Packaging materials: Paper based packaging for food

Packaging Materials
Paper Based Packaging for Food
Dr. Jilen M. Mayani
Assistant Professor (PHT)
Department of Post-Harvest Technology,
(An ISO 22000:2005 Certified Unit)
ASPEE College of Horticulture and Forestry,
Navsari Agricultural University, Navsari
Dr. Jilen M. Mayani [Assistant Professor (Post Harvest Technology)], NAU, Navsari

Paper and Paper based Packaging Materials
 The oldest and most versatile packaging
materials
 They are made and used by the millions of
tonnes or may be so rare that only a few
tonnes of hand-made paper are produced in
a year. Paper and board, alone or
associated with other materials, has been
used in food packaging or food contact for
many years.
Ironic
material
Permanent
or
temporary
Gentle or
strong
Cheap or
expensive
In plenty or
limited

Use
 A particular effort for
alteration to the
environmental concerns and
the users’ needs was made at
the same time as the use of
paper and board was
increasing. Paper and board
is indeed an essential part of
our lives and satisfies many
human needs.
Use
Communicate
information
(newspapers, books,
documents and
writing paper)
Cultural and artistic
purposes
Transport and
protect goods
(packaging, sacks,
liquid packaging
board)
Personal hygiene
(tissues, napkins,
nappies, etc.)

WHAT IS PAPER?
 Paper is made from cellulose fibres, which are obtained from trees,
recovered papers and annual plant fibres like cereal straws.
 Today about 97 per cent of the world's paper and board is made from
wood-pulp, and about 85 per cent of the wood-pulp used is from
spruces, firs and pines.
 Nowadays, hardwoods such as birch, aspen and other hardwoods are
used as an ideal raw material for processing into fluting for corrugated
cases as well as printing and writing papers, while eucalyptus as raw
material for high-quality pulp suitable for a wide range of papers.

How Paper is Formed?
 Paper is called board when it is heavier than 224 g/m2.
Glucose
• Carbon,
• Hydrogen
• Oxygen
Cellulose
• Long, ribbon-
like molecules
made up of
smaller glucose
units
Sheets
• Molecules are
held together
side-by-side by
hydrogen
bonds
Microfibrils
• Sheets are piled
together in
tightly packed
layers
Bundles
• Group of
Microfibrils
Paper fibre
• Groups of
Bundles

The demands placed on the form of paper and board vary widely
with the intended use but some are common to all grades, i.e.,
the paper must be strong enough to fulfil its technical function
and also be able to be printed upon in a way that makes it
striking to the customer.
Paper and board can be used in contact with food in many
different ways, either directly or indirectly, and either singly or
laminated with other materials such as plastic or metal foil. In the
latter case, so-called "functional barriers" are aimed at
suppressing any substance transfer between food and the base
paper material.

MANUFACTURE OF PAPER AND BOARD
 Beginning with the ancient Chinese
 Hand-made methods dominated for thousands of years
 The first machine to manufacture paper continuously was invented by the
Frenchman Louis-Nicolas Robert in 1799.
 Originally intended purely for writing and printing purposes, a wide variety
of paper grades and uses are now available to the consumer.
 Each paper or board grade is produced on equipment tailored for this
particular grade and mill.
 Production processes are optimised for each grade. There are many
variables: raw material composition (mixture of chemical softwood and
hardwood pulp, mechanical pulp, recovered paper, fillers, pigments,
additives, etc.), machine size (width, speed), type of production equipment
and automation level.

Paper and board production involves two steps.
First, the fibres need to be produced. This is done in a pulp mill
where pulp is produced using chemical or/and mechanical
processes. Pulp production can be integrated with paper
production, or the pulp can be produced in a separate pulp mill.
The paper itself is then produced on a paper machine from a
mixture of fibres, chemicals and additives.
All paper and board machines are based on a similar
basic process. There are seven distinct sections: head box,
wire section (wet end), press section, drier section, size
press, calender and reel-up.

Process
The preparation and the cleansing of the pulp:
This untwists the fibers. Beating is a mechanical treatment
intended for swelling, fibrillating and shortening the
fibres. The result is a better sheet formation and the
development of paper’s mechanical properties.
Before sending to the paper machine:
The pulp is initially purified, diluted and air bubbles are
eliminated. Sometimes pulp is also bleached if made from
recycled paper.

 The wet-end part:
Raw material fibres and chemicals (and 99% of the water) are
pumped to the head box, which feeds the stock evenly onto the
section.
This is a woven plastic mesh conveyor belt that can be 35 metres
long and up to 10 metres wide. As the paper stock flows from the
head box onto the wire, the water drains away through the mesh
leaving small fibres as a mat on top of the mesh.
The paper machine can travel at speeds of up to 2000 m/minute
by the time the paper stock has travelled half way down the wire, a
high percentage of water has drained away. By the time the thin mat
of fibres has reached the end of the wire section, it has become a
sheet of paper, although very moist and of little strength.

 The press section:
This section consists of a number of sets of felts and heavy cylinders
through which the moist paper web passes. More water is pressed out
to felts and drawn away by suction. Pressure binds the fibres together
and consolidates the web.
 Dryer:
This section consists of a large number of steam-heated drying
cylinders which have a temperature of slightly over 100°C. Synthetic
drier fabrics carry the paper web round the cylinders until the paper is
dry.

 Coating/Calendering:
In many applications, the surface of the sheet needs improvement.
This is achieved by calendering, a process which reorients the
surface fibres in the base sheet of paper (or the coating applied to
the surface) by the use of pressure. This serves to smooth the
surface, control surface texture and develop a glossy finish. Such
papers are known as machine finished.

 Finishing:
At the end of the drying process, the sheet is smoothed using an
"ironing" method, which consists of hot polished iron rollers
mounted in pairs with synthetic material rollers, one above the
other. This also helps to consolidate, polish and glaze the surface
the paper: the characteristics of the surface of the sheet are
improved.
 Shipping:
Still travelling at very high speeds, the paper comes off the
ready for reeling up into large reels (called parent reels), which can
be cut or slit into smaller ones, according to customer
These large reels are produced and changed without any
interruption of the production process.

 Quality control:
 Sensors and computers verify parameters such as the production
speed, the pressure and the resistance at every step of the process
ensure that the paper or board is of a consistently high quality.
Moreover, for food contact applications, microbiological, chemical
and organoleptic controls have to be carried out.
 A board machine often has several formation devices in the wet
producing a multiply sheet, combined on the forming table and
press. Basis weight of the boards can be as high as 500 g/m2,
whereas the printing and writing papers are usually 40-120 g/m2.

RECOVERED PAPER AND BOARD
 Recovered or recycled paper is an important raw material in
terms of volume and utilisation for the paper industry in
many countries.
 The recycling of paper is an example of sustainable use of
resources. Although recycling is both economically and
ecologically sound, recovered paper cannot be used in all
paper grades. The final production process for recycled
paper is the same as the process for paper made from
primary fibres. The main difference is that recovered paper
fibres have already been used, so that non-fibre material, will
have to be removed.

 Collection and Transportation: Recovered paper is sorted, graded,
formed into bales and delivered to a paper mill.
 Repulping and Screening: After reaching the paper mill, recovered
paper is mixed with water and chemicals, which separates the
into individual fibres.
 Cleaning: The pulp mix is diluted with water and passes through a
system of centrifugal cleaning equipment and screens. The pulp is
filtered and screened through a number of cycles to make it more
appropriate for papermaking. This is done to remove large
contaminants like wood, plastic, stones, glass and paper clips, along
with small contaminants like string, glue and other sticky materials.
Pulp is cleaned in a large spinning cylinder and the heavy
contaminants move to the outside of the cylinder and are removed.

 De-inking: For certain uses (e.g. for the production of graphic,
sanitary and domestic papers but rarely for manufacture of
packaging materials) and for certain types of recovered papers
newspapers and magazines), the fibres have to be de-inked. The
deinking process can be carried out by flotation, with or without
washing, with or without kneading, with or without bleaching.
 The finished recycled pulp is now ready to be made into paper

 More than 50 grades of recovered paper and board are defined in the European
List of Standard Grades of Recovered Paper and Boards.
 They can be described as follows
 Low grades (mixed papers, old corrugated containers, board, etc.): These
constitute the main part of the recovered paper consumed. These are used to
produce secondary packaging papers and boards, and are not intended to be in
direct contact with food
 De-inking grades (newspapers and magazines, graphic papers, etc.): They are
usually also considered as low grades because they need extensive recycling
treatments. These are for graphic and sanitary papers.
 High grades (scraps, sheets, print offcuts, etc.): They require little or no
cleaning. They can be used for the production of any paper product as
substitute. They may therefore be suitable for food contact packaging.

TYPES OF PAPER
 Kraft Paper
This is typically a coarse paper with exceptional strength, often
made on a fourdrinier machine and then either machine-glazed
on a machine-finished on a calender. It is sometimes made with
no calendering so that when it is converted into bags, the rough
surface will prevent them from sliding over one another when
stacked on pallets.
 Bleached Paper
These are manufactured from pulps which are relatively white,
bright and soft and receptive to the special chemicals necessary
to develop many functional properties. They are generally more
expensive and weaker than unbleached papers. Their aesthetic
appeal is frequently improved by clay coating on one or both
sides.

 Greaseproof Paper
 This is a translucent, machine-finished paper which has been
hydrated to give oil and grease resistance. Prolonged beating or
mechanical refining is used to fibrillate and break the cellulose
fibres which absorb so much water that they become superficially
gelatinized and sticky. This physical phenomenon is called
hydration and results in consolidation of the web in the paper
machine. The satisfactory performance of greaseproof papers
depends on the extent to which the pores have been closed.
Provided that there are few interconnecting pores between the
fibres, the passage of liquids is difficult. However, they are not
strictly greaseproof since oils and fats will penetrate them after a
sufficient interval of time. Despite this, they are often used for
packaging butter and similar fatty foods since they resist the
penetration of fat for a reasonable period.

Glassine Paper
Glassine paper derives its name from its glassy, smooth
surface, high density and transparency. It is produced by
further treating greaseproof paper in a supercalender
where is it carefully dampened with water and run through
set of steam-heated rollers. The transparency can vary
depending on the degree of hydration of the pulp and the
basis weight of the paper. It is frequently plasticized to
increase its toughness.

 Vegetable Parchment
 Vegetable parchment takes its name from its physical similarity to animal
parchment which is made from animal skins. The process for producing
parchment paper was developed in the 1850s, and involves passing a web of
high-quality, unsized chemical pulp through a bath of concentrated
acid. The cellulosic fibres swell and partially dissolve, filling the spaces
between the fibres and resulting in extensive hydrogen bonding. Thorough
washing in water, followed by drying on conventional papermaking dryers,
causes re precipitation and consolidation of the network, resulting in a paper
that is stronger wet than dry (it has excellent wet strength, even in boiling
water), free of lint, odour and taste, and resistant to grease and oils. Unless
specially coated or of a heavy weight, it is not a good barrier for gases.
 Because of its grease resistance and wet strength, it strips away easily from
food material without defibering, thus finding use as an inter-leaver between
between slices of food such as meat or pastry. Labels and inserts in products
with high oil or grease content are frequently made from parchment. It can
treated with mold inhibitors and used to wrap foods such as cheese.

 Waxed Paper
 Waxed papers provide a barrier against penetration of liquids and vapours.

Paperboards
 Paperboard can be distinguished by thickness (caliper) and
weight of the material. Material is generally termed
“paperboard” when its thickness is more than 300 μm and/or its
weight exceeds 250 g/m2. Various types of paperboard are
manufactured but paperboard for food packaging generally
includes whiteboard, linerboard, foodboard, cartonboard,
chipboard, and corrugated board.

Whiteboard
Whiteboard is made with a bleached pulp liner on one
or both sides to improve appearance and printability,
and the remaining part is filled with low-grade
mechanical pulp. Whiteboard is suitable for contact
with food and is often coated with polyethylene or wax
for heat sealability. It is used for ice cream, chocolate,
and frozen food cartons.
Linerboard
Linerboard is usually made from softwood kraft paper
and is used for the solid faces of corrugated board.
Linerboard may have multiple plies. Increasingly,
linerboards containing recycled fiber are being used in
packaging. The higher quality layer is always placed on
top.

 Foodboard
Foodboard is used to produce cartons that are suitable for direct
food contact. It is normally made using 100% virgin pulp but recently
recycled pulp using an innovative barrier coating with a sustainable
coating material is also being used. Foodboard is a sanitary, coated,
and waterresistant paperboard. It should be designed to protect
against migration of outside contaminants (such as ink or oil) into
packaged food. Foodboard can be used for all types of foods,
particularly frozen and baked foods.
 Cartonboard (boxboard)
Cartonboard is used to make folding cartons and other types of
boxes. Most often, this is a multilayer material made of more than
one type of pulp, and often incorporating recycled fibers. To improve
its appearance, it may be clay coated or may have a ply of virgin
fibers on one or both surfaces.

 Chipboard
Chipboard is the lowest quality and lowest cost paperboard, made
made from 100% recycled fiber, and is not used in direct contact
with foods. Outer cartons for tea and breakfast cereals are some
examples. It is also commonly lined with whiteboard to produce a
multi-ply board such as cartonboard.
 Corrugated board
Corrugated board has an outer and inner lining of kraft paper with
with a central corrugating (fluted) material. Corrugated boards
resist impact, abrasion, and compression forces so they are
commonly used in shipping containers.

Paperboard cartons and other containers
for food packaging
 Folding cartons are made of paperboard, typically between 300 and 1100 μm in
thickness. They are creased, scored, cut, and folded into the desired shape. The cartons
usually are shipped flat to the product manufacturer (or carton assembler). Paperboard
can be coated or laminated when improved function is desired. For example, wax
lamination provides moisture resistance, glassine lamination provides oil/grease
resistance, and PE lamination provides heat sealing and moisture resistance. Clay and
mineral coatings on the exterior provide improved appearance and printing quality.
 Molded pulp containers are produced by placing aqueous slurry of cellulosic fibers into
a screened mold. Since molded pulp containers are regarded as a sustainable
packaging material, they are gaining popularity. Typical applications in food packaging
include egg cartons, food trays, and other tray type containers for fruits. Molded pulp
containers can be laminated with thermally resistant plastics such as PET to provide
functionality as dualovenable containers (suitable for use in conventional ovens as well
as microwaves).

CFB Boxes
Many years ago in England, corrugated paper, the ridged and
grooved part of shipping and packaging boxes, was used as a
liner for English top hats. However it wasn’t until 1871 that it
was patented by Albert Jones of New York City for packaging
purposes. Since then, corrugated paper has evolved from top
hat liners into various cardboard box types, like pizza, bakery,
and take-out boxes. Cardboard fluting is also used in
some eco-friendly disposables, deli trays, paper plates,
and disposable bakeware.

Benefits of corrugated boxes
 Sandwiched between two pieces of cardboard, the ridged
flutes of these products are designed to support a great deal
of weight. Not only is this beneficial for shipping purposes, but
it also plays an important part in supporting the weight of
food. This cardboard fluting construction also plays an integral
role in protecting items during transportation. The curved
arches created by these flutes make boards durable and resist
pressure applied from any angle. The empty space located
between the flutes and under the arches even provides
cushioning, as well as insulation in the event of extreme
temperature changes.

What do the flute letter designations mean?
Flute
Designation
# of Flutes /
Linear Foot
Flute
Height
Qualities Common Uses
A 36 1/4"
Excellent compression and
cushioning; good stacking
strength
Packaging fragile items; used for its
structural strength
B 49 1/8"
Excellent crush resistance and
printing surface; good puncture
resistance
Inner packaging, like pads and
C 41 11/64"
Good printing surface,
compression, and crush
resistance
Most common flute used for shipping
boxes; used for its structural strength;
used for glass, furniture, food, etc.
E 90 1/16"
Excellent crush resistance;
exceptional printing surface; thin
construciton helps to reduce
storage space
Consumer goods packaging, like boxes
for cosmetics, glass, and ceramics; used
for displays, ballot boxes, and pizza
boxes
F 128 1/32"
Outstanding printing surface;
excellent crush resistance; thin
construction allows for stiffer
boxes with less fiber
Consumer goods packaging, like boxes
for cosmetics, jewelry, and shoes; used
for software packaging and fastfood
clamshells

Half Slotted Container (HSC) Regular Slotted Container (RSC)
Center Special Slotted Container (CSSC) Snap or 1-2-3 Bottom Container with Tuck Top

Integral Divider Container, RSC with Internal
Divider or Self Divider
Full Telescope Design Style Container (FTD)
One Piece Folder (OPF) Wrap Around Blank

Five Panel Folder (FPF) or Harness Style Five
Panel Folder
Rock End Tray with Locking Cover
Display Tray or High Wall Tray A Bliss Style Container

Self-Erecting Six Corner Tray Pre-Glued Auto Bottom with RSC Top Flap
Overlap Slotted Container (OSC) Full overlap Slotted Container (FOL)

Full Telescope Half Slotted Container (FTHS) Partitions (or Dividers)

Packaging materials: Paper based packaging for food

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