Glass manufacturing – Processes – With chemically reactive treatment of glass preform
Patent
1977-06-13
1978-07-04
Lindsay, Jr., Robert L.
Glass manufacturing
Processes
With chemically reactive treatment of glass preform
65 18, 65 63, 65 64, 65136, 106 52, 106 53, 106472, C03C 1700, C03C 310
Patent
active
040985962
ABSTRACT:
A glass article having an optical quality surface smoothness can be formed by molding a "silanol" glass material against a die having a molding surface which is a mirror of that required for the glass article, thereby obviating glass grinding and polishing steps. The article is prepared by first forming an anhydrous base glass comprising, in mole percent on the oxide basis, about 72 to 82% SiO.sub.2, 10 to 17% Na.sub.2 O and/or K.sub.2 O, and 5 to 15% of an oxide or oxides selected from ZnO and PbO. The base glass may include up to 5% Al.sub.2 O.sub.3 and up to 3% of B.sub.2 O.sub.3, BaO and/or MgO. The anhydrous base glass is then hydrated to include a water content ranging from 0.5 to 10% by weight to form a "silanol" glass. That glass is then molded against the die surface at a temperature ranging from about 250.degree. C. to 500.degree. C. and a pressure ranging from about 4,000 to 20,000 psi for a period of time sufficient to replicate the surface smoothness of the die on the glass and, depending on the molding process, yield a glass article containing about 0.5 to 10% by weight of "tightly" bound total water.
REFERENCES:
patent: 3498802 (1970-03-01), Bickford et al.
patent: 3498803 (1970-03-01), Stookey
patent: 3811853 (1974-05-01), Bartholomew et al.
patent: 3837825 (1974-09-01), Loxley
patent: 3912481 (1975-10-01), Bartholomew et al.
patent: 3915720 (1975-10-01), Tarcza
patent: 3940277 (1976-02-01), Pierson et al.
patent: 3948629 (1976-04-01), Bartholomew et al.
Corning Glass Works
Giblin James A.
Janes Jr. Clinton S.
Lindsay, Jr. Robert L.
Patty, Jr. Clarence R.
LandOfFree
Method for preparing optical articles from hydrated glasses does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for preparing optical articles from hydrated glasses, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for preparing optical articles from hydrated glasses will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-275780