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US4076121A Expired / Lapsed US ⏱️ 0.0 years remaining

Reinforced thin wall plastic bag, and method and apparatus to make material for such bags

Assignee: Mobil Oil AS
•
Filing: 1976-02-17
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Granted: 1978-02-28
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Expires: 1996-02-17
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Abstract

Abstract A plastic bag such as trash can liners, grass and leaf bags, sandwich bags and the like is reinforced by placing spaced ribs therein, integral with the wall structure, the ribs having a rib-to-rib spacing in the order of 1/8 to 2 cm, the ribs being peaked and merging smoothly from a projecting peak to the thickness of the walls between the ribs, the peaks extending about 1.5 to 10 times the wall thickness of the film which is preferably, in the order of about 0.4 to 2.0 mils. Upon extrusion, the extrusion die is formed with small notches with rounded corners so that the ribs are extruded while the film material is extruded, and provide additional material in the region of the ribs which merges smoothly with the material being extruded to form the film. Such rib-reinforced bag structures may be produced by forming a continuous roll of such bags, the individual bags in such a roll being readily separated along predetermined lines of weakness.

Inventors

  • 👤 William J. Clayton
  • 👤 Robert H. Olson
  • 👤 Donald F. Kutniewski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 06:18
CPC Classifications
B; B65; B65D; B65D33/00; B65D33/02; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/09; B29C48/10; B29C48/12; B29C48/25; B29C48/30; B29C48/32; B31; B31B; B31B70/00; B31B70/008; B29C48/001; B29C48/0019; B29L; B29L2023/00; B29L2023/003; B31B2155/00; B31B2155/002; B31B2155/003; Y; Y10; Y10S; Y10S206/00; Y10S206/819; Y10S206/824; Y10S428/00; Y10S428/906; Y10T; Y10T428/00; Y10T428/15; Y10T428/24; Y10T428/24479; Y10T428/2457; Y10T428/24628; Y10T428/24669; Y10T428/24694

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 122 words
A continuous roll of thermoplastic bags, said bags having been fabricated from a film of low density polyethylene material having a wall thickness on the order of about 0.02 to 0.05 mm and spaced, peaked ribs integral with the film being formed in the film and having a rib-to-rib spacing on the order of 1/8 cm to 2 cm, said ribs merging smoothly from a projecting peak to the thickness of the walls between the ribs, each individual bag being joined in side-by-side relationship by a transversely positioned heat seal line and having a transversely disposed weakened area in the area of said heat seal line whereby removal of a bag from said roll is effected by tearing along said weakened area.
Claim 2
Dependent Claim 122 words
A continuous roll of thermoplastic bags, said bags having been fabricated from a film of low density polyethylene material having a wall thickness on the order of about 0.02 to 0.05 mm and spaced, peaked ribs integral with the film being formed in the film and having a rib-to-rib spacing on the order of 1/8 cm to 2 cm, said ribs merging smoothly from a projecting peak to the thickness of the walls between the ribs, each individual bag being joined in side-by-side relationship by a transversely positioned heat seal line and having a transversely disposed weakened area in the area of said heat seal line whereby removal of a bag from said roll is effected by tearing along said weakened area.
Claim 3
Dependent Claim 22 words
A roll of thermoplastic bags in accordance with claim 1, having a weakened area within the confines of said heat seal line.
Claim 4
Dependent Claim 25 words
A roll of thermoplastic bags, in accordance with claim 1, having a weakened area extending parallel to and being adjacent to said heat seal line.

References Cited (Backward Citations)

US2582294A Cited
US2750631A Cited
US3201506A Cited
US3466212A Cited
US3608815A Cited
US3707431A Cited
US3684642A Cited
GB1331354A Cited
DE2303923A1 Cited
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US4015635A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-02-27 1981-08-29 1982-02-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-02-27 1985-08-29 1986-02-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-02-27 1989-08-29 1990-02-28 $7700.00 Window Closed / Lapsed

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