Flexible Packaging Flexible Packaging Design & Selection Design & Selection Bhupendra Singh
Oct 14, 2014
Flexible Packaging Flexible Packaging Design & SelectionDesign & Selection
Bhupendra Singh
PACKAGING FUNCTIONS
Package is the means of providing
PROTECTION CONTAINMENT
PRESENTATIONIDENTIFICATION/
INFORMATION
CONVENIENCE
BRAND PROTECTION
PACKAGING FUNCTIONS
•• ““Packaging must protect Packaging must protect what it sells, and sell what it sells, and sell what it protectswhat it protects””
Flexible Packaging
Flexible Packaging is defined as construction made from flexible substrates.E.g. Paper, plastic films, aluminum foil
and other laminates. These materials can be coated or laminated.
Applications
A Flexible Pack Offers the Following Advantages: -
• Variety, reduction in size.• Convenience of storage resulting in
space saving.• Ease of opening and reclosing.• Light weight.• Disposability.
Components used :-• Paper, Metallic Foil, Cellophane, LDPE, HDPE,
Polypropylene, Polyester, Nylon, and Oriented Polypropylene etc.
Substrate combination selected On the Basis of:-
• Strength, printability, heat salability, opacity, barrier to moisture & oxygen and similar type of characteristic.
E.g Paper - Stiffness & printability Foil - Barrier properties & aesthetic appeal HDPE - Stiffness& low WVTR
Factors influencing Flexible Packaging Design & Selection
0 . Spoilage of Product1 . Factors Influencing
Pack Design2 . Factors Influencing Package
Material Selection
Spoilage of Product
0 . Spoilage of product results from
- Chemical Incompatibility between the
ingredients of the product / packaging material
-Moisture,
-Oxygen,
-Light &
-Temperature changes
Spoilage of Product
0 .1 Effects of Moisture
Ψ Crystalline substances absorb moisture, e.g.
CaCO3, Na-Sulphate
Ψ Aspirin can be hydrolyzed by water absorption
Ψ Vitamins are also susceptible to moisture
Ψ Suitable packaging material should be used to
prevent / reduce the effect of water / moisture.
Spoilage of Product
0 .2 Effects of Light & OxygenΨ Light has a catalyzing effect on degradation by
oxygen.Ψ The degradation products may be toxic.Ψ It is essential that light does not affect the
product.Ψ Suitable packaging material should be used (e.g.
Amber colour glass Bottle) to prevent / reduce the effect of light or the product should be modified if possible.
Spoilage of Product
0 .3 Effects of HeatΨ Heat can cause product to loose the water of
crystallization & convert the product into amorphous state.
Ψ The rate of vaporization of some products are affected by changes in heat (liquid products).
Ψ Many medications are deactivated / degraded by heat & exposure to light further accelerate the heating effect.
Ψ Suitable packaging material with adequate protection from heat should be used. Insulation may also be used along with coolant for long term transport & storage.
Spoilage of Product
0 .4 Effects of Other FactorsDistribution Hazards
• Mechanical Hazards of transportation• Climatic Hazards of distribution• Biological hazards of distribution• Compatibility
Spoilage of Product
0 .4.1Mechanical Hazards of transport• Hazards of loading & Unloading
• Drops, Height of drop
• Hazards of Movements– Rail : (Shunting Shocks, Vibration, Acceleration /
Deceleration hazards )
– Road : (Vibration, Bouncing of load, Acceleration / Deceleration hazards )
– Water : (Staking, Vibration hazards )
– Air : (Low pressure, High frequency Vibration hazards )
– Multi-modal Transport– Hazards of warehousing
Spoilage of Product
0 .4.2 Climatic Hazards of distribution
• Exposure to liquids/ water
• Exposure to vapour/ humidity
• Temperature Change (Low / High)
• Pressure Changes (Low / High)
• Dust storms
Spoilage of Product
0 .4.3 Biological Hazards of distribution
• Biological Hazards– Microorganisms
• Fungi
• Moulds
• Bacteria
– Insects• Beetle, Ants, Termites
– Mites
– Rodents
• Metal Containers• Fiber / Plywood• Drums• Multi-wall• Heavy-duty Plastics Sacks
Package Design - Bulk Packaging
FLEXIBLE PACKAGING –Manufacturing
(CO-EXTRUSION ANDLAMINATES)
Manufacturing processes of Flexible Composites
i. Laminationii. Extrusion coatingiii. Co-extrusion
LAMINATIONFLEXIBLE LAMINATES FOR
PACKAGINGIt consists of superimposed layers of plastics,
paper or foil bonded together by heat or adhesive or polymer melt to form a composite film of uniform thickness and flexibility.
A Laminate is defined flexible, when substantially parts of it can be folded to 180°without cracking and without the need of pre-crease.
Any desired properties can obtained by different combination.
TECHNIQUES OF LAMINATION
• Extrusion coating• Extrusion lamination • Adhesive lamination• Heat lamination • Wax lamination • Hot melt coating
1. Extrusion Coating• Involves the
application of molten polymer from an extruderto the surface of flexible substrate
• Polymer used is LDPE, EVA, HDPE, PP etc.
2) Extrusion lamination :-Hot extruded film is trapped between two other
webs and cooled.3) Adhesive lamination: -
Applying adhesive to one ply then combining with another
4) Heat Lamination :–Heat sealable performed film like polyethylene is
laminated to the backing substrate 5) Wax lamination :–
Molten wax is applied to one ply of material then combined with second ply.
APPLICATION
1) Cellophane/ Polyethylene/ Foil/ Polyethylene
Excellent gas barrier,sandwich printing wv resistance
Pharmaceutical tablets, chocolates.
2) Foil/ Adhesive/ Paper/ Polyethylene
WVbarrier, good machnability, good appearance.
Soup mixes, drink powder and dry milk solids.
APPLICATION3) Foil/ Polyethylene
Excellent barrier to gas, Water vapors and light
Hygroscopic products in strip packaging4) Polyamide/ Polyethylene
Good gas barrier, Good W V resistance, and Aroma retention.
Meat packing, cheese, boil in a bag pouches, heavy machinery parts.
Aluminum foil bearing laminates (food packaging)
• Waxed rappers:-foil /paper/wax• Toffee rappers;-foil/ adhesive/paper/wax • Food overwrapes:-foil/ adhesive/ paper• Boil in bag pouch:-PET/foil/LDPE• Instant coffee:- paper/ foil/ PE • Soft drink conc. :- glassine/foil/LDPE
(withstands product sterilization in package)• Retort pouch:- polyester/foil/HDPE• M.R.E package (meal ready to eat):- PET/ foil /PP
CO-EXTRUSION
Co-extruded film is defined as a multiplayer film in each distinct layer is formed by simultaneous extrusion process through a single die.
Co-extrusion allows one to prepare a multifunctional packaging material in one manufacturing step as opposed to traditional multistep process of coating and lamination.
TECHNOLOGY OF CO-EXTRUSION
• Extrusion of different polymers through different extruders.
• Combining them at a common die as different layers.
• Then blown by compressed air,which forms bubble between the die head and nip rollers
• The nip rollers make the tabular film in lay flats, passed on, to the winding and slitting unit.
• The compressed air settles the bubbles is important to create uniform width
Co-extrusion could be considered depending upon application and number as: -
• Two Layers• Three Layers• Five Layers or more
Extruder
Fig : Schematic illustration of a typical extruder for plastics, elastomers, and composite materials.
Sheet Extruder
Fig : Die geometry (coat-hanger) for extruding sheet.
Film Extruder
Fig : Schematic illustration of the production of thin film and plastic bags from tube first produced by an extruder and then blown by air.
Principle Processes utilizing Co-extrusion Technology
1. Cast Film Co-extrusion.2. Blown film Co-extrusion.3. Co-extrusion Coating.4. Co-extrusion Lamination5. Cast-sheet Co-extrusion.
Cast Film Co-extrusion:-
Main Focal Point of Technology in the Cast Film Process is a Design of Die.
Two Types of Dies used:-
Blown film Co-extrusion
Separate resins are extruded into a Circular die.The molten resin streams are blown into a bubble, cooled by air rings and collapsed in the primary nip. The tabular film is generally slit for specific packaging application.
PRINCIPLE RAW MATERIALS
• Polyolefin (polyethylene and polypropylene)
• HDPE-LDPE resin• Copolymers of Ethylene Vinyl Acetate
(EVA), Ethylene Acrylic Acid (EAA) and Ethylene Methacrylic Acid (EMA)
• nylon, polyvinylidine chloride, PVDC and ethylene-vinyl alcohol (EVOH)
RAW MATERIALS FOR LAMINATES
• Paper• Aluminum foil• Plastic film • Rubber hydrochloride• Regenerated cellulose
Materials Involved
• PET -- 10, 12 micron• BOPP -- 15 to 30 micron• Met PET -- 10, 12 micron• MetBOPP -- 15 to 30 micron• Foil – 7 to 12 micron• PE Sealant – 20 to 140 micron• Paper – Maplitho, Glassine, Kraft
Sealant Layer
• Polyethylene based -- LDPE, LLDPE,
• Metallocene LLDPE, Nylon PE, EVOH PE,
• MDPE, HDPE,
• Polypropelene Based -- CPP
PVDC
Acrylic
PVOH
LTS
Methyl Acrylic Acid
Matt
U. V. Varnish
Hotmelt
Heat Resistant
Holograph Effect
Release
Nano Composite Materia
Al203
Siox
SPECIALITY COATINGS
SIOX Coated Film
AL203 Coated Film
Methyl Acrylic Acid Coated Film
Breathable Films
PP / PE Composite Film
Susceptor Film
NEW BARRIER SUBSTRATES
MATERIAL COMBINATION AND PURPOSES
In multilayer film specific function of each layer can be obtained by designing a symmetrical or non-symmetrical structure.
A/B/C/B/A –symmetrical structure
A/B/C/B/D –non-symmetrical structure
For E.g. 3-layer co extrusion process one layer of material A, tie layer & material B.
tie layer consists of a chemically modified polymer that possesses good bonding properties for adhesion to material A as well as B.
Plasma
Metallizing process
MetallizedSubstrate
Wafer
Gas
Cathode Power Uncoated
PLASMA PROCESS
Combination Application Achievable Property
LDPE/LDPE Milk film Two colors
HDPE/EVA a) Blood plasma b) Food products
Good mechanical and sealing property
Nylon/Tie/EVOH/tie/ LLDPE
Ketch –up moisture & gas barrier
PP/HDPE/PA Cosmetics & pharmaceutical products.
Printable, scratch resistant surface
PP/Tie/ EVOH/Tie/ PP
Fruit juice Gas, steam & aroma barrier
ADVANTAGES OF CO-EXTRUSION OVER LAMINATION
• Eliminates the extra production cost involve in Adhesive Lamination.
• Eliminates the use of solvent-based adhesives • Reduce the amount of expensive polymer, by
reducing film thickness
DI SADVANTAGES OF CO-EXTRUSION
Laminate with sandwich printing can not be produced
Scraped produced can not be regranulated
Typical Structures for Typical applications
DESIGN
OPP OR PETPRINTADHESIVEFOIL OR METOPP
PE, OPP ORCPP
REVERSEPRINTEDFILM
BARRIER
SEALING
METALLISED
PRODUCT
ADHESIVE
LAMINATE STRUCTURE
Developments in Flexible Packaging
Biscuits
• BOPP / BOPP hs• BOPP / Met BOPP hs• BOPP / Met PE• PET / Met PET / PE
Biscuits
Biscuits
Candies :
Medium Barrier :• BOPP / CPP• PET / PE• PET / PP-PE
Candies – High Barrier
• BOPP / Met BOPP Hs
Candies :
Candies :
Chocolates :
Bars :
• Cold Seal For :1. Sealing without exposure to heat.2. Excellent seal integrity.3. High line speeds.4. “Registered”
Chocolates :
Chocolates :
Chocolates :
Cakes and bakery products :
Bakery products :
Snack Food
Gas Flushed
• PET / Met PET / PE
Snack Food
Snack Food
Beverages
TEA COFFEEPET / PE PET/Foil/PEBOPP / Paper / PE PET/Met PET/PE
Milk & Health drink
LDPE co-ex LLDPEPET / FOIL / PEPET / Met PET / PE
Milk & Health drink
Milk & Health drink
Ketch – Up
PET / Foil / PET / PEPET / Met PET / PEPET / PE / Foil / Special Poly
Retort Application
PET / Foil / CPP
Retort Application
Retort Application
Retort Application
Oil Packaging
• PET/PE• PET/Met PET/PE
Ice Creams
• BOPP / PE• PEARLISED BOPP hs
Vegetables
Vegetables
Vegetables
Vegetables
Other applications
Flexible Pack
Flexible Pack
Flexible Pack
Flexible Pack
Flexible Pack
Flexible Pack
BOND / SEAL STRENGTH
DYNAMIC / STATIC COF
COLD / HEAT SEAL
BALLOON BURST
SEAL LEAKAGE
BURSTING STRENGTH
ORGANOLEPTIC TESTS
COLOUR SPECTROMETER
INSPECTION / TESTS
OPTICAL DENSITY
DART IMPACT
COMPRESSION STRENGTH
BLOCKING MEASURE
SCUFF RESISTANCE
PIN HOLE MEASUREMENT
GAS CHROMOTOGRAPHY
OTHER RM TESTS
THICKNESSUNIT : (mm/GAUGE/Microns)EQUIPMENT : DIAL GAUGE MICROMETER
IMPORTANT PROPERTY - AFFECTING:• MECHANICAL PROPERTIES• SEALABILITY• BARRIER PROPERTIES• PERFORMANCE• PRODUCT PROTECTION.
TENSILE STRENGTH / ELONGATIONASTM D. 638
• IMPORTANT MECHANICAL PROPERTY.
• RESPONSIBLE FOR HIGH SPEED PACKAGING OPERATIONS.
• EQUIPMENT : INSTRON TYPE TENSILE TESTER.
• UNIT : kg/cm2
PERCENTAGE(%).
IMPACT RESISTANCEIS : 2508
• DART IMPACT TEST.• UNIT g f at 50% FAILURE• DROP HEIGHT : 66 CMS• DROP HEIGHT : 155 CMS.
STATIC COEFFICIENT OF FRICTIONASTM D.1894
• RELATED TO SLIP PROPERTIES.• TILTING PLANE METHOD• SLEDGE 200g.• AGE OF FILM• BLOOMING ACTION OF SLIP ADDITIVES.
KINETIC COEFFICIENT OF FRICTION ASTM D.1894
• FRICTION BETWEEN STEEL COLLAR AND FILM.
HEAT SEAL STRENGTHASTM F-88
DIRECTLY RELATED TO:
1. DWELL TIME ,TEMPERATURE , PRESSURE.2. SEAL CONTAMINATION.3. THICKNESS VARIATION.4. MFI.5. TYPE OF SEALANT LAYER• TYPE OF SEALING PROCESS (IMPULSE /
HIGH FREQUENCY / ULTRASONIC).• UNIT : kg/15 mm.• EQUIPMENT : TENSILE TESTER.
BOND STRENGTHASTM D-904.
• RELIABILITY OF CONTINUING ADHESION DURING PACKAGING, SEALING AND STORAGE.
• THE DEGREE OF BOND VARIES1. THE INFLUENCE OF OILS / SOLVENTS.2. THE ADHESIVE USED.3. THE QUANTITY OF ADHESIVE.4. AFFINITY TO MOISTURE.5. EXCESS SOLVENT RETENTION.6. CLIMATIC CONDITIONS.
UNIT : g / 15mm.EQUIPMENT : TENSILE TESTER.
WATER VAPOUR TRANSMISSION RATE IS 1060 –II, ASTM E-96, ASTM E-398
UNIT: (G/M2/24 HRS.) AT 38 ±1°C & 90± 2% RH.
• MOST IMPORTANT BARRIER PROPERTY FOR MOISTURE SENSITIVE PRODUCTS
• DECIDES SHELF LIFE OF THE PRODUCTS
• DIRECTLY PROPORTIONAL TO THICKNESS
• VARIES FROM POLYMER TO POLYMER
OXYGEN TRANSMISSION RATEASTM D – 3985.
1. MANOMETRIC METHOD.
2. CARRIER GAS (SENSOR).
• UNIT : cc / m2/ 24 hrs / ATM.
• MOST IMPORTANT PROPERTY FOR GAS SENSITIVE PRODUCTS
• VACCUUM PACKAGING / GAS PACKAGING MATERIALS
New Concepts/Materials
Holograms
Bar coding
Expanded content labels
RFID tags