US20190009970A1 - Paperboard, paperboard container, and method for using a paperboard article - Google Patents

Paperboard, paperboard container, and method for using a paperboard article Download PDF

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Publication number
US20190009970A1
US20190009970A1 US16/023,754 US201816023754A US2019009970A1 US 20190009970 A1 US20190009970 A1 US 20190009970A1 US 201816023754 A US201816023754 A US 201816023754A US 2019009970 A1 US2019009970 A1 US 2019009970A1
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United States
Prior art keywords
paperboard
density polyethylene
major side
container
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/023,754
Inventor
Chitai C. Yang
Rahul Bhardwaj
Chester E. Alkiewicz
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WestRock MWV LLC
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WestRock MWV LLC
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Publication date
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Priority to US16/023,754 priority Critical patent/US20190009970A1/en
Assigned to WESTROCK MWV, LLC reassignment WESTROCK MWV, LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ALKIEWICZ, CHESTER E., BHARDWAJ, RAHUL, YANG, Chitai C.
Publication of US20190009970A1 publication Critical patent/US20190009970A1/en
Abandoned legal-status Critical Current

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    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/10Coatings without pigments
    • D21H19/14Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
    • D21H19/20Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D81/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D81/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package
    • B65D81/3446Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package specially adapted to be heated by microwaves
    • B65D81/3453Rigid containers, e.g. trays, bottles, boxes, cups
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/10Coatings without pigments
    • D21H19/14Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
    • D21H19/20Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D21H19/22Polyalkenes, e.g. polystyrene
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/36Coatings with pigments
    • D21H19/38Coatings with pigments characterised by the pigments
    • D21H19/40Coatings with pigments characterised by the pigments siliceous, e.g. clays
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/36Coatings with pigments
    • D21H19/44Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
    • D21H19/56Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/80Paper comprising more than one coating
    • D21H19/82Paper comprising more than one coating superposed
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00Special paper not otherwise provided for, e.g. made by multi-step processes
    • D21H27/10Packing paper
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3401Cooking or heating method specially adapted to the contents of the package
    • B65D2581/3435Package specially adapted for defrosting the contents by microwave heating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves

Definitions

  • This application relates to polymer coated paperboard and, more particularly, to polymer coated paperboard that can be converted into containers suitable for food heating or cooking by way of microwave radiation.
  • Extrusion coating of low-density polyethylene was first used to coat butcher paper in the 1950s, and low-density polyethylene is widely used as a barrier coating for hot and cold beverage cups and in a variety of other applications.
  • Polypropylene resin has been used in all-plastic containers for microwave heating of foods.
  • Polypropylene coated paperboard can be converted into containers or cups suitable for food heating or cooking by way of microwave radiation.
  • the extrusion coating of polypropylene onto paperboard and the converting of the polypropylene coated paperboard into containers and cups has created challenges for the paperboard industry.
  • a mixture of polypropylene with 20% low-density polyethylene is coated on paperboard to make polymer coated paperboard that can be converted into containers suitable for food heating or cooking by way of microwave radiation.
  • the disclosed method for using a paperboard article includes heating a paperboard article by way of microwave radiation.
  • the paperboard article includes a paperboard substrate having a first major side and a second major side and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate.
  • the disclosed paperboard container includes a paperboard substrate having a first major side facing an interior of the paperboard container and a second major side facing an exterior of the paperboard container, and one or more high-density polyethylene layers directly on the first major side of the paperboard substrate.
  • a paperboard consisting of a paperboard substrate having a first major side and a second major side, one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate, and optionally, a clay coating layer between the paperboard substrate and the one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate.
  • FIG. 1 is a cross-section of a paperboard according to a first embodiment
  • FIG. 2 is a cross-section of a paperboard according to a second embodiment
  • FIG. 3 is a cross-section of a paperboard according to a third embodiment
  • FIG. 4 is a cross-section of a paperboard according to a fourth embodiment
  • FIG. 5 is a cross-section of a paperboard according to a fifth embodiment
  • FIG. 6 is a cross-section of a paperboard according to a sixth embodiment
  • FIG. 7 is a cross-section of a paperboard according to a seventh embodiment
  • FIG. 8 is a cross-section of a paperboard according to an eighth embodiment
  • FIG. 9 is a schematic view of an extrusion coating system for coating a high-density polyethylene layer onto a paperboard substrate
  • FIG. 10 is a top view of an unprinted sidewall blank
  • FIG. 11 is a top view of a printed sidewall blank having indicia printed on a major side thereof;
  • FIG. 12 is a perspective view of an embodiment of an exemplary paperboard container
  • FIG. 13 is a cross-sectional side view of the paperboard container of FIG. 12 ;
  • FIG. 14 is a perspective view of a lid of the paperboard container of FIG. 12 ;
  • FIG. 15 is a perspective view of another embodiment of an exemplary paperboard container
  • FIG. 16 is a cross-sectional side view of the paperboard container of FIG. 15 ;
  • FIG. 17 is a graph relating to a polymer extrusion coating trial showing a melt curtain neck-in of a paperboard having a high-density polyethylene coating compared to a melt curtain neck-in of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 18 is a graph relating to a polymer extrusion coating trial showing a corona treatment level of a paperboard having a high-density polyethylene coating compared to a corona treatment level of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 19 is a graph relating to a polymer extrusion coating trial showing a Coefficient of Friction (CoF) of a paperboard having a high-density polyethylene coating compared to a Coefficient of Friction (CoF) of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 20 is a graph relating to a polymer extrusion coating trial showing an abrasion resistance of a paperboard having a high-density polyethylene coating compared to an abrasion resistance of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 21 is a graph relating to a polymer extrusion coating trial showing a Water Vapor Transmission Rate (WVTR) of a paperboard having a high-density polyethylene coating compared to a Water Vapor Transmission Rate (WVTR) of a paperboard having a polypropylene/low-density polyethylene coating; and
  • WVTR Water Vapor Transmission Rate
  • FIG. 22 is a graph relating to a polymer extrusion coating trial showing a cup forming heat sealing profile of a paperboard having a high-density polyethylene coating compared to a cup forming heat sealing profile of a paperboard having a polypropylene/low-density polyethylene coating.
  • a paperboard includes a paperboard substrate having a first major side and a second major side, and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate.
  • the paperboard may further include a clay coating layer between the paperboard substrate and the one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate.
  • FIG. 1 is a cross-section of a paperboard 10 according to a first embodiment.
  • the paperboard 10 includes a paperboard substrate 11 having a first major side 12 and a second major side 13 and a high-density polyethylene layer 15 on the first major side 12 of the paperboard substrate 11 .
  • the high-density polyethylene layer 15 may be directly, i.e. with no intervening layer, disposed on the first major side 12 of the paperboard substrate 11 .
  • the high-density polyethylene layer 15 may be disposed at an outermost surface of the paperboard 10 at the first major side 12 .
  • the paperboard substrate 11 may be disposed at an outermost surface of the paperboard 10 at the second major side 13 .
  • FIG. 2 is a cross-section of a paperboard 20 according to a second embodiment.
  • the paperboard 20 includes a paperboard substrate 21 having a first major side 22 and a second major side 23 , a clay coating layer 24 on the first major side 22 of the paperboard substrate 21 , and a high-density polyethylene layer 25 on the clay coating layer 24 .
  • the clay coating layer 24 may be directly, i.e. with no intervening layer, disposed on the first major side 22 of the paperboard substrate 21 .
  • the high-density polyethylene layer 25 may be directly, i.e. with no intervening layer, disposed on the clay coating layer 24 .
  • the high-density polyethylene layer 25 may be disposed at an outermost surface of the paperboard 20 at the first major side 22 .
  • the paperboard substrate 21 may be disposed at an outermost surface of the paperboard 20 at the second major side 23 .
  • FIG. 3 is a cross-section of a paperboard 30 according to a third embodiment.
  • the paperboard 30 includes a paperboard substrate 31 having a first major side 32 and a second major side 33 , a high-density polyethylene layer 35 on the first major side 32 of the paperboard substrate 31 , and a clay coating layer 36 on the second major side 33 of the paperboard substrate 31 .
  • the high-density polyethylene layer 35 may be directly, i.e. with no intervening layer, disposed on the first major side 32 of the paperboard substrate 31 .
  • the clay coating layer 36 may be directly, i.e. with no intervening layer, disposed on the second major side 33 of the paperboard substrate 31 .
  • the high-density polyethylene layer 35 may be disposed at an outermost surface of the paperboard 30 at the first major side 32 .
  • the clay coating layer 36 may be disposed at an outermost surface of the paperboard 30 at the second major side 33 .
  • FIG. 4 is a cross-section of a paperboard 40 according to a fourth embodiment.
  • the paperboard 40 includes a paperboard substrate 41 having a first major side 42 and a second major side 43 , a first clay coating layer 44 on the first major side 42 of the paperboard substrate 41 , and high-density polyethylene layer 45 on the first clay coating layer 44 , and a second clay coating layer 46 on the second major side 43 of the paperboard substrate 41 .
  • the first clay coating layer 44 may be directly, i.e. with no intervening layer, disposed on the first major side 42 of the paperboard substrate 41 .
  • the high-density polyethylene layer 45 may be directly, i.e. with no intervening layer, disposed on the first clay coating layer 44 .
  • the second clay coating layer 46 may be directly, i.e. with no intervening layer, disposed on the second major side 43 of the paperboard substrate 41 .
  • the high-density polyethylene layer 45 may be disposed at an outermost surface of the paperboard 40 at the first major side 42 .
  • the second clay coating layer 46 may be disposed at an outermost surface of the paperboard 40 at the second major side 43 .
  • FIG. 5 is a cross-section of a paperboard 50 according to a fifth embodiment.
  • the paperboard 50 includes a paperboard substrate 51 having a first major side 52 and a second major side 53 , a first high-density polyethylene layer 55 on the first major side 52 of the paperboard substrate 51 , and a second high-density polyethylene layer 57 on the second major side 53 of the paperboard substrate 51 .
  • the first high-density polyethylene layer 55 may be directly, i.e. with no intervening layer, disposed on the first major side 52 of the paperboard substrate 51 .
  • the second high-density polyethylene layer 57 may be directly, i.e. with no intervening layer, disposed on the second major side 53 of the paperboard substrate 51 .
  • the first high-density polyethylene layer 55 may be disposed at an outermost surface of the paperboard 50 at the first major side 52 .
  • the second high-density polyethylene layer 57 may be disposed at an outermost surface of the paperboard 50 at the second major side 53 .
  • FIG. 6 is a cross-section of a paperboard 60 according to a sixth embodiment.
  • the paperboard 60 includes a paperboard substrate 61 having a first major side 62 and a second major side 63 , a clay coating layer 64 on the first major side 62 of the paperboard substrate 61 , a first high-density polyethylene layer 65 on the clay coating layer 64 , and a second high-density polyethylene layer 67 on the second major side 63 of the paperboard substrate 61 .
  • the clay coating layer 64 may be directly, i.e. with no intervening layer, disposed on the first major side 62 of the paperboard substrate 61 .
  • the first high-density polyethylene layer 65 may be directly, i.e.
  • the second high-density polyethylene layer 67 may be directly, i.e. with no intervening layer, disposed on the second major side 63 of the paperboard substrate 61 .
  • the first high-density polyethylene layer 65 may be disposed at an outermost surface of the paperboard 60 at the first major side 62 .
  • the second high-density polyethylene layer 67 may be disposed at an outermost surface of the paperboard 60 at the second major side 63 .
  • FIG. 7 is a cross-section of a paperboard 70 according to a seventh embodiment.
  • the paperboard 70 includes a paperboard substrate 71 having a first major side 72 and a second major side 73 , a first high-density polyethylene layer 75 on the first major side 72 of the paperboard substrate 71 , a clay coating layer 76 on the second major side 73 of the paperboard substrate 71 , and a second high-density polyethylene layer 77 on the clay coating layer 76 .
  • the first high-density polyethylene layer 75 may be directly, i.e. with no intervening layer, disposed on the first major side 72 of the paperboard substrate 71 .
  • the clay coating layer 76 may be directly, i.e.
  • the second high-density polyethylene layer 77 may be directly, i.e. with no intervening layer, disposed on clay coating layer 76 .
  • the first high-density polyethylene layer 75 may be disposed at an outermost surface of the paperboard 70 at the first major side 72 .
  • the second high-density polyethylene layer 77 may be disposed at an outermost surface of the paperboard 70 at the second major side 73 .
  • FIG. 8 is a cross-section of a paperboard 80 according to an eighth embodiment.
  • the paperboard 80 includes a paperboard substrate 81 having a first major side 82 and a second major side 83 , a first clay coating layer 84 on the first major side 82 of the paperboard substrate 81 , a first high-density polyethylene layer 85 on the first clay coating layer 84 , a second clay coating layer 86 on the second major side 83 of the paperboard substrate 81 , and a second high-density polyethylene layer 87 on the second clay coating layer 86 .
  • the first clay coating layer 84 may be directly, i.e. with no intervening layer, disposed on the first major side 82 of the paperboard substrate 81 .
  • the first high-density polyethylene layer 85 may be directly, i.e. with no intervening layer, disposed on the first clay coating layer 84 .
  • the second clay coating layer 86 may be directly, i.e. with no intervening layer, disposed on the second major side 83 of the paperboard substrate 81 .
  • the second high-density polyethylene layer 87 may be directly, i.e. with no intervening layer, disposed on the second clay coating layer 86 .
  • the first high-density polyethylene layer 85 may be disposed at an outermost surface of the paperboard 80 at the first major side 82 .
  • the second high-density polyethylene layer 87 may be disposed at an outermost surface of the paperboard 80 at the second major side 83 .
  • any of the high-density polyethylene layers may be substituted with multiple high-density polyethylene layers.
  • the present application includes such modifications and is limited only by the scope of the claims.
  • the paperboard substrate may include any web of fibrous material that is capable of applying a high-density polyethylene layer thereon.
  • the paperboard substrate may be bleached or unbleached.
  • the paperboard substrate may include a coated natural kraft board, a solid bleached sulfate board, a solid unbleached sulfate board, a coated recycled board, a coated white lined chipboard, or a folding boxboard.
  • the thickness of the paperboard substrate may depend on various factors, such as the density of the paperboard substrate.
  • the paperboard substrate may have a caliper thickness in a range of 6 points to 36 points (1 point equals 0.001 inch).
  • the paperboard substrate may have a caliper thickness of 7 points to 30 points.
  • the paperboard substrate may have a caliper thickness in a range of 14 points to 20 points.
  • the paperboard substrate may have a caliper thickness in a range of 16 points to 18 points.
  • 1 point equals 0.001 inches, which equals 25.4 micrometers ( ⁇ m).
  • the weight of the paperboard substrate may depend on various factors.
  • the paperboard substrate may have a basis weight ranging from 60 to 350 pounds per 3,000 square feet.
  • the paperboard substrate may have a basis weight of 100 to 150 pounds per 3000 ft 2 .
  • the paperboard substrate may have a basis weight of 150 to 180 pounds per 3000 ft 2 .
  • the paperboard substrate may have a basis weight of 180 to 220 pounds per 3000 ft 2 .
  • the clay coating layer may be applied to the paperboard substrate to improve a printing quality of a surface of the paperboard.
  • the clay coating layer may include a mixture of inorganic pigment and one or more other materials, such as binders (e.g. emulsion polymer binders) and dispersing agents.
  • binders e.g. emulsion polymer binders
  • dispersing agents e.g. kaolin clay.
  • the clay coating layer may be applied in any manner that is capable of applying the clay coating layer onto a paperboard substrate.
  • the clay coating layer may be coated onto the paperboard substrate.
  • coaters which may be employed include air knife coaters, blade coaters, rod coaters, bar coaters, multi-head coaters, roll coaters, roll/blade coaters, cast coaters, laboratory coaters, gravure coaters, kiss coaters, liquid application systems, reverse roll coaters, curtain coaters, spray coaters and extrusion coaters.
  • high-density polyethylene protects the paperboard substrate from moisture even after heating the same by way of microwave radiation.
  • the density of the high-density polyethylene of the one or more high-density polyethylene layers may range from 0.93 to 0.97 g/cm 3 . In one example, the density of the high-density polyethylene ranges from 0.95 to 0.96 g/cm 3 .
  • the high-density polyethylene may have a melt index of greater than 0.3 g/10 min (190° C./2.16 kg). In another aspect, the high-density polyethylene may have a melt index of greater than 4 g/10 min (190° C./2.16 kg). In yet another aspect, the high-density polyethylene may have a melt index of greater than 8 g/10 min (190° C./2.16 kg).
  • a first layer of the one or more high-density polyethylene layers may have a first density and first melt index
  • a second layer of the one or more high-density polyethylene layers may have a second density and second melt index different from the first density and first melt index
  • An exemplary high-density polyethylene layer is a single layer of 100% high-density polyethylene resin extrusion coated on either or both sides of the paperboard substrate, in which the high-density polyethylene has a density of 0.950 g/cm 3 per ASTM D792 and the melt index (MI) is 12 g/10 min per ASTM D1238 testing at 2.16 kg load and 190° C.
  • the one or more high-density polyethylene layers may be applied to the paperboard substrate using any available technique.
  • suitable techniques for applying the one or more high-density polyethylene layers include extrusion coating, extrusion laminate, curtain coating, and adhesive lamination.
  • multiple high-density polyethylene layers may be coextruded onto the paperboard substrate.
  • a first high-density polyethylene layer may be laminated onto the paperboard, and then a second high-density polyethylene layer may be extruded onto the paperboard.
  • a first high-density polyethylene layer may be extruded onto the paperboard, and then a second high-density polyethylene layer may be laminated onto the paperboard.
  • FIG. 9 illustrates an exemplary extrusion coating system 90 for coating a high-density polyethylene layer onto a paperboard substrate.
  • a paperboard substrate 91 may be unwound from an unwind roll 92 and passed between a nip roll 93 and a chill roll 94 and wound to a rewind roll 95 .
  • resin 96 may be extruded from a slot die 97 at elevated temperatures onto the moving paperboard substrate.
  • the resin-coated paperboard substrate 91 may then be passed through the nip roll 93 and the chill roll 94 to cool the resin 96 and impart a desired finish.
  • the coating thickness may be controlled by controlling a ratio of the speed of the moving paperboard substrate 91 and the speed at which resin 96 is extruded from the slot die 97 .
  • the composition of the one or more high-density polyethylene layers may be pure high-density polyethylene layer or may be a mixture of high-density polyethylene and one or more other materials that do not inhibit the capability of the high-density polyethylene layer from protecting the paperboard substrate from moisture even after heating the same by way of microwave radiation.
  • the one or more high-density polyethylene layers may include high-density polyethylene in an amount of 50% or greater, such as 60% or greater, 70% or greater, 80% or greater, 90% or greater, 95% or greater, 99% or greater, or 100% high-density polyethylene layer.
  • a first high-density polyethylene layer may include a first percentage of high-density polyethylene and a second high-density polyethylene layer may include a second percent of high-density polyethylene different from the first percentage of high-density polyethylene.
  • the disclosed paperboard may be made into a paperboard article using any available technique. Although various operations of making paperboard articles are described below, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.
  • the disclosed paperboard may be printed with indicia, such as high-quality advertising text and graphics, on one or both major sides by a printing operation.
  • the printing operation may include any apparatus or system capable of marking the paperboard with indicia.
  • the printing operation may include a printing press capable of printing high quality text and/or graphics (e.g., advertising text and graphics) onto the paperboard.
  • Specific examples of printing techniques include offset printing, gravure printing, flexographic printing and digital printing.
  • the disclosed paperboard may be cut into blanks by way of a cutting operation.
  • the cutting operation may include any apparatus or system capable of cutting blanks from the paperboard.
  • the cutting operation may include a die cutting machine.
  • the cutting operation may provide the blanks with the desired shape.
  • the shape of the blanks may depend on the intended shape and configuration of the paperboard article.
  • the cutting operation may cut the blanks such that the printed indicia are positioned at the desired location.
  • the blanks may be formed into a paperboard article by a forming operation.
  • the forming operation may shape and assemble one or more blanks into a paperboard article having the desired shape and configuration.
  • the forming operation may include any apparatus or system capable of forming one or more blanks into a paperboard article having the desired shape and configuration.
  • the forming operation may, for example, include a press mold or thermoforming mold.
  • An embodiment of a method for using a paperboard article may include heating the disclosed paperboard article by way of microwave radiation.
  • a paperboard article including a paperboard substrate having a first major side and a second major side, and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate may be heated by way of microwave radiation, such as by heating the paperboard article in a microwave oven.
  • a food product e.g. soup, oatmeal, coffee, water, etc.
  • the paperboard article may be a paperboard container (e.g. cup, bowl).
  • the paperboard container may have any desired container configuration.
  • paperboard container may be made from a disclosed paperboard using any available technique. Although various operations of making paperboard containers are described below, modifications may occur to those skilled in the art upon reading the specification.
  • a roll of the disclosed paperboard may be printed with indicia on one or both major sides by a printing operation, such as by way of offset printing, gravure printing, flexographic printing or digital printing.
  • the printed or unprinted paperboard may be cut into container blanks, such as sidewall blanks, bottom blanks, or lid blanks, by way of a cutting operation, such as by way of a die cutting machine.
  • FIGS. 10 and 11 illustrate exemplary sidewall blanks 100 , 110 that may be used in the manufacture of a paperboard container.
  • FIG. 10 shows an unprinted sidewall blank 100
  • FIG. 11 shows a printed sidewall blank 110 having indicia 112 printed on a major side thereof.
  • a sidewall blank 100 , 110 of FIG. 10 or 11 may be shaped by wrapping the sidewall blank 100 , 110 around a mandrel to form a frustoconical-shaped sidewall.
  • a sidewall blank may have a caliper thickness of 16 points.
  • the sidewall may be completed by overlapping and sealing longitudinal ends of the shaped sidewall blank to form an overlapped and sealed seam.
  • the seam may be sealed using any available technique.
  • the seam may be sealed by heating and connecting a first high-density polyethylene layer with a second high-density polyethylene layer at the overlapped portion.
  • the seam may be sealed by folding a first longitudinal end and heating and connecting the first high-density polyethylene layer at the first longitudinal end with the first high-density polyethylene layer at the second longitudinal end.
  • the container may include a bottom.
  • the bottom may be made from the disclosed paperboard, a different paperboard, or a non-paperboard material.
  • a bottom blank may have a caliper thickness of 13 points.
  • the bottom may be sealed to the sidewall using any available technique.
  • a lower end of the sidewall may be shaped to form a circumferential recess.
  • the bottom may be placed into the circumferential recess and sealed to the sidewall.
  • at least one of the sidewall and the bottom have a high-density polyethylene layer, which facilitates excellent sealing.
  • the container may include a lid.
  • the lid may be made from the disclosed paperboard, a different paperboard, or a non-paperboard material, such as a film material (e.g., polymer; metal; metal-polymer combination), press-on lids (e.g., molded plastic lids) and the like.
  • the lid may be sealed to the sidewall or may remain an unsealed lid.
  • the lid may be sealed to the sidewall using any available technique and may depend on, among other possible factors, the type of lid being used.
  • at least one of the sidewall and the lid have a high-density polyethylene layer, which facilitates excellent sealing.
  • a food product e.g. soup, oatmeal, etc.
  • a food product e.g. soup, oatmeal, etc.
  • the lid may be sealed to the sidewall of the paperboard container, such as with a heat-seal, an adhesive or an interference fit.
  • an upper end of a sidewall may be rolled over to form a flange and the lid may be sealed to the flange.
  • a film material may be sealed, such as by way of lamination onto the sidewall to seal the paperboard container.
  • a second non-sealing lid may be provided to cover the film material.
  • a paperboard container 120 formed from the disclosed paperboard may include a sidewall 122 , a bottom 124 and a lid 126 .
  • the sidewall 122 may be formed by, for example, die-cutting a sidewall blank from a sheet of the disclosed paperboard into the desired configuration (e.g., trapezoidal), such the sidewall blanks 100 , 110 of FIGS. 10 and 11 .
  • the sidewall blank may include a first longitudinal end and a second longitudinal end.
  • the sidewall 122 may be formed by overlapping both longitudinal ends to surround an interior cavity of the container, forming an overlapped seam 128 in which the first longitudinal end is positioned inside the second longitudinal end.
  • the seam 128 may be sealed by, for example, connecting a high-density polyethylene layer of the first longitudinal end to a high-density polyethylene layer of the second longitudinal end.
  • the bottom 124 may formed from the disclosed paperboard.
  • Various techniques may be used to seal the bottom 124 to the sidewall 122 .
  • a lower end of the sidewall 122 may be shaped to form a circumferential recess 130 .
  • the bottom 124 may be placed into the recess 130 and sealed to the sidewall 122 .
  • Suitable techniques for sealing the bottom 124 to the sidewall 122 include hot air heat seal and ultrasound sealing.
  • the lid 126 may be an unsealed plastic lid 126 .
  • the lid 126 may attach to the sidewall 122 by way of, for example, an interference fit.
  • An upper end of the sidewall 122 may be rolled over to form a bead 132 .
  • the lid 126 may be made to form an interference fit with the bead 132 at the upper end of the sidewall 122 , such that the lid 126 may be repeatedly removed and attached to cover the paperboard container 120 .
  • a paperboard container 140 formed from the disclosed paperboard may include a sidewall 142 , a bottom 144 and a lid 146 .
  • the sidewall 142 may be formed by, for example, die-cutting a sidewall blank from a sheet of the disclosed paperboard into the desired configuration (e.g., trapezoidal), such the sidewall blanks 100 , 110 of FIGS. 10 and 11 .
  • the sidewall blank may include a first longitudinal end and a second longitudinal end.
  • the sidewall 142 may be formed by overlapping both longitudinal ends to surround an interior cavity of the container, forming an overlapped seam (not shown) in which the first longitudinal end is positioned inside the second longitudinal end.
  • the seam may be sealed by, for example, connecting and heating a high-density polyethylene layer of the first longitudinal end to a high-density polyethylene layer of the second longitudinal end.
  • the bottom 144 may formed from the disclosed paperboard.
  • Various techniques may be used to seal the bottom 144 to the sidewall 142 .
  • a lower end of the sidewall 142 may be shaped to form a circumferential recess 150 .
  • the bottom 144 may be placed into the recess 150 and sealed to the sidewall 142 .
  • Suitable techniques for sealing the bottom 144 to the sidewall 142 include hot air heat seal and ultrasound sealing.
  • the lid may be sealed to the sidewall 142 .
  • the paperboard lid 146 may be made from the disclosed paperboard, a different paperboard or a different material such as a film material (e.g., polymer; metal; metal-polymer combination).
  • a film material e.g., polymer; metal; metal-polymer combination.
  • Various techniques may be used to seal the lid 146 to the sidewall 142 .
  • an upper end of the sidewall may be rolled over to form a flange 152 and the lid 146 may be sealed to the flange 152 .
  • the lid 146 may be sealed to the flange 152 by, for example, connecting and heating a high-density polyethylene layer of a paperboard lid 146 to a high-density polyethylene layer of the flange 152 .
  • a film lid 146 may be sealed to the flange 152 , by, for example, a heat-seal or an adhesive, and a second lid may
  • an exemplary paperboard container may include a food product contained in an internal volume of the paperboard container and a lid sealing the internal volume of the paperboard container.
  • the lid may be sealed using any available technique and may depend on, among other possible factors, the type of lid being used.
  • Indicia may include instructions for heating the food product by way of microwave radiation.
  • the instructions may be included with the paperboard container in any manner, such as by printing on an exterior of the paperboard container or by way of an additional packaging material attached with the paperboard container. Accordingly, the paperboard container containing the food product may be purchased by a consumer and the food product may be heated by way of microwave radiation according to the instructions while the food product is contained in the paperboard container. Additional steps may be included without departing from the scope of the present disclosure.
  • FIGS. 17-22 show comparative results of a high-density polyethylene (HDPE) coating on a paperboard substrate relative to a conventional polypropylene with 20% low-density polyethylene (PP/LDPE) coating on a paperboard substrate.
  • HDPE high-density polyethylene
  • PP/LDPE low-density polyethylene
  • FIG. 17 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate.
  • a die width for the polymer extrusion coating trial was 19 inches.
  • a width of the polymer coating on the paperboard was measured after the extrusion coating process.
  • a difference between the die width (19 inches) and the width of the polymer coating on the paperboard is referred to as a total neck-in.
  • Reduced neck-in is favorable for a polymer extrusion process to increase material utilization by reducing trim waste.
  • the HDPE extrusion coating showed much less total neck-in (1.5 inches) than PP/LDPE (3.6 inches).
  • the HDPE extrusion coating shows better process performance by increasing material utilization than the PP/LDPE extrusion coating.
  • FIG. 18 relates to polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate.
  • Corona treatment was imparted onto the polymer coating surface after extrusion.
  • Polymer surface energy measured by dyne level was monitored over a period of 28 days (4 weeks).
  • a higher dyne level is favorable for a polymer coating surface to ensure easy printability on the polymer surface.
  • the HDPE surface can be Corona-treated initially at a higher dyne level than the PP/LDPE surface.
  • the dyne level also decays slower for the HDPE surface than the PP/LDPE surface.
  • the HDPE coating shows better printability characteristics than the PP/LDPE coating.
  • FIG. 19 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate.
  • Coefficient of Friction was measured as a frictional force to slide two surfaces, i.e. the polymer coating and a polymer coating of the same type.
  • a lower CoF is favorable to reduce a force required to facilitate slide two polymer surfaces against each other.
  • Static CoF is a measure of the initial force required to begin the sliding movement.
  • Kinetic CoF is a measure of force required to maintain the movement.
  • the HDPE surface shows a lower static CoF and a lower kinetic CoF than the PP/LDPE surface. This implies that HDPE surface would be more favorable in converting and packaging processes.
  • FIG. 20 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate.
  • the abrasion resistance of a polymer coating surface was tested by subjecting the polymer surface to a 2-lb weight sled sliding and rubbing reciprocally 999 times.
  • the high-density polyethylene surface showed better abrasion resistant than the polypropylene/low-density polyethylene surface as less material was lost due to rubbing.
  • FIG. 21 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate.
  • Water Vapor Transmission Rate (WVTR) also known as Moisture Vapor Transmission Rate (MVTR) of the polymer coated paperboard was measured at 100° F. (37.8° C.) and 90% RH (Relative Humidity) conditions.
  • WVTR is a measure of water vapor transmission though a substrate.
  • high-density polyethylene shows lower WVTR than polypropylene/low-density polyethylene. This implies that high-density polyethylene has better moisture resistance or water vapor barrier property than polypropylene/low-density polyethylene.
  • FIG. 22 relates to a polymer extrusion coating trial conducted on solid bleached sulfate paperboard substrates.
  • the polymer coated paperboards were then cut into sidewall blanks and bottom blanks suitable for 16-oz beverage cup forming.
  • the cup converting trial was conducted on a PMC-1250 cup forming machine at a speed of 165 cups per minute.
  • the sidewall temperature settings were varied.
  • the fiber tear of cup side-seam sealing was measured as an indication of side-seam heat seal performance.
  • high-density polyethylene coated paperboard can heat-seal at lower temperature and shows better fiber tear than polypropylene/low-density polyethylene coated paperboard at the same cup converting speed.
  • Tables 1 and 2 relates to polymer extrusion coating trial conducted on a one-side kaolin clay coated paperboard for sidewall stock and solid bleached sulfate paperboard for bottom stock.
  • the sidewall and bottom stock rolls were cut to proper sizes suitable for forming 12-oz and 17-oz cups.
  • high-density polyethylene coated paperboard formed and sealed at lower sidewall temperatures and faster converting speeds.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Dispersion Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Food Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Wrappers (AREA)
  • Cookers (AREA)
  • Package Specialized In Special Use (AREA)

Abstract

A method for using a paperboard article includes heating a paperboard article by way of microwave radiation. The paperboard article includes a paperboard substrate having a first major side and a second major side and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate.

Description

    FIELD
  • This application relates to polymer coated paperboard and, more particularly, to polymer coated paperboard that can be converted into containers suitable for food heating or cooking by way of microwave radiation.
  • BACKGROUND
  • Extrusion coating of low-density polyethylene was first used to coat butcher paper in the 1950s, and low-density polyethylene is widely used as a barrier coating for hot and cold beverage cups and in a variety of other applications.
  • Polypropylene resin has been used in all-plastic containers for microwave heating of foods. Polypropylene coated paperboard can be converted into containers or cups suitable for food heating or cooking by way of microwave radiation. However, the extrusion coating of polypropylene onto paperboard and the converting of the polypropylene coated paperboard into containers and cups has created challenges for the paperboard industry. To address the challenges with extrusion coating of polypropylene onto paperboard and converting of the polypropylene coated paperboard, a mixture of polypropylene with 20% low-density polyethylene is coated on paperboard to make polymer coated paperboard that can be converted into containers suitable for food heating or cooking by way of microwave radiation.
  • Those skilled in the art continue with research and developments efforts in the field of polymer coated paperboard.
  • SUMMARY
  • In one aspect, the disclosed method for using a paperboard article includes heating a paperboard article by way of microwave radiation. The paperboard article includes a paperboard substrate having a first major side and a second major side and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate.
  • In another aspect, the disclosed paperboard container includes a paperboard substrate having a first major side facing an interior of the paperboard container and a second major side facing an exterior of the paperboard container, and one or more high-density polyethylene layers directly on the first major side of the paperboard substrate.
  • In another aspect, disclosed is a paperboard consisting of a paperboard substrate having a first major side and a second major side, one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate, and optionally, a clay coating layer between the paperboard substrate and the one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate.
  • Other aspects of the disclosed paperboard, paperboard container, and method for using a paperboard article will become apparent from the following description, the accompanying drawings and the appended claims.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a cross-section of a paperboard according to a first embodiment;
  • FIG. 2 is a cross-section of a paperboard according to a second embodiment;
  • FIG. 3 is a cross-section of a paperboard according to a third embodiment;
  • FIG. 4 is a cross-section of a paperboard according to a fourth embodiment;
  • FIG. 5 is a cross-section of a paperboard according to a fifth embodiment;
  • FIG. 6 is a cross-section of a paperboard according to a sixth embodiment;
  • FIG. 7 is a cross-section of a paperboard according to a seventh embodiment;
  • FIG. 8 is a cross-section of a paperboard according to an eighth embodiment;
  • FIG. 9 is a schematic view of an extrusion coating system for coating a high-density polyethylene layer onto a paperboard substrate;
  • FIG. 10 is a top view of an unprinted sidewall blank;
  • FIG. 11 is a top view of a printed sidewall blank having indicia printed on a major side thereof;
  • FIG. 12 is a perspective view of an embodiment of an exemplary paperboard container;
  • FIG. 13 is a cross-sectional side view of the paperboard container of FIG. 12;
  • FIG. 14 is a perspective view of a lid of the paperboard container of FIG. 12;
  • FIG. 15 is a perspective view of another embodiment of an exemplary paperboard container;
  • FIG. 16 is a cross-sectional side view of the paperboard container of FIG. 15;
  • FIG. 17 is a graph relating to a polymer extrusion coating trial showing a melt curtain neck-in of a paperboard having a high-density polyethylene coating compared to a melt curtain neck-in of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 18 is a graph relating to a polymer extrusion coating trial showing a corona treatment level of a paperboard having a high-density polyethylene coating compared to a corona treatment level of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 19 is a graph relating to a polymer extrusion coating trial showing a Coefficient of Friction (CoF) of a paperboard having a high-density polyethylene coating compared to a Coefficient of Friction (CoF) of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 20 is a graph relating to a polymer extrusion coating trial showing an abrasion resistance of a paperboard having a high-density polyethylene coating compared to an abrasion resistance of a paperboard having a polypropylene/low-density polyethylene coating;
  • FIG. 21 is a graph relating to a polymer extrusion coating trial showing a Water Vapor Transmission Rate (WVTR) of a paperboard having a high-density polyethylene coating compared to a Water Vapor Transmission Rate (WVTR) of a paperboard having a polypropylene/low-density polyethylene coating; and
  • FIG. 22 is a graph relating to a polymer extrusion coating trial showing a cup forming heat sealing profile of a paperboard having a high-density polyethylene coating compared to a cup forming heat sealing profile of a paperboard having a polypropylene/low-density polyethylene coating.
  • DETAILED DESCRIPTION
  • A paperboard includes a paperboard substrate having a first major side and a second major side, and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate. The paperboard may further include a clay coating layer between the paperboard substrate and the one or more high-density polyethylene layers on one or both of the first major side and the second major side of the paperboard substrate.
  • FIG. 1 is a cross-section of a paperboard 10 according to a first embodiment. The paperboard 10 includes a paperboard substrate 11 having a first major side 12 and a second major side 13 and a high-density polyethylene layer 15 on the first major side 12 of the paperboard substrate 11. The high-density polyethylene layer 15 may be directly, i.e. with no intervening layer, disposed on the first major side 12 of the paperboard substrate 11. The high-density polyethylene layer 15 may be disposed at an outermost surface of the paperboard 10 at the first major side 12. The paperboard substrate 11 may be disposed at an outermost surface of the paperboard 10 at the second major side 13.
  • FIG. 2 is a cross-section of a paperboard 20 according to a second embodiment. The paperboard 20 includes a paperboard substrate 21 having a first major side 22 and a second major side 23, a clay coating layer 24 on the first major side 22 of the paperboard substrate 21, and a high-density polyethylene layer 25 on the clay coating layer 24. The clay coating layer 24 may be directly, i.e. with no intervening layer, disposed on the first major side 22 of the paperboard substrate 21. The high-density polyethylene layer 25 may be directly, i.e. with no intervening layer, disposed on the clay coating layer 24. The high-density polyethylene layer 25 may be disposed at an outermost surface of the paperboard 20 at the first major side 22. The paperboard substrate 21 may be disposed at an outermost surface of the paperboard 20 at the second major side 23.
  • FIG. 3 is a cross-section of a paperboard 30 according to a third embodiment. The paperboard 30 includes a paperboard substrate 31 having a first major side 32 and a second major side 33, a high-density polyethylene layer 35 on the first major side 32 of the paperboard substrate 31, and a clay coating layer 36 on the second major side 33 of the paperboard substrate 31. The high-density polyethylene layer 35 may be directly, i.e. with no intervening layer, disposed on the first major side 32 of the paperboard substrate 31. The clay coating layer 36 may be directly, i.e. with no intervening layer, disposed on the second major side 33 of the paperboard substrate 31. The high-density polyethylene layer 35 may be disposed at an outermost surface of the paperboard 30 at the first major side 32. The clay coating layer 36 may be disposed at an outermost surface of the paperboard 30 at the second major side 33.
  • FIG. 4 is a cross-section of a paperboard 40 according to a fourth embodiment. The paperboard 40 includes a paperboard substrate 41 having a first major side 42 and a second major side 43, a first clay coating layer 44 on the first major side 42 of the paperboard substrate 41, and high-density polyethylene layer 45 on the first clay coating layer 44, and a second clay coating layer 46 on the second major side 43 of the paperboard substrate 41. The first clay coating layer 44 may be directly, i.e. with no intervening layer, disposed on the first major side 42 of the paperboard substrate 41. The high-density polyethylene layer 45 may be directly, i.e. with no intervening layer, disposed on the first clay coating layer 44. The second clay coating layer 46 may be directly, i.e. with no intervening layer, disposed on the second major side 43 of the paperboard substrate 41. The high-density polyethylene layer 45 may be disposed at an outermost surface of the paperboard 40 at the first major side 42. The second clay coating layer 46 may be disposed at an outermost surface of the paperboard 40 at the second major side 43.
  • FIG. 5 is a cross-section of a paperboard 50 according to a fifth embodiment. The paperboard 50 includes a paperboard substrate 51 having a first major side 52 and a second major side 53, a first high-density polyethylene layer 55 on the first major side 52 of the paperboard substrate 51, and a second high-density polyethylene layer 57 on the second major side 53 of the paperboard substrate 51. The first high-density polyethylene layer 55 may be directly, i.e. with no intervening layer, disposed on the first major side 52 of the paperboard substrate 51. The second high-density polyethylene layer 57 may be directly, i.e. with no intervening layer, disposed on the second major side 53 of the paperboard substrate 51. The first high-density polyethylene layer 55 may be disposed at an outermost surface of the paperboard 50 at the first major side 52. The second high-density polyethylene layer 57 may be disposed at an outermost surface of the paperboard 50 at the second major side 53.
  • FIG. 6 is a cross-section of a paperboard 60 according to a sixth embodiment. The paperboard 60 includes a paperboard substrate 61 having a first major side 62 and a second major side 63, a clay coating layer 64 on the first major side 62 of the paperboard substrate 61, a first high-density polyethylene layer 65 on the clay coating layer 64, and a second high-density polyethylene layer 67 on the second major side 63 of the paperboard substrate 61. The clay coating layer 64 may be directly, i.e. with no intervening layer, disposed on the first major side 62 of the paperboard substrate 61. The first high-density polyethylene layer 65 may be directly, i.e. with no intervening layer, disposed on the clay coating layer 64. The second high-density polyethylene layer 67 may be directly, i.e. with no intervening layer, disposed on the second major side 63 of the paperboard substrate 61. The first high-density polyethylene layer 65 may be disposed at an outermost surface of the paperboard 60 at the first major side 62. The second high-density polyethylene layer 67 may be disposed at an outermost surface of the paperboard 60 at the second major side 63.
  • FIG. 7 is a cross-section of a paperboard 70 according to a seventh embodiment. The paperboard 70 includes a paperboard substrate 71 having a first major side 72 and a second major side 73, a first high-density polyethylene layer 75 on the first major side 72 of the paperboard substrate 71, a clay coating layer 76 on the second major side 73 of the paperboard substrate 71, and a second high-density polyethylene layer 77 on the clay coating layer 76. The first high-density polyethylene layer 75 may be directly, i.e. with no intervening layer, disposed on the first major side 72 of the paperboard substrate 71. The clay coating layer 76 may be directly, i.e. with no intervening layer, disposed on the second major side 73 of the paperboard substrate 71. The second high-density polyethylene layer 77 may be directly, i.e. with no intervening layer, disposed on clay coating layer 76. The first high-density polyethylene layer 75 may be disposed at an outermost surface of the paperboard 70 at the first major side 72. The second high-density polyethylene layer 77 may be disposed at an outermost surface of the paperboard 70 at the second major side 73.
  • FIG. 8 is a cross-section of a paperboard 80 according to an eighth embodiment. The paperboard 80 includes a paperboard substrate 81 having a first major side 82 and a second major side 83, a first clay coating layer 84 on the first major side 82 of the paperboard substrate 81, a first high-density polyethylene layer 85 on the first clay coating layer 84, a second clay coating layer 86 on the second major side 83 of the paperboard substrate 81, and a second high-density polyethylene layer 87 on the second clay coating layer 86. The first clay coating layer 84 may be directly, i.e. with no intervening layer, disposed on the first major side 82 of the paperboard substrate 81. The first high-density polyethylene layer 85 may be directly, i.e. with no intervening layer, disposed on the first clay coating layer 84. The second clay coating layer 86 may be directly, i.e. with no intervening layer, disposed on the second major side 83 of the paperboard substrate 81. The second high-density polyethylene layer 87 may be directly, i.e. with no intervening layer, disposed on the second clay coating layer 86. The first high-density polyethylene layer 85 may be disposed at an outermost surface of the paperboard 80 at the first major side 82. The second high-density polyethylene layer 87 may be disposed at an outermost surface of the paperboard 80 at the second major side 83.
  • Although various embodiments of the paperboard are described above with reference to FIGS. 1 to 8, modifications may occur to those skilled in the art upon reading the specification. For example, in any of the above FIGS. 1 to 8, any of the high-density polyethylene layers may be substituted with multiple high-density polyethylene layers. The present application includes such modifications and is limited only by the scope of the claims.
  • The paperboard substrate may include any web of fibrous material that is capable of applying a high-density polyethylene layer thereon. The paperboard substrate may be bleached or unbleached. For example, the paperboard substrate may include a coated natural kraft board, a solid bleached sulfate board, a solid unbleached sulfate board, a coated recycled board, a coated white lined chipboard, or a folding boxboard.
  • The thickness of the paperboard substrate may depend on various factors, such as the density of the paperboard substrate. For example, the paperboard substrate may have a caliper thickness in a range of 6 points to 36 points (1 point equals 0.001 inch). As one specific example, the paperboard substrate may have a caliper thickness of 7 points to 30 points. As another specific example, the paperboard substrate may have a caliper thickness in a range of 14 points to 20 points. As yet another specific example, the paperboard substrate may have a caliper thickness in a range of 16 points to 18 points. As used herein, 1 point equals 0.001 inches, which equals 25.4 micrometers (μm).
  • The weight of the paperboard substrate may depend on various factors. For example, the paperboard substrate may have a basis weight ranging from 60 to 350 pounds per 3,000 square feet. As one specific example, the paperboard substrate may have a basis weight of 100 to 150 pounds per 3000 ft2. As another specific example, the paperboard substrate may have a basis weight of 150 to 180 pounds per 3000 ft2. As yet another specific example, the paperboard substrate may have a basis weight of 180 to 220 pounds per 3000 ft2.
  • The clay coating layer may be applied to the paperboard substrate to improve a printing quality of a surface of the paperboard. The clay coating layer may include a mixture of inorganic pigment and one or more other materials, such as binders (e.g. emulsion polymer binders) and dispersing agents. In a specific example, the clay coating layer may include kaolin clay.
  • The clay coating layer may be applied in any manner that is capable of applying the clay coating layer onto a paperboard substrate. In a specific example, the clay coating layer may be coated onto the paperboard substrate. Examples of coaters which may be employed include air knife coaters, blade coaters, rod coaters, bar coaters, multi-head coaters, roll coaters, roll/blade coaters, cast coaters, laboratory coaters, gravure coaters, kiss coaters, liquid application systems, reverse roll coaters, curtain coaters, spray coaters and extrusion coaters.
  • It was surprisingly discovered by the inventors that high-density polyethylene protects the paperboard substrate from moisture even after heating the same by way of microwave radiation.
  • The density of the high-density polyethylene of the one or more high-density polyethylene layers may range from 0.93 to 0.97 g/cm3. In one example, the density of the high-density polyethylene ranges from 0.95 to 0.96 g/cm3. In an aspect, the high-density polyethylene may have a melt index of greater than 0.3 g/10 min (190° C./2.16 kg). In another aspect, the high-density polyethylene may have a melt index of greater than 4 g/10 min (190° C./2.16 kg). In yet another aspect, the high-density polyethylene may have a melt index of greater than 8 g/10 min (190° C./2.16 kg). In one aspect, a first layer of the one or more high-density polyethylene layers may have a first density and first melt index, and a second layer of the one or more high-density polyethylene layers may have a second density and second melt index different from the first density and first melt index.
  • An exemplary high-density polyethylene layer is a single layer of 100% high-density polyethylene resin extrusion coated on either or both sides of the paperboard substrate, in which the high-density polyethylene has a density of 0.950 g/cm3 per ASTM D792 and the melt index (MI) is 12 g/10 min per ASTM D1238 testing at 2.16 kg load and 190° C.
  • The one or more high-density polyethylene layers may be applied to the paperboard substrate using any available technique. Examples of suitable techniques for applying the one or more high-density polyethylene layers include extrusion coating, extrusion laminate, curtain coating, and adhesive lamination. In an example, multiple high-density polyethylene layers may be coextruded onto the paperboard substrate. In another example, a first high-density polyethylene layer may be laminated onto the paperboard, and then a second high-density polyethylene layer may be extruded onto the paperboard. In yet another example, a first high-density polyethylene layer may be extruded onto the paperboard, and then a second high-density polyethylene layer may be laminated onto the paperboard.
  • FIG. 9 illustrates an exemplary extrusion coating system 90 for coating a high-density polyethylene layer onto a paperboard substrate. As shown, a paperboard substrate 91 may be unwound from an unwind roll 92 and passed between a nip roll 93 and a chill roll 94 and wound to a rewind roll 95. Meanwhile, resin 96 may be extruded from a slot die 97 at elevated temperatures onto the moving paperboard substrate. The resin-coated paperboard substrate 91 may then be passed through the nip roll 93 and the chill roll 94 to cool the resin 96 and impart a desired finish. The coating thickness may be controlled by controlling a ratio of the speed of the moving paperboard substrate 91 and the speed at which resin 96 is extruded from the slot die 97.
  • The composition of the one or more high-density polyethylene layers may be pure high-density polyethylene layer or may be a mixture of high-density polyethylene and one or more other materials that do not inhibit the capability of the high-density polyethylene layer from protecting the paperboard substrate from moisture even after heating the same by way of microwave radiation. For example, the one or more high-density polyethylene layers may include high-density polyethylene in an amount of 50% or greater, such as 60% or greater, 70% or greater, 80% or greater, 90% or greater, 95% or greater, 99% or greater, or 100% high-density polyethylene layer. In an example, a first high-density polyethylene layer may include a first percentage of high-density polyethylene and a second high-density polyethylene layer may include a second percent of high-density polyethylene different from the first percentage of high-density polyethylene.
  • The disclosed paperboard may be made into a paperboard article using any available technique. Although various operations of making paperboard articles are described below, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.
  • The disclosed paperboard may be printed with indicia, such as high-quality advertising text and graphics, on one or both major sides by a printing operation. The printing operation may include any apparatus or system capable of marking the paperboard with indicia. For example, the printing operation may include a printing press capable of printing high quality text and/or graphics (e.g., advertising text and graphics) onto the paperboard. Specific examples of printing techniques include offset printing, gravure printing, flexographic printing and digital printing.
  • The disclosed paperboard may be cut into blanks by way of a cutting operation. The cutting operation may include any apparatus or system capable of cutting blanks from the paperboard. For example, the cutting operation may include a die cutting machine. The cutting operation may provide the blanks with the desired shape. The shape of the blanks may depend on the intended shape and configuration of the paperboard article. Furthermore, in the case of cutting after a printing operation, the cutting operation may cut the blanks such that the printed indicia are positioned at the desired location.
  • The blanks may be formed into a paperboard article by a forming operation. The forming operation may shape and assemble one or more blanks into a paperboard article having the desired shape and configuration. The forming operation may include any apparatus or system capable of forming one or more blanks into a paperboard article having the desired shape and configuration. The forming operation may, for example, include a press mold or thermoforming mold.
  • Although various operations of making paperboard articles are described above in a specific order and as independent operations performed by separate machines or systems, it will be understood that one or more operations may be performed in a different order, that one or more operations may be combined in a single operation, that one operation may be separated into multiple operations, or that one or more operations may be performed by a single machine or system.
  • An embodiment of a method for using a paperboard article may include heating the disclosed paperboard article by way of microwave radiation. For example, a paperboard article including a paperboard substrate having a first major side and a second major side, and one or more high-density polyethylene layers on at least one of the first major side and the second major side of the paperboard substrate may be heated by way of microwave radiation, such as by heating the paperboard article in a microwave oven. A food product (e.g. soup, oatmeal, coffee, water, etc.) may be on a surface of the paperboard article during the heating of the paperboard article.
  • In an example, the paperboard article may be a paperboard container (e.g. cup, bowl). The paperboard container may have any desired container configuration.
  • It will be understood that the paperboard container may be made from a disclosed paperboard using any available technique. Although various operations of making paperboard containers are described below, modifications may occur to those skilled in the art upon reading the specification.
  • A roll of the disclosed paperboard may be printed with indicia on one or both major sides by a printing operation, such as by way of offset printing, gravure printing, flexographic printing or digital printing. The printed or unprinted paperboard may be cut into container blanks, such as sidewall blanks, bottom blanks, or lid blanks, by way of a cutting operation, such as by way of a die cutting machine. FIGS. 10 and 11 illustrate exemplary sidewall blanks 100, 110 that may be used in the manufacture of a paperboard container. FIG. 10 shows an unprinted sidewall blank 100, and FIG. 11 shows a printed sidewall blank 110 having indicia 112 printed on a major side thereof.
  • The printed or unprinted container blanks are then formed into a paperboard container by a forming operation. For example, a sidewall blank 100, 110 of FIG. 10 or 11 may be shaped by wrapping the sidewall blank 100, 110 around a mandrel to form a frustoconical-shaped sidewall. In an example, a sidewall blank may have a caliper thickness of 16 points. The sidewall may be completed by overlapping and sealing longitudinal ends of the shaped sidewall blank to form an overlapped and sealed seam. The seam may be sealed using any available technique. In an example, the seam may be sealed by heating and connecting a first high-density polyethylene layer with a second high-density polyethylene layer at the overlapped portion. In another example, the seam may be sealed by folding a first longitudinal end and heating and connecting the first high-density polyethylene layer at the first longitudinal end with the first high-density polyethylene layer at the second longitudinal end.
  • In a non-limiting embodiment, the container may include a bottom. The bottom may be made from the disclosed paperboard, a different paperboard, or a non-paperboard material. In an example, a bottom blank may have a caliper thickness of 13 points. The bottom may be sealed to the sidewall using any available technique. In an example, a lower end of the sidewall may be shaped to form a circumferential recess. The bottom may be placed into the circumferential recess and sealed to the sidewall. In a specific example, at least one of the sidewall and the bottom have a high-density polyethylene layer, which facilitates excellent sealing.
  • In a non-limiting embodiment, the container may include a lid. The lid may be made from the disclosed paperboard, a different paperboard, or a non-paperboard material, such as a film material (e.g., polymer; metal; metal-polymer combination), press-on lids (e.g., molded plastic lids) and the like. The lid may be sealed to the sidewall or may remain an unsealed lid. The lid may be sealed to the sidewall using any available technique and may depend on, among other possible factors, the type of lid being used. In a specific example, at least one of the sidewall and the lid have a high-density polyethylene layer, which facilitates excellent sealing.
  • During packaging, a food product (e.g. soup, oatmeal, etc.) may be placed into the internal volume of the paperboard container and the lid may be sealed to the sidewall of the paperboard container, such as with a heat-seal, an adhesive or an interference fit.
  • In an example, an upper end of a sidewall may be rolled over to form a flange and the lid may be sealed to the flange.
  • In another example, a film material may be sealed, such as by way of lamination onto the sidewall to seal the paperboard container. A second non-sealing lid may be provided to cover the film material.
  • Although various embodiments of paperboard containers are described below, modifications may occur to those skilled in the art upon reading the specification.
  • An embodiment of an exemplary paperboard container 120 is illustrated in FIGS. 12-14. A paperboard container 120 formed from the disclosed paperboard may include a sidewall 122, a bottom 124 and a lid 126. The sidewall 122 may be formed by, for example, die-cutting a sidewall blank from a sheet of the disclosed paperboard into the desired configuration (e.g., trapezoidal), such the sidewall blanks 100, 110 of FIGS. 10 and 11. The sidewall blank may include a first longitudinal end and a second longitudinal end. The sidewall 122 may be formed by overlapping both longitudinal ends to surround an interior cavity of the container, forming an overlapped seam 128 in which the first longitudinal end is positioned inside the second longitudinal end. The seam 128 may be sealed by, for example, connecting a high-density polyethylene layer of the first longitudinal end to a high-density polyethylene layer of the second longitudinal end.
  • The bottom 124 may formed from the disclosed paperboard. Various techniques may be used to seal the bottom 124 to the sidewall 122. As one example, a lower end of the sidewall 122 may be shaped to form a circumferential recess 130. The bottom 124 may be placed into the recess 130 and sealed to the sidewall 122. Suitable techniques for sealing the bottom 124 to the sidewall 122 include hot air heat seal and ultrasound sealing.
  • The lid 126 may be an unsealed plastic lid 126. The lid 126 may attach to the sidewall 122 by way of, for example, an interference fit. An upper end of the sidewall 122 may be rolled over to form a bead 132. The lid 126 may be made to form an interference fit with the bead 132 at the upper end of the sidewall 122, such that the lid 126 may be repeatedly removed and attached to cover the paperboard container 120.
  • Another embodiment of an exemplary paperboard container 140 is illustrated in FIGS. 15 and 16. A paperboard container 140 formed from the disclosed paperboard may include a sidewall 142, a bottom 144 and a lid 146. The sidewall 142 may be formed by, for example, die-cutting a sidewall blank from a sheet of the disclosed paperboard into the desired configuration (e.g., trapezoidal), such the sidewall blanks 100, 110 of FIGS. 10 and 11. The sidewall blank may include a first longitudinal end and a second longitudinal end. The sidewall 142 may be formed by overlapping both longitudinal ends to surround an interior cavity of the container, forming an overlapped seam (not shown) in which the first longitudinal end is positioned inside the second longitudinal end. The seam may be sealed by, for example, connecting and heating a high-density polyethylene layer of the first longitudinal end to a high-density polyethylene layer of the second longitudinal end.
  • The bottom 144 may formed from the disclosed paperboard. Various techniques may be used to seal the bottom 144 to the sidewall 142. As one example, a lower end of the sidewall 142 may be shaped to form a circumferential recess 150. The bottom 144 may be placed into the recess 150 and sealed to the sidewall 142. Suitable techniques for sealing the bottom 144 to the sidewall 142 include hot air heat seal and ultrasound sealing.
  • The lid may be sealed to the sidewall 142. The paperboard lid 146 may be made from the disclosed paperboard, a different paperboard or a different material such as a film material (e.g., polymer; metal; metal-polymer combination). Various techniques may be used to seal the lid 146 to the sidewall 142. As one example, an upper end of the sidewall may be rolled over to form a flange 152 and the lid 146 may be sealed to the flange 152. The lid 146 may be sealed to the flange 152 by, for example, connecting and heating a high-density polyethylene layer of a paperboard lid 146 to a high-density polyethylene layer of the flange 152. As another example, a film lid 146 may be sealed to the flange 152, by, for example, a heat-seal or an adhesive, and a second lid may be provided to cover the film lid 146.
  • Another embodiment of an exemplary paperboard container may include a food product contained in an internal volume of the paperboard container and a lid sealing the internal volume of the paperboard container. The lid may be sealed using any available technique and may depend on, among other possible factors, the type of lid being used. Indicia may include instructions for heating the food product by way of microwave radiation. The instructions may be included with the paperboard container in any manner, such as by printing on an exterior of the paperboard container or by way of an additional packaging material attached with the paperboard container. Accordingly, the paperboard container containing the food product may be purchased by a consumer and the food product may be heated by way of microwave radiation according to the instructions while the food product is contained in the paperboard container. Additional steps may be included without departing from the scope of the present disclosure.
  • FIGS. 17-22 show comparative results of a high-density polyethylene (HDPE) coating on a paperboard substrate relative to a conventional polypropylene with 20% low-density polyethylene (PP/LDPE) coating on a paperboard substrate.
  • FIG. 17 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate. A die width for the polymer extrusion coating trial was 19 inches. A width of the polymer coating on the paperboard was measured after the extrusion coating process. A difference between the die width (19 inches) and the width of the polymer coating on the paperboard is referred to as a total neck-in. Reduced neck-in is favorable for a polymer extrusion process to increase material utilization by reducing trim waste. In the trial, the HDPE extrusion coating showed much less total neck-in (1.5 inches) than PP/LDPE (3.6 inches). The HDPE extrusion coating shows better process performance by increasing material utilization than the PP/LDPE extrusion coating.
  • FIG. 18 relates to polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate. Corona treatment was imparted onto the polymer coating surface after extrusion. Polymer surface energy measured by dyne level was monitored over a period of 28 days (4 weeks). A higher dyne level is favorable for a polymer coating surface to ensure easy printability on the polymer surface. In this example, the HDPE surface can be Corona-treated initially at a higher dyne level than the PP/LDPE surface. The dyne level also decays slower for the HDPE surface than the PP/LDPE surface. The HDPE coating shows better printability characteristics than the PP/LDPE coating.
  • FIG. 19 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate. Coefficient of Friction (CoF) was measured as a frictional force to slide two surfaces, i.e. the polymer coating and a polymer coating of the same type. A lower CoF is favorable to reduce a force required to facilitate slide two polymer surfaces against each other. Static CoF is a measure of the initial force required to begin the sliding movement. Kinetic CoF is a measure of force required to maintain the movement. In this example, the HDPE surface shows a lower static CoF and a lower kinetic CoF than the PP/LDPE surface. This implies that HDPE surface would be more favorable in converting and packaging processes.
  • FIG. 20 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate. The abrasion resistance of a polymer coating surface was tested by subjecting the polymer surface to a 2-lb weight sled sliding and rubbing reciprocally 999 times. In this trial, the high-density polyethylene surface showed better abrasion resistant than the polypropylene/low-density polyethylene surface as less material was lost due to rubbing.
  • FIG. 21 relates to a polymer extrusion coating trial conducted on a solid bleached sulfate paperboard substrate. Water Vapor Transmission Rate (WVTR) also known as Moisture Vapor Transmission Rate (MVTR) of the polymer coated paperboard was measured at 100° F. (37.8° C.) and 90% RH (Relative Humidity) conditions. WVTR is a measure of water vapor transmission though a substrate. In this example, high-density polyethylene shows lower WVTR than polypropylene/low-density polyethylene. This implies that high-density polyethylene has better moisture resistance or water vapor barrier property than polypropylene/low-density polyethylene.
  • FIG. 22 relates to a polymer extrusion coating trial conducted on solid bleached sulfate paperboard substrates. The polymer coated paperboards were then cut into sidewall blanks and bottom blanks suitable for 16-oz beverage cup forming. The cup converting trial was conducted on a PMC-1250 cup forming machine at a speed of 165 cups per minute. The sidewall temperature settings were varied. The fiber tear of cup side-seam sealing was measured as an indication of side-seam heat seal performance. In this example, high-density polyethylene coated paperboard can heat-seal at lower temperature and shows better fiber tear than polypropylene/low-density polyethylene coated paperboard at the same cup converting speed.
  • Tables 1 and 2 relates to polymer extrusion coating trial conducted on a one-side kaolin clay coated paperboard for sidewall stock and solid bleached sulfate paperboard for bottom stock. The sidewall and bottom stock rolls were cut to proper sizes suitable for forming 12-oz and 17-oz cups. In both examples, high-density polyethylene coated paperboard formed and sealed at lower sidewall temperatures and faster converting speeds.
  • TABLE 1
    Cup Forming Heat Sealing Conditions (12 oz cup)
    Conditions
    Settings PP/LDPE Conditions HDPE Conditions
    Cup Speed (cups/min) 180 210
    Sidewall Temperature (F.) 1075 1025
  • TABLE 2
    Cup Forming Heat Sealing Conditions (17 oz cup)
    Conditions
    Settings PP/LDPE Conditions HDPE Conditions
    Cup Speed (cups/min) 125 135
    Sidewall Temperature (F.) 950 900
  • Although various embodiments of the disclosed paperboard, paperboard containers, and methods for using the same have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.

Claims (22)

What is claimed is:
1. A method for using a paperboard article, the method comprising:
heating a paperboard article by way of microwave radiation, said paperboard article comprising:
a paperboard substrate having a first major side and a second major side; and
one or more high-density polyethylene layers on at least one of said first major side and said second major side of said paperboard substrate.
2. The method of claim 1 wherein said paperboard substrate includes at least one of a coated natural kraft board, a solid bleached sulfate board, a solid unbleached sulfate board, a coated recycled board, a coated white lined chipboard, and a folding boxboard.
3. The method of claim 1 wherein said paperboard substrate has a caliper thickness in a range of 7 points to 30 points.
4. The method of claim 1 wherein at least one high-density polyethylene layer has a density in a range of between 0.93 and 0.97 g/cm3.
5. The method of claim 1 wherein at least one high-density polyethylene layer has a melt index of greater than 0.3 g/10 min (190° C./2.16 kg).
6. The method of claim 1 wherein a food product is on a surface of said paperboard article during said heating of said paperboard article.
7. The method of claim 1 wherein said paperboard article is in a configuration of a container.
8. A paperboard container comprising:
a paperboard substrate having a first major side facing an interior of said paperboard container and a second major side facing an exterior of said paperboard container; and
one or more high-density polyethylene layers directly on said first major side of said paperboard substrate.
9. The paperboard container of claim 8 wherein said paperboard substrate is disposed at an outermost surface of said second major side of said paperboard.
10. The paperboard container of claim 8 further comprising one or more high-density polyethylene layers on said second major side of said paperboard substrate.
11. The paperboard container of claim 8 further comprising a clay coating layer on said second major side of said paperboard substrate.
12. The paperboard container of claim 11 further comprising one or more high-density polyethylene layers on said clay coating layer.
13. The paperboard container of claim 8 wherein said paperboard substrate has a caliper thickness in a range of 7 points to 30 points.
14. The paperboard container of claim 8 wherein at least one high-density polyethylene layer has a density in a range of between 0.93 and 0.97 g/cm3.
15. The paperboard container of claim 8 wherein at least one high-density polyethylene layer has a melt index of greater than 0.3 g/10 min (190° C./2.16 kg).
16. The paperboard container of claim 8 wherein said paperboard container is in a configuration of a cup or a bowl.
17. The paperboard container of claim 8 wherein said paperboard container includes a food product contained in an internal volume of said paperboard container and a lid sealing said internal volume of said paperboard container.
18. The paperboard container of claim 17 wherein indicia on an exterior of said paperboard container or on a packaging material attached to said paperboard container includes instructions for heating said food product by way of microwave radiation.
19. A paperboard consisting of:
a paperboard substrate having a first major side and a second major side;
one or more high-density polyethylene layers on one or both of said first major side and said second major side of said paperboard substrate; and
optionally, a clay coating layer between said paperboard substrate and said one or more high-density polyethylene layers on one or both of said first major side and said second major side of said paperboard substrate.
20. The paperboard of claim 19 wherein said paperboard substrate has a caliper thickness in a range of 7 points to 30 points.
21. The paperboard of claim 19 wherein at least one high-density polyethylene layer has a density in a range of between 0.93 and 0.97 g/cm3.
22. The paperboard of claim 19 wherein at least one high-density polyethylene layer has a melt index of greater than 0.3 g/10 min (190° C./2.16 kg).
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021021319A1 (en) * 2019-07-30 2021-02-04 Westrock Mwv, Llc Compostable paperboard structure and method for manufacturing the same
USD980069S1 (en) 2020-07-14 2023-03-07 Ball Corporation Metallic dispensing lid
EP4031711A4 (en) * 2019-09-20 2023-10-25 Graphic Packaging International, LLC Layer structures, constructs, and methods of forming and using the same

Citations (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5095186A (en) * 1987-01-29 1992-03-10 Waldorf Corporation Method for making selectively metallized microwave heating packages
US5196269A (en) * 1990-07-13 1993-03-23 International Paper Company Paperboard laminates having polar copolymer/nonpolar polymer blend surface coatings
US5818016A (en) * 1992-05-27 1998-10-06 Conagra, Inc. Food trays and the like having press-applied coatings
US5935664A (en) * 1997-10-22 1999-08-10 Westvaco Corporation Packaging material having good moisture barrier
US5981011A (en) * 1992-01-22 1999-11-09 A*Ware Technologies, L.C. Coated sheet material
US20030152724A1 (en) * 1997-02-26 2003-08-14 Fort James Corporation Coated paperboards and paperboard containers having improved tactile and bulk insulation properties
US6670592B2 (en) * 1998-03-20 2003-12-30 Fort James Corporation Thermoformed polypropylene mineral-filled microwaveable containers having food contact compatible olfactory properties and process for their manufacture
US20040052987A1 (en) * 2002-09-12 2004-03-18 Shetty Shankara R. Paper based retortable can and method for making same
US6740373B1 (en) * 1997-02-26 2004-05-25 Fort James Corporation Coated paperboards and paperboard containers having improved tactile and bulk insulation properties
US20040105941A1 (en) * 2001-03-07 2004-06-03 Masaki Terada Packaging material and container
US20050031814A1 (en) * 2001-09-24 2005-02-10 Dawes Mark Edward Multi-layer polymeric film for packaging ovenable meals
US20070262487A1 (en) * 2006-03-10 2007-11-15 Graphic Packaging International, Inc. Injection-molded composite construct
US20080145654A1 (en) * 2002-11-27 2008-06-19 Ladislav Bednarik Enhanced adhesion of polyethylene terephthalate to paperboard
WO2010135613A1 (en) * 2009-05-21 2010-11-25 Meadwestvaco Corporation Hermetically sealed paperboard containers with enhanced barrier performance
US20140274632A1 (en) * 2013-03-14 2014-09-18 Smart Planet Technologies, Inc. Composite structures for packaging articles and related methods
US9132612B2 (en) * 2012-03-30 2015-09-15 Graphic Packaging International, Inc. Composite package
US20160348318A1 (en) * 2015-05-29 2016-12-01 International Paper Company Hydrophobic coated paper substrate for polymer emulsion topcoats and method for making same
US9522499B2 (en) * 2006-06-29 2016-12-20 Graphic Packaging International, Inc. Heat sealing systems and methods, and related articles and materials
US9527615B2 (en) * 2010-09-28 2016-12-27 Tetra Laval Holdings & Finance S.A. Method of producing a packaging material for a retortable package
US9637866B2 (en) * 2013-03-14 2017-05-02 Smart Planet Technologies, Inc. Repulpable and recyclable composite packaging articles and related methods
US20180257349A1 (en) * 2015-11-03 2018-09-13 Westrock Mwv, Llc Multifunctional paperboard structure
US20180347116A1 (en) * 2015-11-23 2018-12-06 Westrock Mwv, Llc Heat sealable coating with filler
US10590606B2 (en) * 2016-08-25 2020-03-17 Cascades Sonoco Inc. Coated paper-based substrate for containers and process for making the same

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5712006A (en) * 1995-09-13 1998-01-27 International Paper Company Non-foil polymer coated carton for packaging food and non-food products
CN1208215C (en) * 2001-02-21 2005-06-29 武汉远东绿世界集团有限公司 Easily openable paperboard can sealed thermally and its production method
JP2007062753A (en) * 2005-08-30 2007-03-15 Dainippon Printing Co Ltd Paper cup having ink permeation preventive layer
JP2007253950A (en) * 2006-03-20 2007-10-04 Dainippon Printing Co Ltd Paper cup for use in microwave oven
WO2008003025A2 (en) * 2006-06-29 2008-01-03 Graphic Packaging International, Inc. Packaging material for food items containing permeating oils
JP2010513086A (en) * 2006-12-21 2010-04-30 テトラ ラバル ホールデイングス エ フイナンス ソシエテ アノニム Packaging laminate material and method for producing packaging laminate material
BRPI0713185B1 (en) * 2007-05-02 2018-08-28 Dow Global Technologies Inc high density polyethylene composition, method for producing a high density polyethylene composition, bottle cap, method for producing a bottle cap and high density polyethylene composition
JP5151463B2 (en) * 2007-12-26 2013-02-27 凸版印刷株式会社 Composite sheet material for paper container and paper container molded using the composite sheet material
JP2009280238A (en) * 2008-05-22 2009-12-03 Toppan Printing Co Ltd Paper container
US20110178245A1 (en) * 2010-01-15 2011-07-21 Tredegar Film Products Corporation Elastic Blends of High Density Polyethylene Polymers with Olefinic Block Copolymers
WO2015009518A1 (en) * 2013-07-19 2015-01-22 Meadwestvaco Corporation Sealable paperboard container and method for manufacturing the same

Patent Citations (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5095186A (en) * 1987-01-29 1992-03-10 Waldorf Corporation Method for making selectively metallized microwave heating packages
US5196269A (en) * 1990-07-13 1993-03-23 International Paper Company Paperboard laminates having polar copolymer/nonpolar polymer blend surface coatings
US5981011A (en) * 1992-01-22 1999-11-09 A*Ware Technologies, L.C. Coated sheet material
US5818016A (en) * 1992-05-27 1998-10-06 Conagra, Inc. Food trays and the like having press-applied coatings
US6193831B1 (en) * 1993-09-20 2001-02-27 A⋆Ware Technologies, L.C. Coated sheet method
US6187389B1 (en) * 1995-01-05 2001-02-13 A*Ware Technologies, L.C. Aqueous based image receptive coating and process for producing same
US6919111B2 (en) * 1997-02-26 2005-07-19 Fort James Corporation Coated paperboards and paperboard containers having improved tactile and bulk insulation properties
US20030152724A1 (en) * 1997-02-26 2003-08-14 Fort James Corporation Coated paperboards and paperboard containers having improved tactile and bulk insulation properties
US7955670B2 (en) * 1997-02-26 2011-06-07 Dixie Consumer Products Llc Paperboard containers having improved bulk insulation properties
US6740373B1 (en) * 1997-02-26 2004-05-25 Fort James Corporation Coated paperboards and paperboard containers having improved tactile and bulk insulation properties
US20070215678A1 (en) * 1997-02-26 2007-09-20 Dixie Consumer Products Llc Paperboard containers having improved bulk insulation properties
US5935664A (en) * 1997-10-22 1999-08-10 Westvaco Corporation Packaging material having good moisture barrier
US6670592B2 (en) * 1998-03-20 2003-12-30 Fort James Corporation Thermoformed polypropylene mineral-filled microwaveable containers having food contact compatible olfactory properties and process for their manufacture
US20040105941A1 (en) * 2001-03-07 2004-06-03 Masaki Terada Packaging material and container
US20050031814A1 (en) * 2001-09-24 2005-02-10 Dawes Mark Edward Multi-layer polymeric film for packaging ovenable meals
US7824749B2 (en) * 2001-09-24 2010-11-02 Dupont Teijin Films U.S. Limited Partnership Multi-layer polymeric film for packaging ovenable meals
US20040052987A1 (en) * 2002-09-12 2004-03-18 Shetty Shankara R. Paper based retortable can and method for making same
US20080145654A1 (en) * 2002-11-27 2008-06-19 Ladislav Bednarik Enhanced adhesion of polyethylene terephthalate to paperboard
US20080145653A1 (en) * 2002-11-27 2008-06-19 Ladislav Bednarik Enhanced adhesion of polyethylene terephthalate to paperboard
US20070262487A1 (en) * 2006-03-10 2007-11-15 Graphic Packaging International, Inc. Injection-molded composite construct
US8124201B2 (en) * 2006-03-10 2012-02-28 Graphic Packaging International, Inc. Injection-molded composite construct
US9522499B2 (en) * 2006-06-29 2016-12-20 Graphic Packaging International, Inc. Heat sealing systems and methods, and related articles and materials
US20120104078A1 (en) * 2009-05-21 2012-05-03 Zhiquan Yan Hermetically Sealed Paperboard Container with Enhanced Barrier Performance
WO2010135613A1 (en) * 2009-05-21 2010-11-25 Meadwestvaco Corporation Hermetically sealed paperboard containers with enhanced barrier performance
US9527615B2 (en) * 2010-09-28 2016-12-27 Tetra Laval Holdings & Finance S.A. Method of producing a packaging material for a retortable package
US9132612B2 (en) * 2012-03-30 2015-09-15 Graphic Packaging International, Inc. Composite package
US20140274632A1 (en) * 2013-03-14 2014-09-18 Smart Planet Technologies, Inc. Composite structures for packaging articles and related methods
US9637866B2 (en) * 2013-03-14 2017-05-02 Smart Planet Technologies, Inc. Repulpable and recyclable composite packaging articles and related methods
US20160348318A1 (en) * 2015-05-29 2016-12-01 International Paper Company Hydrophobic coated paper substrate for polymer emulsion topcoats and method for making same
US9732474B2 (en) * 2015-05-29 2017-08-15 International Paper Company Hydrophobic coated paper substrate for polymer emulsion topcoats and method for making same
CN107709665A (en) * 2015-05-29 2018-02-16 国际纸业公司 Hydrophobicity for polymer emulsion top coat is coated with paper base material and preparation method thereof
US20180257349A1 (en) * 2015-11-03 2018-09-13 Westrock Mwv, Llc Multifunctional paperboard structure
US20180347116A1 (en) * 2015-11-23 2018-12-06 Westrock Mwv, Llc Heat sealable coating with filler
US10590606B2 (en) * 2016-08-25 2020-03-17 Cascades Sonoco Inc. Coated paper-based substrate for containers and process for making the same

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
CN107709665 translation (Year: 2022) *
CN114630752 translation (Year: 2022) *
JP2007253950 translation (Year: 2022) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021021319A1 (en) * 2019-07-30 2021-02-04 Westrock Mwv, Llc Compostable paperboard structure and method for manufacturing the same
US20220275585A1 (en) * 2019-07-30 2022-09-01 Westrock Mwv, Llc Compostable paperboard structure and method for manufacturing the same
EP4031711A4 (en) * 2019-09-20 2023-10-25 Graphic Packaging International, LLC Layer structures, constructs, and methods of forming and using the same
USD980069S1 (en) 2020-07-14 2023-03-07 Ball Corporation Metallic dispensing lid

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KR20200028900A (en) 2020-03-17
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CA3067595A1 (en) 2019-01-17
CN110869558A (en) 2020-03-06
JP2020526421A (en) 2020-08-31
EP3652380A1 (en) 2020-05-20

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