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US3967998A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyethylene terephthalate/paperboard laminate and method of making it, container blank formed from such laminate and container formed from such blank, and cooking method using such container

Assignee: EIDP Inc
•
Filing: 1974-05-09
•
Granted: 1976-07-06
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Expires: 1994-05-09
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Abstract

Abstract A container is provided formed from a blank made of a laminate which includes nonbrowning paperboard and at least an inner layer of substantially amorphous polyethylene terephthalate bonded to the paperboard by its own substance. A method of making this laminate is provided including the steps of heating an uncoated surface or both surfaces of the paperboard to a temperature of at least about 285°F. and extruding the polyethylene terephthalate layer onto this surface or these surfaces. A method of cooking is provided including the steps of forming a container from the blank, placing food in the container and cooking the food at a temperature of up to about 400°F.

Inventors

  • 👤 William Paul Kane

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 05:06
CPC Classifications
D; D21; D21H; D21H19/00; D21H19/10; D21H19/14; D21H19/24; D21H19/28; B; B32; B32B; B32B27/00; B65; B65D; B65D5/00; B65D5/20; B65D5/24; B65D5/248; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1049; Y10T428/00; Y10T428/31504; Y10T428/31786; Y10T428/3179; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T428/31906

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 82 words
A method of forming a container including the steps of: forming a blank formed from a laminate including paperboard having a layer of substantially amorphous polyethylene terephthalate extruded onto an uncoated surface thereof and wherein such surface is heated to a temperature of at least about 285°F. prior to such extrusion; folding the blank to bring surface portions of the amorphous polyethylene terephthalate layer thereof into abutting contact with other surface portions of such layer and heat-sealing these abutting surface portions together.
Claim 2
Independent Claim 82 words
A method of forming a container including the steps of: forming a blank formed from a laminate including paperboard having a layer of substantially amorphous polyethylene terephthalate extruded onto an uncoated surface thereof and wherein such surface is heated to a temperature of at least about 285°F. prior to such extrusion; folding the blank to bring surface portions of the amorphous polyethylene terephthalate layer thereof into abutting contact with other surface portions of such layer and heat-sealing these abutting surface portions together.
Claim 3
Independent Claim 83 words
A method of forming a container including the steps of: forming a blank formed from a laminate including paperboard having a layer of substantially amorphous polyethylene terephthalate extruded onto an uncoated surface thereof and wherein such surface is heated to a temperature of at least about 285°F. prior to such extrusion; folding the blank to bring surface portions of the amorphous polyethylene terephthalate layer thereof into abutting contact with portions of the other surface of the paperboard and heat-sealing these surface portions together.
Claim 4
Independent Claim 83 words
A method of forming a container including the steps of: forming a blank formed from a laminate including paperboard having a layer of substantially amorphous polyethylene terephthalate extruded onto an uncoated surface thereof and wherein such surface is heated to a temperature of at least about 285°F. prior to such extrusion; folding the blank to bring surface portions of the amorphous polyethylene terephthalate layer thereof into abutting contact with portions of the other surface of the paperboard and heat-sealing these surface portions together.
Claim 5
Independent Claim 101 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. prior to such extrusion; folding the blank whereby surface portions of body parts are brought into abutting contact with each other, all of such surface portions being of polyethylene terephthalate; and heat-sealing such abutting surface portions together to form a container.
Claim 6
Independent Claim 101 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. prior to such extrusion; folding the blank whereby surface portions of body parts are brought into abutting contact with each other, all of such surface portions being of polyethylene terephthalate; and heat-sealing such abutting surface portions together to form a container.
Claim 7
Dependent Claim 21 words
The method of claim 3 wherein such abutting surface portions are heat-sealed together at a temperature of at least about 320°F.
Claim 8
Independent Claim 95 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. by flame prior to such extrusion; folding the blank whereby surface portions of the body parts are brought into abutting contact with each other; and securing such abutting surface portions together to form a container.
Claim 9
Independent Claim 95 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. by flame prior to such extrusion; folding the blank whereby surface portions of the body parts are brought into abutting contact with each other; and securing such abutting surface portions together to form a container.
Claim 10
Dependent Claim 21 words
The method of claim 5 wherein such abutting surface portions are heat-sealed together at a temperature of at least about 320°F.
Claim 11
Dependent Claim 37 words
The method of claim 6 wherein at least one of each of such abutting surface portions is of the polyethylene terephthalate layer and the other of each of such abutting surface portions is of the non-browning paperboard.
Claim 12
Independent Claim 82 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. prior to such extrusion; heating the blank to a temperature of at least 320°F., and pressing the blank to form a container.
Claim 13
Independent Claim 82 words
A method of forming a container including the steps of: forming a blank including a bottom part with body parts connected thereto, such blank being formed of a laminate including paperboard having at least an extruded layer of substantially amorphous polyethylene terephthalate bonded to a surface thereof and wherein such surface is heated to a temperature of at least 285°F. prior to such extrusion; heating the blank to a temperature of at least 320°F., and pressing the blank to form a container.

References Cited (Backward Citations)

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GB1119804A Cited
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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) 1979-07-06 1980-01-05 1980-07-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-07-06 1984-01-05 1984-07-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-07-06 1988-01-05 1988-07-06 $7700.00 Window Closed / Lapsed

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