Glass has a refractive index of 1.55 or more, and has, in an x-ray absorption fine structure (XAFS) analysis of platinum, a peak intensity ratio expressed by A.sub.max/A.sub.ave of 1.13 or more, where A.sub.max denotes a maximum value of a white line within an energy range of 13,270 eV to 13,290 eV, and A.sub.ave denotes an average absorption in an energy range of 13,290 eV to 13,390 eV.

Computer-implemented methods and apparatus are provided for predicting/estimating (i) a non-equilibrium viscosity for at least one given time point in a given temperature profile for a given glass composition, (ii) at least one temperature profile that will provide a given non-equilibrium viscosity for a given glass composition, or (iii) at least one glass composition that will provide a given non-equilibrium viscosity for a given time point in a given temperature profile. The methods and apparatus can be used to predict/estimate stress relaxation in a glass article during forming as well as compaction, stress relaxation, and/or thermal sag or thermal creep of a glass article when the article is subjected to one or more post-forming thermal treatments.

To provide a method for manufacturing a medical glass container prevented from breakage and deformation and a fire blasting device. A method for manufacturing a medical glass container includes a processing process of placing a glass container 10 on the outer peripheral surface of each of a first roller 61 and a second roller 62, which are disposed side by side in such a manner that the axis lines are parallel to each other, so that the axis line of the glass container 10 is parallel to the axis lines of the first roller 61 and the second roller 62 and the entire outer peripheral surface in an inner surface 15 of the glass container 10 corresponding to a region deteriorated by processing is made to abut on the outer peripheral surface of each of the first roller 61 and the second roller 62, and then applying a flame ejected from a point burner 30 to the region deteriorated by processing in the inner surface 15 of the glass container 10 while rotating the glass container 10 by rotating the first roller 61 and the second roller 62 around the axis lines.

To provide a method for manufacturing a medical glass container prevented from breakage and deformation and a fire blasting device. A method for manufacturing a medical glass container includes a processing process of placing a glass container 10 on the outer peripheral surface of each of a first roller 61 and a second roller 62, which are disposed side by side in such a manner that the axis lines are parallel to each other, so that the axis line of the glass container 10 is parallel to the axis lines of the first roller 61 and the second roller 62 and the entire outer peripheral surface in an inner surface 15 of the glass container 10 corresponding to a region deteriorated by processing is made to abut on the outer peripheral surface of each of the first roller 61 and the second roller 62, and then applying a flame ejected from a point burner 30 to the region deteriorated by processing in the inner surface 15 of the glass container 10 while rotating the glass container 10 by rotating the first roller 61 and the second roller 62 around the axis lines.

According to one embodiment, a method for thermally treating glass articles may include holding a glass article at a treatment temperature equal to an annealing temperature of the glass article =15° C. for a holding time greater than or equal to 5 minutes. Thereafter, the glass article may be cooled from the treatment temperature through a strain point of the glass article at a first cooling rate CR1 less than 0° C./min and greater than −20° C./min such that a density of the glass article is greater than or equal to 0.003 g/cc after cooling. The glass article is subsequently cooled from below the strain point at a second cooling rate CR.sub.2, wherein |CR.sub.2|>|CR.sub.1|.

According to one embodiment, a method for thermally treating glass articles may include holding a glass article at a treatment temperature equal to an annealing temperature of the glass article =15° C. for a holding time greater than or equal to 5 minutes. Thereafter, the glass article may be cooled from the treatment temperature through a strain point of the glass article at a first cooling rate CR1 less than 0° C./min and greater than −20° C./min such that a density of the glass article is greater than or equal to 0.003 g/cc after cooling. The glass article is subsequently cooled from below the strain point at a second cooling rate CR.sub.2, wherein |CR.sub.2|>|CR.sub.1|.

Glass laminates, comprising more than one glass composition, are becoming increasingly common as the industry moves towards lighter and stronger glazing. Bending dissimilar glass compositions can present problems. A mismatch in the glass viscosity curves, especially in the viscoelastic region of the compositions can result in one layer becoming softer than one of the other layers during the thermal bending process. As a result, economical processes, such as gravity or press bending in which multiple glass layers are simultaneously bent, may not be practical to use forcing the use of more expensive single glass layer bending processes. By thermal treatment processes the fictive temperature of at least one of the glass compositions prior to bending can be shifted to better match the other compositions allowing the glass layers to be simultaneously bent.

A dental bulk block for a CAD/CAM machining process. The dental bulk block is a glass-ceramic block having a crystalline phase embedded in an amorphous glass matrix. The crystalline phase includes lithium disilicate as a main crystalline phase, no sub-crystalline phase exists, and the crystalline phase has a mean grain size of 0.01 to 1.0 μm and a crystallinity degree of 25 to 45%. The dental bulk block can improve machinability during cutting such as CAD/CAM machining in the state of a high-strength workpiece with high flexural strength, thereby reducing a tool resistance and a wear rate, increasing a tool life span, and reducing edge chipping during a machining process. In addition, a dental restoration with desired translucency variations can be manufactured through a simple process of machining a block and altering post-heat treatment conditions, and thus can be realized with various shades.

A glass sheet of the present invention releases CO.sub.2 gas in an amount of 5.0 μL/g or less when the glass sheet is subjected to heat treatment under the conditions of 1,500° C. and 4 hours after having been subjected to preheating under the conditions of 900° C. and 1 hour.

A glass sheet of the present invention releases CO.sub.2 gas in an amount of 5.0 μL/g or less when the glass sheet is subjected to heat treatment under the conditions of 1,500° C. and 4 hours after having been subjected to preheating under the conditions of 900° C. and 1 hour.