A method for strengthening an edge of a glass laminate including a glass core layer positioned between a first glass clad layer and a second glass clad layer may include forming a channel in the edge of the glass laminate. Sidewalls of the channel may be formed from the first glass clad layer and the second glass clad layer. Glass filler material having a filler coefficient of thermal expansion greater than a core coefficient of thermal expansion may be positioned in the channel. The glass filler material and the sidewalls of the channel may be fused to the second glass clad layer thereby forming an edge cap over the channel. The edge of the glass laminate is under compressive stress after the glass filler material is enclosed in the channel.

A method for strengthening an edge of a glass laminate including a glass core layer positioned between a first glass clad layer and a second glass clad layer may include forming a channel in the edge of the glass laminate. Sidewalls of the channel may be formed from the first glass clad layer and the second glass clad layer. Glass filler material having a filler coefficient of thermal expansion greater than a core coefficient of thermal expansion may be positioned in the channel. The glass filler material and the sidewalls of the channel may be fused to the second glass clad layer thereby forming an edge cap over the channel. The edge of the glass laminate is under compressive stress after the glass filler material is enclosed in the channel.

A vitreous composition according to Table (I) is described. Continuous vitreous fibers are obtained by downdrawing said molten composition, with a length ranging from millimeters to kilometers and diameters ranging from 2 μm to 3 mm. The fibers are covered with collagen and form vitreous fabrics. The fabrics form articles with a variety of medical uses.

A vitreous composition according to Table (I) is described. Continuous vitreous fibers are obtained by downdrawing said molten composition, with a length ranging from millimeters to kilometers and diameters ranging from 2 μm to 3 mm. The fibers are covered with collagen and form vitreous fabrics. The fabrics form articles with a variety of medical uses.

A high-modulus glass fiber composition includes the following components with corresponding amounts by weight percentage: 42-56.8% of SiO.sub.2, 15.8-24% of Al.sub.2O.sub.3, 9.2-18% of MgO, 0.1-6.5% of CaO, greater than 8% and less than or equal to 20% of Y.sub.2O.sub.3, 0.01-4% of TiO.sub.2, 0.01-1.5% of Fe.sub.2O.sub.3, 0.01-1.5% of Na.sub.2O, 0-1.5% of K.sub.2O, 0-0.7% of Li.sub.2O, 0-3% of SrO, 0-2.9% of La.sub.2O.sub.3. A total weight percentage of the above components is greater than or equal to 98%, and a weight percentage ratio C1=Y.sub.2O.sub.3/CaO is greater than or equal to 2.1.

A high-modulus glass fiber composition includes the following components with corresponding amounts by weight percentage: 42-56.8% of SiO.sub.2, 15.8-24% of Al.sub.2O.sub.3, 9.2-18% of MgO, 0.1-6.5% of CaO, greater than 8% and less than or equal to 20% of Y.sub.2O.sub.3, 0.01-4% of TiO.sub.2, 0.01-1.5% of Fe.sub.2O.sub.3, 0.01-1.5% of Na.sub.2O, 0-1.5% of K.sub.2O, 0-0.7% of Li.sub.2O, 0-3% of SrO, 0-2.9% of La.sub.2O.sub.3. A total weight percentage of the above components is greater than or equal to 98%, and a weight percentage ratio C1=Y.sub.2O.sub.3/CaO is greater than or equal to 2.1.

A high-modulus glass fiber composition includes the following components with corresponding amounts by weight percentage: 43-58% of SiO.sub.2, 15.5-23% of Al.sub.2O.sub.3, 8-18% of MgO, ≥25% of Al.sub.2O.sub.3+MgO, 0.1-7.5% of CaO, 7.1-22% of Y.sub.2O.sub.3, ≥16.5% of MgO+Y.sub.2O.sub.3, 0.01-5% of TiO.sub.2, 0.01-1.5% of Fe.sub.2O.sub.3, 0.01-2% of Na.sub.2O, 0-1.5% of K.sub.2O, 0-0.9% of Li.sub.2O, 0-4% of SrO, and 0-5% of La.sub.2O.sub.3+CeO.sub.2.

A high-modulus glass fiber composition includes the following components with corresponding amounts by weight percentage: 43-58% of SiO.sub.2, 15.5-23% of Al.sub.2O.sub.3, 8-18% of MgO, ≥25% of Al.sub.2O.sub.3+MgO, 0.1-7.5% of CaO, 7.1-22% of Y.sub.2O.sub.3, ≥16.5% of MgO+Y.sub.2O.sub.3, 0.01-5% of TiO.sub.2, 0.01-1.5% of Fe.sub.2O.sub.3, 0.01-2% of Na.sub.2O, 0-1.5% of K.sub.2O, 0-0.9% of Li.sub.2O, 0-4% of SrO, and 0-5% of La.sub.2O.sub.3+CeO.sub.2.

Provided is a glass composition for glass fiber allowing spinning to be stably performed without mixing of red foreign substances into glass fibers. The glass composition for glass fiber includes, in relation to the total amount thereof, SiO.sub.2 in a content falling within a range from 57.0 to 60.0% by mass, Al.sub.2O.sub.3 in a content falling within a range from 17.5 to 20.0% by mass, MgO in a content falling within a range from 8.5 to 12.0% by mass, CaO in a content falling within a range from 10.0 to 13.0% by mass and B.sub.2O.sub.3 in a content falling within a range from 0.5 to 1.5% by mass, the total content of SiO.sub.2, Al.sub.2O.sub.3, MgO and CaO being 98.0% by mass or more.

Provided is a glass composition for glass fiber allowing spinning to be stably performed without mixing of red foreign substances into glass fibers. The glass composition for glass fiber includes, in relation to the total amount thereof, SiO.sub.2 in a content falling within a range from 57.0 to 60.0% by mass, Al.sub.2O.sub.3 in a content falling within a range from 17.5 to 20.0% by mass, MgO in a content falling within a range from 8.5 to 12.0% by mass, CaO in a content falling within a range from 10.0 to 13.0% by mass and B.sub.2O.sub.3 in a content falling within a range from 0.5 to 1.5% by mass, the total content of SiO.sub.2, Al.sub.2O.sub.3, MgO and CaO being 98.0% by mass or more.