Positive pressure-supported glass bending method and device suitable therefor

A method for bending a glass pane with a size of at least 0.8 m2, comprising:

• providing a glass pane;
• heating the glass pane to its softening temperature;
• providing a lower bending mould with a working surface;
• providing an upper shaping tool having a membrane and a hollow space with an opening, the membrane closing the opening;
• arranging the upper shaping tool opposite the working surface such that the opening is oriented toward the lower bending mould;
• arranging the glass pane between the lower bending mould and the upper shaping tool;
• introducing, via a gas inlet, a gas into the hollow space to deform the membrane in a direction of the lower bending mould such that the membrane contacts a main surface of the glass pane facing away from the working surface, thereby generating a positive pressure on the main surface of the glass pane, and
• cooling the glass pane,
• wherein the membrane consists of a stainless steel felt, stainless steel fleece, or woven stainless steel fabric, and
• wherein the membrane has a first main surface facing the gas inlet and a second main surface opposite the first main surface, the membrane being gas permeable such that gas introduced by the gas inlet directly impinges on the first main surface of the membrane and is sufficient to deform said membrane so that the second main surface contacts the main surface of the glass pane and exerts said positive pressure on the main surface of the glass pane.

A method for bending a glass pane with a size of at least 0.8 m2, comprising:

• providing a glass pane;
• heating the glass pane to its softening temperature;
• pre-bending the glass pane on a gravity bending mould;
• providing a lower bending mould with a full-surface working surface equipped with working surface openings;
• providing an upper shaping tool having a membrane and a cover forming a hollow space with an opening, the membrane closing the opening, the upper shaping tool further having an edge section surrounding the opening, an air deflector plate surrounding the opening and means associated therewith for generating a sucking action;
• lifting the glass pane with the upper shaping tool from the gravity bending mould;
• generating a stream of air by the air deflector to sweep a side edge of the glass pane;
• placing the lower bending mould underneath the glass pane;
• introducing, via a gas inlet, a gas into the hollow space to deform the membrane in a direction of the lower bending mould such that the membrane contacts a first surface of the glass pane facing away from the working surface, thereby generating a positive pressure on the surface of the glass pane;
• exerting the sucking action through the working surface openings to a second surface of the glass pane facing the working surface;
• placing the glass pane down onto the gravity mould using the upper shaping tool, and
• cooling the glass pane,
• wherein the membrane consists of a stainless steel felt, stainless steel fleece, or woven stainless steel fabric, and
• wherein the membrane has a first main surface facing the gas inlet and a second main surface opposite the first main surface, the membrane being gas permeable such that gas introduced by the gas inlet directly impinges on the first main surface of the membrane and is sufficient to deform said membrane so that the second main surface contacts the first surface of the glass pane and exerts said positive pressure on the first surface of the glass pane.

A method of generating a positive pressure on a main surface of a glass pane comprising:

• providing a shaping tool with a hollow space;
• providing a membrane;
• closing an opening of the hollow space using the membrane;
• introducing, via a gas inlet, a gas in a direction of the glass pane to deform the membrane such that the membrane contacts the main surface of the glass pane thereby generating the positive pressure on the main surface,
• wherein the membrane consists of a stainless steel felt, stainless steel fleece, or woven stainless steel fabric, and
• wherein the membrane has a first main surface facing the gas inlet and a second main surface opposite the first main surface, the membrane being gas permeable such that gas introduced by the gas inlet directly impinges on the first main surface of the membrane and is sufficient to deform said membrane so that the second main surface contacts the main surface of the glass pane and exerts said positive pressure on the main surface of the glass pane.