Microwave Heating Glass Bending Process

Abstract

Methods and systems are provided for automated shaping of a glass sheet. The methods comprise preheating the glass, bending the glass through selective, and focused beam heating through the use of an ultra-high frequency, high-power electromagnetic wave, and computer implemented processes utilizing thermal and shape (positional) data obtained in real-time, and cooling the glass sheet to produce a glass sheet suitable for use in air and space vehicles.

1 . (canceled) 
     
     
         2 . A furnace system, comprising:
 a first chamber comprising at least one first infrared heater and at least one first thermal sensor;   a second chamber comprising:
 at least one second infrared heater, 
 a device that produces ultra-high frequency, high-power electromagnetic waves, 
 an optical system for controlling shape, location, and/or movement of a beam of the device to a glass sheet on a bending iron within the second chamber, 
 at least one second thermal sensor, and 
 at least one positional sensor in the second chamber to obtain positional data for at least one portion of the glass sheet during bending; 
   a conveyor system for carrying the glass sheet on the bending iron through the first and second chambers; and   a computer system connected to the at least one second thermal sensor, the at least one positional sensor, and at least one of the device that produces ultra-high frequency, high-power electromagnetic waves or the optical system, the computer system comprising one or more processors programmed or configured to control selective heating by the device that produces ultra-high frequency, high-power electromagnetic waves to heat and bend the glass sheet in the second chamber, wherein the one or more processors are further programmed or configured to:
 obtain a temperature profile of the glass sheet at a plurality of time points during bending of the glass sheet in the second chamber from the at least one second thermal sensor; 
 obtain data from the at least one positional sensor at the plurality of time points during the bending of the glass sheet in the second chamber; 
 produce a shape profile for the glass sheet from the obtained data from the at least one positional sensor at the plurality of time points; 
 concurrently compare the obtained shape profile to a reference shape profile and compare the obtained temperature profile to a reference temperature distribution; and 
 during the bending of the glass sheet, control the device that produces ultra-high frequency, high-power electromagnetic waves to selectively heat the glass sheet to match the shape profile of the glass sheet to the reference shape profile and to match the obtained temperature profile of the glass sheet with the reference temperature distribution. 
   
     
     
         3 . The system of  claim 2 , wherein the device producing ultra-high frequency, high-power electromagnetic waves is a gyrotron configured to produce waves with a frequency of at least 20 GHz and power of at least 5 kW. 
     
     
         4 . The system of  claim 2 , wherein the at least one first thermal sensor or the at least one second thermal sensor comprise at least one of an infrared (IR) scanner, an IR imaging sensor, a charged-coupled device (CCD), an IR laser-light sensor device, a thermal imaging device, or a thermal scanner. 
     
     
         5 . The system of  claim 2 , wherein the first chamber comprises a first tunnel furnace comprising:
 a first entrance end and a first exit end;   a first heating system comprising the at least one first infrared heater configured to heat the glass sheet passing through the first tunnel furnace to a first predetermined temperature, and   a first portion of the conveying system configured to move the glass sheet through the first tunnel furnace from the first entrance end toward the first exit end.   
     
     
         6 . The system of  claim 5 , wherein the second chamber comprises a shaping furnace, comprising:
 a second entrance connected to the first exit end and a second exit end, and   a mirror system to direct the device that produces ultra-high frequency, high-power electromagnetic waves to a predetermined area within the shaping furnace to shape a predetermined portion of the glass sheet passing through the shaping furnace.   
     
     
         7 . The system of  claim 6 , further comprising a third chamber, which comprises another tunnel furnace, the third chamber comprising:
 a third entrance end connected to the second exit end and a third exit end;   a heating system to controllably cool the shaped glass sheet passing through the third chamber, and   a third portion of the conveying system to move the glass sheet through the third chamber from the third entrance end toward the third exit end.   
     
     
         8 . The system of  claim 7 , wherein the third chamber cools the glass sheet directly after the bending of the glass sheet in the second chamber, and
 wherein, directly after the bending of the glass sheet in the second chamber, the third portion of the conveyor system carries the glass sheet through the third chamber.   
     
     
         9 . The system of  claim 7 , wherein the first chamber, the second chamber, and the third chamber form a single tunnel. 
     
     
         10 . The system of  claim 7 , further comprising doors between the first chamber and the second chamber and doors between the second chamber and the third chamber. 
     
     
         11 . The system of  claim 2 , wherein, after the bending of the glass sheet in the second chamber according to the reference temperature distribution, the conveyor system removes the glass sheet from the second furnace and the glass sheet is cooled. 
     
     
         12 . The system of  claim 2 , wherein the at least one positional sensor comprises at least one charge-coupled device (CCD). 
     
     
         13 . The system of  claim 2 , wherein the at least one positional sensor comprises a plurality of charge-coupled devices (CCD), and
 wherein the shape profile is a three-dimensional shape profile assembled from data obtained from the plurality of CCDs.   
     
     
         14 . The system of  claim 2 , wherein the at least one positional sensor comprises a laser-light sensor. 
     
     
         15 . The system of  claim 2 , wherein the at least one positional sensor comprises a plurality of the laser-light sensors, and
 wherein the shape profile is a three-dimensional shape profile assembled from data obtained from the plurality of laser light sensors.   
     
     
         16 . The system of  claim 2 , wherein the reference temperature distribution defines a plurality of reference temperatures of a plurality of portions of the glass sheet at the plurality of time points during the bending of the glass sheet in the second chamber. 
     
     
         17 . The system of  claim 16 , wherein a first reference temperature of a first portion of the glass sheet at a first time point in the reference temperature distribution during the bending of the glass sheet in the second chamber is different than a second reference temperature of the first portion of the glass sheet at a second time point in the reference temperature distribution during the bending of the glass sheet in the second chamber. 
     
     
         18 . A method of shaping a glass sheet, comprising:
 preheating the glass sheet on a bending iron to a predetermined preheating temperature;   bending the preheated glass sheet by selectively heating the glass sheet with a device that produces a beam of electromagnetic waves to a temperature at which at least a portion of the glass sheet sags;   scanning the glass sheet with at least one thermal sensor at a plurality of time points during the bending of the glass sheet and obtaining a temperature profile of the glass sheet at the plurality of time points from data obtained from the at least one thermal sensor;   scanning the glass sheet with at least one positional sensor at the plurality of time points during the bending of the glass sheet to obtain positional data for portions of the glass sheet;   producing a shape profile for the glass sheet from the obtained positional data;   concurrently comparing the obtained shape profile to a reference shape profile and comparing the obtained temperature profile to a reference temperature distribution; and   controlling the device that produces ultra-high frequency, high-power electromagnetic waves to selectively heat the glass sheet to match the shape profile of the glass sheet to the reference shape profile and to match the temperature profile with the reference temperature distribution.   
     
     
         19 . The method of  claim 18 , wherein the device producing ultra-high frequency, high-power electromagnetic waves is a gyrotron configured to produce waves with a frequency of at least 20 GHz and power of at least 5 kW. 
     
     
         20 . The method of  claim 18 , wherein the at least one thermal sensor comprises at least one of an infrared (IR) scanner, an IR imaging sensor, a charged-coupled device (CCD), an IR laser-light sensor device, a thermal imaging device, or a thermal scanner, and wherein the at least one positional sensor comprises at least one of a charge-coupled device (CCD) or a laser-light sensor. 
     
     
         21 . The method of  claim 18 , wherein the reference temperature distribution defines a plurality of temperatures of a plurality of portions of the glass sheet at the plurality of time points during the bending of the glass sheet,
 wherein a first temperature of the plurality of portions of the glass sheet at a first time in the reference temperature distribution during the bending of the glass sheet is different than a second temperature of the plurality of portions of the glass sheet at a second time in the reference temperature distribution during the bending of the glass sheet.