Patent US5266256A successfully refreshed from Google Patents.
US5266256A
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US
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Extruder and process modifying residence time distribution
Assignee: Rohm and Haas Co
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Filing: 1993-02-16
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Granted: 1993-11-30
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Expires: 2013-02-16
Abstract
Abstract A process is provided for modifying the residence time distribution of materials in an extruder which results in a residence time distribution comparable to that obtained in a continuous stirred tank reactor. An extruder is provided which has a section which modifies the residence time distribution of materials loaded into the extruder.
Inventors
- 👤 Robert E. Jerman
- 👤 Jeffrey L. Daecher
- 👤 Glenn W. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:06
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/18; B01J19/20; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/395; B29C48/03; B29K; B29K2033/00; B29K2033/04; B29K2033/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
132 words
A process for modifying the mean residence time and residence time distribution of materials in a reaction or mixing zone of an extruder, having twin non-intermeshing counter rotating screws arranged parallel or tangential to one another and an entrance inlet for the introduction of material and a discharge outlet, remote from the entrance inlet, for removing materials, rotating said twin screws with the same directional pitch, restricting the flow of material from the reaction or mixing zone toward the discharge outlet and from the reaction or mixing zone toward the entrance inlet, moving material along one of the screws in a direction, from an area proximate the discharge outlet toward the entrance inlet, transferring material to the second screw and discharging material from said reaction or mixing zone through said discharge outlet.
Claim 2
Dependent Claim
132 words
A process for modifying the mean residence time and residence time distribution of materials in a reaction or mixing zone of an extruder, having twin non-intermeshing counter rotating screws arranged parallel or tangential to one another and an entrance inlet for the introduction of material and a discharge outlet, remote from the entrance inlet, for removing materials, rotating said twin screws with the same directional pitch, restricting the flow of material from the reaction or mixing zone toward the discharge outlet and from the reaction or mixing zone toward the entrance inlet, moving material along one of the screws in a direction, from an area proximate the discharge outlet toward the entrance inlet, transferring material to the second screw and discharging material from said reaction or mixing zone through said discharge outlet.
Claim 3
Dependent Claim
18 words
A process according to claim 1, wherein the reaction conducted in the extruder is a free radical reaction.
Claim 4
Dependent Claim
19 words
A process according to claim 1, wherein the reaction conducted in the extruder is a grafting or block reaction.
Claim 5
Dependent Claim
19 words
A process according to claim 1, wherein the reaction conducted in the extruder is the polymerization of methyl methacrylate.
Claim 6
Dependent Claim
19 words
A process according to claim 1, wherein the reaction conducted in the extruder is the imidization of a polymethacrylate.
Claim 7
Dependent Claim
124 words
In an extruder having an inlet for introduction of material into said extruder and an outlet for discharge of material from said extruder and counter rotating non-intermeshing twin screws having flights thereon and disposed substantially parallel or tangential to one another and means connected operably to the screws for turning the screws during operation of the extruder, a portion of said screws defining a reaction or mixing zone within the extruder, and flow restriction means present on at least one screw at the beginning and end of the reaction or mixing zone, the improvement comprising the flights of each of the screws in the reaction or mixing zone having the same directional pitch whereby the residence time distribution and mean residence time are modified.
Claim 8
Dependent Claim
124 words
In an extruder having an inlet for introduction of material into said extruder and an outlet for discharge of material from said extruder and counter rotating non-intermeshing twin screws having flights thereon and disposed substantially parallel or tangential to one another and means connected operably to the screws for turning the screws during operation of the extruder, a portion of said screws defining a reaction or mixing zone within the extruder, and flow restriction means present on at least one screw at the beginning and end of the reaction or mixing zone, the improvement comprising the flights of each of the screws in the reaction or mixing zone having the same directional pitch whereby the residence time distribution and mean residence time are modified.
Claim 9
Dependent Claim
27 words
An extruder according to claim 6 wherein a compounder is present on at least one screw at the beginning and end of the reaction or mixing zone.
Claim 10
Dependent Claim
35 words
An extruder according to claim 7 wherein the compounder at the beginning of the reaction or mixing zone is on a different screw than the compounder at the end of the reaction or mixing zone.
References Cited (Backward Citations)
US2458068A
Cited
US3642752A
Cited
US4863363A
Cited
US4900156A
Cited
US5047188A
Cited
US4948859A
Cited
EP0370735A2
Cited
US5205973A
Cited
US5056925A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-29 | 1997-05-31 | 1997-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-29 | 2001-05-31 | 2001-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-29 | 2005-05-31 | 2005-11-30 | $7700.00 | Window Closed / Lapsed |