US4534936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removal of organic binding agents from molded bodies
Assignee: Individual
•
Filing: 1983-06-09
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Granted: 1985-08-13
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Expires: 2003-06-09
Abstract
Abstract A method for removal of organic binders from powder compacts is disclosed in which the compact is heated while the weight change is monitored and controlled. The heating is regulated so that the removal rate of the binder is optimized. The removal time can be shortened without creating defects in the powder compact.
Inventors
- 👤 Elis Carlstrom
- 👤 Agneta I. Johnsson
- 👤 Leif A. G. Hermansson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:11
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/638; B; B22; B22F; B22F3/00; B22F3/10; B22F3/1017; B22F3/1021; B22F2203/00; B22F2203/03; B22F2999/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A method of optimizing the removal of a temporary binder from a formed powder compact comprising heating of the powder compact in an inert or reactive gas or vacuum, monitoring the weight loss of the compact, and regulating the heating proportional to the difference between a preset weight-loss rate value and the actual process weight-loss rate value, the preset weight-loss rate value being below the rate above which cracks, blisters or other defects appear in the powder compact.
Claim 2
Independent Claim
78 words
A method of optimizing the removal of a temporary binder from a formed powder compact comprising heating of the powder compact in an inert or reactive gas or vacuum, monitoring the weight loss of the compact, and regulating the heating proportional to the difference between a preset weight-loss rate value and the actual process weight-loss rate value, the preset weight-loss rate value being below the rate above which cracks, blisters or other defects appear in the powder compact.
Claim 3
Dependent Claim
33 words
The method of claim 1, including removing the binder from a compact at the same time as the heating process is monitored and using the obtained heating characteristics for repeated binder removal processes.
Claim 4
Dependent Claim
24 words
The method of claim 1, wherein the compact is cooled when the weight loss rate of the compact exceeds the preset weight-loss rate value.
Claim 5
Dependent Claim
16 words
The method of claim 1, wherein the weight-loss rate is maintained substantially constant through the process.
Claim 6
Independent Claim
80 words
A method to reduce the removal time of temporary binders from a formed powder compact comprising heating of the body in an inert or reactive gas or vacuum and regulating the heating rate during the process to a value calculated from an algorithm with the instantaneous value of time and weight as input data for the calculation, said algorithm being designed to decrease the heating rate when the weight-loss rate increases and to increase the heating rate when it decreases.
Claim 7
Independent Claim
80 words
A method to reduce the removal time of temporary binders from a formed powder compact comprising heating of the body in an inert or reactive gas or vacuum and regulating the heating rate during the process to a value calculated from an algorithm with the instantaneous value of time and weight as input data for the calculation, said algorithm being designed to decrease the heating rate when the weight-loss rate increases and to increase the heating rate when it decreases.
Claim 8
Dependent Claim
46 words
The method as claimed in claim 5 wherein said algorithm gives a fixed heating rate only as long as a critical weight-loss rate is not exceeded, said temperature being kept constant until the weight-loss rate falls below the predetermined limit when said weight-loss rate is exceeded.
Claim 9
Dependent Claim
35 words
The method as claimed in claim 5 wherein said algorithm gives a fixed heating rate only until a predetermined weight-loss rate is exceeded whereafter the temperature is decreased until a desired weight-loss rate is achieved.
Claim 10
Dependent Claim
37 words
The method as claimed in claim 5 wherein said algorithm gives a fixed heating rate only until a critical weight-loss rate is exceeded whereafter the temperature is regulated to keep the weight-loss rate at a desired level.
Claim 11
Dependent Claim
41 words
The method as claimed in claim 5 wherein said algorithm gives a high heating rate at low temperatures, said low temperatures being temperatures where the binders do not react, said high heating-rate being heating rates higher than the permitted heating rate.
Claim 12
Dependent Claim
43 words
The method as claimed in claim 5 including setting a critical weight-loss rate proportional to the surface/volume ratio of the compact, said critical weight-loss rate being obtained by multiplication of the surface/volume ratio by a constant of proportionality dependent on the binder system.
Claim 13
Dependent Claim
35 words
The method as claimed in claim 5 including removing the binders from a compact at the same time as the heating process is monitored and using the obtained heating characteristics for repeated binder removal processes.
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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) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |