Patent ID: 8627683
Filing Date: 2014-01-14
Classification: C03B,G05D

Abstract:
1. A method for producing glass sheets comprising: (I) producing a glass ribbon having a width; (II) using a plurality of thermal elements to control the temperature of the ribbon across its width at a location along the length of the ribbon that is prior to the location where the thickness of the ribbon becomes fixed, said thermal elements being distributed across the width of the ribbon and each element having an independently adjustable operating variable D (III) separating glass sheets from the ribbon; wherein step (II) comprises selecting a set of values for the operating variables D (a) assigning a sheet thickness response function Δt where x is a location on the sheet, x0 i is a location-of-the-thermal-element parameter, w i is a width-of-effect parameter, and func is a function of at least the variable x and the parameters x0 1 and w i ; (b) selecting values for the x0 (c) selecting a set of D (d) applying the set of D (e) measuring a thickness distribution of at least one glass sheet produced in step (d); (f) determining a revised set of A (g) applying a set of D (h) measuring a thickness distribution of the at least one glass sheet produced in step (g); and (i) comparing the thickness distribution measured in step (h) with a thickness variation criterion and, if the criterion is not satisfied, repeating steps (f) through (h), one or more times, until the criterion is satisfied, where for each repetition, the measured thickness distribution and the set of A wherein the thickness variation criterion used in step (i) is selected from the group consisting of: