Glaverbel

Bfg Glassgroup

Albert Van Cauter

Robert Terneu

Robert Van Laethem

Jean-Francois Thomas

Robert Leclercq

Phileas Capouillet

Apparatus for pyrolytically forming a metal compound coating on an upper face of a hot glass substrate 1 comprises conveyor means 2 for conveying the substrate 1 in a downstream direction 3. A coating chamber 6 opening downwardly onto the path 1 and means 7 for spraying coating precursor downwardly towards the substrate. The spraying means 7 is located to spray the coating precursor solution from a height above the substrate path 1 of at least 75 cm. Heating means are provided for supplying heat to the spraying zone 9. Means such as aspirator boxes 39 is provided for generating aspirating forces on atmospheric material within the passageway 13 to encourage such material to flow along the substrate path to the downstream end (27) of the passageway and to enter exhaust ducting leading such material away from the substrate path. In operation, the spraying zone 9 of the coating chamber 6 is heated to cause evaporation of part of the coating precursor material before it reaches the substrate 1 to charge the atmosphere in that zone with vaporized coating precursor material. The solution is sprayed with sufficient energy to ensure positive impact of residual sprayed coating precursor material against the substrate to initiate coating of the substrate face, and atmosphere laden with coating precursor material in the vapor phase is caused to flow in the downstream direction from the spraying zone 9 along and in contact with the coated substrate face for a contact time of at least 10 seconds, whereafter residual material of the precursor laden current is directed away from the substrate.

Apparatus for and process of coating glass

A method is disclosed of forming a pyrolytic tin oxide coating on a face of a hot glass substrate during transport of the glass through a coating station into which a coating precursor solution containing a tin compound is sprayed so that the glass is contacted by material from which the tin oxide coating is formed by pyrolysis. The coating is formed by spraying a solution containing at least two additives. These additives and their amounts, and the thickness to which the coating is formed, are selected so that the coating contains doping atoms and has an emissivity in respect of infra-red radiation having wavelengths greater than 3 micrometers of at most 0.3 and a specific internal haze factor of at most 1.5. The additives dissolved in the coating precursor solution may be selected from at least two of the following groups A, B and C, wherein group A consists of compounds which will result in the coating containing fluorine, group B consists of compounds which will result in the coating containing at least one of antimony, arsenic, vanadium, cobalt, zinc, cadmium, tungsten, tellurium, indium, molybdenum and manganese, and group C consists of oxidizing agents.

Method of coating glass and coated flat glass

Flat glass is disclosed, bearing a tin oxide coating layer which is at least 200 nm in thickness. In order to promote a uniform visual appearance across the coated area, the expected grain area of a representative sample of the tin oxide coating crystals measured in units of 10.sup.-4 .mu.m.sup.2 is numerically equal to a value of at least 0.4 times the layer thickness measured in nanometers.

Coated flat glass

Apparatus for use in pyrolytically forming a metal oxide coating on an upper face of a hot glass substrate 1 in sheet or ribbon form comprises conveyor means 2 for conveying the substrate 1 in a downstream direction 3 along a path also indicated at 1 and a roof structure 5 defining a coating chamber 6 opening downwardly onto the path and comprising a passageway 11 along which coating precursor vapor and oxidizing gas can be conducted downstream in contact with the upper substrate face during the conveyance of the substrate. The roof structure 5 defines, in or adjacent the upstream end of the passageway 11, a mixing zone 7 which opens downwardly onto the substrate path 1. Means such as spray nozzle 35 is provided for injecting coating precursor material into the mixing zone 7 from a height of at least 50 cm above the level of the substate path 1. Means such as ducting 58 is provided for injecting oxidizing gas into the mixing zone in which coating precursor material and oxidizing gas can be brought together, mixed and heated to form an atmosphere comprising an intimate mixture of precursor vapor and oxidizing gas. The mixing zone 7 is in communication with the passageway 11 to permit a stream of such atmosphere to flow along the passageway from the mixing zone.

Process and apparatus for coating glass

Apparatus for pyrolytically forming a metal compound coating on an upper face of a hot glass substrate 1 in sheet or ribbon form comprises conveyor means 2 for conveying a the substrate along a path also indicated at 1 in a downstream direction 3, a roof structure 5 defining a coating chamber 6 opening downwardly onto the path 1 and means 7 for discharging coating precursor material into the chamber 6. Upstream of the coating chamber 6 there is an antechamber 25 which communicates with the coating chamber 6 via an entry slot 24 which is defined in part by the path of the substrate 1, and via which gas can be caused to flow into the coating chamber 6 so as to form (when the apparatus is in use) a blanket layer which covers the upper face of the substrate 1 along a first part of the length of the chamber 6. Means 26 is provided for controllably preheating the gas forming the blanket layer. In operation, the gaseous environment in the immediate vicinity of the upper face of the substrate at least in the zone at which coating formation commences, is controlled by feeding preheated gas in a downstream direction into the chamber 6 to enter the chamber in contact with the substrate and form a blanket layer which covers the substrate at least as far as that zone.

Process and apparatus for pyrolytically coating glass

A hot vitreous substrate 1 travels on a conveyor 2 through a coating station 5 where a metal compound is formed in situ on a face of the substrate 1 by pyrolytic decomposition of coating material 9 sprayed towards the substrate from a spray head 6 which repeatedly traverses the substrate path. Radiant heating means 11 located on the side of the substrate 1 being coated directs radiant heat towards the transverse region swept by the zone of impingement 10 of the coating precursor material 9 on the substrate 1.

Apparatus for forming a coating on a hot vitreous substrate by spraying

A metal or metal compound coating is formed on a face of a hot ribbon 3 of freshly formed glass as it travels forwardly 4 through a coating station 19 where coating precursor material is sprayed onto the surface of the glass. The coating precursor material is sprayed in one or more streams 1 of droplets which is or are directed downwardly and forwardly towards the ribbon 4 and is repeatedly displaced to and fro across the ribbon path so that the ribbon 3 is scanned by the droplet stream(s) 1. Especially in order to form a thick coating of tin oxide on a rapidly moving ribbon, the velocities of the droplets in the stream(s) 1 are such that substantial splashing occurs at the ribbon face. Gas is continuously discharged along axes 6,7,8 behind the droplet stream 1 so as to maintain a forwardly directed flow of gas which envelops the rear half 15 of the or each stream 1 at least at the bottom portion of the stream trajectory and sweeps past the sides of such stream with sufficient velocity to entrain substantially all the splashes away from the stream. The entrained material is then removed from the environment of the ribbon through exhaust ducting 27.

Coating hot glass with metals or metal compounds, especially oxides

Method for forming a coating on a hot vitreous substrate by spraying the

A metal or metal compound coating 6 is deposited on a face of a hot, freshly formed ribbon 1 of glass during the ribbon's forward travel through a coating station 5 between a forming installation 3 and an annealing lehr 4 by contacting the ribbon face with fluid coating precursor material e.g. sprayed from nozzle 17. Preparatory to the coating step, the ribbon 1 is passed through successive thermal conditioning zones comprising a zone 19 in which temperature gradients across the ribbon are reduced and a following zone in which heat is supplied substantially entirely to a surface layer of the glass at the face to be coated by exposing that face to one or more radiant heaters 22 having a black body temperature below 1100.degree. C. to compensate at least partially for the cooling effect of the coating step on the ribbon 1.

Process for producing coated flat glass

In the formation of a metal or metal compound coating on a face of a heated glass substrate during its forward displacement by contacting such face, at a coating station with at least one stream of droplets comprising one or more substances from which said coating is formed there is a problem in forming uniform high quality coatings which are free from structural defects. To help reduce this problem, the stream(s) of droplets (e.g. from spray gun 20) is or are repeatedly displaced along a transverse path (defined by guide 15) across the substrate (4), and gas is propelled (e.g. from discharge nozzles 24) unidirectionally forwardly or rearwardly across said transverse path, out of line with the droplet stream(s).

Process for coating glass

In the formation of a metal or metal compound coating on a face of a heated glass substrate during its forward displacement by contacting such face at a coating station with at least one stream of droplets comprising one or more substances from which the coating is formed, problems are encountered in controlling the thickness of the coating. To facilitate such control, the or each droplet stream (21) is downwardly inclined towards the substrate (4) in the forward (6) direction or in a rearward direction, and at least one current (25) of preheated gas is discharged into the environment above the substrate (4) to flow in the same forward or rearward direction as the droplet stream(s) (21) and into contact therewith, the preheated gas current temperature being such as to influence the temperature of the droplets on their way to the substrate. The invention includes apparatus for performing the method.

In the formation of a metal or metal compound coating on a face of a heated glass substrate during its displacement in a downstream direction through a coating station at which the said face is contacted with at least one downwardly inclined stream of droplets comprising a substance or substances from which said coating is formed, there is a problem in achieving coatings of homogeneous structure and in providing uniform coverage of the substrate. To help reduce these problems each droplet stream delivered by spray guns 9 is inclined downwardly towards the substrate 4 in the upstream or downstream 6 direction, and one or more counter-currents of gas is or are caused to flow adjacent the substrate path from ducts 15, 16 and towards the front of each droplet stream, (the front being where the droplets have the longest trajectories), and suction force is exerted in exhaust ducting 13, 14 whose entrance is located for drawing gases away from the front of the droplet streams at a higher level.

In the formation of a metal or metal compound coating on a face of a heated glass substrate during its forward displacement through a coating station by contacting the substrate with at least one stream of droplets comprising a substance or substances from which said coating is formed there is a problem in achieving coatings of high uniform quality. In order to help meet this problem, the droplet stream(s) 23 from spray gun(s) 20 is or are inclined downwardly and forwardly (6) or downwardly and rearwardly towards the substrate 4 and at least one jet of gas is discharged (from nozzle 22) into the environment above the substrate so that it travels in the same (forward or rearward) direction above the substrate 4 and impinges against such droplet stream(s) 23.

A tin oxide coating is formed on a hot glass substrate during conveyance through two successive coating zones in the first of which it is contacted with an acetylacetonate or alkylate of titanium, nickel or zinc to cause deposition of a metal oxide undercoating on the substrate, and in the second of which zones such metal oxide coating on the still hot substrate is contacted by a gaseous medium comprising a tin halide to cause deposition of a coating of tin oxide.

Process for forming tin oxide glass coating

A process of coating glass with tin oxide by exposing the glass to a gaseous medium containing tin tetrachloride vapor under conditions causing formation of the oxide coating by chemical reaction and/or decomposition. The glass is moved continuously through the coating zone and in order to promote a high optical quality of the coating the gaseous medium is formed with a tin tetrachloride concentration corresponding to a partial pressure of at least 2.5.times.10.sup.-3 atm. and contains water vapor in a concentration corresponding to a partial pressure of at least 10.times.10.sup.-3 atm. and the gaseous medium contacts the glass face to be coated while said medium is at a temperature of at least 300.degree. C. and such face is at a temperature above 550.degree. C.

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Charleroi, Belgium

Albert Van Cauter