摘要:
A ribbon of patterned glass having contiguous areas of thicker and thinner glass is annealed by passing through a lehr having a plurality of heaters arranged for intensive reheating of the glass in spaced-apart zones extending across the lehr and of narrow width in the direction of the length of the lehr, whereby in each said zone a greater reheating occurs in thin areas of the glass than in thicker areas so that the temperature gradient existing between thick and thin areas of the glass is reduced in passage of the glass through each of the zones.
摘要:
A method of cutting an elongated strip of glass comprises modifying the stress pattern in the strip region by treating the glass to form in the glass a line of tensile stress along the strip between a cutting line and the edge of the ribbon or sheet, and the further step after modifying the stress pattern of causing the glass to fracture along the cutting line while the modified stress pattern still exists. Preferably a line of compressive stress is formed along the cutting line.
摘要:
Phenol-formaldehyde resins, which are principally intended for the production of resin foams for use as insulating materials, in particular fire-resistant foams, are produced by reacting a sulphonated novolac resin, which has been condensed from at least one phenol and formaldehyde and subsequently sulphonated, with a resole resin. The novolac resin may be condensed from 1 mole of the phenol or phenols and between 0.3 and 1.0 moles formaldehyde in the presence of an organic acid, such as oxalic acid, and subsequently sulphonated with 0.1 to 1.5 moles 98% sulphuric acid at a temperature not exceeding 150*C. The resole resin may be condensed from 1 mole of a phenol or phenols and 1 to 3 moles formaldehyde in the presence of an alkaline catalyst. An aqueous dispersion of the resole resin is reacted with the sulphonated novolac resin, the viscosities of the two reactants being adjusted to be of the same order of magnitude, e.g. by diluting the sulphonation product with water. A surfactant and a foaming agent are added to the reaction mixture to cause foam formation.
摘要:
Glass sheet material is conveyed along a path passing over an air box for providing a gas cushion. Tilting means is arranged to raise one edge of the air box so that the sheet is laterally displaced while moving over the air box. Datum means is provided at one side of the air box to arrest lateral movement of the sheet when it has reached a required position. Two similar tiltable air boxes may be provided side by side in the conveyor path so that two sheets may be moved apart in opposite directions.
摘要:
A glass composition for forming glass fibers to be used as reinforcement for cementitious products comprises in molecular weight percentages SiO2 62% to 75%. ZrO2 7% to 11% alkali metal oxide 13% to 21%, alkaline earth metal oxide 1% to 10%, and optionally a small percentage of Al2O3, B2O3, Fe2O3, CaF2 or TiO2.
摘要:
Apparatus for conveying a succession of articles, such as glass sheets, by contact with an adjacent edge portion of each article, along a conveying path such as a gas hearth, comprises a plurality of elongated carriage members each carrying one or more drive-transmitting elements (e.g. transverse arms) for engaging edge portions of the articles, particularly of articles presenting indented or skewed edges, and a set of rotary drive elements conical discs on vertical spindles for propelling the carriage members by frictional engagement. The drive elements may be used without the carriage members for directly driving straight-edged articles. A roller conveyor with means for driving the carriage members frictionally alongside the conveyor rollers may precede the gas hearth.
摘要:
THE INVENTION RELATES TO A METHOD OF MANUFACUTRING A FINE-GRAINED GLASS CERAMIC MATERIAL FROM A THERMALLY-CRYSTIALLIZABLE VITREOUS MATERIAL, WHICH MAY BE AN LI2OAL2O3-SIO, 2 COMPOSITION CONTAINING A NUCLEATIG AGENT SUCH AS P2O5, ZRO2 OR TIO2, IN WHICH METHOD THE MATERIAL IS SHAPED AND THREAFTER SUPPORTED THROUGHOUT THE SUBSEQUENT THERMAL PROCESSING, WHICH IS PREFERABLY EFFECTED ON A NON-WETTABLE SUPPORT SUCH AS A BATH OF MOLTEN METAL, E.G. TIN. THE THERMAL PROCESSING ESSENTIALLY COMPRISES SUBJECTING THE SHAPED MATERIAL TO A TEMPERATURE/TIME REGIME WHICH DEVELOPS WITHIN THE MATERIAL A UNIFORM DISPERSION OF EMBRYONIC CENTERS OF INCIPIENT CRYSTAL GROWTH, AND THEN RAPIDLY HEATING THE MATERIAL AT A CONTROLLED RATE TO A PREDETERMINED CRYSTALLIZATION TEMPERATURE TO EFFECT FINE-GRAINED CRYSTAL GROWTH ON THOSE CENTERS WHILE THE VISCOSITY OF THE GLASSY MATRIX OF THE CRYSTALLIZING MATERIAL IS AT A VALUE WHICH PERMITS RAPID STRESS RELAXATION.
摘要:
Toughening of advancing glass sheets is effected in two stages; in the first the glass is supported on a gaseous support and thereafter when the underface of the glass is no longer deformable the advancing glass is mechanically supported as quenching is completed, clearance of cullet being facilitated in the final quenching stage.
摘要:
Thin float glass, e.g. in the range 3 mm to 1.5 mm, is manufactured by forming a ribbon of float glass and attenuating the ribbon by applied tractive effort. Distortion in the eventual ribbon is avoided when operating at high load by creating thermal homogeneity in the molten metal of the bath supporting the ribbon in the region of attenuation and where its viscosity is in the range 105.25 to 106.75 poises.
摘要:
A glass article, e.g. an all-glass multiple glazing unit, is manufactured by uniting at least two glass parts by a continuous weld. The regions of the glass parts to be united are heated to soften the regions and to form the desired weld. This step of heating the regions is performed by passing principal electrical heating currents through the whole of the region and then passing auxiliary electrical heating currents through only a part, i.e. the colder part, of the region.