Process for manufacturing of a knobbed glass or glass-ceramic plate, such plate and a manufacturing tool for it

The invention relates to a process for the preparation of a knobbed Plate made of a glass or a glass ceramic produced thereby knobbed plate and the mold used for this purpose. The knobbed plate can in ovens for thermal decoupling of used hot interior to the cooler outer area (kitchen) be, but also in air conditioning systems for destroying germs.

Following the general state of the art there are different Procedures to holes in glass plates bring. Thus it is possible, with conventional drilling using diamond drill holes in bring a glass plate.

Another well known method is ultrasonic machining, with which you contribute only holes in glass sheets can have a maximum size of 25.4 cm (10 inches). The Hole size in this lapping process is very limited.

Generally known is also the sandblasting technique, with which limited holes can be introduced into the glass plates, and also the Laser method by which one individual small diameter holes can bring in a glass.

The invention is based on the technical problem to a method for provide production of a plate made of a glass or a glass ceramic, with the rapidly a large number of holes with any Contour can be provided.

Furthermore, there is the problem to be solved in the provision of a dimpled glass plate and creating a suitable for this purpose Mold.

According to the invention it was recognized that the method-related part of the above-mentioned technical problem of producing a plate a glass or a glass ceramic is thereby possible that the The method comprises the steps of:<ul><li>Lay the plate on a support with knob-like Elevations and / or depressions,</li><li>Heating together the plate and the support over the Transformation temperature of time, and</li><li>Cooling the slab to room temperature.</li></ul>

The preparation of the plate is carried out in such a way so that the plate the flat carrier is placed, and at a sufficiently high Temperature of the support and plate to a plastic deformation of the Plate comes. If the support has knob-like elevations, so If there is viscous flow of the glass or glass-ceramic material to fill the space area between the elevations. Alternatively, the support knob-like depressions, and flows Glass or glass ceramic material with sufficiently high temperatures in these wells inside. The surface of the carrier is in this Manner depicted by the board. In this sense, the support a kind of negative and the plate a kind of positive represents.

The sheet-like carrier has knob-like elevations or depressions on. By the manufacturing process is at the point of the nub-like Elevation or depression of the support plate with a Shag equipped.

Under a tuft in the context of this invention is a material displacement essentially understood perpendicular to the surface of the plate be formed hump. From one side of the plate considered, there is the material displacement as an elevation with largely arbitrary trained surface is, and of the other Side of the plate considered is as a recess.

The support should in obtaining an accurate pips geometry in Plate made of a glass or a glass ceramic itself no temperature-related Learn deformation sufficiently rigid in other words, be. In addition, the glass should only as little as possible on the carrier stick, so the panel can be detached from the support. In this Sense has been proven as a carrier material, a chromium-nickel steel, and Although especially the one with the material number 1.4122 with a Carbon content from 0.20 to 0.25 wt.%. Best results obtained in an additional compensation of chrome-nickel steel to 800 -1000 N / mm²,

To better ensure delamination plate / carrier, is the latter is provided with a release agent. In the above chromium-nickel steel good results were obtained with boron nitride A 01.

For the process, it is sufficient when the plate and the carrier be heated so common that they shared the transformation temperature exceed. Insofar as it is sufficient if the plate is placed in still warm the solid state to the carrier to then together with him on the transformation temperature away heated to be.

The speed of the manufacturing process, however, is limited to the fact that not only the board but also the Carrier must be heated. For this reason, the production accelerated when the plate placed on a preheated carrier becomes.

In order to fill all the space regions of the carrier between nappy Surveys or the inflow of material into knob-like improving wells, can after exceeding the located above the transformation temperature setpoint temperature a waiting period to be observed by cooling. The glass needs namely a period of time to all wells between nappy Elevations or to reach knob-like depressions. Maintaining a waiting period improved insofar as the exact figure of the carrier through the glass or glass ceramic material.

An accurate impression of the support surface by the glass or to provide the glass-ceramic, it is important that the glass or the Ceramic glass all regions of the carrier between nappy Surveys completely fills. To this can be provided to improve be, these regions of the carrier between nappy Protuberances to apply a negative pressure. The pressure may this range from about 0.4 bar to about 0.6 bar. In the event of knob-like depressions on the depression, a vacuum applied. In this case, the plate material is in the said Space areas drawn.

The application of a negative pressure can be effected by the said regions of the carrier between knob-like elevations or the stud-like indentations with through openings are equipped, and facing away from the plate side of the Carrier, a vacuum is applied. In this manner, the glass or Glass-ceramic material from the backside of the support by the through holes sucked through. In this way the material experiences a force in the direction of the support surface between knob-like elevations or into the nipple-shaped Depressions into, resulting in better filling of these areas leads to the material.

To form the precise image of the support surface with the material guarantee may be provided in addition, the plate with a to apply pressure. In this way, the material of the plate in the regions between the knob-like elevations or in the pressed recesses of the carrier.

It can be provided that the nubs of the cooled plate be partially abraded. In this way, a nub created with a through hole or a hole. The sanding can by grinding plates, diamond grinding wheels, abrasive belts, CNC grinding machines Diamond cutting, or by laser done. When the grinding process carried out in the record groove will succeed at the same knobs openings with identical Edge contour.

The inventive method results in a glass or glass ceramic plate with pimples. The studs are here in their basic form equipped with any surface, and are hollow. It but also open at both ends forming the nubs can be provided be. In this case, the studs have a continuous Opening. The contour of the opening then depends on the geometric Shape of the knob on the one hand, and on the nature of the other hand Abschliffs from which a portion of the knob is removed. Within a plate can differently shaped studs be provided with possibly different opening contours.

The accommodate most with studded panels have a thickness of about 0.5 mm to about 60 mm. Good results have been achieved when the knob-like Increases were slightly higher than the plate was thick, for example by 1/10 mm.

For resulting by grinding holes, a diameter be selected from about 0.5 mm to about 100 mm. The spatial Refinement of the knob can be designed highly variable will. In a plan view of the plate, the nub a round or have a polygonal edge contour. The knobs may also be frustoconical or polyhedral. In case frustoconical Knobs, it has proven to be expedient, the surface area of Noppe towards the knob base surface at an angle of about 20 ° to about 85 ° tilt relative to the base of the pallet. For greater angle grows the surface of a knob of the carrier increasingly, which is a Enthaften of the glass or glass-ceramic material increasingly difficult.

From the foregoing, that the board in its basic form not must be level. It is also possible to provide a curved plate, and bring into this the knobs.

For the production of the studded plate is in a carrier consisting of a high temperature dimensionally stable material is required, which may be chrome-nickel steel. To form the exact figure to ensure support surface, the scale tool between knob-like elevations through openings.

With the inventive method, a high number of Openings in large plates, for example, 1500 mm x 1500 mm size with eg 1000 openings in a short time be created. The time required to create the openings in a disk is only about 50 minutes.

The dimpled plate can also be coated, for example, by sputtering with metal oxide (eg. as with those Gold, chromium or titanium). Because of the large glass surface is the plate then this with an appropriate germicidal layer Type for keeping clean of air in an air conditioner.

Below, the invention is based on an embodiment are explained in detail.

The carrier 2 has according to FIG. 1 wells 3, each having a through opening 4 have. The carrier 2 is provided with a base part 7 ', 5' connected by means of screws. 5 via the vacuum duct 6 the recesses 3 are subjected to a negative pressure of 0.8 bar.

Fig. 2 shows the support 2 in a side view. The carrier has knob-like elevations 8 and 8 '. The figure shows the carrier 2 and Elevations 8 on average, whereas the projections 8 'behind the Elevations 8 are positioned. The surveys are frustoconical with a height of 5 mm and a cone angle of 45 °.

A 2 mm thick, flat plate made of a soda-lime glass with a transformation temperature of 630 ° C is on in a cold state a preheated to 450 ° C carrier plate made of a chrome-nickel steel placed. The carrier has frustoconical nubs with a Height of 5 mm and a cone angle of 45 °. Carrier and plate be together in an oven to a final temperature of 740 ° C brought and remain for about 10 minutes in the oven. Subsequently, a defined cooling process to the thermal stresses in the glass dismantle.

The process has the soda-lime glass knob-like elevations receive. This is shown in FIG. 3, in which the front and rear plate 1 Elevations 8 and 8 '. The knobs are with a belt sander 9 partially ground down through openings to create. For this, the top 2.1 mm with the belt sander were abraded.

The section A in Fig. 1 results in the plate of FIG. 3 above in a Side view and FIG. 4 below in a plan. The circular edge contour the regularly arranged frustoconical nubs is clearly recognizable.

The dimpled glass plate is used for an oven for thermal decoupling hot and less hot room areas, in particular by hot interior of the kitchen than outside.