GB1307361A - Treating glass - Google Patents

Abstract

1307361 Coating glass with metal oxides PILKINGTON BROS Ltd and C R BAMFORD 21 April 1970 [23 April 1969] 20770/69 Headings C1A and C1M Metal oxides are produced as coatings on glasses in a process which comprises spraying an aqueous solution of an inorganic salt on to a hot glass ribbon as it is passed through an enclosed space whilst blowing through the said enclosed space a gas stream so as to maintain a controlled atmosphere therein. The compound sprayed is such as will pyrolize on contact with the hot glass to form the metal oxide, e.g. ferric chloride or cobaltous acetate, and the gas used to maintain the controlled atmosphere may be air. Glass ribbon 1 passes after formation in region 2 to the annealing lehr 4 via spray zone 5, being carried on rollers 3. Suitable gas is passed into the zone through manifolds 9 and exhausted through ducts 10 and butterfly valves 13 to hood 11 and hence to the extraction system 12. The spraying zone is isolated from forming area and annealing lehr by known means, such as raisable wall 14, in which is mounted a manifold 15 supply gast o form a screen, used in conjunction with flexible aprons 16 and 18. Spraying is by means of one or more spray guns 8 which spray through a slot 7 in the stepped ceiling 6. The temperature of the enclosed zone is maintained by heating the gas supplied through manifolds 9 at a value near to that of the hot glass so as to prevent adverse cooling effects.