Patent US4169679A successfully refreshed from Google Patents.
US4169679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the extrusion of cellular thermoplastic material
Assignee: Union Carbide Corp
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Filing: 1977-12-12
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Granted: 1979-10-02
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Expires: 1997-12-12
Abstract
Abstract The invention provides apparatus for the production of cellular thermoplastic material comprising an extruder having a hollow barrel, screw means mounted in said barrel to advance material therethrough, mixer head means mounted in said barrel and gaseous blowing agent inlet means positioned in said barrel near the upstream end of said mixer head means, said mixer head means having in the surface thereof a plurality of alternate land and groove means, said land means having close clearance with the internal walls of said barrel near the upstream end thereof in the region of said blowing agent inlet means and alternately spaced and close clearance with said walls in the mixing region downstream of said blowing agent inlet means.
Inventors
- 👤 John C. Miller
- 👤 Archibald L. Burnett
- 👤 Leonard S. Scarola
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:46
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/20; B29C44/32; B29C44/322; B29C48/00; B29C48/03; B29C48/05; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/51
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
An extruder having a hollow barrel, screw means mounted in said barrel to advance material therethrough, mixer head means mounted in said barrel and gaseous blowing agent inlet means positioned in said barrel near the upstream end of said mixer head means, said mixer head means having in the surface thereof a plurality of alternate land means and groove means, said land means having close clearance with the internal walls of said barrel at the point of positioning of said blowing agent inlet means so that said blowing agent inlet means is intermittently opened and closed by said land means to the passage of blowing agent to said plurality of groove means, and land pairs alternately in spaced clearance and close clearance with said walls in the mixing region downstream of said blowing agent inlet means.
Claim 2
Dependent Claim
136 words
An extruder having a hollow barrel, screw means mounted in said barrel to advance material therethrough, mixer head means mounted in said barrel and gaseous blowing agent inlet means positioned in said barrel near the upstream end of said mixer head means, said mixer head means having in the surface thereof a plurality of alternate land means and groove means, said land means having close clearance with the internal walls of said barrel at the point of positioning of said blowing agent inlet means so that said blowing agent inlet means is intermittently opened and closed by said land means to the passage of blowing agent to said plurality of groove means, and land pairs alternately in spaced clearance and close clearance with said walls in the mixing region downstream of said blowing agent inlet means.
Claim 3
Dependent Claim
51 words
An extruder in accordance with claim 1 wherein said mixer head means has hollow internal passage means positioned therein over a substantial portion of its terminal length, and a plurality of inlet conduits severally communicating between said land pairs of said plurality of land means and said hollow internal passage means.
Claim 4
Dependent Claim
26 words
An extruder in accordance with claim 2 wherein means for disruption of flow channeling are positioned in said hollow internal passage of said mixer head means.
Claim 5
Dependent Claim
28 words
An extruder in accordance with claim 3, wherein said means for disruption of flow channeling is mounted so as to be stationary with respect to said extruder barrel.
Claim 6
Dependent Claim
27 words
An extruder in accordance with claim 3, wherein said means for disruption of flow channeling is mounted so as to corotate with said rotating mixer head means.
Claim 7
Dependent Claim
231 words
An extruder having a hollow barrel, screw means mounted in said barrel to advance material therethrough, mixer head means longitudinally mounted in said barrel near the terminal end of said screw means and gaseous blowing agent inlet means positioned in said barrel near the upstream end of said mixer head means, said mixer head means having in the surface thereof a plurality of alternate land and groove means arranged to extend substantially longitudinally defining a plurality of grooves open at the upstream ends and closed at the downstream ends, said land means having close clearance with the internal walls of said barrel at the point of positioning of said blowing agent inlet means, so that said blowing agent inlet means is intermittently opened and closed by said land means to the passage of blowing agent to said plurality of groove means, and land pairs alternately in spaced clearance and close clearance with said walls in the mixing region downstream of said inlet means, said mixer head means having hollow internal passage means positioned therein over a substantial portion of its terminal length, and a plurality of inlet conduits severally communicating between said plurality of land means and said hollow internal passage means, said inlet conduits being positioned between said plurality of alternate spaced clearance and close clearance land pairs of said land means which are, in turn, positioned between said grooves.
Claim 8
Dependent Claim
231 words
An extruder having a hollow barrel, screw means mounted in said barrel to advance material therethrough, mixer head means longitudinally mounted in said barrel near the terminal end of said screw means and gaseous blowing agent inlet means positioned in said barrel near the upstream end of said mixer head means, said mixer head means having in the surface thereof a plurality of alternate land and groove means arranged to extend substantially longitudinally defining a plurality of grooves open at the upstream ends and closed at the downstream ends, said land means having close clearance with the internal walls of said barrel at the point of positioning of said blowing agent inlet means, so that said blowing agent inlet means is intermittently opened and closed by said land means to the passage of blowing agent to said plurality of groove means, and land pairs alternately in spaced clearance and close clearance with said walls in the mixing region downstream of said inlet means, said mixer head means having hollow internal passage means positioned therein over a substantial portion of its terminal length, and a plurality of inlet conduits severally communicating between said plurality of land means and said hollow internal passage means, said inlet conduits being positioned between said plurality of alternate spaced clearance and close clearance land pairs of said land means which are, in turn, positioned between said grooves.
Claim 9
Dependent Claim
26 words
An extruder in accordance with claim 6, wherein means for disruption of flow channeling are positioned in said hollow internal passage of said mixer head means.
Claim 10
Dependent Claim
28 words
An extruder in accordance with claim 6, wherein said means for disruption of flow channeling is mounted so as to be stationary with respect to said extruder barrel.
Claim 11
Dependent Claim
27 words
An extruder in accordance with claim 6, wherein said means for disruption of flow channeling is mounted so as to corotate with said rotating mixer head means.
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) | 1982-10-01 | 1983-04-02 | 1983-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-01 | 1987-04-02 | 1987-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-01 | 1991-04-02 | 1991-10-02 | $7700.00 | Window Closed / Lapsed |