Powder-coated glass products

Abstract

A method of manufacturing a powder-coated glass product. The method comprises depositing thermosetting powder on the upper most first surface of the glass substrate and curing the thermosetting powder to form a coating on the first surface. The curing step comprises applying heat via infra-red radiation located below the second surface of the glass substrate and via the second surface of the glass substrate. The source of infra-red radiation comprises a box having an internally-reflective surface and a heat-transmissive lid located below the second surface of the glass substrate. At least one infra-red lamp is located within the box to emit the infra-red radiation into the box, and the infra-red radiation emitted into the box heats the air within the box for conduction of heat from the air through the lid to the second surface across the gap between the lid and the second surface of the glass substrate.

1 - 24 . (canceled) 
     
     
         25 . A method of manufacturing a powder-coated glass product with the product including a glass substrate having first and second surfaces, the method comprising:
 a step of depositing thermosetting powder on the first surface of the glass substrate with the first surface uppermost of the first and the second surfaces of the glass substrate; and   a step of curing the thermosetting powder to form a coating on the first surface of the glass substrate, the step of curing the thermosetting powder comprising application of heat to the thermosetting powder from a source of infra-red radiation located below the second surface of the glass substrate, the source of infra-red radiation applying the infra-red radiation via the second surface of the glass substrate to heat the thermosetting powder, the application of heat to the thermosetting powder being partly by transmission of the heat conducted through the glass substrate from the second surface to the first surface of the glass substrate and partly by transmission of the infra-red radiation through the glass substrate to the thermosetting powder;   wherein the source of infra-red radiation comprises a box having an internally-reflective surface and a heat-transmissive lid, the box being located below the second surface of the glass substrate with the lid spaced by a gap from the second surface, and at least one infra-red lamp located within the box to emit the infra-red radiation into the box, the infra-red radiation emitted into the box heating air within the box for conduction of heat from the air through the lid to the second surface across the gap between the lid and the second surface of the glass substrate.   
     
     
         26 . The method according to  claim 25 , further comprising the step of forming the lid from borosilicate glass. 
     
     
         27 . The method according to  claim 25 , further comprising the step of enhancing adherence of the coating to the first surface of the glass substrate by an adhesion promoter included within the thermosetting powder. 
     
     
         28 . The method according to  claim 25 , further comprising the step of treating the first surface of the glass substrate with an adhesion promoter prior to the step of depositing of the thermosetting powder on the first surface of the glass substrate. 
     
     
         29 . The method according to  claim 25 , further comprising the step of regulating the frequency of the infra-red radiation from a higher frequency to a lower frequency as the thermosetting powder progresses from melt to cure. 
     
     
         30 . The method according to  claim 25 , further comprising the step of depositing two thermosetting powders, one after the other, on the first surface of the substrate for forming a first coating on the substrate and a second coating on the first coating, and heating to cure both of the two thermosetting powders into the first and the second coatings is applied by transmission through the substrate. 
     
     
         31 . The method according to  claim 25 , further including a preliminary step of heating the glass substrate, prior to the step of depositing the thermosetting powder on the first surface of the glass substrate, with the preliminary step being carried out for adhesion of the thermosetting powder to the first surface of the glass substrate during the step of depositing the thermosetting powder on the first surface of the glass substrate. 
     
     
         32 . A method of manufacturing a powder-coated glass product, the product including a glass substrate having first and second surfaces, and the method comprising the steps of:
 depositing thermosetting powder on the first surface of the glass substrate with the first surface uppermost of the first and the second surfaces of the glass substrate; and   curing the thermosetting powder deposited on the first surface by application of heat to the deposited thermosetting powder to form a coating on the first surface of the glass substrate,   the application of the heat to the thermosetting powder being from a source of infra-red radiation located below the second surface of the glass substrate to apply the infra-red radiation to the second surface, the source of infra-red radiation comprising a box having a borosilicate glass lid and at least one infra-red lamp within the box for emitting the infra-red radiation through the glass lid for transmission of the infra-red radiation through the glass substrate from the second surface to the thermosetting powder deposited on the first surface of the glass substrate, the transmission of the infra-red radiation through the glass substrate to the thermosetting powder deposited on the first surface fusing the thermosetting powder progressively upwards within the thermosetting powder from the first surface to cure the thermosetting powder.   
     
     
         33 . A method of manufacturing a powder-coated glass product with the product including a glass substrate having an upper surface and a lower surface, and the method comprising:
 a step of depositing thermosetting powder on the upper surface of the glass substrate; and   a step of curing, within an oven, the thermosetting powder deposited on the upper surface to form a coating on the upper surface of the glass substrate, the step of curing the thermosetting powder comprising application of heat to the thermosetting powder from a source of infra-red radiation located within the oven under the lower surface of the glass substrate, the source of infra-red radiation applying the infra-red radiation via the lower surface of the glass substrate to heat the thermosetting powder, the application of heat to the thermosetting powder being by transmission of the infra-red radiation through the glass substrate from the lower surface to the upper surface of the glass substrate while maintaining an environment of near-ambient temperature above the glass substrate within the oven.   
     
     
         34 . The method according to  claim 33 , wherein the source of infra-red radiation is mounted within a box having a reflective internal surface. 
     
     
         35 . The method according to  claim 34 , wherein the heat is transmitted to the glass substrate by conduction from the box, and to the thermosetting powder by the radiation through the substrate. 
     
     
         36 . A method of manufacturing a powder-coated glass product with the product including a glass substrate having first and second surfaces, the method comprising:
 a step of depositing two thermosetting powders on the first surface of the glass substrate with the first surface being an uppermost surface of the first and the second surfaces of the glass substrate;   a step of curing the two thermosetting powders to form a coating on the first surface of the glass substrate, the step of curing the thermosetting powder comprising application of heat to the two thermosetting powders from a source of infra-red radiation located below the second surface of the glass substrate, the source of infra-red radiation applying the infra-red radiation, via the second surface of the glass substrate, to heat the thermosetting powder, and the application of heat to the thermosetting powder being partly by transmission of the heat conducted through the glass substrate from the second surface to the first surface of the glass substrate and partly by transmission of the infra-red radiation through the glass substrate to the thermosetting powder;   the step of depositing the two thermosetting powders further comprises the step of depositing the two thermosetting powders, one after the other, on the first surface of the substrate for forming a first coating on the substrate and a second coating on the first coating, and applying heat to cure both of the two thermosetting powders into the first and the second coatings by transmission through the substrate; and   bonding a metal foil to a back surface of the second coating for reduction of thermal stress in the glass substrate, the metal foil extending inwardly from edges of the second coating across its back surface by a distance within a range 100-150 mm.