Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene &...

45
2009 Consumer Packaging Solutions for Barrier Performance Course Polyethylene & Polypropylene in Flexible Barrier Packaging Presented by: Kelly R. Frey Extrusion Coating – Technical Service Chevron Phillips Chemical Company, LP

Transcript of Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene &...

Page 1: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

2009 Consumer Packaging Solutions for Barrier Performance Course

Polyethylene & Polypropylene in Flexible

Barrier Packaging

Presented by:Kelly R. FreyExtrusion Coating – Technical ServiceChevron Phillips Chemical Company, LP

Page 2: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 3: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 4: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 5: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 6: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 7: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 8: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 9: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 10: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 11: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 12: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 13: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Learning OutcomesHow polyethylene & polypropylene is used in barrier packaging. Barrier properties of PE & PP. Properties of PE which affect barrier performance.How film & coating processing influences barrier performance.

Page 14: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

How does PE & PP fit into flexible barrier packaging?

By itself (monolayer)…

Combined (coex or lamination)…

Page 15: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

How Does PE & PP Provide Barrier?

Polyethylene is used by itself or combined with other materials to create a torturous path to create a barrier. Polyethylene and polypropylene can have good-moderate moisture barrier properties. HDPE MVTR grades are higher in density and can provide improved moisture barrier over LDPE and PP. Good moisture barrier can be achieved with monolayer HDPE MVTR grades.

Page 16: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

How Does PE & PP Provide Barrier? Fair moisture barrier can be achieved with monolayer LDPE grades. Polyethylene and polypropylene have poor oxygen (gas) barrier but good-moderate moisture barrier properties.

Page 17: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

PE & PP MVTR Properties

Page 18: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

PE & PP OTR Properties

0.1

1

10

100

1000

cc-m

il/10

0in2 /d

ay

Foil

PVdC or metP

ET

PVdC or metO

PP

Cello

OPETNylo

n 66

OPPHDPE PPLDPEPap

erNon

-Wov

en

Page 19: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5

Gauge (mils)

g/10

0in2 /d

ay

HDPE MVTR

HDPE MVTR Grade Blown Film

Page 20: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Using PE & PP for BarrierPE & PP can be combined (blended, coexed, or laminated) with other materials for exceptional MVTR & OTR.

PE & PP properties and processing methods influence barrier properties.

Page 21: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

H H

H

C C

H

ETHYLENEETHYLENE

Colorless GasOdor = Slightly SweetOrigins = Refinery Gas &Liquefied Petroleum GasesMol. Wt. = 28

World Capacity*128 Million Tons. (2005 est.)

* World Petrochemical Review (Oct 2005)

Colorless GasOdor = Slightly SweetOrigins = Refinery Gas &Liquefied Petroleum GasesMol. Wt. = 28

World Capacity*128 Million Tons. (2005 est.)

* World Petrochemical Review (Oct 2005)

Page 22: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

H H

H

C C

H

Catalyst/InitiatorTemperature

Pressure

Catalyst/InitiatorTemperature

PressureH H

H

C C

H

H H

H

C C

H

H H

H

C C

H

Polyethylene Reaction

H H

H

C C

H

H H

H

C C

H

H H

H

C C

H

H H

H

C C

H

Page 23: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

HDPEHDPE

LDPELDPE

LLDPELLDPE

Page 24: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

MOLECULAR WEIGHT

DISTRIBUTION (MWD) HDPE

MOLECULAR WEIGHT

DISTRIBUTION (MWD)

COMONOMBER TYPE (SCB)LLDPE

MOLECULAR WEIGHT

DISTRIBUTION (MWD)

LONG CHAIN BRANCHING (LCB)

CRYSTALLINITY

CRYSTALLINITY

CRYSTALLINITY

LDPE

Page 25: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Critical Polyethylene Properties

Melt Index / Mol. Wt. Density / Crystallinity

Morphology (shape, size & distribution of the PE molecules & crystals)

Molecular Weight Dist.Long Chain BranchingRheology

Page 26: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

DensityDensity is a measure of the crystallinity of the polymer.Higher density polymers have more closely packed molecules and are more stiff in nature.Lower density polymers have loosely packed molecules and are more flexible.Density is measured as the weight of material occupying a specific volume (g/cc).

No Branching – High Density

Short Chain Branching –Med Density

Short & Long Chain Branching –Low Density

Page 27: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

CrystallineRegions

AmorphousRegions

Page 28: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Density Test

Density is an indirect measure ofthe crystallinity of a polymer.

Standard Procedure : ASTM D1505Units = g/cc

Calibrated Density Standards

Sample

Controlled TemperatureGradient Column

Other accepted techniques for measuring density include ultrasonic velocity and buoyancy (densimeter).

Page 29: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 30: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

As Crystallinity IncreasesThese Properties

Increase

DensityStiffnessTensile StrengthSoftening PointDead FoldCurl

Chemical ResistanceHeat ResistanceWrinkling TendencySeal Initiation Temp.Barrier (Moisture, Light, & Grease)

Decrease

MD Tear StrengthImpact

Puncture ResistanceCOF

Optics (Clarity)

Page 31: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Crystallinity

For polyethylene, the degree of crystallinity has the largest influence on barrier properties.

Randomly oriented, large crystals, create the most tortuous path.

% crystallinity can be measured and is influenced primarily by polymer type, but also by processing.

LDPE/LLDPE ~ 30% - 55% crystallinityHDPE up to 85% crystallinity

In addition to % crystallinity, morphology (alignment, shape & dimensions of crystals), also affects barrier performance. Processing methods also influence the degree of crystallinity and polymer morphology, which will also directly affect barrier properties. Types of processing methods….

Page 32: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Produces high barrier structures by coextruding PE & PP with high barrier

materials, predominantly nylon and EVOH.

Page 33: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Produces high barrier structures by coextruding PE & PP with high barrier

materials, predominantly nylon and EVOH. Also produces good moisture barrier monolayer films using HDPE

MVTR grades.

Page 34: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Capital CostOutputGauge ControlOptical PropertiesRetrofit to CoexAdditive LoadingFilm StrengthBiax OrientationMVTR Barrier

CAST FILM BLOWN FILM

Page 35: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Processing Conditions Affecting Barrier

Page 36: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5

Gauge (mils)

g/10

0in2 /d

ay

HDPE MVTR

HDPE MVTR Grade Blow Film

Page 37: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1.25 1.75 2.25 2.75 3.25

Gauge (mils)

g/10

0in2 /d

ay

HDPE MVTR

HDPE MVTR Grade Blow Film

BUR = 1.5

BUR = 2.5

Page 38: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Extrusion Coating Process

Page 39: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Barrier Considerations in Extrusion Coating

HDPE must be blended or coextruded with LDPE for processability in extrusion coating.Blending with highly branched LDPE extrusion coating grades disrupts crystallinity and reduces barrier. Most orientation is in machine direction (similar to cast film). Lack of biax orientation reduces barrier compared to MVTR blown film.Properties dependent on level of comonomerSome applications only require “moderate” barrier and LDPE or HDPE in extrusion coating can work (e.g. sugar pouch).

Page 40: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

Extrusion Coating MVTR

HDPE

00.5

11.5

22.5

0 20 40 60 80% HDPE

g-m

il/10

0in2 /d

ay

BlendCoex

Page 41: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

How to Destroy Barrier in

Extrusion Coating

Page 42: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 43: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties
Page 44: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

SummaryPE & PP are used directly or indirectly in flexible barrier packaging. To achieve oxygen (gas) barrier, PE & PP are typically coextruded or laminated with other materials. HDPE MVTR grades provide good moisture barrier properties.Manufacturing methods and process conditions influence barrier properties.

Page 45: Polyethylene & Polypropylene in Flexible Barrier Packaging · Learning Outcomes yHow polyethylene & polypropylene is used in barrier packaging. yBarrier properties of PE & PP. yProperties

PRESENTED BY

Kelly R. FreyExtrusion Coating – Technical ServiceChevron Phillips Chemical Company, LP

Please remember to turn in your evaluation sheet...