Collection of glass ribbon from float glass tank - with gas cushion, forming a central bow to avoid damage to the undersurface

Glass ribbon is produced using a float glass tank where the glass is smoothed, shaped and cooled, then a gas cushion is formed beneath the ribbon. Specifically, in the direction of movement of the glass ribbon, the initial cross-section of the gas cushion, the cross-section of the glass ribbon takes the shape of an arc as a result of the control of the supply and removal of the gases forming the gas cushion. The ratio of the arc height to the ribbon width is 1:100-1000. The risk of contact between the glass ribbon and the glass cushion producing appts. at the point of transfer between the metal surface and the gas cushion, is avoided, thus avoiding damage to the under surface of the glass. Le procédé consiste à amener la masse de verre 5 à la surface du métal fondu 6, à la transformer en une bande de verre 12 qui est ensuite refroidie sur un métal fondu et ensuite sur un matelas de gaz. A l'entrée de la bande de verre 12 sur le coussin de gaz, on lui confère une forme voûtée suivant sa section transversale.