WO2011090934A1 - Packaging and method of making packaging - Google Patents

Packaging and method of making packaging Download PDF

Info

Publication number
WO2011090934A1
WO2011090934A1 PCT/US2011/021533 US2011021533W WO2011090934A1 WO 2011090934 A1 WO2011090934 A1 WO 2011090934A1 US 2011021533 W US2011021533 W US 2011021533W WO 2011090934 A1 WO2011090934 A1 WO 2011090934A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
packaging
coextrusion
ethylene vinyl
substrate
Prior art date
Application number
PCT/US2011/021533
Other languages
French (fr)
Inventor
Gary H. Knauf
Original Assignee
Thilmany Llc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Thilmany Llc filed Critical Thilmany Llc
Priority to CA2797570A priority Critical patent/CA2797570A1/en
Priority to US13/521,019 priority patent/US9610755B2/en
Publication of WO2011090934A1 publication Critical patent/WO2011090934A1/en
Priority to US15/477,492 priority patent/US20170259546A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B29/00Layered products comprising a layer of paper or cardboard
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/06Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/06Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/10Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/16Layered products comprising a layer of synthetic resin specially treated, e.g. irradiated
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/28Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/30Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/30Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/308Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/32Layered products comprising a layer of synthetic resin comprising polyolefins
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/32Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/322Layered products comprising a layer of synthetic resin comprising polyolefins comprising halogenated polyolefins, e.g. PTFE
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/32Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/327Layered products comprising a layer of synthetic resin comprising polyolefins comprising polyolefins obtained by a metallocene or single-site catalyst
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/34Layered products comprising a layer of synthetic resin comprising polyamides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/36Layered products comprising a layer of synthetic resin comprising polyesters
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B29/00Layered products comprising a layer of paper or cardboard
    • B32B29/002Layered products comprising a layer of paper or cardboard as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04Interconnection of layers
    • B32B7/12Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2250/00Layers arrangement
    • B32B2250/24All layers being polymeric
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00Coating on the layer surface
    • B32B2255/10Coating on the layer surface on synthetic resin layer or on natural or synthetic rubber layer
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00Coating on the layer surface
    • B32B2255/20Inorganic coating
    • B32B2255/205Metallic coating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00Coating on the layer surface
    • B32B2255/26Polymeric coating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2270/00Resin or rubber layer containing a blend of at least two different polymers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/50Properties of the layers or laminate having particular mechanical properties
    • B32B2307/546Flexural strength; Flexion stiffness
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/70Other properties
    • B32B2307/724Permeability to gases, adsorption
    • B32B2307/7242Non-permeable
    • B32B2307/7244Oxygen barrier
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/70Other properties
    • B32B2307/724Permeability to gases, adsorption
    • B32B2307/7242Non-permeable
    • B32B2307/7248Odour barrier
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00Containers; Receptacles
    • B32B2439/70Food packaging
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31725Of polyamide
    • Y10T428/31739Nylon type
    • Y10T428/31743Next to addition polymer from unsaturated monomer[s]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31786Of polyester [e.g., alkyd, etc.]
    • Y10T428/31797Next to addition polymer from unsaturated monomers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31855Of addition polymer from unsaturated monomers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31855Of addition polymer from unsaturated monomers
    • Y10T428/3188Next to cellulosic
    • Y10T428/31895Paper or wood
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31855Of addition polymer from unsaturated monomers
    • Y10T428/31909Next to second addition polymer from unsaturated monomers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31855Of addition polymer from unsaturated monomers
    • Y10T428/31909Next to second addition polymer from unsaturated monomers
    • Y10T428/31913Monoolefin polymer
    • Y10T428/3192Next to vinyl or vinylidene chloride polymer
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31855Of addition polymer from unsaturated monomers
    • Y10T428/31909Next to second addition polymer from unsaturated monomers
    • Y10T428/31928Ester, halide or nitrile of addition polymer

Definitions

  • This disclosure relates to packaging and, in particular, to layered packaging for food or other items in which freshness is to be maintained.
  • the packaging needs to be workable in such a way that the packaging material may be quickly placed around the item to be packaged using machinery.
  • the packaging material must also be of such a quality that it adequately stores the product before the packaging is open. In the case of food products, this typically means that the packaging materials provide an oxygen barrier to maintain freshness.
  • Ethylene vinyl alcohol is an extrudable resin that has excellent oxygen, flavor, and aroma barrier properties.
  • EVOH resins and packaging materials have been used for several decades as meat and cheese film wrappers and the barrier properties of EVOH with respect to oxygen, grease, oil, flavor additives, and aroma is well understood.
  • the barrier properties of EVOH degrade.
  • the EVOH is typically extruded in a multi- layer symmetrical coextrusion in which
  • tie resins are used to adhere the EVOH to outer polyolefin layers that protect the EVOH from humidity.
  • coextrusion of EVOH may include LDPE-Tie Resin-EVOH-Tie
  • the LDPE low density polyethylene
  • the LDPE and Tie Resin are extruded each from one extruder where they are split into two layers and directed to either side of the EVOH layer by a feedblock device.
  • the LDPE and Tie Resin are exactly the same material on both sides of the EVOH, thus it is called a symmetrical coextrusion.
  • EVOH when melted, EVOH becomes fluid very quickly with very low melt strength and cannot be extruded as a separate thin film.
  • a melt curtain is formed between the exit of the extruder die and the extruder nip.
  • the melt curtain is completely unsupported in this air gap between the die and the extruder nip. Therefore, the melt curtain needs to have enough viscosity and melt strength to keep from tearing apart.
  • EVOH has traditionally required the above-described five layer structure not only to maintain its barrier properties, but also to provide adjacent structural layers (such as polyethylene) that physically support the coextruded layer of the EVOH.
  • EVOH has excellent oxygen barrier properties
  • EVOH has been considered unsuitable as a barrier layer in some applications for a number of reasons.
  • production of EVOH has required extrusion machines capable of coextruding more than two resins. Such machines are very expensive and not as common as those extruding only two resins.
  • dual tie resin and polyolefin layers are provided on both sides of the EVOH coextrusion to protect the EVOH layer from humidity; however, these multiple layers can
  • Packaging for food and a method of making the packaging is disclosed.
  • This packaging incorporates an EVOH layer which serves as an oxygen barrier to the surrounding environment.
  • the packaging does not include the symmetrical five layer coextruded structure heretofore believed to be necessary both to support an EVOH layer and to further protect this EVOH layer from moisture which can compromise its effectiveness.
  • the packaging can be formed using a standard two resin capable coextruder station which reduces the cost of fabricating the packaging - in comparison to the traditional five layer structure using a three resin coextruder station.
  • the packaging includes a substrate and an asymmetrical coextrusion attached to the substrate.
  • the asymmetrical coextrusion includes an ethylene vinyl alcohol layer that is disposed toward the substrate.
  • the packaging may further include a polymeric moisture barrier layer applied to at least one side of the substrate.
  • the polymeric barrier layer may be a polymeric moisture barrier layer and be used to protect one side of the ethylene vinyl alcohol from exposure to moisture in the packaging.
  • This polymeric barrier layer may include any of a number of materials including low density polyethylene, medium density polyethylene, high density polyethylene, linear low-density polyethylene,
  • This polymeric barrier layer may also include additives such as colorants, EVOH tie resin, and fillers such as calcium carbonate.
  • This polymeric barrier layer may also include blends or multilayered coextrusions of the above listed materials. This polymeric barrier layer is not extruded from any materials used in the asymmetrical EVOH coextrusion.
  • a surface of the polymeric barrier layer to which the ethylene vinyl alcohol layer is attached may be treated to promote attachment of the ethylene vinyl alcohol layer to the polymeric barrier layer.
  • the treatment may be a flame treatment, liquid priming, or a corona treatment.
  • the substrate may include paper or another cellulosic material.
  • the substrate may be a clear or metallized film selected from a group consisting of polyethylene terephthalate, polypropylene, nylon, and PLA (polylactic acid) films.
  • the substrate may be a lamination of paper and clear or metallized film substrates listed above.
  • the asymmetrical coextrusion may further include a tie resin and a sealant.
  • the tie resin and the sealant may be blended together to form a tie sealant resin blend.
  • the asymmetrical coextrusion may be a two layer coextrusion including the ethylene vinyl alcohol layer and a tie sealant resin blend layer which is formable using a two resin capable coextruder.
  • the asymmetrical coextrusion may include the ethylene vinyl alcohol layer, a tie resin layer, and a sealant layer. The tie resin layer may be disposed between the ethylene vinyl alcohol layer and the sealant layer forming a three layer asymmetrical coextrusion.
  • a method of making the packaging of the type described above is disclosed.
  • a substrate is provided and an asymmetrical coextrusion including an ethylene vinyl alcohol layer is extruded.
  • the ethylene vinyl alcohol layer of the asymmetrical coextrusion is attached to the substrate to form the packaging.
  • the method may further include the step of applying a polymeric barrier layer to at least a portion of at least one side of the substrate before attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging.
  • the ethylene vinyl alcohol layer may be directly attached to the polymeric barrier layer.
  • the polymeric barrier layer could be made of low density polyethylene or one or more of the materials listed above.
  • the method may further include the step of treating a surface of the polymeric barrier layer prior to attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging. Treating promotes adhesion between the polymeric barrier layer and the ethylene vinyl alcohol layer.
  • This treatment may be, for example, a flame treatment, liquid priming, or a corona treatment.
  • FIGS. 1 through 3 illustrate the layer
  • FIG. 4 illustrates an exemplary process line which may be used to make or fabricate the packaging.
  • a "-" is used to indicate layers that are coextruded with one another and "/" is used to indicate layers that are separated attached to one another.
  • FIGS. 1 through 3 a number of packaging structures are illustrated including:
  • TSRB refers to a tie resin and sealant resin blend in which the tie resin and sealant are blended together such that the blend may be coextruded as a single layer
  • EVOH-TIE-SEALANT refers to three discrete separately formed layers of EVOH, tie resin (which is a type of resin designed to adhere the EVOH and the sealant layers together) , and sealant .
  • like reference numerals are used to describe like items in which the hundreds digit has been increased to correspond to the figure number (e.g., TSRB layer 110 corresponds to TSRB layer 310) .
  • a packaging 100 includes a paper substrate 102 with a polymeric barrier layer 104 coating one side thereof and an asymmetrical coextrusion 106 having an ethylene vinyl alcohol layer 108 and a TSRB layer 110.
  • the ethylene vinyl alcohol layer 108 of the coextrusion 106 is
  • TSRB layer 110 on the opposite side of the coextrusion 106 constitutes one of the outer surfaces of the packaging 100.
  • the exposed TSRB surface could be contacted with another exposed TSRB surface and subjected to heat and pressure to form a seal there between.
  • the paper substrate may be a paper of a type having a machine glazed (MG) or a machine finished (MF) type finish, may be clay coated paper, may be of a white or a natural color, and may be of a Kraft, ground wood, recycled, or sulfite furnish.
  • the paper may include laminations of one or more layers of paper or include a clear or metallized PET, OPP,
  • Nylon Nylon, or PLA film laminated to the paper.
  • the polymeric barrier layer is low density polyethylene (LDPE) .
  • LDPE low density polyethylene
  • the polymeric barrier layer on the paper may alternatively be MDPE, HDPE, LLDPE, POP, mLLDPE, or blends thereof as well as coextrusions thereof .
  • Additives such as colors can be used.
  • Other resins can be used in place of LDPE such as PP, EVA, IONOMER, Nylon, EAA, EMAA, EMAC, EnBA, and the like.
  • EVOH tie resin can be blended into the poly layer for improved adhesion, especially if PP or
  • HDPE is used in place of LDPE. In all cases, the
  • materials used for the polymeric barrier layer are not extruded from the extruders used to make the asymmetrical EVOH coextrusion.
  • the paper and/or polymeric barrier layers may be subjected to flame treatment, corona treatment, or other such priming to ready the surfaces for attachment.
  • the ethylene vinyl alcohol may be 35 mol% ethylene EVOH (available as EVAL C109B from Eval Company of America) and the TSRB may be 50% POP (polyolefin plastomer, available as DOW PT1450 from Dow Chemical Company) , 25% tie resin (such as ADMER AT1000A available from Mitsui Chemicals America, Inc.), and 25%
  • LDPE low-density polyethylene, available as CHEVRON 1013 available from Chevron Chemical
  • the exact percentages of the constituent components may be varied depending on the temperatures, times, and pressures used to form the heat seal and the quality of the seal desired.
  • EVOH with 35 mol% or higher ethylene content is believed to provide the best results, EVOH is available in 24% ethylene to 48% ethylene content. It is contemplated that any amount of ethylene content might be used or selected based on the desired properties of the barrier or for appropriate economy. Generally speaking, the lower the ethylene content, the better the aroma and oxygen barrier provided by the EVOH layer. It is contemplated that the basis weight of the EVOH layer may be in the range of . l#/3, 000ft 2 to 10.0#/3,000 ft 2 .
  • the TSRB may have a tie resin content from 10wt% to 80wt and a polyethylene content from 20wt% to 90wt%.
  • the tie resin may be an anhydride modified LDPE based adhesive resin concentrate such as ADMER AT1000A or DUPONT BYNEL 41E170.
  • the polyethylene sealant resin may be LDPE, MDPE, HDPE, LLDPE, POP, mLLDPE and blends thereof, and copolymers of polyethylene such as, for example: EVA, IONOMER, EAA, EMAA, EMAC, EnBA, and the like.
  • TSRB can be further modified with slip, antiblock, or color concentrates depending upon customer needs .
  • the particular tie sealant resin blend selected may be configured to maximize the quality of the seal.
  • the basis weight of the TSRB layer may be in the range of
  • EVOH is not extrusion coated as its own single layer, but can be coextruded with the TSRB or, as will be described with respect to structures (2) and (3) below, the tie resin and sealant layers.
  • a benefit of using the tie sealant resin blend as in structures (1) and (3) is that a three resin capable coextruder is not required, but a two resin capable coextruder will be sufficient.
  • asymmetrical coextrusion 206 is a three layer coextrusion with the tie resin layer 214 sandwiched between the ethylene vinyl alcohol layer 208 and the sealant layer 216. This configuration eliminates any tie and sealant resin layers between the EVOH and substrate.
  • the sealant layer 216 is disposed such that it is on an attachment face (i.e., the face that will be attached to another face of the packaging) when the packaging is heat sealed.
  • Structure (3) is similar to structure (1) , except that the paper substrate 102 has been replaced with a clear polyethylene terephthalate
  • the polymeric barrier layer 304 coats at least a portion of one side of the PET film substrate 302.
  • the PET film in structure [0034] in alternative forms, the PET film in structure
  • (3) might alternatively be any kind of clear or metalized polyethylene terephthalate, polypropylene, nylon, or PLA
  • the EVOH coextrusion is asymmetrical in all forms, unlike the LDPE-Tie Resin-EVOH-Tie Resin-LDPE structures which have been previously produced.
  • the EVOH layer is initially at least partially exposed with one side of the layer being supported and protected by either the tie sealant resin blend layer or the tie resin and sealant layers.
  • this initially exposed side of the EVOH layer is attached or laminated to the substrate, or polymeric barrier coating thereon, such that this exposed face is no longer exposed.
  • the polymeric barrier layer may be eliminated and the EVOH layer directly attached to the paper substrate or PET film substrate. To some extent, the removal of the polymeric barrier layer will increase the exposure of the EVOH layer to moisture which increases the rate of oxygen or aroma transmission through the EVOH layer.
  • the PET film substrate may, at least to some degree, serve as a moisture barrier. Accordingly, by increasing either the substrate thickness and/or the EVOH layer thickness, the integrity of the product may be preserved for a longer period of time, even in the absence of the polymeric barrier layer. If the product to be housed in the packaging does not require good moisture vapor barrier, then it may be acceptable to remove the polymeric barrier layer.
  • the packaging has a structure of 25#PAPER/10#LDPE/4#EVOH- 7#TSRB. (#/ream is based on a 3,000 ft 2 ream size) The paper basis weight can range from 9#/ream to 100#/ream.
  • the paper may be Kraft paper with a machine glaze type finish and of bleached white color which may be flame treated for good adhesion of the LDPE to the paper.
  • the LDPE may be corona treated for good adhesion of the EVOH coextrusion to the LDPE coated paper.
  • the LDPE for the polymeric layer (Chevron 4517) would be of slightly higher density than the LDPE used in the TSRB (Chevron 1013) . This will provide improved moisture barrier for protection of the EVOH, while the LDPE used in the TSRB would be optimized for heat seal properties.
  • the EVOH in the 4#EVOH-7#TSRB coextrusion is 35 mol% ethylene EVOH.
  • the composition of the TSRB in the coextrusion may be tweaked.
  • the TSRB may be 25% tie resin (ADMER AT1000A) and 75% LDPE (CHEVRON 1013) .
  • ADMER AT1000A 25% tie resin
  • CHEVRON 1013 75% LDPE
  • a LDPE layer is present between the paper and the EVOH, it should be appreciated that the EVOH-TSRB coextrusion is formed from a single die and this part of the structure does not require more than a two resin coextruder station.
  • the structure of the packaging material is 25#PAPER/10#LDPE/4#EVOH-1.5#TIE-5.5# PE
  • the structure of the packaging material is 25#PAPER/l0#LDPE/l#TIE-4#EVOH-l#TIE-5# PE SEALANT to introduce a tie layer between the EVOH and the
  • the type of polyethylene in the polymeric layer can be different than the LDPE used in the sealant and the thickness of the LDPE layer can be independently adjusted to optimize product performance .
  • a line 400 for making the packaging is disclosed.
  • the line 400 is disclosed.
  • the line 400 includes two sections.
  • the first section forms a coated substrate including the paper or PET layer with the polymeric barrier layer coated there on.
  • the second section then applies the EVOH coextrusion to the coated substrate.
  • the first section of the line 400 prepares the substrate, which may be, for example, the paper or PET film substrate.
  • the substrate is unrolled from a main substrate roll 402 and fed toward an extrusion coater 406 which coats the substrate with the polymeric barrier layer.
  • the substrate from the main substrate roll 402 is fed past a treater 404 such as a flame treater or a corona treater that treats the surface of the substrate from the main substrate roll 402 such that the polymeric barrier layer created at the extrusion coater 406 will adhere well to the substrate.
  • a liquid primer might also be applied to treat the surface.
  • the substrate is fed through a nip point at which point the polymeric barrier layer is applied on the substrate as a melt curtain.
  • the nip point occurs between a rubber nip roll 410 and a chill roll 412.
  • a die 412 supplies a molten resin A (which may be, for example, low density polyethylene or any of the polymeric barrier materials listed above) as a melt curtain.
  • This molten resin A is applied to a top surface of the substrate at the nip point, is cooled by the chill roll 410 to form a substrate / polymeric barrier layer structure, and then this coated substrate exits the extrusion coater 406.
  • the line 400 is shown including the extrusion coater 406 for the formation of the substrate / polymeric barrier layer structure, that if the coextrusion is to be directly applied to the paper that the extrusion coater station may be eliminated. Further, it is possible that the substrate could be coated by the polymeric barrier layer using methods other than an extrusion coater. For example, a spray coating could be applied to the paper or
  • the substrate may be optionally fed past a treater 414 that treats the surface of the substrate for better adhesion to the coextrusion further down the line 400.
  • the treater 414 may
  • a coextrusion coater 416 applies or coats the substrate with the EVOH coextrusion to form the packaging.
  • the substrate is fed between a rubber nip roll 418 and a chill roll 420.
  • a feedblock 422 of the coextruder 424 receives molten EVOH and at least one other molten resin B and/or C.
  • the molten TSRB is also fed into the feedblock 422 (as B, with no C resin being fed) and a two layer coextrusion of EVOH-TSRB is extruded by the die 426 proximate the nip point such that the EVOH layer side contacts the paper substrate.
  • the coextruder 424 may be only a two resin capable coextruder (i.e., the coextruder 424 does not need to be capable of receiving or extruding a molten resin C) .
  • the feedblock 422 receives both a molten tie resin (as B) and a molten sealant (as C) and the die 426 extrudes an EVOH-Tie-Sealant
  • the packaging is wound up on a product wind-up roll 428.

Abstract

Packaging and a method of making the packaging is disclosed. The packaging includes a substrate with an asymmetrical coextrusion attached there to. The coextrusion includes an ethylene vinyl alcohol layer that is disposed toward the substrate.

Description

PACKAGING AND METHOD OF MAKING PACKAGING
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. provisional patent application serial number 61/296,321 titled "Packaging Materials" and filed on January 19, 2010. The full contents of that application is
incorporated by reference as if set forth in its entirety herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
TECHNICAL FIELD
[0003] This disclosure relates to packaging and, in particular, to layered packaging for food or other items in which freshness is to be maintained.
BACKGROUND OF THE INVENTION
[0004] Flexible packaging, particularly for food, is subj ect to many demands . The packaging needs to be workable in such a way that the packaging material may be quickly placed around the item to be packaged using machinery. The packaging material must also be of such a quality that it adequately stores the product before the packaging is open. In the case of food products, this typically means that the packaging materials provide an oxygen barrier to maintain freshness.
[0005] Ethylene vinyl alcohol (EVOH) is an extrudable resin that has excellent oxygen, flavor, and aroma barrier properties. EVOH resins and packaging materials have been used for several decades as meat and cheese film wrappers and the barrier properties of EVOH with respect to oxygen, grease, oil, flavor additives, and aroma is well understood.
[0006] However, when exposed to humidity levels of 85% or higher, the barrier properties of EVOH degrade. To avoid this degradation, the EVOH is typically extruded in a multi- layer symmetrical coextrusion in which
specialized tie resins are used to adhere the EVOH to outer polyolefin layers that protect the EVOH from humidity. For example, a three resin, five layer
coextrusion of EVOH may include LDPE-Tie Resin-EVOH-Tie
Resin-LDPE. In this five layer structure, the LDPE (low density polyethylene) layers protect the EVOH layer from exposure to moisture. Also, the LDPE and Tie Resin are extruded each from one extruder where they are split into two layers and directed to either side of the EVOH layer by a feedblock device. The LDPE and Tie Resin are exactly the same material on both sides of the EVOH, thus it is called a symmetrical coextrusion.
[0007] It should be further understood that, when melted, EVOH becomes fluid very quickly with very low melt strength and cannot be extruded as a separate thin film. In extrusion coating, a melt curtain is formed between the exit of the extruder die and the extruder nip. The melt curtain is completely unsupported in this air gap between the die and the extruder nip. Therefore, the melt curtain needs to have enough viscosity and melt strength to keep from tearing apart. Thus, EVOH has traditionally required the above-described five layer structure not only to maintain its barrier properties, but also to provide adjacent structural layers (such as polyethylene) that physically support the coextruded layer of the EVOH. Thus, while EVOH has excellent oxygen barrier properties, EVOH has been considered unsuitable as a barrier layer in some applications for a number of reasons. For one, production of EVOH has required extrusion machines capable of coextruding more than two resins. Such machines are very expensive and not as common as those extruding only two resins. Further, dual tie resin and polyolefin layers are provided on both sides of the EVOH coextrusion to protect the EVOH layer from humidity; however, these multiple layers can
increase the material cost of the packaging and increase the thickness of the packaging. This has made EVOH-based packaging less competitive for certain packaging
applications .
[0008] Hence, there is a continuing need for improved and lower cost EVOH packaging and a method of making the same .
SUMMARY OF THE INVENTION
[0009] Packaging for food and a method of making the packaging is disclosed. This packaging incorporates an EVOH layer which serves as an oxygen barrier to the surrounding environment. However, the packaging does not include the symmetrical five layer coextruded structure heretofore believed to be necessary both to support an EVOH layer and to further protect this EVOH layer from moisture which can compromise its effectiveness.
Moreover, in some forms, the packaging can be formed using a standard two resin capable coextruder station which reduces the cost of fabricating the packaging - in comparison to the traditional five layer structure using a three resin coextruder station.
[0010] The packaging includes a substrate and an asymmetrical coextrusion attached to the substrate. The asymmetrical coextrusion includes an ethylene vinyl alcohol layer that is disposed toward the substrate.
[0011] In some preferred forms, the packaging may further include a polymeric moisture barrier layer applied to at least one side of the substrate. The ethylene vinyl alcohol layer of the asymmetrical
coextrusion may be attached to the polymeric barrier layer. The polymeric barrier layer may be a polymeric moisture barrier layer and be used to protect one side of the ethylene vinyl alcohol from exposure to moisture in the packaging. This polymeric barrier layer may include any of a number of materials including low density polyethylene, medium density polyethylene, high density polyethylene, linear low-density polyethylene,
metallocene catalyzed linear low density polyethylene, polypropylene, ethylene vinyl acetate resin, IONOMER, Nylon, EAA, EMAA, EMAC, and EnBA. This polymeric barrier layer may also include additives such as colorants, EVOH tie resin, and fillers such as calcium carbonate. This polymeric barrier layer may also include blends or multilayered coextrusions of the above listed materials. This polymeric barrier layer is not extruded from any materials used in the asymmetrical EVOH coextrusion.
[0012] A surface of the polymeric barrier layer to which the ethylene vinyl alcohol layer is attached may be treated to promote attachment of the ethylene vinyl alcohol layer to the polymeric barrier layer. For example, the treatment may be a flame treatment, liquid priming, or a corona treatment.
[0013] In some forms, the substrate may include paper or another cellulosic material. In other forms, the substrate may be a clear or metallized film selected from a group consisting of polyethylene terephthalate, polypropylene, nylon, and PLA (polylactic acid) films.
Additionally, the substrate may be a lamination of paper and clear or metallized film substrates listed above.
[0014] In addition to the ethylene vinyl alcohol layer, the asymmetrical coextrusion may further include a tie resin and a sealant. In one form, the tie resin and the sealant may be blended together to form a tie sealant resin blend. In this form, the asymmetrical coextrusion may be a two layer coextrusion including the ethylene vinyl alcohol layer and a tie sealant resin blend layer which is formable using a two resin capable coextruder. In another form, the asymmetrical coextrusion may include the ethylene vinyl alcohol layer, a tie resin layer, and a sealant layer. The tie resin layer may be disposed between the ethylene vinyl alcohol layer and the sealant layer forming a three layer asymmetrical coextrusion.
[0015] Additionally, a method of making the packaging of the type described above is disclosed. In this method, a substrate is provided and an asymmetrical coextrusion including an ethylene vinyl alcohol layer is extruded. The ethylene vinyl alcohol layer of the asymmetrical coextrusion is attached to the substrate to form the packaging.
[0016] The method may further include the step of applying a polymeric barrier layer to at least a portion of at least one side of the substrate before attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging. The ethylene vinyl alcohol layer may be directly attached to the polymeric barrier layer. The polymeric barrier layer could be made of low density polyethylene or one or more of the materials listed above.
[0017] The method may further include the step of treating a surface of the polymeric barrier layer prior to attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging. Treating promotes adhesion between the polymeric barrier layer and the ethylene vinyl alcohol layer. This treatment may be, for example, a flame treatment, liquid priming, or a corona treatment.
[0018] As mentioned and listed above, both the
substrate and the coextrusion may be made of various materials and/or blends of materials. [0019] The foregoing and still other advantages of the invention will appear from the following description. In that description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Rather, the claims should be looked to in order to judge the full scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIGS. 1 through 3 illustrate the layer
structure of the three exemplary embodiments of the packaging; and
[0021] FIG. 4 illustrates an exemplary process line which may be used to make or fabricate the packaging.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Disclosed below are structures for a packaging containing EVOH which do not require complex coextrusion machinery configurations capable of forming five layer coextrusions . As used herein, a "-" is used to indicate layers that are coextruded with one another and "/" is used to indicate layers that are separated attached to one another.
[0023] Now with reference to FIGS. 1 through 3, a number of packaging structures are illustrated including:
(1) PAPER/LDPE/EVOH-TSRB
(2) PAPER/LDPE/EVOH-TIE-SEALANT
(3) PET FILM/LDPE/EVOH-TSRB
As used herein, TSRB refers to a tie resin and sealant resin blend in which the tie resin and sealant are blended together such that the blend may be coextruded as a single layer, whereas EVOH-TIE-SEALANT refers to three discrete separately formed layers of EVOH, tie resin (which is a type of resin designed to adhere the EVOH and the sealant layers together) , and sealant . With respect to the figures, like reference numerals are used to describe like items in which the hundreds digit has been increased to correspond to the figure number (e.g., TSRB layer 110 corresponds to TSRB layer 310) .
[0024] Looking first at FIG. 1, the layers of
structure (1) listed above are illustrated. In FIG. 1, a packaging 100 includes a paper substrate 102 with a polymeric barrier layer 104 coating one side thereof and an asymmetrical coextrusion 106 having an ethylene vinyl alcohol layer 108 and a TSRB layer 110. The ethylene vinyl alcohol layer 108 of the coextrusion 106 is
directly attached to the polymeric barrier layer 104 along a polymeric barrier layer - ethylene vinyl alcohol layer interface 112 such that the TSRB layer 110 on the opposite side of the coextrusion 106 constitutes one of the outer surfaces of the packaging 100. The exposed TSRB surface could be contacted with another exposed TSRB surface and subjected to heat and pressure to form a seal there between.
[0025] It is contemplated that the paper substrate may be a paper of a type having a machine glazed (MG) or a machine finished (MF) type finish, may be clay coated paper, may be of a white or a natural color, and may be of a Kraft, ground wood, recycled, or sulfite furnish. The paper may include laminations of one or more layers of paper or include a clear or metallized PET, OPP,
Nylon, or PLA film laminated to the paper.
[0026] In one preferred form, the polymeric barrier layer is low density polyethylene (LDPE) . However, the polymeric barrier layer on the paper may alternatively be MDPE, HDPE, LLDPE, POP, mLLDPE, or blends thereof as well as coextrusions thereof . Additives such as colors can be used. Other resins can be used in place of LDPE such as PP, EVA, IONOMER, Nylon, EAA, EMAA, EMAC, EnBA, and the like. If needed, EVOH tie resin can be blended into the poly layer for improved adhesion, especially if PP or
HDPE is used in place of LDPE. In all cases, the
materials used for the polymeric barrier layer are not extruded from the extruders used to make the asymmetrical EVOH coextrusion.
[0027] To ensure good adhesion, the paper and/or polymeric barrier layers may be subjected to flame treatment, corona treatment, or other such priming to ready the surfaces for attachment.
[0028] With respect to the specific chemical
composition of the layers, the ethylene vinyl alcohol may be 35 mol% ethylene EVOH (available as EVAL C109B from Eval Company of America) and the TSRB may be 50% POP (polyolefin plastomer, available as DOW PT1450 from Dow Chemical Company) , 25% tie resin (such as ADMER AT1000A available from Mitsui Chemicals America, Inc.), and 25%
LDPE (low-density polyethylene, available as CHEVRON 1013 available from Chevron Chemical) . The exact percentages of the constituent components may be varied depending on the temperatures, times, and pressures used to form the heat seal and the quality of the seal desired. Although
EVOH with 35 mol% or higher ethylene content is believed to provide the best results, EVOH is available in 24% ethylene to 48% ethylene content. It is contemplated that any amount of ethylene content might be used or selected based on the desired properties of the barrier or for appropriate economy. Generally speaking, the lower the ethylene content, the better the aroma and oxygen barrier provided by the EVOH layer. It is contemplated that the basis weight of the EVOH layer may be in the range of . l#/3, 000ft2 to 10.0#/3,000 ft2.
[0029] The TSRB may have a tie resin content from 10wt% to 80wt and a polyethylene content from 20wt% to 90wt%. The tie resin may be an anhydride modified LDPE based adhesive resin concentrate such as ADMER AT1000A or DUPONT BYNEL 41E170. The polyethylene sealant resin may be LDPE, MDPE, HDPE, LLDPE, POP, mLLDPE and blends thereof, and copolymers of polyethylene such as, for example: EVA, IONOMER, EAA, EMAA, EMAC, EnBA, and the like. TSRB can be further modified with slip, antiblock, or color concentrates depending upon customer needs .
[0030] The particular tie sealant resin blend selected may be configured to maximize the quality of the seal. The basis weight of the TSRB layer may be in the range of
1.0#/3, 000ft2 to 30.0#/3,000 ft2 and modified to provide enough TSRB material to form a robust seal .
[0031] In order to achieve a thin and stable coating layer, EVOH is not extrusion coated as its own single layer, but can be coextruded with the TSRB or, as will be described with respect to structures (2) and (3) below, the tie resin and sealant layers. Of course, a benefit of using the tie sealant resin blend as in structures (1) and (3) is that a three resin capable coextruder is not required, but a two resin capable coextruder will be sufficient. In contrast, standard three resin, five layer EVOH extrusion coating production would require a more complex and costly coextruder, and add sealant and tie resin layers to the inside of the EVOH layer which have been rendered unnecessary by the inclusion of the polymeric barrier coating on the substrate which serves as a moisture barrier on that side of the EVOH layer.
[0032] Turning now to FIG. 2, structure (2) is
illustrated which is similar to structure (1) , but in which the TSRB layer 110 of the asymmetrical coextrusion 106 has been replaced by separate tie resin and sealant layers 214 and 216, respectively. This means that the asymmetrical coextrusion 206 is a three layer coextrusion with the tie resin layer 214 sandwiched between the ethylene vinyl alcohol layer 208 and the sealant layer 216. This configuration eliminates any tie and sealant resin layers between the EVOH and substrate.
Accordingly, the sealant layer 216 is disposed such that it is on an attachment face (i.e., the face that will be attached to another face of the packaging) when the packaging is heat sealed.
[0033] Now with reference to FIG. 3, the structure (3) listed above is illustrated. Structure (3) is similar to structure (1) , except that the paper substrate 102 has been replaced with a clear polyethylene terephthalate
(PET) film substrate 302. According to this form, the polymeric barrier layer 304 coats at least a portion of one side of the PET film substrate 302.
[0034] In alternative forms, the PET film in structure
(3) might alternatively be any kind of clear or metalized polyethylene terephthalate, polypropylene, nylon, or PLA
(polylactic acid) film.
[0035] Looking at the structures (l)-(3) above, it can be seen that the EVOH coextrusion is asymmetrical in all forms, unlike the LDPE-Tie Resin-EVOH-Tie Resin-LDPE structures which have been previously produced. Now, when extruded, the EVOH layer is initially at least partially exposed with one side of the layer being supported and protected by either the tie sealant resin blend layer or the tie resin and sealant layers. As will be described in more detail below with respect to the method of making the packaging, this initially exposed side of the EVOH layer is attached or laminated to the substrate, or polymeric barrier coating thereon, such that this exposed face is no longer exposed.
[0036] It should be appreciated that in all three structures (1) through (3) , the initially-exposed face of the EVOH layer is attached to a polymeric barrier layer which helps to protect that side of the EVOH layer from moisture . While this polymeric barrier layer is
preferable for many applications, it is also contemplated that the polymeric barrier layer may be eliminated and the EVOH layer directly attached to the paper substrate or PET film substrate. To some extent, the removal of the polymeric barrier layer will increase the exposure of the EVOH layer to moisture which increases the rate of oxygen or aroma transmission through the EVOH layer.
However, the PET film substrate may, at least to some degree, serve as a moisture barrier. Accordingly, by increasing either the substrate thickness and/or the EVOH layer thickness, the integrity of the product may be preserved for a longer period of time, even in the absence of the polymeric barrier layer. If the product to be housed in the packaging does not require good moisture vapor barrier, then it may be acceptable to remove the polymeric barrier layer.
[0037] These structures provide a number of advantages over known flexible packaging solutions. In applications where a moderate oxygen barrier is required, EVOH
provides good oxygen barrier at a lower cost than Al foil, MPET film, and PVDC (polyvinylidene chloride) coated PET or OPP films. Further, for those applications which previously included PVDC in the packaging materials as a barrier material, the EVOH replaces the PVDC coated flexible packaging materials with a product that can be incinerated without worries of producing hydrochloric acid or other chlorinated hydrocarbon fumes into the air. [0038] In one preferred form for the packaging, the packaging has a structure of 25#PAPER/10#LDPE/4#EVOH- 7#TSRB. (#/ream is based on a 3,000 ft2 ream size) The paper basis weight can range from 9#/ream to 100#/ream. The paper may be Kraft paper with a machine glaze type finish and of bleached white color which may be flame treated for good adhesion of the LDPE to the paper. The LDPE may be corona treated for good adhesion of the EVOH coextrusion to the LDPE coated paper. The LDPE for the polymeric layer (Chevron 4517) would be of slightly higher density than the LDPE used in the TSRB (Chevron 1013) . This will provide improved moisture barrier for protection of the EVOH, while the LDPE used in the TSRB would be optimized for heat seal properties. The EVOH in the 4#EVOH-7#TSRB coextrusion is 35 mol% ethylene EVOH.
However, for other applications the composition of the TSRB in the coextrusion may be tweaked. In this form, the TSRB may be 25% tie resin (ADMER AT1000A) and 75% LDPE (CHEVRON 1013) . Even though a LDPE layer is present between the paper and the EVOH, it should be appreciated that the EVOH-TSRB coextrusion is formed from a single die and this part of the structure does not require more than a two resin coextruder station.
[0039] Some specific additional variations are
provided below with respect to the disclosed structures.
According to one form, the structure of the packaging material is 25#PAPER/10#LDPE/4#EVOH-1.5#TIE-5.5# PE
SEALANT. In another form, the structure of the packaging material is 25#PAPER/l0#LDPE/l#TIE-4#EVOH-l#TIE-5# PE SEALANT to introduce a tie layer between the EVOH and the
LDPE deposited on the paper. Similarly, the type of polyethylene in the polymeric layer can be different than the LDPE used in the sealant and the thickness of the LDPE layer can be independently adjusted to optimize product performance .
[0040] Now with reference to FIG. 4, a line 400 for making the packaging is disclosed. The line 400
illustrated is suitable for making any of the structures
(l)-(3) listed above. One of ordinary skill in the art will readily appreciate, however, that segments of the line 400 may be eliminated or not used based on the desired structure of the final product.
[0041] The line 400 includes two sections. The first section forms a coated substrate including the paper or PET layer with the polymeric barrier layer coated there on. The second section then applies the EVOH coextrusion to the coated substrate.
[0042] In the form shown, the first section of the line 400 prepares the substrate, which may be, for example, the paper or PET film substrate. The substrate is unrolled from a main substrate roll 402 and fed toward an extrusion coater 406 which coats the substrate with the polymeric barrier layer.
[0043] On the way to the extrusion laminator 406, the substrate from the main substrate roll 402 is fed past a treater 404 such as a flame treater or a corona treater that treats the surface of the substrate from the main substrate roll 402 such that the polymeric barrier layer created at the extrusion coater 406 will adhere well to the substrate. A liquid primer might also be applied to treat the surface. Although treatment of the substrate is depicted, it should be appreciated that such treatment is not required and some substrate materials may not need treatment prior to application of the polymeric barrier layer .
[0044] At the extrusion coater 406, the substrate is fed through a nip point at which point the polymeric barrier layer is applied on the substrate as a melt curtain. The nip point occurs between a rubber nip roll 410 and a chill roll 412. As the substrate approaches the nip point, at a location above the nip point, a die 412 supplies a molten resin A (which may be, for example, low density polyethylene or any of the polymeric barrier materials listed above) as a melt curtain. This molten resin A is applied to a top surface of the substrate at the nip point, is cooled by the chill roll 410 to form a substrate / polymeric barrier layer structure, and then this coated substrate exits the extrusion coater 406.
[0045] It should be appreciated that while the line 400 is shown including the extrusion coater 406 for the formation of the substrate / polymeric barrier layer structure, that if the coextrusion is to be directly applied to the paper that the extrusion coater station may be eliminated. Further, it is possible that the substrate could be coated by the polymeric barrier layer using methods other than an extrusion coater. For example, a spray coating could be applied to the paper or
PET substrate.
[0046] In any event, the substrate may be optionally fed past a treater 414 that treats the surface of the substrate for better adhesion to the coextrusion further down the line 400. Again, the treater 414 may
incorporate a flame treatment, liquid priming, or a corona treatment to prepare the surface of the substrate.
[0047] In the second portion of the line 400, a coextrusion coater 416 applies or coats the substrate with the EVOH coextrusion to form the packaging. In the coextrusion coater 416, the substrate is fed between a rubber nip roll 418 and a chill roll 420. A feedblock 422 of the coextruder 424 receives molten EVOH and at least one other molten resin B and/or C. If an EVOH-TSRB coextrusion is being formed, then the molten TSRB is also fed into the feedblock 422 (as B, with no C resin being fed) and a two layer coextrusion of EVOH-TSRB is extruded by the die 426 proximate the nip point such that the EVOH layer side contacts the paper substrate. In this form, the coextruder 424 may be only a two resin capable coextruder (i.e., the coextruder 424 does not need to be capable of receiving or extruding a molten resin C) . If an EVOH-Tie-Sealant coextrusion is being formed, then in addition to the molten EVOH, the feedblock 422 receives both a molten tie resin (as B) and a molten sealant (as C) and the die 426 extrudes an EVOH-Tie-Sealant
coextrusion such that the EVOH layer is applied to the substrate and laminated to the substrate at the nip point. After exiting the coextrusion coater 416, the packaging is wound up on a product wind-up roll 428.
[0048] While specific embodiments of the present invention has been shown, various modifications falling within the breadth and scope of the invention will be apparent to one skilled in the art. Thus, the following claims should be looked to in order to understand the full scope of the invention.

Claims

CLAIMS What is claimed is :
1. A packaging comprising:
a substrate; and
an asymmetrical coextrusion attached to the
substrate and including an ethylene vinyl alcohol layer that is disposed toward the substrate.
2. The packaging of claim 1, further comprising a polymeric barrier layer applied to at least one side of the substrate and wherein the ethylene vinyl alcohol layer of the asymmetrical coextrusion is attached to the polymeric barrier layer.
3. The packaging of claim 2, wherein the polymeric barrier layer is low density polyethylene.
4. The packaging of claim 2, wherein the polymeric barrier layer includes at least one of low density polyethylene, medium density polyethylene, high density polyethylene, linear low-density polyethylene, and metallocene catalyzed linear low density polyethylene.
5. The packaging of claim 2, wherein the polymeric barrier layer includes at least one of polypropylene, ethylene vinyl acetate resin, IONOMER, Nylon, EAA, EMAA, EMAC, and EnBA.
6. The packaging of claim 2, wherein a surface of the polymeric barrier layer to which the ethylene vinyl alcohol layer is attached is treated to promote
attachment of the ethylene vinyl alcohol layer to the polymeric barrier layer.
7. The packaging of claim 6, wherein the treatment is flame treatment.
8. The packaging of claim 6, wherein the treatment is corona treatment.
9. The packaging of claim 6, wherein the treatment is a liquid primer.
10. The packaging of claim 1, wherein the substrate comprises paper.
11. The packaging of claim 1, wherein the substrate comprises a clear or metallized film selected from the group consisting of polyethylene terephthalate, OPP, nylon, and PLA films.
12. The packaging of claim 1, wherein the
asymmetrical coextrusion further includes a tie resin and a sealant.
13. The packaging of claim 12, wherein the tie resin and the sealant are blended together to form a sealant resin blend.
14. The packaging of claim 13, wherein the
asymmetrical coextrusion is a two layer coextrusion including the ethylene vinyl alcohol layer and a tie sealant resin blend layer.
15. The packaging of claim 14, wherein the
asymmetrical coextrusion is formable using a two res capable coextruder .
16. The packaging of claim 12, wherein the
asymmetrical coextrusxon includes the ethylene vinyl alcohol layer, a tie resin layer, and a sealant layer and wherein the tie resin layer is disposed between the ethylene vinyl alcohol layer and the sealant layer.
17. A method of making packaging, the method comprising :
providing a substrate;
extruding an asymmetrical coextrusion including an ethylene vinyl alcohol layer; and
attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging .
18. The method of claim 17, further comprising the step of applying a polymeric barrier layer to at least a portion of at least one side of the substrate before attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging.
19. The method of claim 18, wherein the ethylene vinyl alcohol layer is directly attached to the polymeric barrier layer.
20. The method of claim 18, further comprising the step of treating a surface of the polymeric barrier layer prior to attaching the ethylene vinyl alcohol layer of the asymmetrical coextrusion to the substrate to form the packaging.
21. The method of claim 20, wherein step of treating includes flame treating the surface.
22. The method of claim 20, wherein step of
treating includes corona treating the surface.
23. The method of claim 20, wherein step of
treating includes liquid priming the surface.
24. The method of claim 18, wherein the polymeric barrier layer is low density polyethylene.
25. The method of claim 18, wherein the polymeric barrier layer includes at least one of low density polyethylene, medium density polyethylene, high density polyetheylene, linear low-density polyethylene, and metallocene catalyzed linear low density polyethylene .
26. The method of claim 18, wherein the polymeric barrier layer includes at least one of polypropylene, ethylene vinyl acetate resin, IONOMER, Nylon, EAA, EMAA, EMAC, and EnBA.
27. The method of claim 17, wherein the substrate comprises paper.
28. The method of claim 17, wherein the substrate comprises a clear or metallized film selected from the group consisting of polyethylene terephthalate, OPP, nylon, and PLA films.
29. The method of claim 17, wherein the
asymmetrical coextrusion further includes a tie resin and a sealant .
30. The method of claim 29, wherein the tie resin and the sealant are blended together to form a tie sealant resin blend.
31. The method of claim 30, wherein the
asymmetrical coextrusion is a two layer coextrusion including the ethylene vinyl alcohol layer and a tie sealant resin blend layer.
32. The method of claim 31, wherein the
asymmetrical coextrusion is formable using a two resin capable coextruder .
33. The method of claim 29, wherein the
asymmetrical coextrusion includes the ethylene vinyl alcohol layer, a tie resin layer, and a sealant layer and wherein the tie resin layer is disposed between the ethylene vinyl alcohol layer and the sealant layer.
PCT/US2011/021533 2010-01-19 2011-01-18 Packaging and method of making packaging WO2011090934A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CA2797570A CA2797570A1 (en) 2010-01-19 2011-01-18 Packaging and method of making packaging
US13/521,019 US9610755B2 (en) 2010-01-19 2011-01-18 Packaging and method of making packaging
US15/477,492 US20170259546A1 (en) 2010-01-19 2017-04-03 Packaging and method of making packaging

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US29632110P 2010-01-19 2010-01-19
US61/296,321 2010-01-19

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US13/521,019 A-371-Of-International US9610755B2 (en) 2010-01-19 2011-01-18 Packaging and method of making packaging
US15/477,492 Division US20170259546A1 (en) 2010-01-19 2017-04-03 Packaging and method of making packaging

Publications (1)

Publication Number Publication Date
WO2011090934A1 true WO2011090934A1 (en) 2011-07-28

Family

ID=44307158

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/US2011/021533 WO2011090934A1 (en) 2010-01-19 2011-01-18 Packaging and method of making packaging
PCT/US2011/021535 WO2011090936A1 (en) 2010-01-19 2011-01-18 Packaging for a tea pouch

Family Applications After (1)

Application Number Title Priority Date Filing Date
PCT/US2011/021535 WO2011090936A1 (en) 2010-01-19 2011-01-18 Packaging for a tea pouch

Country Status (3)

Country Link
US (3) US20130037556A1 (en)
CA (2) CA2797763A1 (en)
WO (2) WO2011090934A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITMI20111692A1 (en) * 2011-09-20 2013-03-21 Fattoria La Vialla Di Gianni Anton Io E Bandino L PACKAGING FOR FOOD IN THE FORM OF A BAG OR ENVELOPE
EP3015264A1 (en) * 2014-10-29 2016-05-04 Sonoco Development, Inc. Extrusion laminate mineral oil barrier
US9610755B2 (en) 2010-01-19 2017-04-04 Prolamina Midwest Corporation Packaging and method of making packaging

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103329300B (en) * 2011-03-30 2016-05-04 海洋王照明科技股份有限公司 Substrate and preparation method thereof and use the organic electroluminescence device of this substrate
ITBO20120208A1 (en) * 2012-04-17 2013-10-18 Ima Ind Srl SOVRA ENVELOPE ENVELOPE FOR BAGS - INFUSION AND WELDER DEVICE PRODUCT FILTER TO OBTAIN THE LARGE ENVELOPE ENVELOPE
EP3230173A4 (en) * 2014-12-08 2018-05-16 Entegris, Inc. Film with improved flex crack resistance
WO2018165116A1 (en) * 2017-03-06 2018-09-13 Evergreen Packaging, Inc. Extrusion coated paper for flexible packaging
DE102020123123A1 (en) 2020-09-04 2022-03-10 Koehler Innovation & Technology Gmbh Packing with paper material
US11827397B2 (en) 2021-06-17 2023-11-28 Evergreen Packaging Llc Multilayer paperboard pouch and method of making the same using conventional bag-making equipment (CBME)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5679422A (en) * 1995-01-25 1997-10-21 American National Can Company Coextruded film for chub packages
US6063417A (en) * 1996-02-28 2000-05-16 Cryovac, Inc. Cheese packaging film
US6242087B1 (en) * 1998-10-07 2001-06-05 Kuraray Co., Ltd. Multilayer structure and process for producing the same
US6383589B1 (en) * 1999-03-29 2002-05-07 Pechiney Plastic Packaging, Inc. Multilayer plastic structures, containers made therefrom, and methods of making the structures
US20060074393A1 (en) * 2001-04-17 2006-04-06 Baxter International Inc. Multiple layer polymeric structure
US20080274245A1 (en) * 2004-04-08 2008-11-06 Lee Eric K C Multicomponent Structures Having Improved Adhesion Between Components

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4701360A (en) * 1986-05-16 1987-10-20 International Paper Company Heat sealable barrier material for improved juice packaging (EVOH)
US5059459A (en) * 1989-05-17 1991-10-22 Westvaco Corporation Paperboard laminate
EP0750573A4 (en) 1994-03-24 1997-09-03 Union Camp Corp Flip side box with moisture barrier
US6333087B1 (en) * 1998-08-27 2001-12-25 Chevron Chemical Company Llc Oxygen scavenging packaging
US6479154B1 (en) * 1999-11-01 2002-11-12 Kimberly-Clark Worldwide, Inc. Coextruded, elastomeric breathable films, process for making same and articles made therefrom
US6521312B1 (en) * 2000-11-28 2003-02-18 Loparex, Inc. Multilayered film structures and methods of making and using the same
US8043674B2 (en) * 2001-02-22 2011-10-25 Exxonmobil Oil Corporation Sealable packaging structures and applications related thereto
FI117748B (en) * 2001-10-15 2007-02-15 Stora Enso Oyj The lid of the package, the method of its manufacture and the sealed packaging
JP3828861B2 (en) 2002-12-03 2006-10-04 東京製紙株式会社 Laminated body and paper container and package using the same
US20060172143A1 (en) * 2003-07-23 2006-08-03 Breese David R Extrusion coating process and coated substrates having improved heat seal properties
US7318498B2 (en) * 2004-04-06 2008-01-15 Azdel, Inc. Decorative interior sound absorbing panel
WO2007062391A2 (en) * 2005-11-22 2007-05-31 Triton Systems, Inc. Multilayer flame retardant barrier films and fabrics
FI20060701A (en) * 2006-07-27 2008-01-28 Stora Enso Oyj Polymer coated heat sealable packaging material and sealed product packaging formed therefrom
CA2797763A1 (en) 2010-01-19 2011-07-28 Prolamina Midwest Corporation Packaging for a tea pouch

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5679422A (en) * 1995-01-25 1997-10-21 American National Can Company Coextruded film for chub packages
US6063417A (en) * 1996-02-28 2000-05-16 Cryovac, Inc. Cheese packaging film
US6242087B1 (en) * 1998-10-07 2001-06-05 Kuraray Co., Ltd. Multilayer structure and process for producing the same
US6383589B1 (en) * 1999-03-29 2002-05-07 Pechiney Plastic Packaging, Inc. Multilayer plastic structures, containers made therefrom, and methods of making the structures
US20060074393A1 (en) * 2001-04-17 2006-04-06 Baxter International Inc. Multiple layer polymeric structure
US20080274245A1 (en) * 2004-04-08 2008-11-06 Lee Eric K C Multicomponent Structures Having Improved Adhesion Between Components

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9610755B2 (en) 2010-01-19 2017-04-04 Prolamina Midwest Corporation Packaging and method of making packaging
ITMI20111692A1 (en) * 2011-09-20 2013-03-21 Fattoria La Vialla Di Gianni Anton Io E Bandino L PACKAGING FOR FOOD IN THE FORM OF A BAG OR ENVELOPE
EP3015264A1 (en) * 2014-10-29 2016-05-04 Sonoco Development, Inc. Extrusion laminate mineral oil barrier

Also Published As

Publication number Publication date
CA2797570A1 (en) 2011-07-28
US20130040155A1 (en) 2013-02-14
US9610755B2 (en) 2017-04-04
US20130037556A1 (en) 2013-02-14
CA2797763A1 (en) 2011-07-28
US20170259546A1 (en) 2017-09-14
WO2011090936A1 (en) 2011-07-28

Similar Documents

Publication Publication Date Title
US20170259546A1 (en) Packaging and method of making packaging
EP1082220B1 (en) A laminated packaging material, method of manufacturing of said laminated material and packaging containers produced therefrom
EP0931646B1 (en) Improvements in or relating to laminates and packaging materials
DE60319977T2 (en) PACKAGING LAMINATE, METHOD FOR THE PRODUCTION THEREOF, AND PACKAGING CONTAINER PRODUCED FROM THE PACKAGING LAMINATE
US5506011A (en) Paperboard packaging containing a PVOH barrier
US7252878B2 (en) High barrier flexible packaging structure
US20110300363A1 (en) High-strength polypropylene-base barrier film for packing purposes, method for the production and the use thereof
AU711380B2 (en) A multilayered packaging material, in particular for flexible packagings
JP4974893B2 (en) Packaging laminate material
CA2627749C (en) Multilayer foil and packaging made of this foil
US20170087814A1 (en) Process of Making Laminate Structures with High Barrier Extrusion Coating for Flexible Packaging
KR101663497B1 (en) Linear Low Density Polyethylene Complex Film and Packing Material Comprising The Same
US20130323488A1 (en) Packaging Film and Method of Manufacture
KR20190118334A (en) Co-extruded antibiotics multi-layer film
US8986823B1 (en) Microlayer extrusion coating and laminating for flexible packaging
WO2014178000A1 (en) A laminate structure
AU673788B2 (en) Lamination
EP4096924A1 (en) A packaging sheet for packaging of butterable products
AU733002C (en) A method of and apparatus for use in manufacturing a packaging laminate
AU657270C (en) Improvements in or relating to laminates and packaging materials

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11735039

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2797570

Country of ref document: CA

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 13521019

Country of ref document: US

122 Ep: pct application non-entry in european phase

Ref document number: 11735039

Country of ref document: EP

Kind code of ref document: A1