2010-02-05

1

History of Packaging

•6000 B.C. Clay vessels (Keramos=krukmakarlera)

•2500 B.C.= Glass pearls in Babylonia•1500 B.C.= Glass vessels in Egypt•1000 B.C.= Blowing glass in Syria•1600 B.C.= Glass bottles in Sveden

•0-500 A.D.=Wood barrels in the Roman empire•1300 century=”Laggade” wood barrels in Sweden

The packaging history

•1600’s = Paper in Sweden •1800’s = Paper machine •1850’s = Machine made bags•1871 = Corrugated board

•1812= Canning technique, Napoleon (tin cans)

•1950’s= Plastics in packagings

•New needs: 18000 manual stores (1950), 1000 in 1975

2010-02-05

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The packaging-the myth-Material need for 500 g coffee

•Glass 470 g

•Laminate 11g

•Plate 120 g

A car full of laminate packagings replaces three cars with glass packagings for the same amount of coffee

Estimated end uses of plastics, by weight

v Packaging 37%v Building and construction 23v Electrical and electronic 10v Transport 9v Furniture 5v Housewares 3v Agriculture 2v Medical 2v Sport 2v Clothing 1v Others 3

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MaterialsPolyethylenePolypropylenePolypropylenePolyamidePolystyrenePVCPETPPolycarbonateEpoxyPUR

Polyethylene

HH

VLDPE, LDPE, LLDPE, MDPE, HDPE, UHMWPE

+• high toughness• resistant to chemicals• low price• low water absorption

• Tg≈-70°C• Tm≈105-140°C

C C

H

HH

Hn

-• low creep resistance• high shrinkage• UV-sensitive•difficult to glue

• pipes, cables• packaging• housewares

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Polyethylene copolymerspolar copolymers, E/VA, E/BA

+• high toughness• transparent• easy to glue

C C C

O

HH

Hn

C

H

H

H

H

C O

CH3

•

-• higher water absorption• weaker than HDPE

• tie-layer in laminates• packagings, cable insulations• emulsion paints

Aseptic packaging

Aseptic packaging with PE

hydrogen peroxide

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Extrusion Blow MoldingHDPE bottles for milk

E t i bl ldiExtrusion blow molding

Shrink film

Stretch film at softened state (but below melting T)

PVC and polyolefins

Stretch film at softened state (but below melting T)

Tenter frame or bubble process to yield uni- or biaxial orientation

Heat will cause shrinkage

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Stretch film

El ti l ti filElastic-plastic film

LLDPE, PVC or EVA

Cast (clear) or blown (hazy) films

Blown film with cling properties:Polyisobutylene tackifier

”Clings only to itself”

Extrusion coating

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PE or PP bags

<30 µm films

”Bubble, tubular or blown film process”

µ(bags/packagings)

<250 µm films(2 m wide LDPE, low MFIconstruction, extension max. 1:1.8)

Shrink films (1:3, 1:5)

Position of blowing equipmentEasy start, high melt strength

Thin films40 m/min

Short distance for melt, PVC

Large thick partsFrostline

Important: temperature control (even thickness)

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Polypropylene

CH3H

+• stiffer than HDPE• low density• steam sterilisation• high fatigue strength

• Tg≈-10°C• Tm≈165°C

C C

HHn

high fatigue strength

-• brittle below -20°C• UV-sensitive• relatively difficult to glue

• car panels• ropes, pipes• chassis • packagings

Blow-fill-seal (BFS)

Blow-fill-seal (BFS)

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Oriented PP

Hot fillingKill microorganismsLower viscosity of foodLower viscosity of food

JamFruit juicesTeaKetchup

77-100°C

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Polyamide (PA)PA6, PA6,6

H O

+• abrasion resistant• fatigue and creep resistant• high chemical resistance• can endure high T

• Tg≈50°C• Tm≈175°C

N (CH2)5 C

n

can endure high T

-• UV-sensitive• high water absorption

• gears• screws• cable isolation• oil-contact applications

Polystyrene (PS)

C C

HH

+• low mould shrinkage• hard, stiff • low price

-• Tg≈100°C

Hn

-• brittle (HIPS, ABS tough)• low Tg• low chemical resistance• UV-sensitive

• Packaging (HIPS)• Cellplastics (EPS)• Cars, whitewares (ABS)

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High impact polystyrene (HIPS)

Acrylonitrile-butadiene-styrene (ABS)

a b

c

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Thermoforming PS and others

Expanded polystyrene

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Blowing agents

v Polymers in a cellular form are used in very large volumes for thermal insulation and ”soft damping” (furnitures)Cells can be interconnected or notv Cells can be interconnected or not.

v Different gases can be housed in the cells

Blowing agents-mechanisms

v Chemical blowing agents: compounds decompose at some stage to yield volatile species (ex. Azocarbonamide yields CO, CO2 and N2)

v Incorporation of low boiling liquids which volatilise during processing (PS, PUR)

v Diffusion of gases into polymer under pressure with ff f g p y psubsequent expansion at elevated temp. under decompression (a wide variety of polymers)

v Incorporation of solid CO2 in plastic (plasticized PVC)v Mechanical whipping of liquid - setting of whipped state

(latex rubber foam)

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PETPPoly(ethylene terephthalate)

+• stiff, hard• good chemical resistance• UV-resistant

i i d di i

• Tg≈70°C

O C

O

C O CH2

n

O

CH2

• creep resistant in dry conditions

-• sensitive to hydrolysis• high mould shrinkage/warping• low ductility at cracks

• photofilms• bottles• packagings

PETP copolymers1, 4 - Cyclohexane dimethanol

PETP

aPET

HOH2C CH2OHIsophthalic acid

PETP

CPET

Extruded sheet for blister-pack applications

High melt strength and amorphous material

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2010-02-05

15

PETP copolymers

CPET QuickTime och enTIFF (LZW)-dekomprimerare

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Longer alkane part (”PBT”)PlasticisersNucleating fillers

PETP bottlesPETP bottles (“homopolymer”)

h bl ld

Biaxial orientation≤40% crystallinity

Stretch blow molding

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Biaxially oriented PETP(tenter process)

TENTER(T.D. Draw)

WIND UP

RECYCLE PETEG

DMT

PETMELT

CONTINUOUS

POLYMERIZATION

UNIT

➋➌

➍

M.D. DrawMD drawPETP l

Recycled PETP

Wind up

DMT+EG

CASTING DRUM

EXTRUDER

MELT

DIRECTION OF FILM PATH

➊

➍

Casting drum

PETP meltTD draw

Biaxially oriented PETP

Property: MDTD

Ultimate tensile strength (MPa) 200

240Strength at 5% strain (MPa) 100 100

Modulus (GPa) 4.95.1

F t t i (%) 116 91

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Blister packs

aPET

Foamed PETPLow density

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PVC

+• high chemical resistance• stiff • low price

• Tg≈80°C

C C

Cl

HH

Hn

Poly(vinyl chloride)

p

-• brittle at low T• low Tg

• Leather imitations• Cables• Pipes• Construction

PVC Bags

Blow casing or calendering QuickTime och enTIFF (LZW)-dekomprimerare

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RF welding

2010-02-05

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Thermoformed rigid PVC as clam-shells

Polycarbonate (PC)

+• excellent ductility (also at low T)• good weatherability• glassfiber

i i d di i

• Tg≈150°C

C

CH3

CH3

O C

O

O

n

• creep resistant in dry conditions

-• sensitive to hot water• environmental stress cracking• scratch sensitive

• safety glass• propellants• helmets• CD/DVD

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Polycarbonate (PC)

Epoxy

+• excellent adhesion• abrasion resistant• stiff, hard• chemical resistance• dimensional stability

HO C

CH3

CH3

OH

H2CHC CH2

ClO

crosslinked with a diamin• dimensional stability

-• sensitive to alcohol• monomers unhealthy

• paints, lacquers, glue• coating of metals• encapsulation of electric components

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Aluminium cans

Epoxy coatingsp y g

PURpolyurethane thermoset

+• stiff, ductile, abrasion resistant• chemical resistance• large range in properties

HO R OH N C O R' O+

R N C O R'

C N

H O

large range in properties• UV resistant

-• smoke and dang. gases upon fire• opaque

• electronic incapsulation, casings• prototypes

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PURpolyurethane cellplastics (stiff)

+• stiff, ductile, abrasion resistant• chemical resistance• low heat conduction

HO R OH N C O R' O+

R N C O R'

C N

H O

+ water = CO and cellplastic • low heat conduction• low mold pressure

-• UV-sensitive• smoke and dang. gases upon fire

• casings, covers• furnitures

+ water CO2 and cellplastic

PUR

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