Improvement in the production of flat glass

摘要

PICT:1028321/C1/1 Sheets of glass or similar thermoplastic material are supported, particularly during transport, on a number of liquid supports. The liquid, which is preferably a metal such as tin or lead, may be supplied through orifices in a solid base or through a porous base, and the supports can be obtained by filling cavities formed in the surface of a solid base. The liquid is non-reactive towards the glass and may also be non-wetting towards the base so that its surface tends to extend above the surface of the base to form a support for the glass; alternatively, it may be placed on limited regions of the support which are wettable by the liquid. The cavities may be in the form of circular or elliptical recesses or rectilinear or non-rectilinear channels, e.g. in the form of arcs or chevrons with the apex pointing in the direction of travel of the glass. The channels are preferably arranged transverse to the direction of travel; if, however, they are arranged longitudinally, sections are staggered relatively to one another. The underlying support may be flat, curved, or undulating, and may slope upwardly or downwardly in the direction of travel to retard or accelerate the movement respectively. Passages may be formed in the support for the passage of a heating or cooling medium. The edges of the glass sheet may overlap the recesses and contact a cooled solid surface. Provision may be made for the supply of a neutral gas, e.g. hydrogen, to prevent oxidation when a molten metal is used. As shown, the apertures may be formed in a block 34 and channels 36, 37 provided for leading the liquid back for recirculation.