US5314646A
Expired / Lapsed
US
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Method for the production of a ceramic moulding
Assignee: Hutschenreuther AG
•
Filing: 1991-04-19
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Granted: 1994-05-24
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Expires: 2011-04-19
Abstract
Abstract According to one example of embodiment of the invention a ceramic pre-moulding 81 of stable form is pressed from ceramic composition in powder form in a first isostatic pressing action, at least a part of its surface being formed in contact with rigid shaping surfaces 42. The pre-moulding 81 thus obtained is then--possibly after glazing-subjected to a higher pressure, in a further pressing operation on all sides and then fired in a ONCE-ONLY quick-firing method.
Inventors
- 👤 Klaus Strobel
- 👤 Karl Schwarzmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:13
CPC Classifications
B; B28; B28B; B28B3/00; B28B3/003; B28B11/00; B28B11/003; B28B11/04; B28B11/044; B28B13/00; B28B13/02; B28B13/021; B28B3/02; B28B3/021; B30; B30B; B30B11/00; B30B11/001
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
188 words
A method for making a ceramic product, comprising shaping a ceramic moulding composition into a moulding of stable form and firing of the moulding, wherein shaping comprises: a first shaping operation in which the moulding composition is shaped to a pre-moulding of stable form geometrically similar to the moulding, performed in a mould cavity comprising a substantially rigid shaping surface and while the moulding composition is in shaping contact with the substantially rigid shaping surface; and a second shaping operation in which the pre-moulding is reduced in volume and reshaped into the moulding while enclosed by a protective skin system, performed by pressing with a pressing fluid acting on all sides of the pre-moulding and as the enclosed pre-moulding is substantially out of contact with the substantially rigid shaping surface, the protective skin system having such thickness and flexibility as to have substantially no influence on the reshaping; the protective skin system being formed by first and second diaphragms, each having a side remote from the moulding composition, and the second shaping operation comprising subjecting the diaphragms to fluid pressure on the respective sides remote from the pre-moulding.
Claim 2
Independent Claim
188 words
A method for making a ceramic product, comprising shaping a ceramic moulding composition into a moulding of stable form and firing of the moulding, wherein shaping comprises: a first shaping operation in which the moulding composition is shaped to a pre-moulding of stable form geometrically similar to the moulding, performed in a mould cavity comprising a substantially rigid shaping surface and while the moulding composition is in shaping contact with the substantially rigid shaping surface; and a second shaping operation in which the pre-moulding is reduced in volume and reshaped into the moulding while enclosed by a protective skin system, performed by pressing with a pressing fluid acting on all sides of the pre-moulding and as the enclosed pre-moulding is substantially out of contact with the substantially rigid shaping surface, the protective skin system having such thickness and flexibility as to have substantially no influence on the reshaping; the protective skin system being formed by first and second diaphragms, each having a side remote from the moulding composition, and the second shaping operation comprising subjecting the diaphragms to fluid pressure on the respective sides remote from the pre-moulding.
Claim 3
Dependent Claim
78 words
The method of claim 1, wherein the first and second diaphragms line the mold cavity and wherein: prior to the first shaping operation, the moulding composition is introduced into the mould cavity between the diaphragms as the diaphragms are in substantial contact with respective supporting surfaces; the first shaping operation comprises subjecting the first diaphragm to fluid pressure on its side remote from the mould cavity while the second diaphragm is in substantial contact with its supporting surface.
Claim 4
Dependent Claim
24 words
The method of claim 1, wherein, in the second shaping operation, the pressing fluid is pressurized to a pressure of at least 500 bars.
Claim 5
Dependent Claim
19 words
The method of claim 3, wherein the pressing fluid is pressurized to a pressure of at least 750 bars.
Claim 6
Dependent Claim
19 words
The method of claim 4, wherein the pressing fluid is pressurized to a pressure of at least 1000 bars.
Claim 7
Dependent Claim
19 words
The method of claim 5, wherein the pressing fluid is pressurized to a pressure of at least 1200 bars.
Claim 8
Dependent Claim
19 words
The method of claim 1, wherein, in the second shaping operation, pressing is effected while the pre-moulding contains water.
Claim 9
Dependent Claim
20 words
The method of claim 7, wherein the pre-moulding contains water in the approximate range from 2 to 15 weight percent.
Claim 10
Dependent Claim
20 words
The method of claim 8, wherein the pre-moulding contains water in the approximate range from 3.5 to 10 weight percent.
Claim 11
Dependent Claim
22 words
The method of claim 1, wherein, in the second shaping operation, pressing is effected while the pre-moulding contains a high-molecular-weight organic binder.
Claim 12
Dependent Claim
13 words
The method of claim 10, wherein the organic binder comprises carboxy methyl cellulose.
Claim 13
Dependent Claim
15 words
The method of claim 10, wherein the organic binder comprises a liquid synthetic plastics material.
Claim 14
Dependent Claim
16 words
The method of claim 1, wherein the protective skin system has an approximately constant skin thickness.
Claim 15
Dependent Claim
12 words
The method of claim 1, wherein the moulding composition has powder form.
Claim 16
Dependent Claim
14 words
The method of claim 14, wherein the moulding composition is produced by spray drying.
Claim 17
Dependent Claim
25 words
The method of claim 14, wherein the pre-moulding is shaped at a pressure which is less than a pressure applied in the second shaping operation.
Claim 18
Dependent Claim
22 words
The method of claim 16, wherein the pre-moulding is shaped at a pressure in the approximate range from 100 to 300 bars.
Claim 19
Dependent Claim
18 words
The method of claim 1, wherein a space between the protective skin system and the pre-moulding is evacuated.
Claim 20
Dependent Claim
13 words
The method of claim 1, wherein the pre-moulding is printed with a decoration.
Claim 21
Dependent Claim
16 words
The method of claim 19, wherein printing the decoration is comprised in the first shaping operation.
Claim 22
Dependent Claim
22 words
The method of claim 1, further comprising, before the second shaping operation, a step of coating the pre-moulding with a glazing composition.
Claim 23
Dependent Claim
11 words
The method of claim 21, wherein coating comprises spraying or dipping.
Claim 24
Dependent Claim
9 words
The method of claim 1, wherein firing comprises quick-firing.
Claim 25
Dependent Claim
113 words
The method of claim 23, wherein firing is for a time in the approximate range from 6 to 8 hours and comprises: a first temperature phase having a duration in the approximate range from 3 to 4 hours, during which the pre-moulding is heated from a temperature of approximately 450° C. to a temperature of approximately 1450° C.; a second temperature phase having a duration of approximately 1 hour, during which the pre-moulding is maintained at a substantially constant temperature of approximately 1450° C.; and a third temperature phase having a duration of approximately 2.5, hours during which pre-moulding temperature drops from the substantially constant temperature to a temperature of approximately 100° C.
Claim 26
Dependent Claim
20 words
The method of claim 1, wherein the protective skin system is formed by applying a coating composition to the pre-moulding.
Claim 27
Dependent Claim
13 words
The method of claim 25, wherein the coating composition is applied in vacuo.
Claim 28
Dependent Claim
16 words
The method of claim 25, wherein the protective skin system is formed from a thermoplastifiable composition.
Claim 29
Dependent Claim
11 words
The method of claim 27, wherein the thermoplastifiable composition comprises wax.
Claim 30
Dependent Claim
44 words
The method of claim 25, wherein the protective skin system is formed from a solution or suspension of a film-forming composition, comprising the steps of: applying a liquid coating of the film-forming composition; and removing a solvent or suspending agent from the liquid coating.
Claim 31
Dependent Claim
35 words
The method of claim 25, wherein the protective skin system is formed from a liquid composition hardenable by chemical reaction, comprising the steps of: applying the liquid composition as a coating; and hardening the coating.
Claim 32
Dependent Claim
21 words
The method of claim 1, wherein the pressing fluid is a liquid, and wherein the protective skin system is liquid tight.
Claim 33
Dependent Claim
21 words
The method of claim 1, wherein the pressing fluid is a gas, and wherein the protective skin system is gas tight.
Claim 34
Dependent Claim
11 words
The method of claim 1, wherein the ceramic product is thin-shelled.
Claim 35
Dependent Claim
15 words
The method of claim 33, wherein the ceramic product is a plate, dish or cup.
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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) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |