Patent US4329313A successfully refreshed from Google Patents.
US4329313A
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Apparatus and method for extruding ethylene polymers
Assignee: Union Carbide Corp
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Filing: 1980-11-12
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Granted: 1982-05-11
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Expires: 2000-11-12
Abstract
Abstract A novel extruder screw having at least three segments wherein the pitch remains constant in each segment and changes abruptly from one segment to the following segment and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Inventors
- 👤 John C. Miller
- 👤 Archibald L. Burnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:27
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/535; B29C48/022; B29C48/03; B29C48/07; B29C48/08; B29K; B29K2023/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
52 words
A method for extruding low density narrow molecular weight distribution, linear, ethylene polymers which comprises passing said polymers through an extruder apparatus including an extruder screw having a flight and having an inlet end and a discharge end and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 2
Independent Claim
52 words
A method for extruding low density narrow molecular weight distribution, linear, ethylene polymers which comprises passing said polymers through an extruder apparatus including an extruder screw having a flight and having an inlet end and a discharge end and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 3
Dependent Claim
20 words
A method according to claim 1 wherein said flight decreases in pitch from said inlet end to said discharge end.
Claim 4
Dependent Claim
19 words
A method according to claim 2 wherein said pitch decreases uniformly from said inlet end to said discharge end.
Claim 5
Dependent Claim
39 words
A method according to claim 1 wherein said screw includes from three to four equal segments, each having a constant depth, wherein said pitch remains constant in each segment and wherein said pitch abruptly decreases from segment to segment.
Claim 6
Dependent Claim
50 words
A method according to claim 1 wherein said screw includes from three to eight unequal segments, with a constant pitch in each segment and a decreasing pitch from segment to segment and wherein said screw has a constant depth in each segment and a decreasing depth from segment to segment.
Claim 7
Dependent Claim
27 words
A method according to claim 1 wherein said polymer leaving said extruder screw is introduced into and passed through a mixing zone associated with said extruder screw.
Claim 8
Independent Claim
36 words
A method according to claims 1 in which said polymer is a copolymer of ethylene and at least one C 3 to C 8 alpha olefin having a melt index of about ≧0.1 to about ≦20.
Claim 9
Dependent Claim
33 words
A method according to claim 7 in which said polymer is a copolymer of ≧90 mol percent ethylene and ≦10 mol percent of at least one C 3 to C 8 alpha olefin.
Claim 10
Dependent Claim
33 words
A method according to claim 8 in which said copolymer has a molecular weight distribution of about ≧2.7 to ≦6.0 and a total unsaturation content of about ≧0.1 to ≦0.3 C=C/1000 C atoms.
Claim 11
Dependent Claim
33 words
A method according to claim 9 in which said copolymer has a melt flow ratio of about ≧22 to ≦40 and a total unsaturation content of about ≧0.1 to ≦0.3 C=C/1000 C atoms.
Claim 12
Dependent Claim
66 words
A novel extruder screw for extruding polymers which comprises a screw root with at least one flight having an entry end and a discharge end, said screw being divided into at least three segments wherein the pitch remains constant within each segment and changes abruptly from one segment to the following segment and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 13
Dependent Claim
66 words
A novel extruder screw for extruding polymers which comprises a screw root with at least one flight having an entry end and a discharge end, said screw being divided into at least three segments wherein the pitch remains constant within each segment and changes abruptly from one segment to the following segment and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 14
Dependent Claim
18 words
An extruder screw according to claim 11 wherein said screw is divided into from three to eight segments.
Claim 15
Dependent Claim
19 words
An extruder screw according to claim 11 wherein said pitch abruptly decreases from one segment to the following segment.
Claim 16
Dependent Claim
33 words
An extruder screw according to claim 10 wherein said screw is divided into three equal segments wherein said pitch is constant in each segment and wherein said pitch decreases from segment to segment.
Claim 17
Dependent Claim
19 words
An extruder screw according to claim 14 wherein the depth of said screw is substantially constant in each segment.
Claim 18
Dependent Claim
32 words
An extruder screw according to claim 11 wherein said screw is divided into about five unequal segments, each segment having a constant pitch, and wherein said pitch decreases from segment to segment.
Claim 19
Dependent Claim
19 words
An extruder screw according to claim 16 wherein the depth of said screw is substantially constant in each segment.
Claim 20
Dependent Claim
18 words
An extruder screw according to claim 16 wherein the depth of said screw decreases from segment to segment.
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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) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |