Patent US4682995A successfully refreshed from Google Patents.
US4682995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of glass bodies by extrusion
Assignee: US Philips Corp
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Filing: 1986-03-06
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Granted: 1987-07-28
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Expires: 2006-03-06
Abstract
Abstract Method and equipment for the manufacture of glass bodies wherein a porous green body is formed by extrusion from the starting material for the glass body in the form of a thixotropic suspension and this green body is then purified and sintered, during which process the starting material is brought in a state of minimum viscosity into an extruding press closed at its outlet end, is heated in the extruding press to a temperature below the boiling point of the dispersing liquid and then, after the extruding press is opened, is extruded into a green body of dimensionally stable shape by means of the die of the extruding press.
Inventors
- 👤 Rolf Clasen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:45
CPC Classifications
C; C03; C03B; C03B17/00; C03B17/04; C03B19/00; C03B19/12; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/016; Y; Y10; Y10S; Y10S65/00; Y10S65/90; Y10S65/901
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
123 words
A method for the manufacturing of glass bodies, said method comprising: (a) forming a thixotropic suspension of silicon dioxide particles in a dispersing liquid; (b) converting said thixotropic suspension to a state of minimum viscosity; (c) charging an extruding press closed at its outlet with said thixotropic suspension while said suspension is in a state of minimum viscosity; (d) heating said suspension, while in said extruding press to a temperature below the boiling point of said dispersing liquid to thereby cause linking of silicon dioxide particles dispersed in said suspension and solidification of said suspension; (e) opening said extruding press and extruding a dimensionally stable green body formed of said solidified suspension from said press and (f) purifying and sintering said green body.
Claim 2
Independent Claim
123 words
A method for the manufacturing of glass bodies, said method comprising: (a) forming a thixotropic suspension of silicon dioxide particles in a dispersing liquid; (b) converting said thixotropic suspension to a state of minimum viscosity; (c) charging an extruding press closed at its outlet with said thixotropic suspension while said suspension is in a state of minimum viscosity; (d) heating said suspension, while in said extruding press to a temperature below the boiling point of said dispersing liquid to thereby cause linking of silicon dioxide particles dispersed in said suspension and solidification of said suspension; (e) opening said extruding press and extruding a dimensionally stable green body formed of said solidified suspension from said press and (f) purifying and sintering said green body.
Claim 3
Dependent Claim
41 words
The method as claimed in claim 1 wherein the suspension is a suspension containing SiO 2 particles with a diameter in the range from 10 to 500 nm, preferably 15 to 100 nm, with a mean particle diameter of 40 nm.
Claim 4
Dependent Claim
23 words
The method as claimed in claim 1 wherein a suspension with a solids: dispersing liquid weight ratio of 1:0.8 to 1:2 is used.
Claim 5
Dependent Claim
15 words
The method as claimed in claim 1 wherein water is used as the dispersing liquid.
Claim 6
Dependent Claim
29 words
The method as claimed in claim 1 wherein an ionogenic substance which shifts the pH-value of the suspension towards the basic region (pH ≦10) is added to the suspension.
Claim 7
Dependent Claim
17 words
The method as claimed in claim 5 wherein an ammonium compound is used as the inorganic additive.
Claim 8
Dependent Claim
19 words
The method as claimed in claim 6 wherein an aqueous 5% NH 4 F-solution is used as the additive.
Claim 9
Dependent Claim
29 words
The method as claimed in claim 5 wherein the ionogenic substance is added in a quantity of 0.1 to 5.0 wt %, of the solids content of the suspension.
Claim 10
Dependent Claim
59 words
The method as claimed in claim 7 wherein the suspension is an aqueous suspension which contains SiO 2 particles with a mean particle diameter of 40 nm and with a solids:water weight ratio of 1:1.1 and to which an aqueous NH 4 F-solution is added in a quantity of 0.75 wt. % of the solids content of the suspension.
Claim 11
Dependent Claim
41 words
The method as claimed in claim 1 wherein the suspension is transformed into a state of minimum viscosity by the action of sound at a frequency of f=20 to 200 Hz or ultrasound at a frequency of f=20 to 50 kHz.
Claim 12
Dependent Claim
44 words
The method as claimed in claim 1 wherein the suspension is heated in the extruding press to a temperature below the boiling point of the dispersing liquid by the introduction of microwave energy of frequency f=2.5 GHz or high-frequency energy of frequency f=27 Mhz.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |