Abstract: In the diffusion of ions from a contacting medium constituting a source of such ions into surface layers of a body of glass or vitrocrystalline material for the purpose of modifying at least one property of the body, the uniformity of the diffusion across the surface of the body is improved by placing the medium contacting the body in the form of a mist composed of suspended droplets of the treating medium.

Abstract: A fire screening glazing panel and a method of producing same. A panel is formed of at least two structural plies and at least one of which is a vitreous sheet, layers of heat convertible thermally insulating barrier forming material are placed on a face of each ply, and a plastic membrane is sandwiched between the layered plies, the layers being adjacent the plastic membrane. When formed in this way, the plastic membrane makes the transfer of heat from one barrier-forming material layer to the other more uniform and prolongs the time taken for the vitreous sheet to reach a given temperature, while the panel as a whole is in itself sufficient to prevent or delay propagation of fire across an opening closed by the panel. Protective strata may be applied to each vitreous ply on its face that will be in contact with the barrier forming material layer to inhibit interaction between the ply and the layer and preserve the transparency (if the ply is transparent) of the ply over an extended period of time.

Abstract: A heat insulating screen forming a part of an oven or furnace comprising two or more sheets of glass of vitrocrystalline material mounted in facing relationship, one sheet providing one exterior face of the screen having been subjected to a chemical tempering treatment, the other sheet providing the other exterior face of the screen having improved thermal properties which are obtained either by utilizing a borosilicate glass which has a coefficient of thermal expansion of less than 5 x 10.sup.-6 /.degree. C or a sheet bearing at least one coating capable of screening off a significant amount of incident infrared radiation.

Abstract: Process and apparatus for the production or treatment of flat glass in an elongate tank containing a bath of molten material. Glass is delivered to the bath, and it is advanced along a path in contact with the bath towards an outlet for the glass from the tank. At least one current is induced in the molten material in at least one portion of the tank where the viscosity of the glass lies in the range between 10.sup.4.5 and 10.sup.10 poise to flow across substantially the full width of the glass.

Abstract: A laminated glazing pane comprised of at least two sheets of vitreous material joined together by an intervening layer of plastic material given improved sound attenuation properties by constructing the pane in such a manner that its base frequency (f) is between 0.70 and 0.97 times its theoretical base frequency (f.sub.0).

Abstract: The invention relates to a fire screening glazing panel and a method for forming the panel. The panel is composed of at least two structural plies, at least one of which is a vitreous sheet, and a layer therebetween composed at least in part of a heat convertible barrier forming material, which material forms a solid porous or cellular thermally insulating body when subjected to sufficient heat, as during a fire. The barrier forming material is an hydrated metal salt selected from the group consisting of aluminates, plumbates, stannates, alums, borates, and phosphates. The barrier forming material does not significantly reduce the transparency of the structural sheets, if they are transparent, even over extended use during normal conditions.

Abstract: A metallic oxide coating is formed on a substrate which may be vitreous, partially vitreous or nonvitreous by applying to the substrate a solution of one or more metallic salts selected from the group of the acetates, halides and nitrates in an aprotic solvent having a dielectric constant greater than 15 and a dipolar moment greater then 3D. The substrate and applied solution are then subjected to heat to convert in situ the metallic salt to form a coating comprising at least one metallic oxide.

Abstract: The invention relates to a fire screening glazing panel and a method for forming the panel. The panel is composed of at least two structural plys, at least one of which is a vitreous sheet, and a layer therebetween composed at least in part of a heat convertible carrier forming material which material forms a solid porous or cellular thermally insulating body when subjected to sufficient heat, as during a fire. A protective stratum is applied to at least one of the vitreous sheet plys for inhibiting interaction between the barrier forming material and the ply, thereby maintaining the transparency of the ply if it is formed of transparent material, and maintaining its color.

Abstract: In the coloring of bodies of glass by diffusion of coloring ions from a treatment medium into surface layers thereof, the repeatability of the resulting coloration is improved by controlling not only the treatment temperature and composition of the medium and the treatment time, but also by controlling the electrical potential within the medium between a pair of electrodes in contact therewith. Preferably, for electrodes of specified composition and structure, this potential is maintained at a value between -600 mV and +300 mV.

Abstract: Glass bodies formed from a vitrifiable composition are given a desired coloration by introducing a reducing agent into surface layers of the body, during or after its formation from a molten composition, and the then the body surface into contact with a diffusion medium composed of a mixture of a salt furnishing reducible metal ions which are capable of being reduced by the reducing agent, and a diluting agent constituted by a salt of another metal, the body being subjected to temperature conditions such as to cause the reducible metal ions to diffuse into the body surface layers and to there be chemically reduced by the reducing agent.

Abstract: A process for manufacturing a glazing unit by jointing a metallized margin of a sheet of glass to an intervening spacer strip following a course along the peripheral margin of the unit, the joint between the sheet and the strip along at least a section of such course being formed by applying molten solder into the corner angle between the sheet and the strip to form a solder bead along the section, the joint being progressively traversed by at least one flame so that at each moment during its progress along the joint such flame acts on such solder metal before it has completely solidified whereby the final bead is formed by solidification of solder metal from the molten condition in which it is left by such flame and apparatus for carrying out such process.

Abstract: Method and apparatus for pre-heating a vitrifiable batch before it is introduced into a glass melting furnace. The hot gases from the furnace are used for this purpose. The batch is fed onto a support which provides apertures or openings. The support and the batch on it are heated by hot gases from the furnace until the batch is in at least a partly molten condition in which it flows through the support apertures.

Abstract: In the manufacture of sheet glass by drawing a ribbon of glass upwardly from a molten glass bath via a meniscus located at the glass surface in the drawing zone, a pool of molten material is contained in the bath beneath the drawing zone by a refractory member and the molten material pool is thermally conditioned to maintain a predetermined temperature profile in at least part of the drawing zone.

Abstract: In the severing of bodies of glass or vitrocrystalline materials by the application of a laser beam, the severing operation is improved by employing a beam of which at least the predominent wavelength is such that at least 10% of the beam energy penetrates the body to a depth of at least 0.2 mm.

Abstract: In the severing of glass by irradiating it with a laser beam along the line where it is to be severed, the quality and speed of the severing operation are improved by preliminarily scoring the glass along such line.

Abstract: An impact resistant panel composed of a group of at least three sheets of vitreous material bonded together via intervening layers of plastic material. According to one form of construction, the group includes a set of consecutive vitreous sheets of at least three different thicknesses which are arranged in order of thickness, and at least the first sheet, taken in the direction from the highest sheet thickness end of the set, is tempered. According to a second form of construction, the group includes a set of consecutive sheets of at least two different thicknesses arranged in order of thickness and at least two of the plastic layers are of different thicknesses and are arranged so that one of the layers having the smallest thickness is nearer the first sheet, taken in the direction from the thickest sheet, than is any other layer.