US 12,065,872 B2
Top frit heat treatment
Thibault De Rycke, Hørsholm (DK); Peter Sønderkær, Hørsholm (DK); Thomas Villiam Sejer Mikkelsen, Hørsholm (DK); and Søren Vejling Andersen, Hørsholm (DK)
Assigned to VKR HOLDING A/S, Horsholm (DK)
Appl. No. 16/487,398
Filed by VKR HOLDING A/S, Hørsholm (DK)
PCT Filed Feb. 19, 2018, PCT No. PCT/EP2018/053991
§ 371(c)(1), (2) Date Aug. 20, 2019,
PCT Pub. No. WO2018/150016, PCT Pub. Date Aug. 23, 2018.
Claims priority of application No. PA201770108 (DK), filed on Feb. 17, 2017; and application No. PA201770109 (DK), filed on Feb. 17, 2017.
Prior Publication US 2020/0056421 A1, Feb. 20, 2020
Int. Cl. C03B 37/012 (2006.01); C03C 8/24 (2006.01); C03C 27/08 (2006.01); E06B 3/66 (2006.01); E06B 3/663 (2006.01); E06B 3/673 (2006.01); E06B 3/677 (2006.01); C03B 37/027 (2006.01); C03B 37/03 (2006.01)
CPC E06B 3/66314 (2013.01) [C03C 8/24 (2013.01); C03C 27/08 (2013.01); E06B 3/6612 (2013.01); E06B 3/66304 (2013.01); E06B 3/66357 (2013.01); E06B 3/6736 (2013.01); E06B 3/6775 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of producing a vacuum insulated glazing unit, the vacuum insulated glazing unit comprising:
a first tempered glass pane and a second tempered glass pane arranged in parallel, having a surface of each pane opposing each other,
a plurality of pillars arranged as spacers between the opposed surfaces,
a side frit material peripherally arranged between the first tempered glass pane and the second tempered glass pane creating an internal void between the glass panes,
an evacuation opening in the first glass pane, the evacuation opening comprises an evacuation member through which the evacuation member the internal void can be evacuated, and
a top frit material made of lead-free solder frit material comprising a glass content, the top frit material being arranged around the evacuation opening and comprising a surface defining an exterior boundary of the top frit material between the outside of the vacuum insulated glazing unit and the inside of the top frit material, wherein the glass content thereof is in an amorphous state,
wherein the method comprises the steps of:
placing an evacuation cup over the evacuation opening, covering a portion comprising at least the evacuation opening, the evacuation member and the top frit material, wherein the evacuation cup comprises a first heat source, a second heat source, and an exhaust opening for evacuating the internal void,
placing the vacuum insulated glazing unit with the evacuation cup into a furnace,
heating the vacuum insulated glazing unit using the furnace to a softening temperature (Ts),
heating the top frit material to a heat treatment temperature (Th) using the first heat source, wherein the heat treatment temperature (Th) provided by the first heat source is greater than the softening temperature (Ts) provided by at least the furnace,
maintaining the heat treatment temperature (Th) of the top frit material in the evacuation cup at about the same temperature for a time sufficient to ensure that glass content at the surface of the top frit material is in a state facilitating crystallization,
lowering the heat treatment temperature (Th) of the top frit material towards a curing temperature (Tcure) so as to cure the top frit material, and so that the glass content at the surface of the top frit material undergoes crystallization,
evacuating the internal void through the evacuation member using a pump connected to the exhaust opening in the evacuation cup, and
sealing the evacuation member at a sealing temperature (Tseal) using a second heat source that is different from the first heat source and the furnace, so as to prevent gas from transferring between the internal void and the outside of the glass panes thereby obtaining the vacuum insulated glazing unit.