Abstract: Glass is heated from above and below while the glass resides on rolls (3) in a tempering furnace (1). The upper surface of the glass (4) is heated by hot air jets formed by sucking air from inside the furnace (1) and pressurizing the hot air and recycling it back to the upper surface of the glass. Air which has been taken from outside the furnace (1) and pressurized by a compressor (17) and heated is blown to the lower surface of the glass.

Abstract: A method and apparatus for heating glass, in which glass (4) is heated upon rollers (3) in a tempering furnace (1) from above and below of the glass (4). At least the upper surface of the glass (4) is heated with hot air jets directed substantially perpendicularly relative to the surface of the glass (4). The air jets have been provided by sucking air mainly from the inside of the furnace and by pressurizing the air taken from the inside of the tempering furnace (1) to an overpressure of over 0.1 bar relative to the pressure in the tempering furnace (1).

Abstract: A method of bending glass, in which glass (5) is heated in a bending furnace (1). Before the bending, the glass (5) is transferred from the heating point or zone onto a mould (7) located thereafter. While the glass (5) is being transferred onto the mould (7), the mould (7) moves in such a way that the horizontal velocity of at least the front edge of the mould (7) is substantially as high as the horizontal velocity of the glass (5).

Abstract: A method and apparatus for heating glass, in which glass (4) is heated upon rollers (3) in a tempering furnace (1) from above and below of the glass (4). At least the upper surface of the glass (4) is heated with hot air jets directed substantially perpendicularly relative to the surface of the glass (4). The air jets have been provided by sucking air mainly from the inside of the furnace and by pressurizing the air taken from the inside of the tempering furnace (1) to an overpressure of over 0.1 bar relative to the pressure in the tempering furnace (1).

Abstract: A method of bending glass, in which glass (5) is heated in a bending furnace (1). After the heating, the glass (5) is transferred onto a mould (7). The glass-bending mould (7) is at at least one point arranged to be bent substantially in its entirety when the mould (7) is transferred from the position it had during the initial heating of the glass (5) into a position where the glass (5) is arranged upon the mould (7).

Abstract: A method of bending glass, in which glass (5) is heated in a bending furnace (1). Before the bending, the glass (5) is transferred from the heating point or zone onto a mould (7) located thereafter. While the glass (5) is being transferred onto the mould (7), the mould (7) moves in such a way that the horizontal velocity of at least the front edge of the mould (7) is substantially as high as the horizontal velocity of the glass (5).

Abstract: The invention relates to a method for heating glass sheets to be tempered or heat-strengthened, in which method glass sheets are heated in a preheating furnace (1) by applying a hot-air blast and convection heating produced thereby to the opposite sides of a glass sheet and the preheated glass sheet is transferred from the preheating furnace (1) into a radiation heating furnace (2) for heating the glass sheet to a tempering temperature. During the convection heating of a glass sheet, the rotating speed of a hot-air fan (5) is increased while adjusting the heating effect of heating resistances (6) so as to maintain the temperature of blasted air substantially constant. Thus, the diminishing temperature difference between glass and air is compensated for by controlling the coefficient of heat transfer.

Abstract: A method and an apparatus for heating glass sheets in a tempering furnace. The tempering furnace (1) includes rollers (3) for conveying and oscillating the glass sheets (4) during heating, and resistors (5, 6) for heating the glass sheets (4) from above and from below. The lower part of the tempering furnace (1) is cooled at the initial stage of the heating period, and the lower surfaces of the glass sheets (4) are heated at the final stage of the heating period by forced convection. This ensures good control over heat equalization in the tempering furnace (1), increases furnace power, prevents curving of the glass sheets (4), and also reduces heat shock from ceramic rollers at the initial heating stage.

Abstract: A method and an equipment for adjusting the cooling air of a glass tempering machine. Cooling air is led by at least one fan (1, 2) to a tempering area (4) for cooling the glass exiting a tempering furnace (11). By means of a closing device (10) the tempering area (4) can be reduced such that a tempering zone with a pressure that can be raised sufficiently high for tempering thin glass can be formed out of the reduced tempering area. In this manner the tempering result becomes very even, and no separate tempering zone is needed even for thin glass.

Abstract: A method and an equipment for heating glass in a tempering furnace provided with rollers. In a tempering furnace glass (3) is heated from above with upper resistors (4) and from below with lower resistors (5). The heating resistors (4, 5) are dimensioned such that their combined power is greater than the maximum heating power needed by the furnace, and that the resistors are controlled such that the maximum amount of resistor power being used simultaneously corresponds to the maximum heating power needed by the furnace. This allows heat to be directed at a desired place in the furnace also at the initial stage of heating, and a single resistor is efficient and fast, allowing heat to be directed quickly at places where it is needed.

Abstract: A method and equipment for adjusting the temperature of glass sheets in a tempering furnace. The tempering furnace (1) comprises rollers (3) for conveying and oscillating the glass sheets (4) during heating, and resistors (5, 6) for heating the glass sheets (4) from above and from below. The temperature of the glass sheets (4) is measured inside the tempering furnace (1) during heating and the dwell time of the glass sheets (4) in the furnace is adjusted based on the temperature measurements. This enables exact control of the final temperature of the glass from the beginning, and the temperature can be kept uniform independently of the measures taken by the operator.

Abstract: The invention relates to a method and furnace apparatus for bending and tempering glass sheets. A glass sheet is supported on the same outline mold throughout the entire handling process. A bending furnace (10) is designed to be sufficiently long in the traveling direction for carrying a partially bent glass sheet towards a tempering section (16) in such a manner that the glass sheet reaches its final shape during the passage occurring within the bending furnace (10). For this purpose, the glass sheet is heated in the bending furnace (10) with such a high effect that it reaches its tempering temperature before reaching its final shape. The movements and heating of glass sheets are controlled individually on the basis of the thickness and measured temperature of each glass sheet.