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US3676535A
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Method and apparatus for controlling orientation of needle-like carbon particles in extruded carbon stock
Assignee: Individual
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Filing: 1969-11-07
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Granted: 1972-07-11
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Expires: 1989-11-07
Abstract
Abstract A means and method are provided for extruding compositions, particularly for extruding mixes of carbon and/or graphite particles and carbonizable binder, whereby the composition is subjected to greater working than normally encountered in conventional extrusion practices. This extrusion technique results in the elimination of or minimization of the effects of batch interfaces and in better consolidation of the mix. The means and method can additionally be employed to control the orientation of acicular particles in a composition during the extrusion thereof so as to control the properties of the extruded product. In all cases, the extrusion die''s internal configuration is defined by at least three ''''working'''' sections, (which may be interrupted by one or more sections of substantially constant cross section, e.g. cylindrical sections), consisting of a first converging section, then a diverging section, and then a second converging section. When employed in the extrusion of a carbonaceous mix containing needle-like carbon particles, dies of the present invention of appropriate design can be used to produce stock which after baking and graphitizing is characterized by having a transverse to longitudinal average coefficient of thermal expansion (CTE) ratio considerably less than that characteristic of corresponding stock in which the particles are all axially aligned.
Inventors
- 👤 Leslie H Juel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:46
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/22; B30B11/221; C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528; C04B35/532; H; H05; H05B; H05B7/00; H05B7/02; H05B7/06; H05B7/08; H05B7/085; Y; Y10; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
16 words
A method according to claim 1 wherein the sections of said forming die are coaxially aligned.
Claim 2
Dependent Claim
26 words
A method according to claim 1 wherein the minimum cross-sectional area of the stock emerging from the second converging section is at least 6 square inches.
Claim 3
Dependent Claim
55 words
A method according to claim 1 wherein the reduction ratios of the cross-sectional areas in each of the converging sections is between about 1.25 to 1 and about 15.0 to 1 and wherein the expansion ratio of the cross-sectional areas in the diverging section is between about 1 to 1.25 and about 1 to 15.
Claim 4
Dependent Claim
31 words
A method according to claim 1 wherein the average angle of divergence in the diverging section is between about 15* and about 45* with respect to the axis of the die.
Claim 5
Dependent Claim
34 words
A method according to claim 1 wherein after being forced through the diverging section, the mix is next forced through a section of substantially constant cross-section before being forced through the second converging section.
Claim 6
Dependent Claim
35 words
A method according to claim 1 wherein the cross-sectional area of the stock leaving the first converging section is equal to or less than the cross-sectional area of the stock leaving the second converging section.
Claim 7
Dependent Claim
26 words
A method according to claim 1 wherein the mix is forced through a section of substantially constant cross-section after being forced through the second converging section.
Claim 8
Dependent Claim
24 words
A method according to claim 4 wherein the cross-section of the mix being extruded at any location in each of the sections is circular.
Claim 9
Dependent Claim
37 words
A method according to claim 8 wherein after being forced through said section of substantially constant cross-section, the mix is then forced through another die forming zone comprising first a diverging section and then a converging section.
Claim 10
Dependent Claim
24 words
A method according to claim 10 wherein said diverging section and said conVerging section are each followed by a section of substantially constant cross-section.
Claim 11
Independent Claim
185 words
A method for controlling the thermal expansion properties and improving the structure of carbonaceous stock comprising the step of forcing by means of a conventional hydraulically or mechanically actuated ram press a carbonaceous mix containing a preponderance of needle-like coke particles or needle-like graphite particles or mixtures thereof and a carbonizable binder through a forming die which is free from any obstructions and which possesses at least three sections defined by the walls of the die comprising a first converging section, then a gradually diverging section possessing no abrupt contour changes, and then a second converging section, the reduction ratio of the cross-sectional areas of the stock entering and leaving the second converging section being less than the reduction ratio in the first converging section, whereby the alignment of said particles is lessened to such an extent that the ratio of the transverse to the longitudinal average coefficient of thermal expansion of said stock, after baking and graphitizing, is reduced from that characteristic of axial alignment, the structural integrity of said needle-like coke or graphite particles also being maintained substantially unchanged during the extrusion operation.
Claim 12
Dependent Claim
16 words
A method according to claim 12 wherein the sections of said forming die are coaxially aligned.
Claim 13
Dependent Claim
38 words
A method according to claim 12 wherein the cross-sectional area reduction ratio in the first converging section is between about 1.25 and about 12 times as great as the cross-sectional area reduction ratio in the second converging section.
Claim 14
Independent Claim
155 words
An apparatus for subjecting an extrudable mass containing a preponderance of particulate material to a high degree of working while being extruded, comprising a cylindrical chamber into which the material to be extruded is charged, a conventional hydraulically or mechanically actuated ram press for forcing the extrudable mass through the apparatus, and a forming die leading from the outlet of the cylindrical chamber, said forming die being characterized by being free from any obstructions and by possessing at least three sections defined by the walls of the die comprising a first converging section, then a gradually diverging section possessing no abrupt contour changes, and the second converging section, the reduction ratios of the cross-sectional areas in each of the converging sections being between about 1.25 to 1 and about 15 to 1, and the expansion ratio of the cross-sectional areas in the diverging section being between about 1 to 1.25 and about 1 to 15.
Claim 15
Dependent Claim
16 words
An apparatus according to claim 15 wherein the sections of said forming die are coaxially aligned.
Claim 16
Dependent Claim
34 words
An apparatus according to claim 15 wherein the cross-sectional area reduction ratio in the second converging section of the forming die is less than the cross-sectional area reduction ratio in the first converging section.
Claim 17
Dependent Claim
34 words
An apparatus according to claim 16 wherein said coaxially aligned sections are each also characterized by possessing smooth interior contours and wherein a cross-section at any location in each of the sections is circular.
Claim 18
Dependent Claim
42 words
An apparatus according to claim 17 wherein the cross-sectional area reduction ratio in the first converging section of the forming die is between about 1.25 and about 12 times as great as the cross-sectional area reduction ratio in the second converging section.
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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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |