Abstract: In a process for improving the smoothness of the surfaces of foils made from thermoplastics materials, particularly glass, the foil is stretched in two directions or dimensions. In a particular method, the foil is laid on top of a first frame and subsequently heated to a temperature which lies in a temperature range within which the foil starts to soften. A second frame which is at the same temperature as that of the foil is then placed on top of the foil so that the latter is effectively clamped between the frames. The two frames and foil is then cooled. The material chosen for the frames is one having a coefficient of thermal expansion smaller than or equal to that of the material of the foil.

Abstract: A process and apparatus for producing glass foil is disclosed in which a thin glass foil is produced by conveying a glass melt from a rotatable crucible of a smelting furnace through an annular distribution reservoir and a distributing disk having flow-through slots. Jets of glass emerge from the flow-through slots and are combined at a funnel-shaped wall into a hollow, cylindrical glass mass. Due to its weight and to heating by pressurized, gas-heated heating and cooling zones, the cylindrical glass mass flows downward, and is stretched until it reaches a pre-determined wall thickness by auxiliary conveyor belts. The hollow cylinder of glass is then split on one side by a separating device, flattened, conveyed to a bath of liquids, and then drawn-off at full width in the form of a glass foil by a draw-off guide roller. After the glass foil is drawn-off, the auxiliary conveyor belts are moved laterally so that they are no longer in physical contact with the glass cylinder.

Abstract: The invention provides a method and apparatus for the manufacture of glass film having a thickness not in excess of 0.003 inches and accomplished by drawing the film through a narrow slot-like orifice. The walls of the orifice are defined by an electrically conductive, hot glass resistant metal and electrical currents are introduced into the metal walls of the orifice to effectively maintain the central portions of the orifice walls at a higher temperature than each of the two lateral end walls of the orifice, thereby producing a temperature differential in the drawn film on the order of 40.degree. F. between the edges of the film and the central portions of the film.

Abstract: The invention provides a method and apparatus for the manufacture of glass film having a thickness not in excess of 0.003 inches and accomplished by drawing the film through a narrow slot-like orifice. The walls of the orifice are defined by an electrically conductive, hot glass resistant metal and electrical currents are introduced into the metal walls of the orifice to effectively maintain the central portions of the orifice walls at a higher temperature than each of the two lateral end walls of the orifice, thereby producing a temperature differential in the drawn film on the order of 40.degree. F. between the edges of the film and the central portions of the film.