EP0050496A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for extruding linear polyolefin materials having high viscosities
Assignee: Union Carbide Corp
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Filing: 1981-10-16
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Granted: —
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Expires: 2001-10-16
Abstract
Abstract A method is disclosed for the extrusion of low-density linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder having feeding, transition and metering sections which comprises employing, in the extruder screw forming such sections in cooperation with the cylindrical interior of the extruder housing, opened leading edges for the screw flights of said sections; and gall-resistant coated surfaces on the screw flights of said sections.
Inventors
- 👤 Theodore Robert Blakeslee Iii
- 👤 Stuart Jacob Kurtz
- 👤 Leonard Sebastian Scarola
- 👤 John Clark Miller
- 👤 James David Engle
- 👤 Jerome Thomas Horner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 09:24
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/56; B29C48/022; B29C48/507; B29C48/509; B29C48/53; B29C48/68; B29C48/6803; B29C48/03; B29K; B29K2023/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A'method for the extrusion of low-density, linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder including an extruder housing defining a cylindrical interior and containing an extruder screw having helical screw flights having feeding, transition and metering sections, characterised by employing, in said extruder screw in cooperation with the cylindrical interior of said extruder housing, opened leading edges for said screw flights of said sections; and surfaces of the screw flights of said sections coated with gall-resistant material.
Claim 2
Dependent Claim
87 words
A'method for the extrusion of low-density, linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder including an extruder housing defining a cylindrical interior and containing an extruder screw having helical screw flights having feeding, transition and metering sections, characterised by employing, in said extruder screw in cooperation with the cylindrical interior of said extruder housing, opened leading edges for said screw flights of said sections; and surfaces of the screw flights of said sections coated with gall-resistant material.
Claim 3
Dependent Claim
47 words
A method for the extrusion of low-density linear polyolefin materials having high viscosities as claimed in claim 1 wherein the screw flights of said feeding, transition, and metering sections are increased at least 20% in width over conventional widths to increase the bearing surface of said screw.
Claim 4
Dependent Claim
34 words
A method as claimed in claim 1 or claim 2 wherein the depth of the screws of the feed section is reduced at least 10% from conventional depths in order to stiffen said screw.
Claim 5
Independent Claim
48 words
A method as claimed in any one of the preceding claims wherein the length of the transition section is increased by at least 50% over conventional lengths employed in such a section between a feeding and metering section in order to reduce the rate of pressure rise therein.
Claim 6
Independent Claim
41 words
A method as claimed in any one of the preceding claims wherein the radial clearance between said extruder screw and the walls of said cylindrical interior of the extruder housing is increased of the order of 100% over conventional clearance employed.
Claim 7
Independent Claim
24 words
A method as claimed in any one of the preceding claims wherein a mixing section is additionally employed downstream of said extruder screw sections.
Claim 8
Independent Claim
179 words
A method for the extrusion of linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder having feeding, transition and metering sections, characterised by employing, in the extruder screw forming such sections in cooperation with the cylindrical interior of the outer extruder housing, opened leading edges for the screw flights of said sections; surfaces of the-screw flights of said sections coated with gall-resistant material; screw flights of said feeding, transitiion and metering sections are increased at least 20% in width to increase the bearing surface of said screw; the depth of the screws of the feed section is reduced at least 10% in order to stiffen said screw; the length of the transition section is increased by at least 50% over those normally employed in such a section between a feeding and metering section in order to reduce the rate of pressure rise therein; and the radial clearance between. said extruder screw . and the walls of said cylindrical interior of the extruder housing is increased of the order of 100%.
Claim 9
Independent Claim
179 words
A method for the extrusion of linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder having feeding, transition and metering sections, characterised by employing, in the extruder screw forming such sections in cooperation with the cylindrical interior of the outer extruder housing, opened leading edges for the screw flights of said sections; surfaces of the-screw flights of said sections coated with gall-resistant material; screw flights of said feeding, transitiion and metering sections are increased at least 20% in width to increase the bearing surface of said screw; the depth of the screws of the feed section is reduced at least 10% in order to stiffen said screw; the length of the transition section is increased by at least 50% over those normally employed in such a section between a feeding and metering section in order to reduce the rate of pressure rise therein; and the radial clearance between. said extruder screw . and the walls of said cylindrical interior of the extruder housing is increased of the order of 100%.
Claim 10
Dependent Claim
20 words
A method as claimed in claim 7 wherein a mixing section is additionally employed downstream of said extruder screw sections.
References Cited (Backward Citations)
No citation records indexed.
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