Patent US2220602A successfully refreshed from Google Patents.
Patent US3947255A successfully refreshed from Google Patents.
US3947255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of extruding bark and of forming a solid synthetic fuel
Assignee: Georgia Pacific Consumer Products LP
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Filing: 1973-01-10
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Granted: 1976-03-30
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Expires: 1993-01-10
Abstract
Abstract A method of extruding bark and of forming a solid article, solid synthetic fuel or fireplace log comprising from about 60 to 95 percent by weight bark, which comprises physically blending pieces of combustible thermoplastic of an extrudable size with pieces of bark also of an extrudable size and having less than 7 percent preferably less than 2 percent moisture, to form a bark thermoplastic mixture of from about 60 to 95 percent by weight bark and about 2.5 to 40 percent by weight thermoplastic, feeding the mixture to an extruder, heating the bark thermoplastic mixture in the extruder, controlling the heat of the extruder so that its temperature is insufficient to char the bark pieces yet sufficient to melt the thermoplastic and disperse it between the bark pieces so that it acts as a binder therefor and adheres sufficiently to the interior barrel wall surface of the extruder to allow the mixture to be moved therethrough by the extruder screw, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid synthetic fuel. Preferably, the extruder screw tip is cooled and the heat of the extruder is controlled to range from about 200° to 400° F. with certain temperatures maintained in the respective extruder barrel zones.
Inventors
- 👤 William H. Hartman
- 👤 Raymond E. Mietz
- 👤 John R. Peschke
- 👤 Donald H. Ruge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:24
CPC Classifications
C; C10; C10L; C10L5/00; C10L5/40; C10L5/44; Y; Y02; Y02E; Y02E50/00; Y02E50/10; Y02E50/30
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
182 words
A method of forming a solid synthetic fuel comprised of from about 60 to 95% by weight bark, the method which comprises: drying pieces of bark of an extrudable size to a moisture content of less than 7%, physically blending pieces of combustible non-noxious non-odor-producing thermoplastic of an extrudable size with said dried pieces of bark to form a bark-thermoplastic mixture of from about 60 to 95% by weight bark and about 5 to 40% by weight thermoplastic, feeding the mixture to an extruder, heating the bark thermoplastic mixture in the extruder, controlling the heat of the extruder to range from about 250°-400°F so that its temperature is insufficient to char the bark pieces yet sufficient to melt the thermoplastic and disperse it between the bark pieces so that it acts as a binder therefor and adheres sufficiently to the interior barrel wall surface of the extruder to allow the mixture to be moved therethrough by the extruder screw, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid synthetic fuel.
Claim 2
Independent Claim
182 words
A method of forming a solid synthetic fuel comprised of from about 60 to 95% by weight bark, the method which comprises: drying pieces of bark of an extrudable size to a moisture content of less than 7%, physically blending pieces of combustible non-noxious non-odor-producing thermoplastic of an extrudable size with said dried pieces of bark to form a bark-thermoplastic mixture of from about 60 to 95% by weight bark and about 5 to 40% by weight thermoplastic, feeding the mixture to an extruder, heating the bark thermoplastic mixture in the extruder, controlling the heat of the extruder to range from about 250°-400°F so that its temperature is insufficient to char the bark pieces yet sufficient to melt the thermoplastic and disperse it between the bark pieces so that it acts as a binder therefor and adheres sufficiently to the interior barrel wall surface of the extruder to allow the mixture to be moved therethrough by the extruder screw, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid synthetic fuel.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the extruder heat controlling step includes cooling the extruder screw tip to prevent charring of compressed bark pieces adjacent to the screw tip.
Claim 4
Dependent Claim
60 words
The method of claim 2 wherein the extruder heat controlling step includes controlling respective extruder barrel zone temperatures by maintaining barrel zone (1) at from about 250° to 300° F, barrel zones (2 and 3) from about 275° to 325° F, the metering zone from about 250° to 300° F, and the extruder gate from about 250° to 300° F.
Claim 5
Dependent Claim
58 words
The method of claim 3 wherein the bark pieces are dried to less than 2% moisture, the combustible thermoplastic is polyethylene, and barrel zone (1) is maintained at about 275° F, barrel zones (2 and 3) at about 300° F, the metering zone at about 275° F, and the extruder gate is liquid cooled to about 255° F.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein the extruding step includes extruding the composite extrudate through a die.
Claim 7
Dependent Claim
76 words
The method of claim 5 wherein the heat controlling step includes controlling the respective extruder barrel zone temperatures by maintaining barrel zone (1) at from about 250° to 300° F, barrel zones (2 and 3) from about 275° to 325° F, the metering zone from about 250° to 300° F, and the extruder gate from about 250° to 300° F, and wherein the cooling step includes cooling the die to from about 80° to 150° F.
Claim 8
Dependent Claim
25 words
The method of claim 6 wherein the die is profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 9
Dependent Claim
20 words
The method of claim 4 wherein the cooling step includes cooling the die to from about 80° to 150° F.
Claim 10
Dependent Claim
33 words
The method of claim 1 wherein the extruding step includes extruding the composite extrudate through a die profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 11
Dependent Claim
33 words
The method of claim 2 wherein the extruding step includes extruding the composite extrudate through a die profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 12
Dependent Claim
33 words
The method of claim 3 wherein the extruding step includes extruding the composite extrudate through a die profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 13
Dependent Claim
25 words
The method of claim 4 wherein the die is profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 14
Dependent Claim
40 words
The method of claim 1 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 15
Dependent Claim
40 words
The method of claim 3 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 16
Dependent Claim
40 words
The method of claim 8 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 17
Dependent Claim
102 words
The method of claim 1 wherein the blending step includes blending with the bark pieces and thermoplastic pieces, pieces of extrudable size of from 0 to 20% by weight combustible wax-treated fibrous material, and the heating step is at a temperature sufficient to also melt the wax of the wax-treated fibrous material and substantially separate the wax therefrom so that the separated wax is dispersed with the thermoplastic and acts as a binder for the bark pieces, the separated wax comprising from 0 to about 7%, and the fibrous material from 0 to about 13%, of the total weight of the fuel.
Claim 18
Dependent Claim
48 words
The method of claim 16 wherein the bark pieces contain less than 2% moisture, the bark is about 80% by weight, and the percent combustible thermoplastic and percent wax-treated fibrous material are in a ratio of 1:1, the percents being based on the total weight of the fuel.
Claim 19
Dependent Claim
83 words
The method of claim 17 wherein the extruder heat controlling step includes cooling the extruder screw tip to prevent charring of compressed bark pieces in the extruder metering zone adjacent the screw tip, and includes controlling the respective barrel zone temperatures by maintaining barrel zone (1) at from about 250° to 300° F, barrel zones (2 and 3) from about 275° to 325° F, the metering zone from about 250° to 300° F, and the extruder gate from about 250° to 300° F.
Claim 20
Dependent Claim
32 words
The method of claim 18 wherein the extruding step includes extruding the composite extrudate through a die, and the cooling step includes cooling the die to from about 80° to 150° F.
Claim 21
Dependent Claim
25 words
The method of claim 19 wherein the die is profiled to form, and the solid synthetic fuel is formed as, a solid synthetic fireplace log.
Claim 22
Dependent Claim
40 words
The method of claim 16 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 23
Dependent Claim
40 words
The method of claim 17 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 24
Dependent Claim
40 words
The method of claim 18 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 25
Dependent Claim
41 words
The method of claim 19 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic treated fibrous material.
Claim 26
Dependent Claim
40 words
The method of claim 20 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 27
Independent Claim
165 words
A method of extruding bark into the form of a solid article, which comprises: drying pieces of bark of an extrudable size to a moisture content of less than 7%, physically blending pieces of combustible non-noxious non-odor-producing thermoplastic of an extrudable size with said dried pieces of bark to form a bark-thermoplastic mixture of from about 60 to 95% by weight bark and about 10 to 40% by weight thermoplastic, feeding the mixture to an extruder, heating the bark-thermoplastic mixture in the extruder, controlling the heat of the extruder to range from about 250° to 325°F so that the temperature does not char the bark pieces yet melts the thermoplastic and disperses it between the bark pieces so that it binds the bark and adheres it to the interior barrel wall surface of the extruder to allow the mixture to be extruded therethrough, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid article.
Claim 28
Independent Claim
165 words
A method of extruding bark into the form of a solid article, which comprises: drying pieces of bark of an extrudable size to a moisture content of less than 7%, physically blending pieces of combustible non-noxious non-odor-producing thermoplastic of an extrudable size with said dried pieces of bark to form a bark-thermoplastic mixture of from about 60 to 95% by weight bark and about 10 to 40% by weight thermoplastic, feeding the mixture to an extruder, heating the bark-thermoplastic mixture in the extruder, controlling the heat of the extruder to range from about 250° to 325°F so that the temperature does not char the bark pieces yet melts the thermoplastic and disperses it between the bark pieces so that it binds the bark and adheres it to the interior barrel wall surface of the extruder to allow the mixture to be extruded therethrough, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid article.
Claim 29
Dependent Claim
28 words
The method of claim 26 wherein the extruder heating step includes cooling the extruder screw tip to prevent charring of compressed bark pieces adjacent to the screw tip.
Claim 30
Dependent Claim
56 words
The method of claim 27 wherein the extruder heating step includes controlling the respective extruder barrel zone temperatures by maintaining barrel zone (1) at from about 250° to 300°F., barrel zones (2 and 3) from about 275° to 325°F., the metering zone from about 250° to 300°F., and the extruder gate from about 250° to 300°F.
Claim 31
Dependent Claim
52 words
The method of claim 28 wherein the bark pieces have less than 2% moisture, the combustible thermoplastic is polyethylene, and barrel zone (1) is maintained at about 275°F., barrel zones (2 and 3) at about 300°F., the metering zone at about 275°F., and the extruder gate is liquid cooled to about 255°F.
Claim 32
Dependent Claim
36 words
The method of claim 29 wherein the extruding step includes extruding the composite extrudate through a die to form the article and wherein the cooling step includes cooling the die to from about 80° to 150°F.
Claim 33
Dependent Claim
40 words
The method of claim 26 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 34
Dependent Claim
40 words
The method of claim 28 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 35
Dependent Claim
40 words
The method of claim 29 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 36
Dependent Claim
102 words
The method of claim 26 wherein the blending step includes blending with the bark pieces and thermoplastic pieces, pieces of extrudable size of from 0 to 20% by weight combustible wax-treated fibrous material, and the heating step is at a temperature sufficient to also melt the wax of the wax-treated fibrous material, and substantially separate the wax therefrom so that the separated wax is dispersed with the thermoplastic and acts as a binder for the bark pieces, the separated wax comprising from 0 to about 7%, and the fibrous material from 0 to about 13% of the total weight of the article.
Claim 37
Dependent Claim
48 words
The method of claim 34 wherein the bark pieces contain less than 2% moisture, the bark is about 80% by weight, and the percent combustible thermoplastic and percent wax-treated fibrous material are in a ratio of 1:1, the percents being based on the total weight of the article.
Claim 38
Dependent Claim
80 words
The method of claim 15 wherein the extruder heat controlling step includes cooling the extruder screw tip to prevent charring of compressed bark pieces in the extruder metering zone adjacent the screw tip, and includes controlling the respective extruder barrel zone temperatures by maintaining barrel zone (1) at from about 250° to 300°F. barrel zones (2 and 3) from about 275° to 325°F., the metering zone from about 250° to 300°F., and the extruder gate from about 250° to 300°F.
Claim 39
Dependent Claim
31 words
The method of claim 36 wherein the extruding step includes extruding the composite extrudate through a die, and the cooling step includes cooling the die to from about 80° to 150°F.
Claim 40
Dependent Claim
40 words
The method of claim 34 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
Claim 41
Dependent Claim
119 words
The method of claim 36 wherein the bark pieces contain less than 2% moisture, the bark is about 80% by weight, the percent combustible thermoplastic and percent wax-treated fibrous material are in a ratio of 1:1, the percents being based on the total weight of the article, and wherein the extruder heat controlling step includes cooling the extruder screw tip to prevent charring of compressed bark pieces adjacent to the screw tip, and includes controlling the respective extruder barrel zone temperatures by maintaining barrel zone one at from about 250° to 300°F., barrel zones (2 and 3) from about 275° to 325°F., the metering zone from about 250° to 300°F., and the extruder gate from about 250° to 300°F.
Claim 42
Dependent Claim
40 words
The method of claim 39 wherein the pieces of combustible thermoplastic are pieces of combustible thermoplastic-treated fibrous material of an extrudable size, and the thermoplastic dispersed during the heating step is separated from the pieces of combustible thermoplastic-treated fibrous material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |