US4465729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-tearable plastic films
Assignee: Clopay Corp
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Filing: 1983-04-05
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Granted: 1984-08-14
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Expires: 2003-04-05
Abstract
Abstract A plastic film is disclosed having a fine grid of embossed intersecting hand-tear lines formed in the surface of the film whereby the film may be torn by hand in more than one direction. The film is composed of a polymeric material incorporating a dispersed phase. The film is particularly suited for the manufacture of articles requiring sizing of the material in both lengthwise and widthwise direction to conform the film to a desired size.
Inventors
- 👤 Leopoldo V. Cancio
- 👤 Pai-Chuan Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:08
CPC Classifications
B; B44; B44C; B44C1/00; B44C1/10; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1007; Y10T156/1023; Y10T428/00; Y10T428/15; Y10T428/24; Y10T428/24479; Y10T428/2457; Y10T428/24612; Y10T428/25; Y10T428/26; Y10T428/28; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
126 words
A method of producing a plastic film which may be torn by hand along one or more hand-tear lines without the use of cutting tools comprising the steps of: providing a polymeric material, introducing into said polymeric material a material forming a dispersed second phase in a matrix of said polymeric material, forming said polymeric material containing said dispersed second phase into a film, and embossing said film to form a series of substantially parallel continuous, imperforate hand-tear lines of reduced film thickness therein, said lines being spaced less than about 1/16" apart, said material forming said dispersed second phase being present in said film in an amount effective to initiate and propagate tear along said hand-tear lines by hand-tearing without the use of cutting tools.
Claim 2
Independent Claim
126 words
A method of producing a plastic film which may be torn by hand along one or more hand-tear lines without the use of cutting tools comprising the steps of: providing a polymeric material, introducing into said polymeric material a material forming a dispersed second phase in a matrix of said polymeric material, forming said polymeric material containing said dispersed second phase into a film, and embossing said film to form a series of substantially parallel continuous, imperforate hand-tear lines of reduced film thickness therein, said lines being spaced less than about 1/16" apart, said material forming said dispersed second phase being present in said film in an amount effective to initiate and propagate tear along said hand-tear lines by hand-tearing without the use of cutting tools.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said film is formed of a polymeric material chosen from the group consisting of polyolefins, copolymers of polyolefins and blends thereof.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said material forming said dispersed phase is calcium carbonate.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said polymeric material is low density polyethylene and said material forming said dispersed phase is calcium carbonate.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein said film is composed of about 50-60% by weight low density polyethylene and about 40-50% by weight calcium carbonate.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein said material forming said dispersed phase is a polyester copolymer of terephthalic acid, ethylene glycol and cyclohexane dimethanol.
Claim 8
Dependent Claim
16 words
The method of claim 1 further comprising applying an adhesive to one side of said film.
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein said film is co-extruded with another polymer.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein said film is laminated to another sheet material.
Claim 11
Dependent Claim
13 words
The method of claim 9 wherein said lamination is achieved by extrusion coating.
Claim 12
Dependent Claim
12 words
The method of claim 9 wherein said another sheet material is paper.
Claim 13
Dependent Claim
16 words
The method of claim 1 wherein said film is formed and embossed by a melt-embossing process.
Claim 14
Dependent Claim
39 words
The method of claim 1 wherein said film is embossed with a pattern of intersecting hand-tear lines and wherein said film may be torn in at least two directions by hand with generally the same degree of tearing force.
Claim 15
Dependent Claim
89 words
A hand-tearable plastic film which may be torn by hand along one or more hand-tear lines without the use of cutting tools comprising an embossed polymeric film having a series of substantially parallel continuous imperforate hand-tear lines of reduced film thickness spaced less than about 1/16 inch apart, said film being formed of a polymeric matrix containing a dispersed second phase in an amount effective to initiate and propagate tear along said hand-tear lines such that said film may be torn by hand without the use of cutting tools.
Claim 16
Dependent Claim
89 words
A hand-tearable plastic film which may be torn by hand along one or more hand-tear lines without the use of cutting tools comprising an embossed polymeric film having a series of substantially parallel continuous imperforate hand-tear lines of reduced film thickness spaced less than about 1/16 inch apart, said film being formed of a polymeric matrix containing a dispersed second phase in an amount effective to initiate and propagate tear along said hand-tear lines such that said film may be torn by hand without the use of cutting tools.
Claim 17
Dependent Claim
23 words
The hand-tearable plastic film of claim 14 wherein said film is a melt-embossed film of from about 1 to 10 mils in thickness.
Claim 18
Dependent Claim
25 words
The hand-tearable plastic film of claim 14 wherein said dispersed second phase is calcium carbonate in an amount of at least about 40% by weight.
Claim 19
Dependent Claim
20 words
The hand-tearable plastic film of claim 16 wherein the calcium carbonate has an average particle size of about 12 microns.
Claim 20
Dependent Claim
24 words
The hand-tearable plastic film of claim 14 wherein said polymeric matrix chosen from the group consisting of polyolefins, copolymers of polyolefins and blends thereof.
Claim 21
Dependent Claim
26 words
The hand-tearable plastic film of claim 14 wherein said polymeric matrix is formed of low density polyethylene with calcium carbonate dispersed therein as said second phase.
Claim 22
Dependent Claim
81 words
The hand-tearable plastic film of claim 14 wherein said film has substantially parallel free lengthwise edges extending in the machine direction of said film and a widthwise direction perpendicular thereto and including a first set of hand-tear lines extending in said widthwise direction from lengthwise edge to lengthwise edge, and a second set of hand-tear lines intersecting said first set of hand-tear lines perpendicularly, said film being sizable by hand in two directions with generally the same degree of tearing force.
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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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |