1. 1
INDEX
S.NO: TOPIC PAGE NO:
Certificate 1
Acknowledgement 2
1 About the Firm 3
2 Introduction 4
3 Standard Manufacture Process in U-FLEX 5
3.1 Designing 6
3.2 Pre - Press 6
3.3 Raw Materials 7-8
3.4 Film Production 9-12
3.5 Cylinders 13-17
3.6 Inks 18
3.7 Printing 19-22
3.8 Lamination 23-27
3.9 Slitting 28
3.10 Pouching 29-31
3.11 Testing 31-34
4 CONCLUSION 35

2. 2
ACKNOWLEDGEMENT
I extend special thanks to my prestigious institution Karunya University and the Head
of the Department, respected, Dr.T.V Ranganathan for supporting and encouraging
me to explore the industrial environment and discover my potential as a food
processing engineer.
I would also like to express my gratitude to U-FLEX PVT. LTD for providing me an
opportunity to pursue an internship in their firm. U-FLEX being the largest flexible
food packaging firm in Asia provided me an excellent exposure to the latest
technologies in the field enabling me to gain a world class work experience in the
field.
I acknowledge my parents for arranging the internship and the necessary , without
which it would not have been possible.

3. 3
1. ABOUT THE FIRM
Over the last three decades, Uflex has earned an irreproachable reputation defining the
contours of the ‘Packaging Industry’ in India and overseas. Since its inception in 1983, it has
turned into a multi- billion company focusing on trust, value creation for customers, quality
innovation and customer satisfaction. Uflex has grown from strength to strength with large
manufacturing capacities of Packaging Films and packaging products providing end-to-end
solutions to clients across over 140 countries where it enjoys a formidable market presence
thereby becoming India’s largest flexible packaging company.
Uflex enjoys a global reach with unhindered speed making it truly multinational.
Headquartered in Noida (National Capital Region, New Delhi) it has state-of the-art
manufacturing facilities in India, UAE, Mexico, Poland, Egypt and USA. Uflex serves as one
stop shop flexible packaging solution provider cutting across varied sectors spanning USA,
Canada, South America, UK, Europe, Russia, CIS countries, South Africa and other African
countries, Middle East and the South Asian Countries.
Uflex manufacturing facilities enjoy ISO 9001, ISO 14001 and HACCP accreditations. Its
products are approved by FDA and BGA. It is also a part of the D& B Global Database and
winner of various prestigious national and international awards. FPA and AIMCAL Awards
have been conferred to Uflex on several occasions, latest being the prestigious Dupont
Packaging Innovation Award in May 2015.
Uflex stands committed to the industry by providing technical know-how, establishing
thought leadership and being the trend-setter in the flexible packaging industry. Being on the
edge of innovation, Uflex endeavors to be the first to come up with advanced products that
cater to the ever-changing demands of the packaging industry. Integrated within its core
business profile are allied businesses like Engineering, Cylinders and Chemicals which
further give Uflex a superior edge above competition. The organization is in the process of
setting up first of its kind Aseptic Packaging Plant for liquid packaging in Sanand, Gujarat
with an investment of approximately INR 550 crores.
Uflex has over thirty years of experience in polymer technology. Setting milestones of
success and innovation, Uflex is known for manufacturing and supplying products, delivering
customized flexible packaging solutions and services across the globe to become an
inextricable part of customers’ life.

4. 4
2. INTRODUCTION
Food packaging is packaging for food. A package provides protection, tampering resistance,
and special physical, chemical, or biological needs. It may bear a nutrition facts label and
other information about food being offered for sale.
Packaging serves many objectives such as:-
 Physical Protection - Protection from shock, vibration, compression,
temperature, bacteria etc.
 Barrier Protection - A barrier from oxygen, water vapor, dust etc. Modified
atmospheres or controlled atmospheres are also maintained in some food packages,
keeping contents clean, fresh, and safe for the intended shelf life is a primary
function.
 Containment - Small items are typically grouped together in one package to allow
efficient handling. Liquids, powders, and granular materials need containment.
 Information transmission - Packages and labels communicate how to use, transport,
recycle, or dispose of the package or product. Some types of information are required
by governments.
 Marketing - The packaging and labels can be used by marketers to encourage
potential buyers to purchase the product. Marketing communications and graphic
design are applied to the surface of the package and (in many cases) the point of sale
display.
 Security - Packaging can play an important role in reducing the security risks of
shipment, preventing any decay or damage to the product. Packages may include
authentication seals to help indicate that the package and contents are not counterfeit.
 Convenience - Packages can have features which add convenience in distribution,
handling, stacking, display, sale, opening, reclosing, use, and reuse.
 Portion control - Single-serving packaging has a precise amount of contents to control
usage. Bulk commodities (such as salt) can be divided into packages that are a more
suitable size for individual households. It also aids the control of inventory: selling
sealed one-liter bottles of milk, rather than having people bring their own bottles to
fill themselves

5. 5
3. STANDARD MANUFACTURE PROCESS IN U-FLEX
DESIGNING
↓
PRE-PRESS
↓
RAW MATERIALS
↓
FILM PRODUCTION
INKS ↓ CYLINDERS
↘ PRINTING ↙
↓
LAMINATION/EXTRUSION
↓
SLITTING
↓
POUCHING
↓
TESTING
↓
MARKETING
(Figure 3.1 – Flowchart for standard manufacture process in U-FLEX)

6. 6
3.1 DESIGNING
Packaging comes in all shapes and sizes, and many different materials can be used. The
design is prepared according to the customer’s demands and specifications.
 Preparing data, which includes copyediting and product photography
 Creating the layout is done using one of the leading design applications three softwares
are used for designing – Photoshop, Coral, Illustrator.
 Four basic colors are used , the combinations of which form other colors.
 Special colors can also be used like red, gold, silver etc.
 The design should be cost effective and easy to print.
 The pictures are selected according t the product.
 Fonts based on the information to be printed.
 The design is prepared and sent to the customer for approval.
 The corrections recommended are rectified. The correction cycle includes proof
reading and image retouching.
 The final design is sent for pre – pressing.
 Preparing data, which includes copyediting and product photography.
3.2 PRE-PRESSING
Prepress is the term to describe all of the processes that occur before printing. It is the stage
where files are prepared, edited, graphics are checked, and all proofing is performed to ensure
the information is correct and arranged so that it will print just the way the customer desire.
This process usually also includes:
 Transparency Flattening: transparency effects such as drop shadows behind text need
to be resolved.
 Color Separation: Before printing one must first separate the design template into the
four basic ink colors: cyan, magenta, yellow, and black (CMYK). Each single-color
layer is then printed separately, one on top of the other, to give the impression of
infinite colors. This type of color separation, mixing three or four colors to produce an
infinite variety of colors, is called process color separation. Another type of color
separation, called spot color separation, is used to separate colors that are not to be
mixed. In this case, each spot color is represented by its own ink, which is specially
mixed. Spot colors are effective for highlighting text but they cannot be used to
reproduce full-color images.
 Color Management: It is a way to set up the workflow to match the colors of the
image displayed on the monitor with the ones produced by the printer.
 Trapping: The term is used to describe the compensation for misregistration between
printing units on a multicolor press .This misregistration causes unsightly gaps or
white-space on the final printed work. Trapping involves creating overlaps (spreads)
or underlaps (chokes) of objects during the print production process to eliminate
misregistration on the press.
 Screening: Screening is the technique that is used in printing to simulate tints or
continuous-tone images such as photographs using dots.

7. 7
3.3 RAW MATERIALS
A variety of raw materials are used for flexible packaging in U-FLEX such as PET, BOPP,
CPP, PET, BOPET, Aluminum Foil, Paper etc. U-FLEX Noida imports the raw materials
from MAX India or Nahar.
The properties of various materials used in U-FLEX are listed below :-
Polyethylene Terephthalate (PET)
 It is a thermoplastic polymer resin of polyester.
 It was patented in 1941 by John Rex Winfield
 It can be coated (chemical method – 50 to 60 dyne) or non-coated (corona treatment).
 It makes a good gas and fair moisture barrier, also, a good barrier to alcohol and
solvents.
 It is strong and impact resistant.
 It is light weight and has a density of 1.414 g/cc.
Polyethylene (PE)
 It is the oldest thermoplastic film and the most common form of plastic used in food
packaging.
 It was first synthesized by Hans Von Pechman (German chemist) who accidently
invented it while investigating Diazomethane.
 It can be transparent, metalized or white, yellow, black depending upon the color of
the master batch and is mainly used as an inner layer of laminates.
 It is only used for flexo printing and protects only against moisture.
 It has excellent heat stability and can be used as single layer for packaging of food
products like frozen vegetables, fish etc.
Cast Polypropylene (CPP)
 It is similar to PE but with better machinability properties and with a more crystal-like
view compared to PE.
 It has very low protection barrier values.
 It is not used as laminating layer and can be used as a single layer for packaging toast
bread or cupcakes.
Bi-Oriented Polypropylene (BOPP)
 It is the most used thermoplastic film.
 It can be transparent, white, metalized, lacquered, pearly etc.
 It has very low heat sealing properties and better barrier properties than PE and CPP.
 It can be used as a simple or laminated layer for packaging of snacks, pasta , biscuits ,
frozen foods etc
Bi-Oriented Polyester (BOPET)
 It has no heat sealing capability.
 It has very high barrier properties and excellent printability properties.
 It is used as a part of lamination for packaging cheese, meat, coffee, soups etc.

8. 8
Paper
 It has no sealing properties (it needs a sealing layer) and has no protection barrier
values.
 It is used in combination with a sealing layer for packaging bread, tea, coffee,
medicines in the form of sachets.
Aluminum
 It has no sealing properties (it needs a sealing layer) but has excellent barrier
properties.
 Its printability is relatively poor.
 Usually it combined as a sandwich between a sealing and printing layer used for tea,
coffee etc.
FACTORS CONSIDERED FOR PACKAGING
 Cost
 Type Of Product
 Location
 Shelf Life
 Barrier Requirement
 Seal Strength
 Atmospheric Pressure
 Legal Compliance
 Temperature
 Transportation

9. 9
3.4 FILM PRODUCTION
3.4.1 BLOWN FILM EXTRUSION
Blown film (Tubular film) extrusion is the process by which most plastic films are made for
the packaging industry. The process involves extrusion of a plastic through a circular die,
followed by "bubble-like" expansion. The principal advantages of manufacturing film by this
process include the ability to:
 Produce tubing (both flat and gusseted) in a single operation
 Regulation of film width and thickness by control of the volume of air in the bubble,
the output of the extruder and the speed
 Eliminate end effects such as non uniform temperature that can result from flat die
film extrusion
 Capability of biaxial orientation (allowing uniformity of mechanical properties)
 Blown Film Extrusion can be used for the manufacture of co-extruded, multi-layer
films for high barrier applications such as food packaging.
RAW MATERIAL
↓
PROCESSING
↓
NIP ROLLS
↓
AIR RING
(Figure 3.2 – Flowchart for Blown Film Extrusion)
Raw Material - Raw material or polymer in the form of small beads or pellets.
Processing – The pellets are fed from a hopper into the barrel of the extruder. The polymer
enters the feed throat and comes into contact with screw. The front of the barrel the molten
plastic leaves the screw.
Nip Rolls - It is then pulled upwards from the die by a pair of nip rolls, high above the die
(the height of which depends on the amount of cooling required). Changing the speed of these
nip rollers will change the gauge of film. The nip rolls flatten the bubble into a double layer
of film, if lay flat or gusseted film can be formed using the gusseted boards
.Air Ring - Around the die sits an air ring. The air ring cools the film as it travels upwards.

10. 10
3.4.2 CAST FILM
 Cast film is manufactured by extruding the melted polymer through a flat die or slot—
forming a thin sheet or film.
 After extrusion, it is attached to the surface of a chilled (rotating) roller so that it is cooled
extremely fast.
 It is the surface of the rotating roller that gives cast film its characteristic smooth and
clear appearance.
 While cast film can be produced at much higher line speeds, there is higher waste along
with little orientation in the cross direction.
The films produced from either of the two processes mentioned are sent for further
treatment
3.4.1.1 METALLIZATION
Metallization is the process of formation of a metallized film which are polymer films coated
with a thin layer of metal, usually aluminum. The aluminum metal is heated and evaporated
under vacuum. This then condenses on the polymer film in the range of 0.5 micrometers. This
coating does not fade or discolor over time.
UNWINDER
↓
ROLLER
↓
PLASMA UNIT
↓
ROLLERS
↓
VACCREATION
↓
METALLIZATION
↓
POLYCOLD
↓
REWINDING
(Figure 5.3 – Flowchart for Metallization)

11. 11
The machine used for the process is K 4000, K 5000 and Galileo. The speed of the machine
depends upon the optical density, but is usually run at a speed of 700m/min. The optical
density has 3 set point:-2.3(Medium), 2.6(Medium High), 2.8(High). The optical density is
set according to the requirements and the polymer to be metallized.
Unwinder -The film roll is loaded on the unwinder and then passes to the roller.
Rollers – The rollers stretch and spread the film to provide the required torque and tension.
Plasma Unit - A plasma treatment unit is used as part of a vacuum system in order to enhance
metal adhesion and/or to improve the film’s qualities as a barrier against oxygen and water
vapor transmission. Here, the surface of the web is hit by plasma just prior to the coating
process. The plasma is formed by applying an electrical voltage to a gas, or combination of
gases (20% argon and 80% oxygen). It is essential for removing moisture and other
contaminants
Vacuum -The vacuum required is at a pressure of 2*10⁴mbar, which is created by 2 rotary
and 3 booster pumps.
Metallization– Once the vacuum is created, metallization begins.
 The boats are heated at 1200°C
 Aluminium wire wounded on the rollers is heated and vaporized.
 The vapors rise to the film roll and get attached
 The cooling roller at a temperature of -10°C cools to set the vapors.
Polycold– This equipment is positioned in the winding section as well as the source section
of the metallized. It consists of a mixture of 9 gases, which absorb the moisture, which is
further heated by the diffusion pumps attached to it resulting in hot air which is finally
discharged.
The chiller unit consists of a mixture of water and glycol, which prevents the freezing of
water even at -10°C.
Rewinding – The film after cooling is finally rewinded and discharged
3.4.1.2 CORONA TREATMENT
Corona treatment (air plasma) is a surface modification technique that uses a low
temperature corona discharge plasma to impart changes in the properties of a surface. The
corona plasma is generated by the application of high voltage to an electrode that has a sharp
tip. The plasma forms at the tip. A linear array of electrodes is often used to create a curtain
of corona plasma. Materials such as plastic or paper may be passed through the corona
plasma curtain in order to change the surface energy of the material. All materials have an
inherent surface energy. Corona treatment is a widely used surface treatment method in the
plastic film, extrusion, and converting industries.

12. 12
3.4.1.3 TREATMENT FOR SURFACE ENERGY
It is performed to check the surface energy of the film once it is processed. A strip of the
required treatment solution is applied on the film and held to check the surface energy which
can be identified by the formation of bubbles.
PREPARATION OF TREATMENT – The treatment solution is a mixture of two chemicals:
- Formamide and 2 Ethoxy Ethanol (CELLOSOLVE). These chemicals are mixed in a specific
ratio to get treatment solution of specific dyne value. A color dye which is not reactive with
these chemicals may be added to make the visibility better. Rhodamine B and Victoria Blue
dye is recommended.
TYPES OF FILMS DYNE LEVEL
PET (CRONA) 48
PET Coated 60
PET G 48
PET HSP (N.H.S Side) 48
PET HSP (HS Side)
42
All Type of BOPP 38
All Type of PE 38
All Type of CPP 38
Nylon 48
PVC 38
Foil 72
(Table 3.1)

13. 13
3.5 CYLINDER
The first step of Gravure is to create the cylinder with the engraved images that need to be
printed - the engraving process will create on the cylinder surface the cells that will contain
the ink in order to transfer it to the paper. Since the amount of ink contained in the cells
corresponds to different color intensities on the web, the dimensions of the cells must be
carefully set; deeper or larger cells will produce more intense colors whereas smaller cells
will produce less intense.
RAW CYLINDERS
↓
PLATING / GALVANISATION
↓
POLISHING
↙ ↘
ELECTRIC ENGRAVING ↓ LASER ENGRAVING
↓ FLEXO PLATE MAKING ↓
CHROMING ↓ ↓
↘ PROOFING ↙
↓
PRINTING
(Figure 5.4 – Flowchart for Cylinder Processing)
Cylinder Engraving FLEXO
Valley ( engraving ) Mountain (upliftment)
Stylus UV Exposure
The image is engraved The image is raised
The photocell of the color to be printed is
engraved to a greater depth than the other
portion.
The part of the image to be printed is lifted
higher than the other portion.
Slower Faster
(Table 3.2)

14. 14
Raw Cylinders– The raw cylinders made up of mild steel or aluminum are imported. The
pipes are selected according to the required outer diameter. The cylinders are reduced through
grinding by 200 microns using a lathe machine. The proper finishing and fabrication is
performed. The cylinders are also prepared in house, where steel flints are welded to pipes.
Plating / Galvanisation– After the finishing process the cylinder are plated with copper
metal.
 The cylinders are mounted.
 They are cleaned with an acid and a base solution to remove impurities.
 A Nickel layer of 10um thickness is coated.
 The cylinder acts as the cathode(+ve) and copper chips as the anode(-ve)
 A d.c electric current is passed through a solution of copper sulphate in between,
through an electrifier.
 Electrolysis takes place and a layer of copper 200um overloaded or 500 um more than
the fabricated cylinder is coated.
 The cylinder is cooled and unmounted.
Polishing – U-FLEX Noida has 2 SUPER FAST machines (Italy), CNC Iron cutting machine
(America), Polish Master (Germany). Two different categories of machines are used.
 The excess material is cut using an Industrial Diamond and polishing is done by
rubbing by a Grinding Stone. Water is continuously passed to prevent heating due to
rubbing.
 In another case, the excess material is cut as well as the polishing done using the
grinding stone.
Electric Engraving– The engraving process encompasses an electronically controlled
diamond stylus that cuts or engraves cells into the cylinder surface. A combination of these
cells forms the image. Before engraving the main image a registration mark is engraved for
the centralization of the image
After the art work is received it is transformed into a format which is understood by the
specialized software (U-FLEX Noida has machines that employ two main software’s :- Hell
and Collage )used for engraving. The artwork is planned into repeats (the particular length
after which the design gets repeated) and coils (the number of repeats in the roll width). The
running time depends upon the image area
Each image is converted into halftone like dots, each having an electric signal depending on
the light density of the image. This image is then converted back into an analogue signal,
which then drives the engraving head, regulating the depth to carve the cells on the cylinder.
A computerized system controls the engraving head, which moves diagonally across cylinder
punching cell holes at between 6000 and 8000 holes per minute. The angle of cells can be
altered by producing elongated or compressed diamond shaped cells if necessary. Different
colors have different depths e.g. : Since black color cells are small their depth is more.

15. 15
LASER ENGRAVING - Laser engraving, is the practice of using lasers to engrave an object.
A laser engraving machine consists of three main parts: a laser, a controller, and a surface.
The laser is like a pencil - the beam emitted from it allows the controller to trace patterns onto
the surface. The controller (usually a computer) controls the direction, intensity, speed of
movement, and spread of the laser beam aimed at the surface. Laser engraving systems
engrave the required cell pattern directly into the polished ceramic surface.
The cylinders are cleaned with 10% HCl solution, and then coated with a Lacquer coating –
sprayed by a gun with a pressure of 0.5bar. A test cut is made before engraving to ensure a
proper process. For special purpose printing, Mica or Leather Embossing is also carried out.
SURFACE JOB REVERSE JOB
The image printed is opposite. The image is printed as it is.
120 styluses is used. 125, 130 styluses are used.
The depth of the cells is more. The depth of the cells is less.
(Table 3.3)
DEFECTS IN ENGRAVING
 Broken Stylus
 Corrupt Image
 Dents

16. 16
3.5.1 FLEXO – Flexographic printing is a method which uses a flexible polymer plate to
print onto a substrate, such as Polyester , OPP , Nylon and PE films Photopolymer printing
plates containing a mirror relief image of the required print are used. The raised areas on the
plate have ink applied to them by an anilox roller and then transfer it onto the substrate. A
photopolymer plate of thickness 1.4 – 1.7mm is used.
A photopolymer printing plates containing a mirror relief image of the required print. The
raised areas on the plate have ink applied to them by an anilox roller and then transfer it onto
the substrate.
RAW PLATE
↓
LASER DESIGN
↓
UV-A LIGHT
↓
PROCESSING
↓
AIR DRYER
↓
UV-C LIGHT
↓
CUTTING
↓
PRINTING
(Figure 5.5 – Flowchart for manufacture of flexo sheets)

17. 17
RAW PLATE – Raw photopolymer plates are imported from DuPont which are initially black
in color.
 It is coated with carbon or fiber layer on the top
 A polyester sheet is attached at the back which provides firmness.
LASER DESIGN – U-FLEX Noida has two laser machines: 42/60, 35/47. The laser light
transfer the design on to the plate and the printable portion is transparent than the rest, so that
it can be hardened upon exposure to UV-A light.
UV LIGHT – U-FLEX Noida has a DuPont CYREL machine in which the sheet is placed.
The exposure of the plate to the UV-A light hardens the printable image area. Another
machine called the Digi flow is also used which consist of an additional nitrogen flushing gas
chamber.
PROCESS – The plate is carried and passed through the plate making machine
 A series of brushes remove the non image area by rubbing action which takes about
30 -45 minutes depending upon the size
 A solvent called Cytosol is poured which prevents any scratches due to the brushes.
AIR DRYER – The plate is then passed through an air dryer maintained at a temperature of
60°C for about 2.5 hours in order to dry any adhering solvent.
UV-C LIGHT – The plate is then exposed to UV-C light where all the stickiness and any
remaining solvent is removed.
CUTTING – The plate is cut in a staggering (zig-zag) manner so that it fixes properly to the
rollers.
A machine called FAST is used in case of emergencies or special job which performs the
entire process within it and produces a finished sheet. However, this machine is seldom used
as it consists of an expensive cloth that sucks the non- image area and acts as the major
component.
PROOFING - The cylinders and the flexo sheets once prepared are sent for proofing where
they are checked for defects and discrepancies. The sample prepared is sent to the customer
for final approval.

18. 18
3.6 INKS
U-FLEX is a leading manufacturer of inks/adhesives. Different substrates require different
categories of inks. The inks can be broadly classified as:
 ORGANIC
 Pigment – Mostly (95%) pigment based organic ink is used which gets
dispersed on the substrate
 Dye – In about 5% case, dye ink is used which gets dissolved. Dye inks are
rarely preferred as:
o They may transfer the contact layers.
o Enables light transmission
o Poor heat resistance
 INORGANIC – Metals are used.
Types of Inks
 Vinyl Based
 PU Based – It gives a superior ink adhesion to most substrates and is costlier than
Vinyl Based.
 NC Based – It is used for paper jobs.
 Polyamide Based
 PVC Based – Acrylic Based
Color Formation
 Basic Colors – Red, Blue, Green (RBG)
 Processing Colors – Cyan, Magenta, Yellow, Black (CMYK)
 Metallic Colors - Gold , Silver
 Fluorescent colors
Most of the colors are formed as a combination of the four processing colors CMYK.

19. 19
3.7 PRINTING
Printing is a process for reproducing text and images using a master form or template. In U-
FLEX, mainly, two printing processes are carried out: Rotogravure and Flexo. Printing can be
broadly classified into two: Surface and Reverse .
Surface Printing Reverse printing
 Opaque or Transparent substrate is
used
 Printing is done on the same front
side
 No direct contact with the product.
 Dark to Light
 Only Transparent substrate is used
 Printing is done on the reverse or
opposite side.
 Direct contact with the product.
 Light to Dark
(Table 5.4)
3.7.1 ROTOGRAVURE PRINTING
U-FLEX Noida has 7 Gravure Printing machines which includes 5 Rotomac , 1 Cerutti and 1
U-Flex produced machine. The process runs at a speed of 450m/min. It takes approximately
1.5 hours to print a roll.
UNWINDER
↓
PRINTER CYLINDERS
↓
DOCTOR’S BLADE
↓
IMPRESSION ROLLER
↓
INKING
↓
DRYING
↓
INSPECTION
↓
REWINDING
(Figure3.6 – Flowchart for Rotogravure Printing)

20. 20
Unwinder – The web is mounted on the unwinder. The movement of the web is due to the
action of tension which depends upon thickness.
Printer Cylinder - A cylinder, made from either steel, aluminum, plastic, or composite
material, is engraved with the image to be printed. Printing cylinder which has been laser
engraved with minute cells is capable of retaining ink, the size and pattern which reflect the
required image. These cells are forced to transfer their ink directly onto the substrate by a
combination of pressure and capillary action, thereby, producing the printed image.
Doctor’ – It is a device that removes ink from the non-engraved portions of the printing
cylinder and also removes excess ink from the engraved sections.
Impression Cylinder - A rubber covered cylinder that is mounted on a steel mandrel. Its main
purpose is to press the substrate against the printing cylinder.
Inking System:- It consists of an ink pan, ink holding tank, and ink pump with supply and
return ink pipes.
Drying System – It consists of a chamber which dries the ink once it is on the substrate and
prior to it reaching the next printing unit. Drier capacities are determined based on the
required printing speed, ink type (solvent or water based), and ink lay down volume.
Inspection – Vigitech / Quadtech is a camera which continuously images the running web and
captures the location of the defects like splashes, ink spots and sleeve marks. These defects
are eliminated during inspection.
Rewinding – The final printed and inspected roll is rewinded.

21. 21
3.7.2 FLEXO PRINTING
U-Flex has 1 Flexography machine of Comexi make. The speed of this process is 400 m/min.
It takes approximately 2 hours for printing a roll. It is cost effective as compared to
rotogravure as it utilizes a small amount of ink but cannot be used for specific materials.
UNWINDER
↓
CYLINDER/DRYER (120˚C)
↓
CENTRAL IMPRESSION ROLLER
↓
MAIN DRYING CHAMBER (120˚C)
↓
INSPECTION
↓
CURING
↓
HOOD
↓
REWINDING
(Figure 3.7 – Flowchart for Flexo Printing)

22. 22
Unwinder - The web is mounted on the unwinder. The movement of the web is due to the
action of tension which depends upon thickness.
Cylinder - A cylinder, made from steel, aluminum, plastic, or composite material is mounted
with a layer of Tape, which is further mounted with a Polymer Plate on which the design is
printed. The major difference between Gravure and Flexography is that the printing is
outwards in the latter rather than engraved as in the former. There are a total of 8 cylinder or
analog rollers.
Dryer - A dryer is coupled with each cylinder and simultaneously dries the ink
Main Drying Chamber – After printing the web passes to the main drying chamber where the
final drying takes place.
Inspection – A camera continuously images the running web and captures the location of the
defects like splashes, ink spots and sleeve marks . These defects are eliminated during
inspection. Strabo lights are also used to detect the defects.
Curing – The running web is cured by 4 bulbs emitting ultraviolet light.
Hood – The odour is absorbed and exhausted through the hood.
Rewinding – The final printed and inspected roll is rewinded.
The final printed roll is inspected for defects like scum, lines, dot skip, grounding, shade
variation etc. If the roll is perfect, it is sent for lamination and if there are any defect the roll
is stopped, cut and a joint is made.
A sample is sent for quality analysis where it is tested for its length, shape, size, color etc.
Any variation from the specification is detected and the roll is held.

23. 23
3.8 LAMINATION
Lamination is a method of combining various layers of similar or different films together
either thermally (extrusion) or chemically using an adhesive. It is used to improve the barrier
properties of substrates such as strength, stability, sound insulation, appearance or other
properties from the use of differing materials. A laminate is a permanently assembled object
by heat, pressure, welding, or adhesives. It plays an important role in protecting the product
from the external atmospheric conditions
There are six types of laminations
3.8.1 Solvent Base Lamination
3.8.2 Solvent Less Lamination
3.8.3 Water Base Lamination
3.8.4 Poly extrusion Lamination
3.8.5 Cold Seal Lamination
3.8.6 Hot Melt Lamination

24. 24
SOLVENT LESS LAMINATION
This type of lamination is mainly used for food products. The speed of the machine is 350
m/min. U-FLEX has 5 solvent less lamination machines, 4 imported from Nordmeccanica
Group (Italy) and 1 produced by U-FLEX.
TANK
↓
MIXING UNIT
↓
HEAD STATIC MIXER
↓
METTERING ROLLERS (45°C)
↓
TRANSFER ROLLER (RUBBER)
↓
COATING ROLLER (55°C)
↓
COMBINATION NIP
↓
DRYING
↓
REWINDING
(Figure 3.8 – Flowchart for Solvent Less Lamination)

25. 25
Adhesive – A two component adhesive is used which consists of NCO (Resin-100) and OH
(Hardener-75) which are given different temperatures and mixed. A high performance
adhesive (7728/6028) is imported by the Hankel Group , Dow Chemical (569/C104) and a
Flex Form adhesive (702A + 702C) are also used.
Metering Rollers (45°C) – They are made up of stainless steel, one is moving and one
stationary with a gap of 80 microns where adhesive is poured. The gap is essential to
maintain the speed of the roller and adhesive gsm which is checked by a metering gauge.
Transfer Rollers - It is a rubber roller which transfers the adhesive for coating.
Coating Rollers (55°C) – The ink is coated on to the web by this roller
Combination Nip – Another substrate is combined to form the lamination by applying
pressure and temperature.
SOLVENT BASE LAMINATION
The solvent base lamination process is similar to solvent less lamination. The solvent used
provides viscosity to the adhesive. Usually Ethyl-Acetate is used as a solvent. The basic
principle is that 1 or more layers are permeable to the solvent used and hence, allows it to
escape. U-FLEX India has 5 solvent base machines out of which 2 run at a speed of 450
m/min and 3 run at a speed of 350 m/min.
TANK
↓
MIXING UNIT
↓
PUMP
↓
COATING CYLINDER
↓
NIP COATING
↓
HEAT TREATMENT / HOOD
↓
DRYING
↓
REWINDING
(Figure 3.9 – Flowchart for Solvent Base Lamination)

26. 26
Adhesive – A three component adhesive is used which consists of NCO (Resin), OH
(Hardener) and Ethyl Acetate (Solvent). A high performance adhesive (545S) is used. An
adhesive (2511/1511) is imported from the Hankel Group.
Pump – The adhesive is pumped onto the coating cylinder.
Coating Cylinder – The adhesive is coated on the substrate using a roller coating cylinder.
NIP COATING – After the adhesive is coated on the substrate it is immediately laminated to
a second substrate layer
HEAT TREATMENT/HOOD – The substrate is air dried at a high temperature, so that the
excessive solvent evaporates and is discharged through the Hood provided at the top.
DRYING - Adequate drying of solvent is important where solvents cannot be absorbed into
the films as excess solvents cause deterioration. It may penetrate and affect the food product.
COLD SEAL
It is used mostly in case of chocolates, where, any heat applied for sealing purposes may
damage the product. A layer of latex is applied on the substrate which can be easily sealed by
applying pressure.
HOT MELT
The Hot Melt Adhesive Spreader includes proper shielding and exhausts hoods to ensure
accurate, consistent glue application. The Rotary Laminator smoothes the adhesive and
eliminates any air entrapment which could cause Speckling and thus rejection.
Defects in Lamination
 Tackiness
 Misting
 Patches
 Adhesive Lines
 Orange Peel
 Speckling
 Turling

27. 27
EXTRUSION
Extrusion coating and extrusion laminating are converting processes that allow different
substrate materials to be combined to obtain a single compound structure. Hot extruded film
is trapped between two other films and cooled. The materials involved may include plastics,
paper or aluminum foil. Extrusion coater laminators deliver a combined substrate, the
component elements of which would be very difficult to separate. The combined substrate
inherits highly enhanced physical properties and barrier protection performance from its
component elements. The machine operates at a speed of 400 m/min.
HOPPER
↓
SCREW (340*C)
↓
EXTRUSION DIE
↓
LDPE FILM
↓
PRESSURE ROLL (12°C)
↓
CHILL ROLL (18°C)
↓
EXTRUSION LAMINATE
(Figure 3.10 – Flowchart for Extrusion)
Hopper – The LDPE pellets are fed to the hopper or accompanied by a master batch
depending upon the color required.
Screw – The pellets are mixed and melted in the screw region at high temperatures.
Extrusion Die – The LDPE film extrudes out of the extrusion die.
Pressure Roll (12°C) – The LDPE film is sandwiched between two substrates by a pressure
roll.
Chill Roll (18°C) – The combined substrate then passes to the chill roll for cooling and
becomes firmly attached
Curing – After lamination/extrusion process the web is cured for a period of 36 – 48 hours at
a temperature of 50°C - 55°C.

28. 28
3.9 SLITTING
Slitting is a simple process. A master roll typically is received from extrusion, printing, or
lamination and curing. The film passes through a series of idler rolls and a set of razor blades
set up to the final roll width. A photo eye reads the edge of the film or printed eye track to
assure the film is slit in register. The outer right and left rolls have a portion of the edge
removed as scrap.
U-FLEX Noida has 10 Kamp machines which can perform both gravure and air cutting
which run at a speed of 600 m/min and 3 Super Slitters which run at a speed of 400 – 450
m/min.
In addition to the above a laser machine is also used which marks the pouch lining for ease
of tearing/opening.
 The web can be unwinded in 4 different ways or directions – which can be numbered
as 1, 2, 5, and 6.
 The slitting of the web is done according to the requirement of the customer.
 The photocells provided on the printed laminate, help align the web for proper
slitting.
 The core diameter is usually taken as 6mm or 10mm, but for big or heavy rolls the
core is imported which may have a diameter of 13mm.
 The machine consists of :
 A static charge eliminator which absorbs the charge on the web.
 A flag detector which senses the hidden joints.
 There are 3 types of cutters: Rotary cutters (paper jobs), Lutz Blade
(Imported), Topaz Blade.
 Cutter shaft , Blade shaft
 The slitting can be done on 2 basis :
 Kg based – It depends upon the quantity of web required and the outer
diameter.
 Impression based – It depends upon the number of pouches required which is
further determined by the distance between two photocells.
 Slitting is also done to remove all the joints and rectify the defects of previous jobs.
 Common defects in Slitting :
 Loose Winding
 Core Collapse
 Trim Pass
 Joint Pass
 Flappiness
 Off Slitting

29. 29
3.10 POUCHING
Pouch is a type of container made of thin, flexible, plastic films used for containing and
transporting goods such as foods, produce, powders, ice etc. Several design options and
features are available. Some bags have gussets to allow a higher volume of contents. Some
have the ability to stand up on a shelf or a refrigerator. Some have easy-opening or reclosable
options. Handles are cut into or added onto some. Bags can be made with a variety of plastics
films. Polyethylene (LDPE, LLDPE, etc.) is the most common. Other forms, including
laminates and coextrusions can be used when the physical properties are needed.
Bags are also made with carrying handles, hanging holes, tape attachments, or security
features. Some bags have provisions for easy and controlled opening as well as reclosable
features, including press-to-seal zipper strips. The bags are usually tough heat-sealed.
Types of pouches
 3D Pouches
 2, 3 or 4 side sealed
 Center Sealed
 Side Gusseted
 Stand Up
 Bottom Fold
 Retort Pouches
 Vaccum Pouches
 Zipper Pouch
 Pillow Pouch
 Spout
 Profile
 Fold All

30. 30
→ 3D ZIPPER POUCH
MAIN ROLL
↓
BLADE
(It cuts the web into two , the front portion moves upwards and the back portion downwards.)
↓
SIDE GUSSET FORMED
↓
CUTTING
↓
SEALING SIDE GUSSET
↓
BOTTOM GUSSET
(The bottom gusset is externally attached and sealed.)
↓
ZIPPER DIAPHRAGM (Nylon)
(The zipper diaphragm is attached on the upper end and sealed which moves along the web.)
↓
BOTTOM GUSSET SEALED
(The bottom gusset is sealed at one end to allow an opening for filling of product. )
↓
COOLING
↓
SLIDER/LOCK
(It is attached for the ease of opening and closing)
↓
CROSS SEALER
↓

31. 31
COOLING
↓
BLADE
(To remove the side ends)
↓
PUNCH
(Rounding the bottom edges .)
↓
CUTTER
(The web is cut into individual pouches)
↓
POUCH
Handles or threads are attached to various pouches to enable ease of hand
(Figure 3.11 – Flowchart for production of 3D Pouches)

32. 32
3.11 TESTING
Testing of packaging involves the measurement of a characteristic or property involved with
packaging. Testing measures the effects and interactions of the levels of packaging, the
package contents, external forces, and end-use. Testing can be a qualitative or quantitative
procedure. For food products, packaging testing is mandatory. Processes may be controlled
by a variety of quality management systems such as HACCP, statistical process control,
validation protocols, ISO 9000, etc. A primary purpose of a package is to ensure the safety of
a product during transportation and storage. If a product is damaged during this process, then
the package has failed to accomplish a primary objective and the customer will either return
the product or be unlikely to purchase the product altogether. Testing a new packaging design
before full scale manufacturing can save time and money.
Several standards organizations publish test methods for package testing such as :
 International Organization for Standardization, ISO
 ASTM International
 European Committee for Standardization. CEN
 HACCP
 Military Standards[7]
 ISTA (International Safe Transit Association)
MECHANICAL PROPERTIES
 Tensile
 Elongation
 Young’s Modulus
 Haze
 Gloss
TESTS PERFORMED
 Stiffness
 Bond Strength
 Seal Strength
 COF Test (Coefficient of Friction)
 WVTR (Water Vapor Transmission rate)
 OTR (Oxygen Transmission Rate)

33. 33
TESTING PARAMETERS
 Appearance
 GSM
 Seal ability
 COF
 Pin Holes (In order to check the pin holes in a metallized material per meter square
which should be less than 200, else, will affect the barrier properties.)
 Tape Test (Metallization Bonding0
 Dyne Level/Treatment/Surface
 Shrinkage (PVC)
 Pressure
 Temperature
 Dwell Time (Incontact Time)
INSTRUMENTS USED
 Xrite OD Meter – To check the optical density of metallized and opaque films.
 UTM (Universal Testing Machine) - To check mechanical properties like Bond, Seal,
Stiffness, Tensile strengths.
 Heat Sealer – To check the sealing behavior of films , laminated at a temperature of
135°C and 3 bar pressure.
 Burst Tester – To check the bursting strength of paper.
 COF Tester – To check the coefficient of friction for film and laminates.
 Light Box – To check the visual defects of films and laminates.
 WVTR Instrument – To check the WVTR of laminates.
 OTR Instrument – To check the OTR of laminates.
GSM Test – The laminate of specific dimensions are taken and weighed. The weight is
divided by the area to obtain the gsm. The layers are separated and this process is repeated for
each layer to find the gsm. The gsm of the individual layers are added and collectively
subtracted from the gsm of the laminate to obtain the ink/adhesive gsm.
Seal Test - Seal strength is a quantitative measure for use in process control, and capability.
Seal strength is not only relevant to opening force and package integrity, but to measure the
packaging processes' ability to produce consistent seals. Seal strength at some minimum level
is a necessary package requirement, and at times it is desirable to limit the strength of the seal
to facilitate opening.
The maximum seal force is important information, but for some applications, average force to
open the seal may be useful, and in those cases also should be reported.
A specimen of required dimensions is taken and each end of the specimen is secured in
opposing grips and the seal remains unsupported while the test is being conducted. This test
method covers the measurement of the strength of seals in flexible barrier materials. The
values stated in either SI units or inch-pound units are to be regarded separately as standard.

34. 34
BOND STRENGTH - Laminates are made by bonding together two or more layers of
material or materials. Their performance is often dependent on the ability of the laminate to
function as a single unit. If the plies have not been properly bonded together, the performance
may be adversely affected.
This test method covers a procedure for comparing the bond strength or ply adhesion of
similar laminates made from flexible materials such as paper, plastic film, and foil. This
includes laminates made by various processes: adhesive laminates, extrusion coatings,
extrusion laminates, and coextrusion.
A specimen of the laminate of specific size is taken and the layers of are separated into two ,
the two ends of the specimen are secured in opposing grip in the UTM and upon the
application of force the two layers get separated giving the bond strength. The values stated
in SI units are regarded as the standard.The UTM is set at a speed of 152 mm/min.
.

35. 35
4. CONCLUSION
A trip down any aisle in the grocery store will show just how far the packaging industry has
come. Today’s consumers are greeted with innovative options from eco-friendly packaging to
designs that actually assist in the food preparation process. So much consideration and
science goes into selecting the correct container that, for manufacturers, packaging is a
strategic decision.
While many products now are available in recyclable packages, some companies have chosen
to use recycled materials in the packaging. This reduces the amount of virgin material
required for packaging and can have a positive impact on the environment.
Packaging is becoming an essential part of the value chain analysis, regarding food safety,
organoleptic characteristics and flexibility.
Food manufacturers are working more closely than ever to create products designed for
contemporary lifestyles, based on the latest technology. This has resulted in an explosion in
the market for ready to eat meals, a market in which packaging is playing an increasingly
important role
Packaging is of great importance in the final choice of the consumer will make because it
directly involves convenience, appeal, information and branding. “In a very broad sense,
food industry is discovering a food service channel as a new distribution alternative”.