Metallocene-catalyzed polyethylene has transformed packaging materials by enabling precise control over molecular architecture. Current films achieve oxygen transmission rates below 100 cc/m²/day and maintain seal integrity at temperatures ranging from -40°C to 120°C, while allowing thickness reductions of up to 30% compared to conventional polyethylene films.

The challenge lies in optimizing molecular weight distribution and comonomer incorporation to balance barrier properties, mechanical strength, and processability in increasingly thin multi-layer structures.

This page brings together solutions from recent research—including soft nitrided layer combinations, hexene-enhanced compositions, cyclic olefin polymer integration, and monomaterial PE laminates. These and other approaches focus on achieving superior performance while maintaining recyclability and reducing material usage in flexible packaging applications.

1. Multilayer Packaging Film with Soft Nitrided Layer and Metallocene Linear Low-Density Polyethylene External Layer

A, 2024

A multilayer film for packaging frozen or refrigerated foods that provides improved oxygen barrier, heat shrinkage, mechanical properties, physical property uniformity, processability, and recyclability compared to existing films. The film has a unique composition and structure. It consists of an external film, an internal adhesive film, a soft nitrided film containing ethylene vinyl acetate copolymer and low-density polyethylene, and another internal adhesive film. The soft nitrided film has a weight ratio of 1:0.25 to 1.5 of ethylene vinyl acetate copolymer and low-density polyethylene. The nitrided film also includes nylon resin. The internal adhesive films have a shrinkable adhesive resin. The external films are made of metallocene linear low-density polyethylene. The film

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2. Skin Pack Packaging Sheet with Propylene-Based Random Copolymer Surface Layer

TOKAN KOGYO CO LTD, 2024

A sheet, container, and package for skin pack packaging that allows skin packs to be formed using multi-layer barrier containers. The key is using a specific surface layer material that provides good adhesion to the skin pack film. The surface layer is made from a propylene-based random copolymer containing metallocene-based random polypropylene. This copolymer has specific properties like storage modulus and loss tangent that enable good adhesion to the skin pack film while maintaining heat resistance.

3. Multi-Layer Packaging Laminate with Outer Polymer Label Layer and Stacked Inner Layer for Enhanced Tear Resistance and Barrier Properties

MANKIND PHARMA LTD, 2024

Packaging laminate for products like medicines, medical devices, and hygiene products that is easy to open, tear-resistant, and has good barrier properties. The laminate has a unique structure with an outer label layer made of a polymer like PP, PET, or PEN, followed by an inner layer stack of materials like LDPE, LLDPE, HDPE, PO, and metallocene PE. This provides a strong, tear-resistant outer layer for handling and tamper evidence, with an inner layer that is easier to tear open for product access. The stacked inner layer materials also enhance barrier properties compared to a single layer.

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4. Coextruded Five-Layer Packaging Film with Enhanced Clarity and Stiffness

NAIR HARIHARAN KRISHNAN, 2024

Packaging film material that improves the clarity of the tubes while maintaining the required stiffness and recyclability. The material is made from 5 film layers through coextmding, wherein each of 5 film layers contains 2-3 of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyvinylidene chloride (PVDC), ethylene vinyl acetate (EVA) and metallocene polyethylene.

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5. Composite Sheet with Multilayer Heat Sealing Structure for Enhanced Barrier and Strength Properties

SHANGHAI ZIJIANG COLOR PRINTING & PACKING CO LTD, 2023

Composite sheet for injection packaging of pesticides that has excellent barrier properties, high heat sealing strength, and pressure-bearing capacity. The composite sheet has layers arranged in sequence: printing layer, first adhesive layer, intermediate layer, second adhesive layer, and heat sealing layer. The heat sealing layer has a composite layer, core layer, and inner layer. The composite layer and core layer are made of combinations of linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) for barrier properties. The core layer further contains cyclic olefin polymer for enhanced barrier. The inner layer is made of metallocene polyethylene (mPE). The heat sealing layer uses polyethylene and cyclic olefin polymers for sealing strength and moisture barrier. This composition provides the desired properties for injection packaging of pesticides.

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6. Polyethylene Resin Composition with Ethylene-α-Olefin Copolymer and Inorganic Compound Integration

SANIPAK COMPANY OF JAPAN, LTD., 2023

Polyethylene-based resin composition for packaging materials that balances moldability, bag-making processability, and film strength when inorganic compounds like calcium carbonate are added. The composition contains a specific ratio of an ethylene-α-olefin copolymer A polymerized with a metallocene-based catalyst. This copolymer, along with a resin component, provides the desired properties when the resin component makes up 25-90% of the total composition.

7. Monomaterial Polyethylene Laminated Packaging with Ethylene Copolymer Printed Film and Thin Multi-layer Sealing Film

DOW GLOBAL TECHNOLOGIES LLC, 2023

Thin, monomaterial polyethylene laminated flexible packaging that has improved recyclability compared to conventional PET/PE laminates. The packaging structures have a printed film made of ethylene copolymer and a sealing film with multiple ethylene polymer layers. The sealing film thickness is 15-30 microns, much thinner than conventional sealant films. The thin sealing film is achieved by using a specific catalyst system for making the inner ethylene copolymer layer. This allows the overall laminate thickness to be reduced below conventional levels while maintaining barrier and strength properties.

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8. Polyethylene Resin Composition with Ethylene-Olefin Copolymer and Metallocene Catalyst Integration

SANIPAK COMPANY OF JAPAN LTD, 2023

Polyethylene-based resin composition, packaging material, and manufacturing method that provide improved properties like moldability, bag-making processability, and film strength when inorganic compounds are added. The composition contains a resin component with at least 50% of an ethylene-olefin copolymer, where 10% of that copolymer is made with a metallocene catalyst. This composition allows forming films with excellent moldability and bag-making properties even when inorganic compounds are added. The packaging material is made by extruding this composition.

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9. PTP Packaging Cover Material with Low Molecular Weight Polyethylene and Controlled Mechanical Properties

ASAHI CHEMICAL IND, 2023

Cover material for PTP (press through pack) packaging that improves push-out properties, opening recognition, and reduces unpleasant odors compared to existing materials. The cover material contains a low molecular weight polyethylene with specific molecular weight and crystallization properties. It also has controlled orientation, strength, elongation, and modulus. This optimized cover material provides better pushability, opening sound, and odor suppression for PTP packages like blister packs.

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10. Single-Material Polyethylene Laminate Structure with Specific Density and Melt Index for Flexible Packaging

DOW GLOBAL TECHNOLOGIES LLC, 2023

Laminate structure for flexible packaging made from single-material polyethylene to improve recyclability. The laminate has a printed film and a sealant film. The sealant film has an inner layer with specific density and melt index. It also contains a composition of ethylene-based polymers with high molecular weight comonomer distribution and a certain melt index ratio. This composition is made using a catalyst system. The laminate's thinner construction and single-polymer materials enable easier recycling compared to conventional multi-polymer laminates.

11. Multilayer Packaging Film with Metallocene Linear Low-Density Polyethylene, Shrinkable Adhesive Resin, and Nylon-Ethylene Vinyl Acetate Core

EDI INC, 2023

Multilayer film for packaging frozen or refrigerated food that provides high oxygen barrier, good heat shrinkage, and recyclability. The film consists of layers like outer films made of metallocene linear low-density polyethylene (mLLDPE), inner adhesive films containing shrinkable adhesive resin, and a central softening film made of nylon, low-density polyethylene, and ethylene vinyl acetate copolymer. The mLLDPE films improve mechanical strength, the shrinkable adhesive films enhance heat sealability, and the softening film provides low oxygen permeability. The layers can be laminated by filming and joining the resin pellets.

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12. Heat-Shrinkable Packaging Film with Recycled Polyethylene Compound and Multilayer Extrusion Structure

JME&C CO LTD, 2022

Carbon-reducing heat-shrinkable packaging film made from recycled polyethylene that can be recycled and reused, reducing waste and carbon footprint compared to virgin polyethylene films. The film is manufactured using a recycled compound layer made from recycled polyethylene pellets mixed with a metallocene resin and elastomer. This allows the recycled film to retain shrinkability and avoid issues like hole formation when recycled. The film structure is formed by extruding and coextruding the recycled compound, upper, and lower layers through dies.

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13. Layered Polyethylene Film with Outer Barrier Coating Layer Comprising Low Xylene Soluble Catalytically Produced Polyethylene

BOREALIS AG, 2022

Layered polyethylene film that has an outer layer for barrier coating which is made of a composition which comprises a catalytically produced polyethylene and which has a comparatively low xylene soluble (XS) content. The film includes an outer layer for barrier coating and a matrix component which is an ethylene copolymer having an MFR2 determined according to ISO 1133 of from 0.5 to 10 g/10min and a density of 920 to 935 kg/m3, wherein the outer layer composition has xylene soluble (XS) fraction determined according to ISO 16152 of 2 wt.% or less, preferably of 1.5 wt.% or less.

14. Polyethylene-Based Resin Composition with Ethylene-α-Olefin Copolymer and High-Density Polyethylene Blended with Inorganic Compounds

JAPAN SANIPAK CO LTD, 2022

Polyethylene-based resin composition, packaging material, and production method that provides good formability, processability, and strength when blended with inorganic compounds like calcium carbonate. The composition has a resin component containing 50% ethylene-α-olefin copolymer and 5-50% high-density polyethylene, with 10% of the copolymer being an ethylene-α-olefin copolymer polymerized by a metallocene-based catalyst. The composition allows reducing resin usage while maintaining properties when blended with inorganics for packaging applications.

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15. Packaging Box with Integrated Wing Surface Walls and Composite Film Construction

KIM SANG KUN, 2022

A packaging box design that reduces material usage and weight compared to conventional boxes for food and beverage containers. The box has open front and back walls with side walls formed by mutually coupling wing surfaces on the left and right sides. The wing surfaces themselves create the front and rear walls when connected. This eliminates the need for separate front and rear walls. The box is made from a composite film with polypropylene, metallocene polyethylene, functional additives, aluminum thin film, flame retardants, and adhesive accelerator. The composite film provides strength, flame resistance, and adhesion between the wing surfaces.

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16. Polyethylene Resin Composition with Ethylene-α-Olefin Copolymer and Inorganic Filler Integration

SANIPAK COMPANY OF JAPAN LTD, 2022

Polyethylene-based resin composition, packaging material, and manufacturing method that balances reducing resin usage with maintaining moldability and film strength when adding inorganic fillers like calcium carbonate. The composition contains a resin component mainly made of a specific ethylene-α-olefin copolymer polymerized with a metallocene catalyst, with 10% or more of the copolymer. This allows reducing the total resin content while maintaining processability and film strength when blended with inorganic fillers.

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17. Polyethylene Copolymers with Distinct Molecular Weight Components and Specific Metallocene Catalysis

CHEVRON PHILLIPS CHEMICAL COMPANY LP, 2021

Polyethylene (PE) copolymers with improved film processability compared to conventional bimodal PE resins. The copolymers have a unique molecular structure with distinct lower and higher molecular weight components. The copolymers have specific properties like molecular weight distribution, viscosity, and density ranges that enable easier film extrusion and processing compared to bimodal PE resins. The copolymers are made by catalytic polymerization of ethylene using specific metallocene compounds. The resulting copolymers have better film properties like reduced break growth, improved tear strength, and reduced film rupture force compared to bimodal PE resins.

18. Headers for Wrapped Paper Rolls with mLLDPE Film Coating for Reduced Toxic Gas Emissions During Heat Sealing

CASCADES SONOCO INC, 2021

Protective headers for wrapped paper rolls that generate lower levels of toxic gases like carbon monoxide and volatile organic compounds (VOCs) during heat sealing compared to conventional headers. The headers have a film coated on the inner surface made from a specific type of linear low density polyethylene (LLDPE) resin called metallocene linear low density polyethylene (mLLDPE). This mLLDPE film on the header substrate is heat sealable and when joined to an interior header during roll wrapping, reduces emissions of toxic gases compared to traditional LDPE films. The mLLDPE film coating on the header provides a protective cap at the roll end while minimizing environmental concerns from the heat sealing process.

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19. Recyclable Flexible Packaging Laminate with Ethylene-Based Print Film and Multi-Layer Sealant Film Featuring High MWCDI Compositions

Dow Global Technologies LLC, 2021

Recyclable laminate structures for flexible packaging that achieve recyclability, barrier protection, and printing properties at lower laminate thicknesses compared to traditional laminates. The laminate has a print film made of ethylene-based polymer and a sealant film with at least 3 layers, including an inner layer with specific properties. The inner layer contains an ethylene interpolymer with density 0.900-0.925 g/cc and melt index 0.5-5 g/10 min. At least one of the inner, middle, or outer layers has a composition with a high Molecular Weighted Comonomer Distribution Index (MWCDI) >0.9 and melt index ratio I10/I2 ≥ 7.0 - 1.2 * log(I2). This composition is made via a specific polymerization process involving ethyl

20. Heavy-Duty Packaging Film with Metallocene-Catalyzed Polyethylene Outer Layer and Specific Density Profile

JAPAN POLYETHYLENE CORP, 2021

Heavy-duty packaging film with low slipperiness and good balance of properties like heat seal strength, impact resistance, and rigidity. The film has an outer layer with specific resin composition and density range. It contains 15-75% metallocene-catalyzed polyethylene with a low melt flow rate (0.1-10 g/10min at 190°C) and a density of 0.860-0.910 g/cm3. The overall layer density is 0.911-0.940 g/cm3. This composition provides slip prevention without sticking or curling issues. The film can be made by coextrusion of layers with the optimized resins.

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21. Cast Polyethylene Films with Enhanced Flex Crack Resistance from Metallocene-Catalyzed Ethylene Polymers

22. Polyethylene Film with Metallocene-Catalyzed Copolymerization and Electron-Withdrawing Anion-Treated Solid Oxide Particles

23. Polyethylene Composition with Dual Metallocene Catalyst and Treated Solid Oxide for Enhanced Barrier Properties

24. Multilayer Heat-Sealable Film with Dual-Catalyst Polypropylene Seal Layer

25. Food Packaging Container with Multilayer Sheet and Specific Polyolefin Resin Adhesive Layer

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