Flexible Packaging Design & Selection Bhupendra Singh
PACKAGING FUNCTIONS Package is the means of providing
PACKAGING FUNCTIONS
• “Packaging must protect what it sells, and sell what it protects”
Flexible Packaging Flexible Packaging is defined as construction made from flexible substrates.. substrates E.g. Paper, plastic films, aluminum foil and other laminates. These materials can be coated or laminated.. laminated
Applications
A Flexible Pack Offers the Following Advantages: • Variety, reduction in size. • Convenience of storage age resulting ing in space saving. • Ease of opening and reclosing. • Light weight. • Disposability.
Components used :• Pape Paper, r, Met Metal alli licc Foil Foil,, Cell Cellop opha hane ne,, LDPE LDPE,, HDP HDPE, E, Polypropylene, Polyester, Nylon, and Oriented Polypropylene etc.
Substrate combination selected Basis of:-
On the
• Stre Streng ngth th,, pri print ntab abil ilit ity, y, heat heat sala salabi bili lity ty,, opa opaci city ty,, barrier to moisture & oxygen and similar type of characteristic. E.g Paper Paper - Stiffn Stiffness ess & printa printabil bility ity Foil - Barrier Barrier properties properties & aesthetic aesthetic appeal appeal HDPE HD PE - Stif Stiffne fness ss& & low low WVTR WVTR
Factors influencing Flexible Packaging Design & Selection
0 . Spoilage of Product 1 . Factors Influencing Pack Design 2 . Factors Influencing Package Material Selection
Spoilage of Product
0.
Spoilage of product results from
- Ch Chem emic ical al Incom Incompa patib tibili ility ty 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 & Oxygen Ψ Ψ
Light has a catalyzing effect on degradation by oxygen. 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 Heat Ψ Heat can cause product to loose the water of
Ψ
Ψ
Ψ
crystallization & convert the product into amorphous state. The rate of vaporization of some products are affected by changes in heat (liquid products). Many medications are deactivated / degraded by heat & exposure to light further accelerate the heating effect. 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 Factors • • • •
Distribution Hazards Mech Me chan anic ical al Haz Hazar ards ds of of tra trans nspo port rtat atio ionn Clim Cl imat atic ic Ha Haza zard rdss of of di dist stri ribu buti tion on Biol Bi olog ogic ical al ha haza zard rdss of of dis distr trib ibut utio ionn Compatibility
Spoilage of Product
0 .4.1Mechanical Hazards of transport • Haza zarrds of of lo loading & Un Unloadin ingg • Dr Drop opss, He Heig ight ht of dr drop op
• 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 ) – Mu Mult ltii-mo moda dall Tra Trans nsppor ortt H ds f w eh in
Spoilage of Product
0 .4.2 Climatic Hazards of distribution • Exposure to liquids/ water • Exposure to to va vapour/ hu humidity • Te Temp mper erat atur ure e Ch Chan ange ge (L (Low ow / Hig igh h) • Pressure Ch Changes (L (Low / High) • Dust storms
Spoilage of Product
0 .4.3 Biological Hazards of distribution • Biological Ha Hazards – Microorganisms • Fungi • Moulds • Bacteria
– Insects • Be Beet etle le,, An Ants ts,, Te Term rmit ites es
– Mites – Rodents
Packa Package ge Des Desig ign n - Bulk Bulk Pack Packag agin ing g
• • • • •
Metal Containers Fiber / Plywood Drums Multi-wall Heav Heavyy-du duty ty Plas Plasti tics cs Sack Sackss
FLEXIBLE PACKAGING – Manufacturing (CO-EXTRUSION AND LAMINATES)
Manufacturing processes of Flexible Composites i. Lamination ii. Extrusion coating iii. Co-extrusion
LAMINATION FLEXIBLE LAMINATES FOR PACKAGING It 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 precrease. Any desired properties different combination.
can
obtained
by
TECHNIQUES OF LAMINATION • • • • • •
Extrusion co coating Extrusion ion laminati ation Adhesive la lamination Heat lamination Wax lamination Hot melt coating
1. Extrusion Coating • Involves the application of molten polymer from an extruder to the surface of flexible substrate • Polymer used is LDPE, EVA, HDPE, PP etc.
2) Extr Extrus usio ionn la lami mina nati tion on :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) Wa Wax x lami lamina nati tion on :– :– 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 resistanc Pharmaceutical tablets, chocolates. 2) Foil/ Adhesive/ Paper/ Polyethylene WVbarrier, good machnability, good appearance. Soup mixes, drink powder and dry milk solids.
APPLICATION 3) Foil/ Polyethylene Excellent barrier to gas, Water vapors and light Hygroscopic products in strip packaging 4) 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) • • • • • •
Wax Waxed rapp appers: ers:-f -foi oill /pap /paper er/w /wax ax Toff To ffee ee rap rappe pers rs;;-fo foil il// adhe adhesi sive ve/p /pap aper er/w /wax ax Food Food over overwr wrap apes es::-fo foil il// adh adhes esiv ive/ e/ pape paperr Boil Bo il in bag pouc pouch: h:-P -PE ET/fo T/foil il/L /LDP DPE E Instant coffee:- paper/ foil/ PE Soft drink ink conc. nc. :- glassine/ ne/foil/ il/LDPE (withstands product sterilization in package) • Reto etort pouch:- polyester/foil/ il/HDPE • M.R M.R.E pac packag kage (me (meal al read readyy to to eat eat): ):-- PET/ PET/ foil foil /PP /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 allows one to prepare a multifunctional multifunctional packaging material in one manufacturing step as opposed to traditional multiste multistepp process process of coating coating and laminati lamination. on.
TECHNOLOGY OF CO-EXTRUSION • Extr Extrus usio ionn of of dif diffe fere rent nt poly polyme mers rs thro throug ugh h different extruders. • Comb Combin inin ingg the them m at at a comm common on die die as as d dif iffe fere rent nt layers. • Th Then en blow blownn by by com compr pres esse sed d air air,w ,whi hich ch form formss bubble bubble betwee betweenn the die die head and and nip roll rollers ers • Th The e nip nip roll roller erss mak make e the the tabu tabula larr fil film m in in lay lay flats, passed on, to the winding and slitting unit. • Th The e com compr pres esse sed d air air sett settle less the the bubb bubble less is is important to create uniform width
Co-ex Co-extru trusio sion n could could be consid consider ered ed depe dependi nding ng upon application and number as: -
• Two Layers • Three Layers • Five Layers or more
Extruder
Fig : Sche Schem matic atic illustr illustrati ation on of a typical extruder for plastics, plastics, elastomers, elastomers, and composit posite e material materials. s.
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. 2. 3. 4. 5.
Cast Film Co-extrusion. Blown film Co-extrusion. Co-extrusion Coating. Co-extrusion Lamination 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 • Polyo lyolefi lefinn (p (poly olyeth ethylen ylene e and and polypropylene) • HDPE-LDPE resin • Copo Copoly lyme mers rs of Ethy Ethyle lene ne Viny Vinyll Ace Aceta tate te (EVA), Ethylene Acrylic Acid (EAA) and Ethylene Methacrylic Acid (EMA) • nylo ylon, polyv olyviinyl nylidin idine e chl chlorid ride, PVDC VDC and ethylene-vinyl alcohol (EVOH)
RAW MATERIALS FOR LAMINATES • • • • •
Paper Aluminum foil Plastic film Rubber hydrochloride Rege egenerate ated ce cellulose ose
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
SPECIALITY COATINGS PVDC
Hotmelt
Acrylic
Heat Resistant
PVOH
Holograph Effect
LTS
Release
Methyl Acrylic Acid
Nano Nano Comp Compos osit ite e Mate Materi ri
Matt
Al203
U. V. Varnish
Siox
NEW BARRIER SUBSTRATES
SIOX Coated Film AL203 Coated Film Methyl Acrylic Acid Coated Film Breathable Films PP / PE Composite Film Susceptor Film
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 PROCESS
Wafer
Gas
Metallizing process
Plasma
Cathode Uncoated
Power
Metallized Substrate
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/EVO Ketch –up H/tie/ LLDPE
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
• Elim Elimin inat ates es the the eext xtra ra prod produc ucti tion on cost cost invo involv lvee in in Adhesive Lamination. • Elim Elimin inat ates es the the use use of of solv solven entt-ba base sed d adhe adhesi sive vess • Redu Reduce ce the the amo amoun untt of of exp expen ensi sive ve poly polyme mer, r, by reducing film thickness DI SADVANTAGES OF CO-EXTRUSION
Laminate with sandwich printing can not be produced Scraped Scraped produc produced ed can can not be be regranula regranulated ted
Typical Structures for Typical applications
LAMINATE STRUCTURE
REVERSE PRINTED FILM
OPP OR PET
DESIGN
PRINT ADHESIVE
BARRIER
METALLISED
FOIL OR METOPP ADHESIVE
SEALING
PRODUCT
PE, OPP OR CPP
Developments 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 Cand Candie iess – High High Barr Barrie ierr • BOPP / Met BOPP Hs
Candies :
Candies :
Chocolates : Bars : • 1. 2. 3. 4.
Cold Seal For : Sealing without exposure to heat. Excellent seal integrity. High line speeds. “Registered”
Chocolates :
Chocolates :
Chocolates :
Cakes and bakery products :
Bakery products :
Snack Food Gas Flushed • PET / Met PET / PE
Snack Food
Snack Food
Beverages TEA PET / PE BOPP / Paper / PE
COFFEE PET/Foil/PE PET/Met PET/PE
Milk & Health drink LDPE co-ex LLDPE PET / FOIL / PE PET / Met PET / PE
Milk & Health drink
Milk & Health drink
Ketch – Up PET / Foil / PET / PE PET / Met PET / PE PET / 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
INSPECTION / TESTS
BOND / SEAL STRENGTH
OPTICAL DENSITY
DYNAMIC / STATIC COF
DART IMPACT
COLD / HEAT SEAL
COMPRESSION STRENGTH
BALLOON BURST
BLOCKING MEASURE
SEAL LEAKAGE
SCUFF RESISTANCE
BURSTING STRENGTH
PIN HOLE MEASUREMENT
ORGANOLEPTIC TESTS
GAS CHROMOTOGRAPHY
COLOUR SPECTROMETER
OTHER RM TESTS
THICKNESS UNIT : (mm/GAUGE/M (mm/GAUGE/Microns) icrons) EQUIPMENT : DIAL GAUGE MICROMETER IMPORT IMPO RTANT ANT PROP PROPER ERTY TY - AFF AFFEC ECTI TING NG:: • MECHANICAL PROPERTIES • SEALABILITY • BARRIER PROPERTIES • PERFORMANCE • PRODUCT PROTECTION.
TENSILE STRENGTH / ELONGATION ASTM D. 638
• IMPORTANT MECHANICAL PROPERTY. • RESPONSIBLE FOR HIGH SPEED PACKAGING OPERATIONS. • EQUIPMENT : INSTRON TYPE TENSILE TESTER. • UNIT : kg/cm2 PERCENTAGE(%).
IMPACT RESISTANCE IS : 2508 • • • •
DART IMPACT TEST. UNIT g f at 50% FAILURE DROP HEIGHT : 66 CMS DROP HEIGHT : 155 CMS.
STATIC COEFFICIENT OF FRICTION ASTM
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 STRENGTH ASTM F-88 DIRECTLY RELATED TO: 1. 2. 3. 4. 5. • • •
DWELL TI TIME ,T ,TEMPERATURE , PR PRE ESSURE. SEAL CONTAMINATION. THICKNESS VARIATION. MFI. TYPE OF SEALANT LAYER TYPE OF SEALING PROCESS (IMPULSE / HIGH FREQUENCY / ULTRASONIC). UNIT : kg/15 mm. EQUIPMENT : TENSILE TESTER.
BOND STRENGTH ASTM D-904. •
RELIABILITY OF CONTINUING ADHESION DURING PACKAGING, SEALING AND STORAGE.
• 1. 2. 3. 4. 5. 6.
THE DEGREE OF BOND VARIES THE INFLUENCE OF OILS / SO SOLVENTS. THE ADHESIVE USED. THE QUANTITY OF ADHESIVE. AFFINITY TO MOISTURE. EXCESS SOLVENT RETENTION. 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 MOST IMPORTA IMPORTANT NT BARRIER BARRIER PRO PROPER PERTY TY FOR MOISTURE SENSITIVE PRODUCTS • DECIDES SHELF LIFE OF THE PRODUCTS • DIRECTLY PROPORTIONAL TO THICKNESS • VARIES FROM POLYMER TO POLYMER
OXYGEN TRANSMISSION RATE ASTM D – 3985. 1. MANOMETRIC ME 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/Mat Concepts/Materials erials Holograms
Bar coding
Expanded content labels RFID tags
