US3899283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for extruding resin film with weakened tear lines
Assignee: Individual
•
Filing: 1973-01-15
•
Granted: 1975-08-12
•
Expires: 1993-01-15
Abstract
Abstract In a packaging method and apparatus, a film forming head is provided with a thin lipped extruding orifice communicating with a central cavity for receiving liquid resin material therein and for extruding a molten sheet of resin film. The extruded film, while still molten, is directly applied to the articles to be packaged. To facilitate the opening of a package formed in this manner, weakened tear lines are automatically formed in the extruded plastic sheet by the provision of small obstructing pins placed at or adjacent the extruding orifice of the head. The weakened lines in the extruded film may be formed as individual easy opening tear lines, or as double tear lines in which a strip of plastic wrapping may be conveniently stripped away from the remaining resin film to facilitate removal of the wrapper. Except for the weakened tear lines, the extruded film is formed with biaxially oriented strength characteristics. The film is projected radially outwardly of the orifice from a central cavity within the head to achieve this biaxial orientation. The location of the easy tear line or lines may be selected by appropriate positioning of the flow obstructing pins relative to the extruding orifice.
Inventors
- 👤 Marvin E Wallis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:55
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/695; B29C48/70; B29C48/001; B29C48/0018; B29C48/03; B29C48/07; B29C48/08; B29C48/30; B29C48/305; Y; Y10; Y10T; Y10T428/00; Y10T428/15
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
91 words
A film forming head for extruding a biaxially oriented film with weakened tear line, comprising head structure defining a cavity for receiving viscous resin material under pressure, means including a thin-lip orifice extending about a curvilinear portion of the cavity for extruding a biaxially oriented film that is wider than the orifice, and means for obstructing the flow of said resin outwardly of said orifice during extrusion at a location where the resin flow is bi-directional, whereby the extruded biaxially oriented film is formed with at least one weakened tear line.
Claim 2
Dependent Claim
91 words
A film forming head for extruding a biaxially oriented film with weakened tear line, comprising head structure defining a cavity for receiving viscous resin material under pressure, means including a thin-lip orifice extending about a curvilinear portion of the cavity for extruding a biaxially oriented film that is wider than the orifice, and means for obstructing the flow of said resin outwardly of said orifice during extrusion at a location where the resin flow is bi-directional, whereby the extruded biaxially oriented film is formed with at least one weakened tear line.
Claim 3
Dependent Claim
91 words
A film forming head as set forth in claim 1 further including a second means for obstructing the flow of said resin outwardly of said orifice during extrusion at a location where the flow is bi-directional and spaced from and out of alignment with said first means considered with respect to the flow direction at said location so as to form a pair of weakened tear lines in the extruded film whereby the resin material between such lines may be torn as a strip away from the remainder of the film.
Claim 4
Dependent Claim
25 words
The combination in claim 1, said obstruction means comprising; a pin member disposed with a portion thereof obstructing flow of resin material at said orifice.
Claim 5
Dependent Claim
23 words
The combination of claim 3, further defined by said member being arranged with said portion inwardly of the discharge side of said orifice.
Claim 6
Dependent Claim
23 words
The combination of claim 4, further defined by said member portion being disposed within said cavity proximate the cavity side of said orifice.
Claim 7
Dependent Claim
44 words
The combination of claim 5, further comprising; a second such pin member having a portion thereof disposed within said cavity proximate the entry side of said orifice and spaced from the first named pin so as to form a pair of weakened tear lines.
Claim 8
Dependent Claim
25 words
The combination of claim 4, further defined by the said pin member having its axis extending generally transversely to a plane defined by said orifice.
Claim 9
Dependent Claim
145 words
In a film forming head for receiving viscous resin material under pressure and forming a resin film therefrom wider than the head, including a body having a central cavity formed therein with an interior wall which is concave in a plane passing through said body, the exterior of said body being formed with a surface which is convex in said plane and generally parallels said interior cavity wall, an extruding orifice extending between said exterior surface and interior wall and being elongated in said plane so as to circumferentially extend along said exterior surface and interior wall, the improvement in said head comprising; at least one obstruction means disposed proximate to or within said orifice intermediate the circumferential extent thereof for obstructing a spreading flow of resin material adjacent said orifice and forming a weakened tear line in the resultant film along the length thereof.
Claim 10
Dependent Claim
145 words
In a film forming head for receiving viscous resin material under pressure and forming a resin film therefrom wider than the head, including a body having a central cavity formed therein with an interior wall which is concave in a plane passing through said body, the exterior of said body being formed with a surface which is convex in said plane and generally parallels said interior cavity wall, an extruding orifice extending between said exterior surface and interior wall and being elongated in said plane so as to circumferentially extend along said exterior surface and interior wall, the improvement in said head comprising; at least one obstruction means disposed proximate to or within said orifice intermediate the circumferential extent thereof for obstructing a spreading flow of resin material adjacent said orifice and forming a weakened tear line in the resultant film along the length thereof.
Claim 11
Dependent Claim
64 words
In the film forming head as set forth in claim 8 wherein said orifice has confronting gapped faces substantially parallel to said plane and at least one of said faces defines a lip connecting said exterior surface with said interior cavity wall, the improvement further defined by said obstruction means being a pin member disposed so as to extend generally perpendicularly to said faces.
Claim 12
Dependent Claim
117 words
In the head of claim 9 wherein said cavity is formed by said interior wall and by another interior wall connected to the face of said orifice confronting said lip, said walls defining a central cavity region of greatest cross section remote from said orifice, said wall connected to said lip being sloped from said central cavity region toward said plane to its circumferential connection with said orifice lip whereby said walls converge from said central cavity region toward said orifice to provide for smooTh acceleration of the viscous resin material prior to being projected outwardly from said orifice, and the improvement being further defined by said pin member being disposed on or adjacent to said lip.
Claim 13
Dependent Claim
96 words
A film forming head for extruding a biaxially oriented film with a weakened tear line, comprising head structure defining a cavity for receiving viscous resin material under pressure, means including a thin-lip orifice extending about a curvilinear portion of the cavity for extruding a biaxially oriented film that is wider than the orifice downstream therefrom, and means for obstructing the flow of said resin outwardly of said orifice during extrusion at a location upstream from where the film reaches its maximum width to form a weakened tear line along the length of the biaxially oriented film.
Claim 14
Dependent Claim
96 words
A film forming head for extruding a biaxially oriented film with a weakened tear line, comprising head structure defining a cavity for receiving viscous resin material under pressure, means including a thin-lip orifice extending about a curvilinear portion of the cavity for extruding a biaxially oriented film that is wider than the orifice downstream therefrom, and means for obstructing the flow of said resin outwardly of said orifice during extrusion at a location upstream from where the film reaches its maximum width to form a weakened tear line along the length of the biaxially oriented film.
References Cited (Backward Citations)
US299591A
Cited
US1025133A
Cited
US2774106A
Cited
US3085289A
Cited
US3451103A
Cited
US3297809A
Cited
US3455755A
Cited
US3387328A
Cited
US3535409A
Cited
US3527859A
Cited
US3557271A
Cited
US3687592A
Cited
US3823053A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |