Method for manufacturing molded glass articles, and use of the glass articles manufactured according to the method
Processes for producing shaped glass articles with a defined geometry are provided. In some embodiment, the process includes arranging a glass pane on a mould, heating the glass pane by infrared radiation, deforming the heated glass pane over the mould by gravity, negative pressure, and/or positive pressure, and cooling the shaped glass pane to obtain the shaped glass article with a defined geometry.
1. A process for producing a shaped glass article with a defined geometry, the process comprising:
arranging a glass pane on a mould;
heterogeneously heating the glass pane in a heating unit to form a heated glass pane that has corner regions heated to a viscosity of less than 10 4 dPas;
deforming the heated glass pane over the mould by a force selected from the group consisting of gravity, negative pressure, excess pressure, and combinations thereof to form a shaped glass pane; and
cooling the shaped glass pane to obtain the shaped glass article with the defined geometry.
2. The process according to claim 1 , wherein the step of heterogeneously heating the glass pane comprises heating by infrared radiation in the heating unit.
3. The process according to claim 2 , wherein the infrared radiation comprises short-wave infrared radiation or medium-wave infrared radiation.
4. The process according to claim 1 , further comprising heating at least one inner wall of the heating unit to a temperature that is higher than a temperature of the heated glass pane.
5. The process according to claim 1 , further comprising shadowing parts of the glass pane with a planar heating mask during the heating step.
6. The process according to claim 1 , further comprising heating regions of the glass pane in which no or only a small degree of shaping is to be carried out to a temperature at which the glass has a viscosity in the range of 10 13 dPas to 10 9 dPas.
7. The process according to claim 1 , wherein the heating the glass pane comprises heating so that the glass has a viscosity that differs at least by a factor of 100 between the corner regions of the glass pane and a coldest part of the glass pane.
8. The process according to claim 1 , wherein the heating comprises using burners of a suitable size or lasers that are suitably controlled or scanned.
9. The process according to claim 1 , wherein the glass pane has a predefined thickness distribution.
10. The process according to claim 1 , wherein, during the deforming of the heated glass pane, the mould has a temperature in the range of 250° C.-800° C.
11. The process according to claim 1 , wherein, during the deforming of the heated glass pane, a temperature difference above 250 K between the mould and the heated glass pane is present.
12. The process according to claim 1 , wherein the shaped glass article comprises a shaped region having a narrow radii of less than 50 mm and a surface quality with less than 1 defect measuring greater than 50 μm per 1 cm 2 in the shaped region.
13. The process according to claim 12 , wherein the narrow radii is less than 15 mm.
14. The process according to claim 12 , wherein the surface quality has less than 1 defect measuring greater than 50 μm per 10 cm 2 .
15. The process according to claim 12 , wherein the surface quality has less than 1 defect measuring greater than 50 μm per 100 cm 2 .
16. The process according to claim 12 , further comprising folds and/or surface undulations that account for at most +/−10% of a thickness of the glass pane.
17. The process according to claim 12 , further comprising folds and/or surface undulations that account for at most +/−5% of a thickness of the glass pane.
18. The process according to claim 12 , further comprising configuring the shaped glass article for use as a device selected from the group consisting part of a screen, part of a housing of electrical or of electronic appliances, part of a housing of mobile telephones, part of a housing of computers, and part of a housing of games consoles.
19. A process for producing a shaped glass article with a defined geometry, the process comprising:
arranging a glass pane on a mould;
heterogeneously heating the glass pane in a heating unit to form a heated glass pane that has corner regions heated to a viscosity of less than 10 4 dPas and so that the glass has a viscosity that differs at least by a factor of 100 between the corner regions and a coldest part of the heated glass pane;
deforming the heated glass pane over the mould so that surface tension forces acting in the glass convert glass mass in the corner regions into a thickened portion with folds and/or surface undulations that account for at most +/−10% of a thickness of the glass pane; and
cooling the glass pane to obtain the shaped glass article with the defined geometry.
20. The process according to claim 19 , wherein, during the deforming of the heated glass pane, the mould has a temperature in the range of 250° C.-800° C.