low liquidus temperature, and besides, having a large difference between the liquidus temperature and the spinning temperature, and a method of manufacturing the same. The glass fiber of the present invention includes as a glass composition, in terms of mass % on an oxide basis, 50% to 65% of SiO.sub.2, 0% to 3% of Al.sub.2O.sub.3, 0% to 1% of MgO, 0% to less than 0.7% of CaO, 0% to 1% of Li.sub.2O, 10% to 20% of Na.sub.2O, 0% to 2% of K.sub.2O, 6% to 10% of TiO.sub.2, and 15% to 20% of ZrO.sub.2, and has a value for (Na.sub.2O+K.sub.2O)/(MgO+CaO) of 6.0 or more.

Provided is a glass fiber having a low spinning temperature and a low liquidus temperature, and besides, having a large difference between the liquidus temperature and the spinning temperature, and a method of manufacturing the same. The glass fiber of the present invention includes as a glass composition, in terms of mass % on an oxide basis, 50% to 65% of SiO.sub.2, 0% to 3% of Al.sub.2O.sub.3, 0% to 1% of MgO, 0% to less than 0.7% of CaO, 0% to 1% of Li.sub.2O, 10% to 20% of Na.sub.2O, 0% to 2% of K.sub.2O, 6% to 10% of TiO.sub.2, and 15% to 20% of ZrO.sub.2, and has a value for (Na.sub.2O+K.sub.2O)/(MgO+CaO) of 6.0 or more.

The present invention relates to a 3D printer printhead, a 3D printer using the same, a method for manufacturing a molded product by using the 3D printer, a method for manufacturing an artificial tooth by using the 3D printer, and a method for manufacturing a machinable glass ceramic molded product by using the 3D printer, the 3D printer printhead comprising: an inlet through which glass wire, which is a raw material, is introduced; a heating means for heating the glass wire introduced through the inlet; a melting furnace for providing a space in which the glass wire is fused; and a nozzle connected to the lower part of the melting furnace so as to temporarily store the fused glass or discharge a targeted amount of the fused glass, wherein the melting furnace includes an exterior frame made from a heat resistant material and an interior frame having a crucible shape, and the interior frame is made from platinum (Pt), a Pt alloy or graphite, which have a low contact angle, or a material having a surface coated with Pt or a diamond-like carbon (DLC) so as to prevent the fused glass from sticking thereto. According to the present invention, the molded product, the artificial tooth, and the machinable glass ceramic molded product can be manufactured with excellent mechanical properties, thermal durability, chemical durability and oxidation resistance and outstanding texture by using the glass wire as a raw material.

The present invention relates to a 3D printer printhead, a 3D printer using the same, a method for manufacturing a molded product by using the 3D printer, a method for manufacturing an artificial tooth by using the 3D printer, and a method for manufacturing a machinable glass ceramic molded product by using the 3D printer, the 3D printer printhead comprising: an inlet through which glass wire, which is a raw material, is introduced; a heating means for heating the glass wire introduced through the inlet; a melting furnace for providing a space in which the glass wire is fused; and a nozzle connected to the lower part of the melting furnace so as to temporarily store the fused glass or discharge a targeted amount of the fused glass, wherein the melting furnace includes an exterior frame made from a heat resistant material and an interior frame having a crucible shape, and the interior frame is made from platinum (Pt), a Pt alloy or graphite, which have a low contact angle, or a material having a surface coated with Pt or a diamond-like carbon (DLC) so as to prevent the fused glass from sticking thereto. According to the present invention, the molded product, the artificial tooth, and the machinable glass ceramic molded product can be manufactured with excellent mechanical properties, thermal durability, chemical durability and oxidation resistance and outstanding texture by using the glass wire as a raw material.

A glass sheet includes a first main surface and a second main surface opposite to the first main surface in a thickness direction. X represented by the following formula (1) is −0.29<X<0.29: A×Δ.sup.1H/.sup.30Si+B×ΔNa.sub.2O+C×ΔSn+D×ΔF=X (1). F.sub.0-3 determined according to the following formula (II) is 0.02 or more: F.sub.0-3=[average fluorine concentration (wt %) by SIMS at depth of 0 to 3 μm in first main surface]×3 (II).

A transparent β-quartz glass ceramic is provided. The glass ceramic includes a primary crystal phase including a β-quartz solid solution, a secondary crystal phase including tetragonal ZrO.sub.2, and a lithium aluminosilicate amorphous phase. The glass ceramic may be ion exchanged utilizing molten nitrate salt baths. Methods for producing the glass ceramic are also provided.

A plate-like chemically strengthened glass having a compression stress layer on the surface of the glass, wherein the compressive stress value (CS.sub.0) at the glass surface of is 500 MPa or more, the plate thickness (t) is 400 .Math.m or more, the compressive stress depth of layer (DOL) is (t × 0.15) .Math.m or more, the compressive stress values (CS.sub.1) and (CS.sub.2) when the depth from the glass surface is ¼ and ½, respectively, are 50 MPa or more, m.sub.1 expressed by {m.sub.1 = (CS.sub.1 - CS.sub.2/(DOL/4 - DOL/2)} is -1.5 MPa/.Math.m or more, m.sub.2 expressed by {m.sub.2 = (CS.sub.2/(DOL/2 - DOL)} is 0 MPa/.Math.m or less, and m.sub.2 is less than m.sub.1.

A plate-like chemically strengthened glass having a compression stress layer on the surface of the glass, wherein the compressive stress value (CS.sub.0) at the glass surface of is 500 MPa or more, the plate thickness (t) is 400 .Math.m or more, the compressive stress depth of layer (DOL) is (t × 0.15) .Math.m or more, the compressive stress values (CS.sub.1) and (CS.sub.2) when the depth from the glass surface is ¼ and ½, respectively, are 50 MPa or more, m.sub.1 expressed by {m.sub.1 = (CS.sub.1 - CS.sub.2/(DOL/4 - DOL/2)} is -1.5 MPa/.Math.m or more, m.sub.2 expressed by {m.sub.2 = (CS.sub.2/(DOL/2 - DOL)} is 0 MPa/.Math.m or less, and m.sub.2 is less than m.sub.1.