A method for controlling the thickness of a glass ribbon and an article produced thereby are provided. The method includes: providing a glass ribbon by drawing from a melt or redrawing from a preform; predefining a nominal thickness of the glass ribbon; determining the thickness of the glass ribbon over its entire net width; determining at least one deviation of the thickness of the glass ribbon from the predefined nominal thickness; identifying the area of the thickness deviation in the glass ribbon; and heating the area of the at least one thickness deviation in the glass ribbon using a laser, so that the glass ribbon attains the predefined thickness.

A method for controlling the thickness of a glass ribbon and an article produced thereby are provided. The method includes: providing a glass ribbon by drawing from a melt or redrawing from a preform; predefining a nominal thickness of the glass ribbon; determining the thickness of the glass ribbon over its entire net width; determining at least one deviation of the thickness of the glass ribbon from the predefined nominal thickness; identifying the area of the thickness deviation in the glass ribbon; and heating the area of the at least one thickness deviation in the glass ribbon using a laser, so that the glass ribbon attains the predefined thickness.

A redrawing method for the production of thin glasses is provided that allows redraw of high refractive index optical glasses. The includes the steps of providing a vitreous preform with a mean width B, a mean thickness D, and a refractive index n.sub.D of at least 1.68 in a redrawing device, heating at least a part of the preform, redrawing of the preform to a thin glass with a mean width b and a mean thickness d. The heated part of the preform exhibits, for the duration of at most 30 minutes, a temperature above a lower limit of devitrification of the glass. The glass of the preform exhibits a dependence of the viscosity on the temperature, which is characterized by a mean decrease of the viscosity with increasing temperature in an viscosity range of 10.sup.8 to 10.sup.5 dPas of at least 3*10.sup.5 dPas/K.

A redrawing method for the production of thin glasses is provided that allows redraw of high refractive index optical glasses. The includes the steps of providing a vitreous preform with a mean width B, a mean thickness D, and a refractive index n.sub.D of at least 1.68 in a redrawing device, heating at least a part of the preform, redrawing of the preform to a thin glass with a mean width b and a mean thickness d. The heated part of the preform exhibits, for the duration of at most 30 minutes, a temperature above a lower limit of devitrification of the glass. The glass of the preform exhibits a dependence of the viscosity on the temperature, which is characterized by a mean decrease of the viscosity with increasing temperature in an viscosity range of 10.sup.8 to 10.sup.5 dPas of at least 3*10.sup.5 dPas/K.

A mold has a sealing surface bearing a sealing profile. A plenum has a sealing surface bearing a sealing profile. The mold and plenum together form an apparatus for reforming a sheet material. In the closed position of the apparatus, the sealing profile of the mold is in opposing relation to the sealing profile of the plenum and the sealing profiles of the mold and plenum together define a profiled sealing gap. When the sheet material is wedged into the profiled sealing gap, a direct seal will be formed between the sheet material and each of the mold and plenum, resulting in two forming areas within the apparatus.

A mold has a sealing surface bearing a sealing profile. A plenum has a sealing surface bearing a sealing profile. The mold and plenum together form an apparatus for reforming a sheet material. In the closed position of the apparatus, the sealing profile of the mold is in opposing relation to the sealing profile of the plenum and the sealing profiles of the mold and plenum together define a profiled sealing gap. When the sheet material is wedged into the profiled sealing gap, a direct seal will be formed between the sheet material and each of the mold and plenum, resulting in two forming areas within the apparatus.

A method of drawing a material into sheet form includes forming a preform comprising at least one material as a large aspect ratio block wherein a first transverse dimension of the preform is much greater than a second transverse dimension substantially perpendicular to the first transverse dimension. A furnace having substantially linearly opposed heating elements one spaced from the other is provided and the heating elements are energized to apply heat to the preform to create a negative thermal gradient from an exterior surface along the first transverse dimension of the preform inward toward a central plane of the preform. The preform is drawn in such a manner that the material substantially maintains its first transverse dimension and deforms across its second transverse dimension.

A method of drawing a material into sheet form includes forming a preform comprising at least one material as a large aspect ratio block wherein a first transverse dimension of the preform is much greater than a second transverse dimension substantially perpendicular to the first transverse dimension. A furnace having substantially linearly opposed heating elements one spaced from the other is provided and the heating elements are energized to apply heat to the preform to create a negative thermal gradient from an exterior surface along the first transverse dimension of the preform inward toward a central plane of the preform. The preform is drawn in such a manner that the material substantially maintains its first transverse dimension and deforms across its second transverse dimension.

A drawing method for glass is described. The method provides glass components that have a strongly increased ratio of width to thickness when compared to the preform, which makes the manufacturing of flat glass components more economical. The method purposefully controls the temperature distribution within the preform.

A drawing method for glass is described. The method provides glass components that have a strongly increased ratio of width to thickness when compared to the preform, which makes the manufacturing of flat glass components more economical. The method purposefully controls the temperature distribution within the preform.