Patent EP0051880A2 successfully refreshed from Google Patents.
EP0051880A2
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An apparatus and method for extruding ethylene polymers
Assignee: Union Carbide Corp
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Filing: 1981-11-11
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Granted: —
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Expires: 2001-11-11
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 Clark Miller
- 👤 Archibald Louis Burnett
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 19:26
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: 12
Claim 1
Independent Claim
62 words
A method for extruding low density narrow molecular weight distribution, linear, ehtylene polymers which comprises passing said polymers through an extruder apparatus including an extruder screw (1 0 , 22, 24) having at least one flight (12) and having an inlet end (16) and a discharge end (2o) and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 2
Independent Claim
62 words
A method for extruding low density narrow molecular weight distribution, linear, ehtylene polymers which comprises passing said polymers through an extruder apparatus including an extruder screw (1 0 , 22, 24) having at least one flight (12) and having an inlet end (16) and a discharge end (2o) and wherein the pitch ratio divided by the depth ratio is greater than 2/3.
Claim 3
Dependent Claim
25 words
A method according to claim 1 wherein said flight decreases in pitch preferably in a uniform manner from said inlet end to said discharge end.
Claim 4
Dependent Claim
41 words
A method according to claim 1 wherein said screw (22) 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 5
Dependent Claim
51 words
A method according to claim 1 wherein said screw (24) 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 6
Independent Claim
32 words
A method according to anyone of the claims 1 - 4 wherein said polymer leaving said extruder screw is introduced into and passed through a mixing zone associated with said extruder screw.
Claim 7
Independent Claim
42 words
A method according to anyone of the claims 1 - 5 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 8
Independent Claim
94 words
A method according to anyone of the claims 1 - 6 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 said copolymer having preferably 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 and/or 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 9
Dependent Claim
70 words
A novel extruder screw for extruding polymers which comprises a screw root with at least one flight (12) having an entry end (16) and a discharge end (20) said screw being preferably 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 10
Dependent Claim
70 words
A novel extruder screw for extruding polymers which comprises a screw root with at least one flight (12) having an entry end (16) and a discharge end (20) said screw being preferably 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 11
Dependent Claim
68 words
An extruder screw according to claim 8 wherein said screw is divided into from three to eight segments preferably said screw is divided into equal segments wherein said pitch is constant in each segment and wherein said pitch decreases from segm nt to segment, especially the depth of said screw is substantially constant in each segment, and/or said pitch abruptly decreases from one segment to the following segment.
Claim 12
Dependent Claim
56 words
An extruder screw according to claim 8 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 and preferably the depth of said screw is substantially constant in each segment or the depth of said screw decreases from segment to segment.
References Cited (Backward Citations)
No citation records indexed.
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