Abstract: Provided is a method, including: a melting step of melting glass in a melting furnace 2; a distribution step of supplying the molten glass in the melting furnace 2 to a plurality of branched channels 4; and a forming step of supplying the molten glass flowing out from each of the plurality of branched channels 4 to one of a plurality of forming apparatuses 51 to 53 communicating with the plurality of branched channels 4, respectively, and forming the molten glass into a plate-shaped glass by a down-draw method, in which one or more of the plurality of forming apparatuses 51 to 53 are used to form a glass film having a thickness of 1 to 200 ?m.

Abstract: Provided is a glass roll formed by winding a glass film into a roll, in which a minimum winding radius of the glass film is optimized. Thus, the glass film is reliably prevented from breaking due to static fatigue, and is able to be stored for long periods. A glass roll (1), which is formed by winding a glass film (2) into a roll, has a configuration in which the glass film has a minimum winding radius (R) satisfying the following relation: R?(T/2)[(2.3/?)×E?1], where ? represents flexural strength of the glass film (2) obtained by a 3-point bending test, T represents a thickness of the glass film, and E represents a Young's modulus of the glass film.

Abstract: Provided is a method, including: performing heat treatment, under a state in which a thick core plate glass (2a) having a higher thermal expansion coefficient and a thin surface-layer plate glass (3a) having a lower thermal expansion coefficient are laminated together, so that the laminated portion has a temperature equal to or higher than the lower softening point out of the softening points of the core plate glass (2a) and the surface-layer plate glass (3a), thereby melt-bonding the core plate glass (2a) and the surface-layer plate glass (3a); and then performing cooling so as to attain a temperature less than the lower strain point out of strain points of the core plate glass (2a) and the surface-layer plate glass (3a), to thereby form a compression stress in a surface layer portion (3) corresponding to the surface-layer plate glass (3a) and form a tensile stress in a core portion (2) corresponding to the core plate glass (2a).

Abstract: Provided is a method, including: performing heat treatment under a state in which a thick core plate glass (2a) having a higher thermal expansion coefficient and a thin surface-layer plate glass (3a) having a lower thermal expansion coefficient are brought into surface-to-surface contact so that a bonding surface (2x) and (3x) of the core plate glass (2a) and the surface-layer plate glass (3a) attain a close contact state, thereby directly bonding the core plate glass and the surface-layer plate glass (2a) and (3a); then, additionally performing heat treatment so that the surface-to-surface contact portion has a temperature equal to or higher than a lower strain point out of strain points of the core plate glass and the surface-layer plate glass; and then, performing cooling so as to attain a temperature lower than the lower strain point, to thereby form a compression stress in a surface layer portion (3) corresponding to the surface-layer plate glass (3a) and form a tensile stress in a core portion (2) corre

Abstract: Provided is a package form, with which cleanness of a glass film is ensured and the glass film is prevented from breaking. The package form is effective in minimizing the number of glass film processing steps to be performed before packaging and after unpackaging. As the package form for a glass film, provided is a glass roll (1) formed by winding a glass film (2) into a roll while superposing the glass film (2) on a protective sheet (3), the glass film (2) being formed by an overflow downdraw method and having exposed front and back surfaces.

Abstract: To provide a glass roll capable of reliably preventing a glass film from breaking from an end surface of the glass film as an origin of breakage, a glass roll (1) is formed by winding a glass film (2) into a roll while superposing the glass film (2) on a protective sheet (3), the glass film (2) being formed by an overflow downdraw method to have a thickness of 1 ?m or more and 200 ?m or less, and to have each end surface in a width direction to form a cut surface cut by laser splitting.

Abstract: Provided is a glass roll utilizing a flanged roll core, and reliably inhibiting a glass film from breaking from an end portion in a width direction thereof as an origin of breakage. A glass roll (1) is formed by winding a glass film (4) and a cushion sheet (5), under a state of being superposed, around a roll core (3) including a flange (2) at each end portion thereof, in which an end portion in a width direction of the glass film (4) is separated from the flange (2) on each side in the width direction of the glass film (4), and the cushion sheet (5) is extended beyond the end portion in the width direction of the glass film (4) to the flange (2) side, to thereby form an extension portion (5a).

Abstract: A method of producing a glass film comprises a first step of forming an inorganic thin film on a surface of a supporting glass so that a surface of the inorganic thin film after being formed has a surface roughness Ra of 2.0 nm or less after film formation, a second step of forming a glass film laminate by laminating a glass film having a surface roughness Ra of 2.0 nm or less on the surface of the inorganic thin film in a state of being in contact with each other, a third step of carrying out treatment involving heating with respect to the glass film laminate, and a fourth step of peeling off the glass film from the supporting glass after the treatment involving heating.

Abstract: The glass film laminate comprises a glass film and a supporting glass. The glass film and the supporting glass have surfaces being brought into contact with each other, and each of the surfaces has a surface roughness Ra of 2.0 nm or less.

Abstract: A glass having a SiO2—Al2O3—B2O3—RO (RO is at least one of MgO, CaO, BaO, SrO and ZnO) based composition, a temperature corresponding to 102.5 poise being 1570° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of 0.01 to 0.3%, as expressed in % by mass. And, a glass having a SiO2—Al2O3—B2O3—RO (RO is at least one of MgO, CaO, BaO, SrO and ZnO) based composition, a density of 2.5 g/cm3 or less, an average thermal expansion coefficient of 25 to 36×10?7/° C. in a temperature range of 30 to 380° C., a strain point of 640° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of not less than 0.01% and less than 0.4%, as expressed in % by mass.

Abstract: A method of producing a glass having a SiO2—Al2O3—B2O3—RO based composition, where RO is at least one of MgO, CaO, BaO, SrO and ZnO, a melting temperature corresponding to 102.5 poise of 1570° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of 0.01 to 0.3%, as expressed in % by mass. And, a method of producing a glass having a SiO2—Al2O3—B2O3—RO based composition, where RO is at least one of MgO, CaO, BaO, SrO and ZnO, a density of 2.5 g/cm3 or less, an average thermal expansion coefficient of 25 to 36×10?7/° C. in a temperature range of 30 to 380° C., a strain point of 640° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of not less than 0.01% and less than 0.4%, as expressed in % by mass.

Abstract: A situation where glass chip produced as a result of breakage of waste glass sheets floats in a cutting chamber when the waste glass sheets produced in glass sheet producing steps are collected is suppressed. Provided is a glass sheet production installation (1), in which a sheetshaped glass ribbon (B) is formed by supplying molten glass (A) into a forming body (2) and causing the molten glass (A) to flow downward on a conveyance path extending in an upper and lower direction from the forming body (2), and the glass ribbon (B) is cut into a predetermined dimension in a cutting chamber (6) provided on the conveyance path so that glass substrates (C) are produced.

Abstract: Provided is a glass ribbon producing apparatus (1), which feeds molten glass (Y) to a forming member (3), and causes the molten glass (Y) to flow downward from the forming member (3) to form a sheet-like glass ribbon (G), including guiding portion (6) which is disposed on a transport route, for the glass ribbon (G) caused to flow downward, and has a gap with a dimension larger than a sheet thickness of each of both widthwide end portions in a thickness direction of the glass ribbon (G) for guiding only the widthwide end portions of the glass ribbon (G) within a range of the gap.

Abstract: A glass ribbon producing apparatus (1) which feeds molten glass (Y) to a forming member (2) and causes the molten glass (Y) to flow downward from the forming member (2) to form a sheet-like glass ribbon (G) includes reheating portion (5) provided on a transport route for the glass ribbon (G) caused to flow downward from the forming member (2), and is configured so that the glass ribbon (G) is reheated by the reheating portion (5) to cause the sheet thickness of the glass ribbon (G) below the reheating portion (5) to be smaller than that of the glass ribbon (G) thereabove.

Abstract: A molten glass supply apparatus including a plurality of stirring vessels (K1, K2) disposed adjacent to each other in the upstream and downstream direction along supply passage (4) for supply of molten glass having flowed out from melting furnace (2) as a molten glass supply source to forming device (3), in which among at least two agitation vessels (K1, K2) disposed adjacent to each other, at least one of upper portion and lower portion of upstream side stirring vessel (K1) is provided with an inflow opening (M1) while the other portion is provided with an outflow opening (N1), and an inflow opening (M2) and an outflow opening (N2) of the downstream side stirring vessel (K2) are provided so that upper and lower portions are the same as the upstream side stirring vessel (K1), and the outflow aperture (N1) of the upstream side stirring vessel (K1) is connected through a communicating passage (R1) to the inflow opening (M2) of the downstream side stirring vessel (K2) whose upper and lower portions are upside-do

Abstract: An alkali-free glass substrate containing, by mass percent, 50-70% of SiO2, 10-25% of Al2O3, 5-20% of B2O3, 0-10% of MgO, 0-15% of CaO, 0-10% of BaO, 0-10% of SrO and 0-5% of ZnO, also containing SnO2 and/or Sb2O3 and having a ?-OH value of at least 0.485/mm.

Abstract: A molten glass supply device is provided, which can solve unavoidable problems for high viscosity characteristics in connection with the conventional molten glass supply device for high viscosity glass. Such problems include improperly high heating cost caused by excessive heat radiation in a melting furnace, reduction in the grade of products deriving from an excess amount of an erosion foreign material and reduction in the product yield. High viscosity molten glass having a property in which a temperature at which the molten glass exhibits a viscosity of 1000 poise is 1350° C. or higher is supplied to a forming device through a melting furnace, a distribution portion in communication with the outlet of the melting furnace, and a plurality of branch paths branching from the distribution portion. In the branch paths, distribution resistance providing portions that provide distribution resistance to molten glass passed through the branch paths are provided.

Abstract: A glass having a SiO2—Al2O3—B2O3—RO (RO is at least one of MgO, CaO, BaO, SrO and ZnO) based composition, a temperature corresponding to 102.5 poise being 1570° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of 0.01 to 0.3%, as expressed in % by mass. And, a glass having a SiO2—Al2O3—B2O3—RO (RO is at least one of MgO, CaO, BaO, SrO and ZnO) based composition, a density of 2.5 g/cm3 or less, an average thermal expansion coefficient of 25 to 36×10?7/° C. in a temperature range of 30 to 380° C., a strain point of 640° C. or higher and an alkali content of 0.01 to 0.2% and a ZrO2 content of not less than 0.01% and less than 0.4%, as expressed in % by mass.

Abstract: An alkali-free glass substrate containing, by mass percent, 50-70% of SiO2, 10-25% of Al2O3, 5-20% of B2O3, 0-10% of MgO, 0-15% of CaO, 0-10% of BaO, 0-10% of SrO and 0-5% of ZnO, also containing SnO2 and/or Sb2O3 and having a B-OH value of at least 0.485/mm.

Abstract: A molten glass supply device is provided, which can solve unavoidable problems for high viscosity characteristics in connection with the conventional molten glass supply device for high viscosity glass. Such problems include improperly high heating cost caused by excessive heat radiation in a melting furnace, reduction in the grade of products deriving from an excess amount of an erosion foreign material and reduction in the product yield. High viscosity molten glass having a property in which a temperature at which the molten glass exhibits a viscosity of 1000 poise is 1350° C. or higher is supplied to a forming device through a melting furnace, a distribution portion in communication with the outlet of the melting furnace, and a plurality of branch paths branching from the distribution portion. In the branch paths, distribution resistance providing portions that provide distribution resistance to molten glass passed through the branch paths are provided.