Manufacture of laminated glazing
A method for manufacturing a laminated glass panel, which includes at least two glass substrates and at least one intermediate layer made of a polymeric material arranged between the substrates, the method including in the following order: the bending of the substrates; the controlled cooling of the substrates; and the formation of a laminated assembly that includes the substrates and the intermediate layer; the cutting of the laminated assembly straight through the entire thickness thereof along a line on one of the main surfaces thereof, the controlled cooling including general controlled cooling and local controlled cooling of an area that includes the cutting line, the local controlled cooling being faster than the general controlled cooling.
1. A process for manufacturing laminated glazing comprising at least two glass substrates and at least one interlayer made of a polymer material arranged between the substrates, the process comprising in the following order:
bending the substrates;
controlled cooling the substrates;
forming a laminated assembly comprising the substrates and the at least one interlayer, and
cutting the laminated assembly through its entire thickness along a cutting line on one of its main faces,
the controlled cooling comprising a general controlled cooling and a local controlled cooling of a zone comprising the cutting line, the local controlled cooling being faster than the general controlled cooling.
2. The process as claimed in claim 1 , wherein the local controlled cooling is obtained by convection, conduction, radiation, or a combination thereof.
3. The process as claimed in claim 1 , wherein the bending and the general and local coolings are carried out on the two glass substrates arranged side-by-side.
4. The process as claimed in claim 3 , wherein the two side-by-side substrates move into at least one bending chamber, and into at least one cooling chamber, the localized controlled cooling beginning in a bending chamber or a cooling chamber.
5. The process as claimed in claim 1 , wherein the local controlled cooling is applied from a single side opposite one of the faces of the two side-by-side glass substrates.
6. The process as claimed in claim 1 , wherein the local controlled cooling is applied from two opposite sides of the two side-by-side glass substrates that are facing each other.
7. The process as claimed in claim 1 , wherein the bending is carried out between 580 and 650° C. and wherein a start of the general cooling is controlled between 0.3 and 8° C./second at least until the temperature of the glass reaches 520° C.
8. The process as claimed in claim 7 , wherein the start of the general cooling is controlled between 0.3 and 2° C./second.
9. The process as claimed in claim 1 , wherein the local controlled cooling is applied by blowing air by means of a nozzle, one end of which has a cross section of shape corresponding to the zone comprising the cutting line.
10. The process as claimed in claim 1 , wherein the local controlled cooling is applied by means of a material with the shape corresponding to the shape of the zone comprising the cutting line, said material having a temperature lower than that of the glass, said material being brought into contact with at least one of the glass substrates at said zone.
11. The process as claimed in claim 1 , wherein the local controlled cooling is applied by means of a material with the shape corresponding to the shape of the zone comprising the cutting line, said material having a temperature lower than that of the glass, said material being brought opposite but not in contact with at least one of the glass substrates at said zone.
12. The process as claimed in claim 1 , wherein the local controlled cooling is obtained by applying against the surface of the glass a temporary coating material, which increases or decreases the emissivity of the glass, and that is provided with at least one opening.
13. The process as claimed in claim 1 , wherein the cutting is obtained by a hole saw, a router or a water jet.
14. The process as claimed in claim 1 , wherein the cutting produces a hole or a notch in the complete thickness of the laminated glazing.
15. The process as claimed in claim 1 , wherein the local controlled cooling is sufficient in duration and in intensity so that edge stresses after cutting of the laminated assembly are greater than 4 MPa.
16. The process as claimed in claim 15 , wherein the edge stresses are greater than 8 MPa.
17. The process as claimed in claim 1 , wherein the general controlled cooling is performed by a first cooling system and the local controlled cooling of the cutting zone is performed by a second cooling system that is different from the first cooling system.
18. The process as claimed in claim 17 , wherein the second cooling system is configured to cool the cutting zone by convection, conduction, radiation or any combination thereof.
19. The process as claimed in claim 17 , wherein the second cooling system includes a nozzle to locally supply blowing air to the glass sheets.
20. The process as claimed in claim 17 , wherein the first cooling system includes a cooling chamber in which the sheets of glass are positioned.
21. The process as claimed in claim 17 , wherein at least part of the local controlled cooling is performed during the general controlled cooling.
22. The process as claimed in claim 17 , wherein the local controlled cooling begins before the general controlled cooling.