US 8,783,065 B2Granted

Method for bending and thermally prestressing radiation shielding glass

AssigneeSchott AG

InventorsHorst Schillert, Dirk Roessler, Detlef Mevers

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Abstract

A method for bending radiation shielding glass which has a heavy metal oxide content of at least 50% by weight is provided, wherein first a mold is provided, a glass plate comprising a radiation shielding glass is then provided, the mold is preheated to a temperature of 300 to 400° C., the glass plate is placed on the mold, the glass plate and the mold are heated in a furnace to a temperature of 370 to 430° C., then heated together to a temperature of 400° C. to 500° C., preferably to 440 to 500° C., the total heating time being at least 30 minutes, preferably at least 60 minutes, the glass plate is then molded and finally the molded glass is cooled by means of a cooling program over a period of at least 60 minutes. For thermal prestressing, the glass body is supported at least at its outer periphery at a number of support points, introduced into a preheated furnace, heated to 400 to 500° C. and then removed, and cold air is blown onto both sides from a multiplicity of nozzles, preferably until cooling to about 100° C. has taken place.

Claims17

Dependent claims

A method for bending and thermally prestressing radiation shielding glass, comprising the following steps:

(a) providing a mold;
(b) providing a glass plate comprising a radiation shielding glass;
(c) preheating said mold to a temperature of 300 to 400° C.;
(d) placing said glass plate on said mold;
(e) heating said glass plate and said mold together to a temperature of 370 to 430° C.;
(f) further heating to a temperature of 400° C. to 500° C., steps (e) and (f) together lasting for at least 30 minutes;
(g) molding said glass plate into its final form;
(h) cooling said glass plate after molding to a temperature of not more than 150° C. by means of a cooling program over a period of at least 60 minutes;
(i) removing the glass body from the mold;
and thereafter thermally prestressing the radiation shielding glass by:
(j) supporting said glass body at a plurality of support points including at least at its outer periphery and at an intermediate point;
(k) introducing said glass body into a furnace which has been preheated to a temperature of 500 to 600° C.;
(l) heating said glass body to 400° C. to 500° C.;
(m) removing said glass body from said furnace;
and
(n) blowing a cold fluid onto said glass body on both sides from a plurality of nozzles until said glass body has cooled to a surface temperature of not more than 150° C.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/790,059Filed 28 May 2010
Priority: DE 10 2009 024 23428 May 2009
Published: US 2010/0316847 A116 Dec 2010
Granted: 22 Jul 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

C03B 23/0252
By gravity: by gravity only, e.g. sagging
C03B 23/0302
By press-bending between shaping moulds: between opposing full-face shaping moulds
C03B 23/0357
By suction or blowing out for providing the deformation force to bend the glass sheet: by suction without blowing, e.g. with vacuum or by venturi…
C03B 27/0413
Using gas: stresses, e.g. patterns, values or formulae for flat or bent glass sheets