US4732727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for producing mesh film
Assignee: Dow Chemical Co
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Filing: 1986-04-03
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Granted: 1988-03-22
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Expires: 2006-04-03
Abstract
Abstract A method and apparatus for producing mesh film include an extrusion die for extruding a tube of a heat-plastified, resinous, mesh film material. A first cooling arrangement, centrally located within the extruded tube, cools the internal surface of the tube. The first cooling arrangement has an outer diameter substantially equal to the inner diameter of the extruded tube. A plurality of cooling nozzles are disposed radially outward from the first cooling arrangement for directing a plurality of streams of a cooling gas toward the exterior surface of the extruded tube. An annular gas bearing is spaced axially from the first cooling arrangement such that the extruded tube passes therethrough after leaving the first cooling arrangement, thereby permitting the diameter of the extruded tube to be increased subsequently by means of a trapped air bubble therewithin.
Inventors
- 👤 Carl B. Havens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:17
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/908; B29C48/03; B29C48/09; B29C48/10; B29C48/885; B29C48/901; B29C48/902; B29C48/911; B29C48/9115; B29C48/912; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
131 words
Apparatus for producing mesh film, comprising: extrusion die means for extruding a tube of a heat-plastified, resinous, mesh film material, first cooling means, centrally located within the extruded tube, for cooling the internal surface of said tube, said first cooling means having an outer diameter substantially equal to the inner diameter of said extruded tube, a plurality of cooling nozzles, disposed radially outward from said first cooling means, for directing a plurality of streams of a cooling gas toward the exterior surface of said extruded tube, and an annular gas bearing spaced axially from said first cooling means such that said extruded tube passes therethrough after leaving said first cooling means, thereby permitting the diameter of said extruded tube to be increased subsequently by means of a trapped air bubble therewithin.
Claim 2
Dependent Claim
131 words
Apparatus for producing mesh film, comprising: extrusion die means for extruding a tube of a heat-plastified, resinous, mesh film material, first cooling means, centrally located within the extruded tube, for cooling the internal surface of said tube, said first cooling means having an outer diameter substantially equal to the inner diameter of said extruded tube, a plurality of cooling nozzles, disposed radially outward from said first cooling means, for directing a plurality of streams of a cooling gas toward the exterior surface of said extruded tube, and an annular gas bearing spaced axially from said first cooling means such that said extruded tube passes therethrough after leaving said first cooling means, thereby permitting the diameter of said extruded tube to be increased subsequently by means of a trapped air bubble therewithin.
Claim 3
Dependent Claim
36 words
The apparatus of claim 1 in which said first cooling means comprises: a generally cylindrical cooled mandrel, and a pair of generally cylindrical gas bearings positioned on either side of said mandrel and axially aligned therewith.
Claim 4
Dependent Claim
23 words
The apparatus of claim 1 in which at least some of said plurality of cooling nozzles are movable circumferentially around said extruded tube.
Claim 5
Dependent Claim
30 words
The apparatus of claim 1 further comprising second cooling means for cooling said tube, after it passes through said annular gas bearing, as the diameter of said tube is enlarged.
Claim 6
Dependent Claim
26 words
The apparatus of claim 4 in which said second cooling means comprises means for directing a cooling gas against the exterior surface of said extruded tube.
Claim 7
Dependent Claim
21 words
The apparatus of claim 1 further comprising third cooling means for cooling said tube as it emerges from said die means.
Claim 8
Dependent Claim
34 words
The apparatus of claim 6 in which said third cooling means comprises means for directing a cooling gas against the exterior surface of said extruded tube immediately after it emerges from the die means.
Claim 9
Dependent Claim
33 words
The apparatus of claim 1 further comprising fourth cooling means, centrally located within said extruded tube, for cooling the internal surface of said tube after said tube emerges from said annular gas bearing.
Claim 10
Dependent Claim
27 words
The apparatus of claim 8 in which the outer diameter of said fourth cooling means is substantially greater than the inner diameter of said annular gas bearing.
Claim 11
Dependent Claim
27 words
The apparatus of claim 8 in which said fourth cooling means is selected from the group consisting of a cooled mandrel, a gas bearing, and combinations thereof.
Claim 12
Dependent Claim
17 words
The apparatus of claim 1 in which said first cooling means comprises a generally cylindrical gas bearing.
Claim 13
Dependent Claim
86 words
The apparatus of claim 1 in which said extrusion die means comprises: an extrusion die for extruding a relatively large diameter tube of a heat-plastified, resinous, mesh film material, and a second annular gas bearing, adjacent said die and coaxially aligned therewith, for receiving said tube therethrough from said extrusion die, said second annular gas bearing having an inner diameter which is less than the diameter of said tube as it leaves said die and substantially equal to the outer diameter of said first cooling means.
Claim 14
Independent Claim
103 words
A method for producing mesh film, comprising the steps of: extruding a heat-plastified, resinous, mesh film material to form a tube of mesh film material, passing said tube of mesh film material over a centrally located generally cylindrical cooling means to cool the internal surface of said tube while directing a plurality of streams of cooling gas toward the exterior surface of said tube, thereafter, passing said tube through an annular gas bearing having an inner diameter approximately equal to the outer diameter of said cooling means, and thereafter, increasing the diameter of said tube by means of a trapped air bubble therewithin.
Claim 15
Independent Claim
103 words
A method for producing mesh film, comprising the steps of: extruding a heat-plastified, resinous, mesh film material to form a tube of mesh film material, passing said tube of mesh film material over a centrally located generally cylindrical cooling means to cool the internal surface of said tube while directing a plurality of streams of cooling gas toward the exterior surface of said tube, thereafter, passing said tube through an annular gas bearing having an inner diameter approximately equal to the outer diameter of said cooling means, and thereafter, increasing the diameter of said tube by means of a trapped air bubble therewithin.
Claim 16
Dependent Claim
35 words
The method of claim 13 in which said cooling means comprises: a generally cylindrical cooled mandrel, and a pair of generally cylindrical gas bearings positioned on either side of said mandrel and axially aligned therewith.
Claim 17
Dependent Claim
23 words
The method of claim 13 in which at least some of said streams of cooling gas are moved circumferentially around said extruded tube.
Claim 18
Dependent Claim
27 words
The method of claim 13 further comprising the step of cooling said tube as its diameter is increased by directing a cooling gas against its exterior surface.
Claim 19
Dependent Claim
27 words
The method of claim 13 further comprising the step of cooling said tube immediately after it is extruded by directing a cooling gas against its exterior surface.
Claim 20
Dependent Claim
39 words
The method of claim 13 further comprising the step of cooling said tube after its diameter is increased by means selected from the group consisting of a cooled mandrel, a gas bearing, and combinations thereof positioned within said tube.
Claim 21
Dependent Claim
16 words
The method of claim 13 in which said cooling means comprises a generally cylindrical gas bearing.
Claim 22
Dependent Claim
57 words
The method of claim 13 in which said step of extruding a heat-plastified, resinous, mesh film material to form a tube of mesh film material comprises the steps of: extruding a relatively large diameter tube of a heat-plastified, resinous, mesh film material, and reducing the diameter of said relatively large diameter tube by stretching said tube axially.
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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) | 1991-03-22 | 1991-09-21 | 1992-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-22 | 1995-09-21 | 1996-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-22 | 1999-09-21 | 2000-03-22 | $7700.00 | Window Closed / Lapsed |