ES2211251A1 - Procedure and apparatus for the plastic deformation of glass plates. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Procedure and apparatus for the plastic deformation of glass plates, using an oven divided into two compartments, with a plane of support for the flat glass plate containing an opening for plastic deformation of the glass plate, where it is foreseen that in the side of the plate rotated towards the lower zone of the furnace and, most heated, there is a tube that surrounds perimeter the deformation opening and that the tube is traversed by a cooling fluid. (Machine-translation by Google Translate, not legally binding)

Description

Procedure and apparatus for deformation plastic glass plates.

The present invention aims at a procedure and an apparatus for deformation and profiling of Glass plates starting from flat glass plates.

The prior art is known as deformation of flat glass plates in special furnaces, in which glass plate to be deformed rests on the oven interior on a plane.

In the area where the deformation of the plate is made in the support plane an opening shape circular, oval or irregular.

On top of the oven, above the support plane, the temperature is, for example, about 500 ° C.

At this temperature a preheat occurs of the plate.

In the lower part of the oven, corresponding with the deformation opening, there is a chamber in which, for example, with the help of electrical resistors, a temperature of about 800 ° C, temperature at which the glass enters the pasty phase and deforms slowly draining towards down.

Just achieved the desired deformation, by For example, for containers of different profiles, the warping phase by removing the profiled part from the oven.

With procedures of this type, known by the prior art, objects such as vessels, glasses or trays.

The procedure described so far is already known for the state of the art and does not require a description More detailed.

Industry experts have observed that at there is a temperature of about 500 ° C, at the top of the oven and a higher temperature (about 800 ° C) in the lower part of the oven, an appreciable temperature difference is created between the two Glass plate faces.

This temperature difference, about 300 ° C, between the upper zone and the lower zone of the oven makes the deformation zone, in the transition between the flat part of the glass and the deformed glass part down, the glass is become rough and opaque, made inadmissible in a production industrial.

Therefore, the object of the present invention is obviate the drawbacks of the prior art, and deform, according to the procedure described above, a flat glass plate in an oven of the type described avoiding that in the transition zone between the flat part of the plate and the part warped appear defects such as roughness or surfaces irregular. In accordance with the present invention, this objective is associated with a procedure that provides for the cooling of the plate glass along the perimeter of the deformation opening, in the deformation zone, and on the face of the plate facing the lower part of the oven that is at a higher temperature.

The procedure can be carried out using a tube that surrounds the opening in the deformation zone of the plate, the tube being positioned below the curved space of the plate and connected to a liquid feeding medium refrigerant.

With these devices you get that in the lower oven chamber, at a temperature of 800 ° C approximately, a lower part of the plate is produced glass cooling in the area or perimeter of deformation correspondent.

Therefore, along the curved area the plate it will cool, going from 800 ° C (lower chamber temperature oven) at approximately 500 ° C (chamber temperature oven top).

This local refrigeration does not affect or hinder the deformation phase, but prevents the formation of cracks and roughness in the curved space between the flat part and the part Deformed plate.

The following describes in greater detail the object of the present invention by a described procedure only as an example and illustrated in the graphics attached.

Figure 1 schematically shows a section of the oven used for deformation of glass plates;

Figure 2 shows a detailed section of the zone of curvature of the glass plate.

As can be seen in Figure 1, an oven of this type (1) is divided by a horizontal support plane (2) in an upper area (3), where the oven is heated to a temperature Approximately 500 ° C

The support plane (2) has an opening (4) which defines the perimeter of the desired deformation in the plate.

The opening (4) gives access to a lower area (5) under the oven that is heated by electric heaters (6) or similar media at an approximate temperature of 800 ° C.

Near the support plane (2), the lower zone (5) presents a perimeter (7) circular, oval-shaped recess or in another geometric form according to the desired profile for the Final product.

A tube is placed in the recess (7) (8) arranged in a ring surrounding the circumference or perimeter, and by this tube it is fed, by means of a conduit (9) and with the support of a pump (10), a coolant, for example, air cooled.

The tube (8) is also connected to a discharge line (11) of the cooling liquid.

In a detail of figure (2) it can be observed enlarged scale the support plane (2) on which it is arranged the glass plate (V) initially flat.

The lower zone can also be observed (5) from the oven heated to approximately 800 ° C.

In the recess (7) surrounding the circumference or the perimeter of the opening (4) is placed the tube (8), arranged in a closed ring.

The pump may be connected, for example, to a liquid cooling installation (20) fed to the annular tube (8).

The pump (10) can be replaced by a vacuum cleaner that sucks hot air from the tube (8).

While in the upper zone (3) of the oven (1) there is a temperature of about 500 ° C, in the lower zone (5) of the oven the temperature is 800 ° C.

The liquid (20) fed to the tube (8) is refrigerated, which allows to reduce the temperature in the proximities of the zone of curvature (21) of the glass (V) from a high temperature (about 800 ° C) at a lower temperature (for example 500 ° C) similar to the temperature of the upper zone (3) of the oven (1).

In this way a stabilization of the plate temperature in the vicinity of the curvature zone at around 500 ° C.

The deformation procedure occurs from the following form:

In the support plane (2) a plate of glass (V) initially flat.

The glass plate (V) covers the opening (4) of profiled and, therefore, in the upper zone (3) of the oven (1) heats at a temperature of approximately 500 ° C.

The underside of the glass plate (V) that covers the opening (4) and is oriented towards the lower area (5) from the oven, it is heated to a temperature of 800 ° C.

This temperature of about 800 ° C makes the plate (V) become plastic and deformable by the action of the gravity as soon as the glass reaches a temperature of around 800 ° C

To avoid that in the zone of curvature (21) rough and opaque areas can be created because of a difference excessive temperature between the upper zone (3) and the zone bottom (5) of the oven (1), efficient cooling is performed, by feeding a liquid (20) through the tube (8), of the perimeter zone at the bottom of the glass plate (V), zone that corresponds to the transition curve zone (21). With this cooling, it reduces the temperature in zone (21) of glass up to about 500 ° C, the formation of spaces is avoided rough and coarse.

Claims (3)

1. Procedure for deformation of a glass plate (V) in an oven (1), divided into two heating compartments (3, 5) separated by a support plane (2) for the glass plate (V) and containing an opening (4) for deformation of the glass plate (V). Said process is characterized by the fact that cooling of the glass plate (V) is provided in correspondence of the deformation zone (21) and on the side of the plate (V) oriented towards the lower compartment (5) of the oven that is heated mostly. 2. Apparatus for deformation of a glass plate (V) according to claim 1, characterized in that a tube (8) is provided in the deformation zone (21) of the flat glass plate (V). surrounding the deformation opening (4), that the tube (8) is located below the curvature section (21) of the plate (V) and that the tube (8) is connected to a means (10) for feeding a cooling fluid (20). 3. Apparatus (1) according to claim 2, characterized in that the tube (8) is located in a recess (7) surrounding the deformation opening (4).