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Polyolefin Dispersion – A New Vistas for Flexible Packaging

Presented by:Ravi Rao, Dow Chemical International Pvt. Ltd.Technical Service and Development - Director

Co-authors:Prashant Mogre, Dow Chemical International Pvt. Ltd.Technical Service and Development LeaderAminur Rahaman, Dow Chemical International Pvt. Ltd.New Venture & Business Development R&D

TAPPI PLACE Conference 10 - 11, Nov 2009, Mumbai, INDIA13 - 14, Nov 2009 , New Delhi, INDIA

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Agenda• Polyolefin Dispersion (POD) Technology• Polyolefin Dispersion – Chemistry• POD –Applications and Performance• Conclusions

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What comes to mind when you think of polyolefins ?

Molded Articles & Containers

PlasticPellets

Films

What comes to mind when you think of polyolefins ?

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Waterborne Polyolefin Dispersions • 40-55 % Solids , < 500 cps Viscosity

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Aqueous Polyolefin Dispersion

Dow’s proprietary BLUEWAVE™ Technology enables » Dispersion of polymers which are not self-dispersing

• Ethylene /Propylene Copolymers• LDPE, HDPE

» Deliver high molecular weight polymers (>75,000 Mw)» Thermoplastic and elastomer formulations» Low viscosity – Typically less than 500 cps» High solids – up to 60%» Solvent free – No solvents added in process

™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow

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POD Technology• Continuous Mechanical Dispersion Process &

High Internal Phase Emulsion (HIPE)

Continuous High Shear Mixer

Optional Surfactant

Dilution Water

Initial Water

Liquid or Molten Polymers

HIPE SystemWater Continuous PhaseRhombohedral ParticlesHigh Viscosity90+% Solids

Conventional LatexSpherical ParticlesLess than 75% Solids

POD

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Polyolefin• Propylene copolymer• Ethylene copolymer

Stabilizing Agent• Polymeric • Surfactant

Aqueous Medium

Chemistry – Overview POD Structure

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Polyolefin Dispersions – Grades

-63122LowOlefin Block Copolymer

Dispersion EDPOD 9501

-3265LowPropylene Copolymer

Dispersion DDPOD 4503

-2685MediumPropylene Copolymer

Dispersion CDPOD 4501

-5363LowEthylene Copolymer

Dispersion BDPOD 8502

-5363MediumEthylene Copolymer

Dispersion ADPOD 8501

Polymer Tg (deg. C)

Polymer Melting Point

(deg. C)

Carboxyl Content

Polymer Composition

TAPPI CodeProduct Designation

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Converting Options for Polyolefin Dispersions

Printing/Coating Processes (Rotogravure)

Spray Application

Dipping

Frothed Foams

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Film Formation – Hot Stage Microscopy

PolyolefinParticles

HomogeneousFilm

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Mechanical Properties• Cast film 250 microns made from dispersion C and dried at different temperatures

0

1

2

3

4

5

6

7

0 100 200 300 400 500 600 700Strain %

Stre

ss M

Pa

60°C, 10 mil, 30 min, VAC

70°C,10 mil, 30 min, VAC

80°C,10 mil, 30 min, VAC

0

1

2

3

4

5

6

7

0 100 200 300 400 500 600 700Strain %

Stre

ss M

Pa

60°C, 10 mil, 30 min, VAC

70°C,10 mil, 30 min, VAC

80°C,10 mil, 30 min, VAC

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Applications - PODs in Flexible Packaging

Tie Layer / Laminating Adhesive• Alternative to extrusion lamination

» Adhesion to polyolefins» Adhesion to polar substrates (paper, glass, foil,

polar polymers)» Adhesion to PE based printing inks» Wet sandwitch lamination possible

Heat Sealable Layer» Apply at low temperatures and high

speeds» Low HSIT (<70°C)» Use existing printing equipment

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0

0.5

1

1.5

2

2.5

3

50 60 70 80 90 100 110 120 130 140 150Heat Seal Temperature (°C)

Hea

t Sea

l Str

engt

h (lb

)

POD, 3.1 g/m2

POD, 12.7 g/m2

POD, 17.8 g/m2

POD - Heat Seal Strength on BOPP film

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Hot Tack strength - POD coated Chromo Paper

0

1

2

3

4

5

6

7

Temperature

Force (N/25 mm)

force N/25 mm

force N/25 mm 1.13 1.21 1.69 5.98 3.25 2.66 1.27

80 90 100 110 120 130 140

Tack

•Substrate: 70 gsm Chromo Paper•Dispersion: Propylene Based Dispersion C•Add-on coating: 5 gsm

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Key Properties of PODs for Flexible Packaging

Water resistanceOil & grease resistance Heat sealability

Elasticity /flexibility

Adhesion to polyolefins

Adhesion to polar substrates

Crystalline structure

Tie Chains

Olefin backbone

Functional

groups

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Application- Paper Coatings

• Extruded polyolefins have been widely used to modify paper

• Limitations exist for extruded polyolefins» Thickness (> 10 microns)» Adhesion to paper

• Beneficial properties of PODs provided to paper and board

» Oil and grease barrier» Moisture resistance» COF modification» Adhesion promoter / tie layer» Heat sealability

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Applications and Properties

Unique Balance of Properties (not possible with conventional dispersions)

» Heat sealability» Moisture resistance/barrier» Soft touch» Elasticity» Adherence to polar and non-polar substrates» Low temperature flexibility» Chemical resistance» Potential for recyclability» Potential for hypoallergenic properties» Food contact compliance» Calibration of hardness and melting points» High filler loading» Toughness» Anti-slip» Embossable

Flex Pkg

Footwear

Frozen Food Pkg

Carpet

Foams

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Summary: Polyolefin Dispersions – Applied Innovation• In POD- polyolefin dispersions put high molecular weight polyolefin in water based

dispersion to enable customers to create differentiated products or structures, eliminate solvent related issues and/or lower system cost

Positive performance of the Polyolefin

• Heat Sealability• Low temperature flexibility

• Water & Chemical Resistance

+Application benefit of water borne

system• Adhesion to polar substrates

• Acceptance of inorganic fillers• Low Viscosity application

• Can be used as an additive in latexes

Polyolefin dispersions promote Differentiation and growth

Waterborne Application Vs Extrusion Coating

• Thinner Coating• Use existing waterborne application equipment• Higher Line speed• Penetrate porous/fibrous webs• Coat at low temperature• Coat complex geometry• Coat in Pattern

Thank you!

Ravi Raoravirao@dow.com

Contact CIG Europe+32 34 50 2240

www.dowpod.com

™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow