US3597795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Die head for the continuous extrusion of plastic film with profiles for a closure for use in plastic bags
Assignee: Minigrip Inc
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Filing: 1968-10-07
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Granted: 1971-08-10
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Expires: 1988-10-07
Abstract
Abstract A die head for the continuous extrusion of plastic for the manufacture of a plastic film having profile ledges for the bag closure which serves for the formation of plastic bags.
Inventors
- 👤 Kakuji Naito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:35
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/695; B29C48/70; B29C48/03; B29C48/09; B29C48/10; B29C48/12; B29C48/30; B29C48/32; B29C48/34; Y; Y10; Y10S; Y10S425/00; Y10S425/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
169 words
A die head for a plastic extrusion machine for forming plastic film with an inner surface profile, comprising: a first extrusion member; a second extrusion member disposed about and in spaced relation to said first extrusion member to define an extrusion gap therebetween for receiving a flow of plastic material and opening to the exterior of the die head for extruding a hollow film; a passageway in said first extrusion member in communication with said extrusion gap and the exterior of the die head, said passage comprising an inlet segment in communication with said extrusion gap, and a discharge segment in communication with the exterior of the die head and having a shape to form a profile on the inner surface of the hollow film; and means for changing the cross-sectional area of said passage including a replaceable flow control member disposed in said inlet segment and having an aperture of selected cross-sectional area therethrough in communication with said passage for determining the flow of plastic through said passage.
Claim 2
Dependent Claim
169 words
A die head for a plastic extrusion machine for forming plastic film with an inner surface profile, comprising: a first extrusion member; a second extrusion member disposed about and in spaced relation to said first extrusion member to define an extrusion gap therebetween for receiving a flow of plastic material and opening to the exterior of the die head for extruding a hollow film; a passageway in said first extrusion member in communication with said extrusion gap and the exterior of the die head, said passage comprising an inlet segment in communication with said extrusion gap, and a discharge segment in communication with the exterior of the die head and having a shape to form a profile on the inner surface of the hollow film; and means for changing the cross-sectional area of said passage including a replaceable flow control member disposed in said inlet segment and having an aperture of selected cross-sectional area therethrough in communication with said passage for determining the flow of plastic through said passage.
Claim 3
Dependent Claim
34 words
A die head as set forth in claim 1, wherein said replaceable flow control member comprises deformable material defining said aperture , said material being workable to change the cross-sectional area of said aperture.
Claim 4
Dependent Claim
22 words
A die head as set forth in claim 1, comprising, means for releaseably securing said replaceable member to said first extrusion member.
Claim 5
Dependent Claim
63 words
The die head set forth in claim 1, wherein said first and second extrusion members include adjacent nonconforming conical surfaces integral with adjacent parallel surfaces to form an extrusion gap of decreasing cross-sectional area changing to a constant cross-sectional area, and said passage includes an inlet segment in communication with the extrusion gap immediately downstream of its transition to a constant cross-sectional area.
Claim 6
Dependent Claim
22 words
The branch extrusion passage set forth in claim 1, wherein said discharge segment is of greater cross-sectional area than said inlet segment.
Claim 7
Dependent Claim
38 words
The branch extrusion passage set forth in claim 5, including an intermediate segment of a cross-sectional area of a size between the inlet and discharge segments and being in communication with said inlet segment and said discharge segment.
Claim 8
Dependent Claim
27 words
The branch extrusion passage set forth in claim 5, comprising an intermediate passage of stepped cross-sectional area in communication between said inlet segment and said discharge segment.
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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |