Precision roll forming of textured sheet glass
AssigneeCorning Incorporated
InventorWilliam Edward Lock
Life of this patent
Estimating the term…
Abstract
A process and apparatus for precision glass roll forming a supply of molten glass at a glass temperature of 1000° C. or higher with a pair of hot forming rolls having a surface temperature of about 500° C. or higher located vertically below the glass feed. The forming rolls thin the supplied stream of molten glass to produce a formed glass ribbon. A pair of cold sizing and texturing rolls maintained at a surface temperature of about 400° C. or lower or 300° C. or lower is located vertically below the forming rolls. The sizing and texturing rolls thin and texture the formed glass ribbon to produce a sized glass ribbon having a desired texture, thickness and thickness uniformity. The sized and textured glass ribbon may have a thickness of 1 mm or less that varies in thickness by no more than +/−0.025 mm.
Claims13
An apparatus for precision roll forming and texturing glass or glass-ceramic sheets comprising:
- a glass feed device for supplying a supplied stream of molten glass or glass-ceramic;
- a pair of forming rolls maintained at a surface temperature of about 500° C. or higher, the forming rolls being spaced closely adjacent each other defining a glass forming gap between the forming rolls with the glass forming gap located vertically below the glass feed device for receiving the supplied stream of molten glass and thinning the supplied stream of molten glass between the forming rolls to form a formed glass ribbon having a formed thickness;
- a pair of sizing rolls maintained at a surface temperature of about 400° C. or lower, the sizing rolls each comprising an insulating cylinder having an outer glass sizing surface, at least one of the sizing surfaces having a textured surface,
- a first pair of spacer rings mounted adjacent each end of the insulating cylinder of the first of the sizing rolls, and a second pair of spacer rings mounted adjacent to each end of the insulating cylinder of the second of the sizing rolls, the first and second sizing rings comprising outer cylindrical bearing surfaces extending radially beyond the outer glass sizing surface of the respective insulating cylinder;
- and
- a translational drive device for pressing the outer cylindrical bearing surfaces of the first and second sizing rolls together with the first pair of spacer rings engaging the second pair of spacer rings and thereby defining the glass sizing gap between the pair of sizing rolls;
- wherein the glass sizing gap is located vertically below the forming rolls for receiving the formed glass ribbon and thinning and imparting texture to the formed glass ribbon to produce a sized glass ribbon having a desired thickness, a desired thickness uniformity, and a desired texture on at least one surface of the glass ribbon.
A process for precision roll forming glass or glass-ceramic into textured glass sheets comprising the steps of:
- supplying a vertical stream of molten glass or glass-ceramic from a feed device;
- forming the supplied stream of molten glass with a pair of forming rolls maintained at a surface temperature of about 500° C. or higher or about 600° C. or higher to form a formed glass ribbon having a formed thickness, the forming rolls being spaced closely adjacent each other defining a glass forming gap between the forming rolls with the glass forming gap located vertically below the glass feed device;
- and
- sizing the formed ribbon of glass with a pair of sizing rolls maintained at a surface temperature of about 400° C. or lower, the sizing rolls being spaced closely adjacent each other defining a glass sizing gap between the sizing rolls with the glass sizing gap located vertically below the forming rolls, at least one of the sizing rolls having a textured surface that imparts a texture to at least one surface of the glass ribbon, thereby producing a sized and textured glass ribbon having a desired thickness less than the formed thickness, a desired texture on at least one surface of the glass ribbon, and a desired thickness uniformity,
- wherein the sizing rolls each comprise as insulating cylinder having an outer glass sizing surface, a first pair of spacer rings mounted adjacent each end of the insulating cylinder of the first of the sizing rolls, and a second pair of spacer rings mounted adjacent each end of the insulating cylinder of the second of the sizing rolls, the first and second sizing rings comprising outer cylindrical bearing surfaces extending radially beyond the outer glass sizing surface of the respective insulating cylinder;
- and
- wherein a transitional drive device presses the outer cylindrical bearing surfaces of the first and second sizing rolls together with the first pair of spacer rings engaging the second pair of spacer rings thereby defining a thickness of the glass sizing gap.
Dependencies are inferred from the claim text.