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5 Major Causes of Food Spoilage/Damage in Supply Chain
hampers, baskets, cartons, bulk bins, and palletized
containers are all examples of the various types of
containers that may be used in different parts of the
journey. There are approximately 1500 different
types of packages that may be used, sometimes in
conjunction with each other (Boyette et al., 1996).
According to one study, a significant percentage of
produce buyer and consumer complaints may be
traced to container failure because of poor design or
inappropriate selection and use (Boyette et al.,
A World Health Organization study has indicated that in developed countries with sophisticated storage, packaging, and distribution systems,
wastage of food is estimated at only 2À3%. In
developing countries without these systems, wastage is estimated at between 30% and 50% (Soroka,
According to the United Nations (1969), food is
packaged for two main reasons; to preserve it and
to present it in an attractive form to the buyer. In
order to successfully satisfy these requirements,
various materials are used. The factors involved in
selecting these materials include:
• the composition of the food product and its
• nature of deteriorative reactions that may occur;
• modes of transportation used to bring the
product to market;
• time before consumption;
• who the target consumer will be; and
• overall budget for the product.
Ideally all food containers should exhibit the following properties:
Protective against light
Easily opened or closed
Impermeable to gases or odors
Resistant to chemical or mechanical damage
Easily printed or labeled.
The following is a brief overview of the packaging materials commonly used for packing as standalone packaging or in conjunction with each other.
Cardboard and pasteboard are both terms used
for corrugated fiberboard, a material commonly
used for boxes. This paper-based product is available in many different styles and weights made to
accommodate a wide variety of food products.
Demand for corrugate has been growing steadily at
an average of 2À3% per year in Europe, where it
dominates with a 63% market share over other
packaging material alternatives such as plastics
According to the Corrugated Packaging Council,
the product is easy to identify. Corrugated, in its
most basic design, has two main components, an
arched, wavy, layer called “fluting”, which is glued
in between two smooth sheets called “liners” (The
Corrugated Packaging Allowance, 2005). Together
they form a double face. The fluted liner can be
made in varying sizes, each size denoted by a letter,
A to E. Size A has the largest flutes and E the
smallest. The grades are assigned according to
paper weight and thickness.
The flutes are the essential component in corrugated material. They give containers strength and
add protection. When the flutes are anchored to the
linerboard with adhesive, they resist bending and
pressure from all directions (fibrebox.org). When a
piece of corrugated fiberboard is placed on its end,
the flutes form rigid columns, capable of supporting
weight without compressing. This allows many
boxes to be stacked on top of each other. When
pressure is applied to the side of the board, the
space in between the flutes serves as a cushion to
protect the container’s contents, thus providing
shock protection. The flutes also provide insulation
against sudden temperature changes. The liners
placed on the outer sides protect the flutes from
damage and increase the container’s overall
For produce transportation, double-faced corrugate is commonly used. The materials used on the
inner and the outer layers are determined by the
product it will hold. For example, the inner layer
may be coated to resist moisture while the outer
layer will usually be printed to identify the contents
and for display inside retail outlets (FEFCO, 2011).
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Corrugated materials have standards to ensure
boxes shipped by rail or truck do not fail during
transportation. The first rules established in the
United States were in 1906. Corrugated fiberboard
must protect from bursting to withstand forces during rough handling, be able to withstand weight
placed on top of the box, and allow for a maximum
weight of contents that can be safely placed in the
box. These measurements are usually printed on the
outside of the container.
Plastics are a versatile medium used to protect
and prevent damage to a variety of food products.
They are available in a variety of thick, thin, rigid,
or flexible forms, ranging from bottles to liners, to
Traditionally, this material is only considered for
primary or secondary packaging. This is changing
as manufacturers and distributors have adopted
RPCs for tertiary packaging use with fresh produce.
Now plastics use may be considered at all levels in
the supply chain (APME, 2001). According to the
American Plastics Council, each pound of plastic
can prevent up to 1.7 lb of food from being wasted
due to spoilage, contamination from foreign substances and organisms, or packaging failure (APC,
Since plastic is light in weight, it also saves costs
in transportation and is therefore a cost-effective
material. Plastic also extends the life of perishable
produce to eliminate waste and preservatives. The
transparent nature allows people to look at food
and touch it without causing bruising or other damage (APME, 2001). The shatterproof material keeps
the package intact, and prevents chips or shards
from contaminating the food. Polyethylene (PE)
films are the dominant material for fruit and
vegetable packaging in retail stores. Produce
remains fresh during transportation and handling
because the material is breathable, allowing the correct ratio of oxygen, carbon dioxide, and water
vapor to fill the bag. Some produce varieties can be
protected by rigid clamshells (Figures 11.11 and
11.12). This inexpensive package encloses highvalue items such as fruit, berries, precut salads, and
mushrooms and prevents delicate items from crushing (The Clemson University Cooperative
Extension Service, 2002).
PE is the dominant plastic material in use today,
with a 56% market share. Other types of plastic
used are polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), EPS, low-density polyethylene
(LDPE), and high-density polyethylene (HDPE).
Material descriptions according to the American
Plastics Council (2005) are as follows:
• PET: Clear and tough material. Has good gas
and moisture barrier properties. Commonly
used for beverage containers, food containers,
boil-in food pouches, and processed meat
• HDPE: Used for milk, juice, and water bottles, as well as cereal box liners. Translucent
material is well suited for products with a
short shelf life. Has good strength, stiffness,
Figures 11.11 and 11.12 Bunches of grapes being packed in plastic clamshell trays.
toughness, and chemical resistance. Gases are
• PVC: Widely used for construction applications because of stable properties. This rigid
plastic is commonly used for clear food packaging such as food wrap, vegetable oil bottles,
and blister packaging. It has great strength
and toughness and resistance to chemicals,
oils, and grease.
• LDPE: This plastic is predominant for film
applications. It is tough and flexible, while
still maintaining transparency. It makes sealing easy and is a good barrier to moisture.
Common applications include shrink-wrap,
plastic bags, and squeezable food bottles.
• PP: This strong material has a high melting
point, making it a good candidate for hot-fill
liquids. Resistant to other chemicals, grease,
oil, and moisture. Commonly used for margarine and yogurt containers, caps for containers, wrapping to replace cellophane, and
• PS: Can come in two different forms, either
rigid or foamed. Usually, it is clear, hard, brittle, and has a low melting point. Typically
used for protective packaging such as egg cartons, containers, lids, fast-food trays, disposable plastic cutlery, and cups.
In the 1790s, Nicolas Appert became the first
person to conserve food in a metal container.
Today, commercial canning is made possible by
materials such as steel, aluminum, tin, and chromium. Each material offers food processors different properties and preservation methods. Producers
choose metal for food and beverages for reasons
including mechanical strength, low toxicity, superior barrier properties to gases, moisture and light,
and ability to withstand a wide extreme of temperatures. These qualities help ensure the integrity and
safety of a wide variety of food products.
The most commonly used metals for packaging
are tinplate, tin-free steel, and aluminum. Tinplate
comprises of low carbon steel with a thin layer of
tin. The tin layer may be as thin as 0.38 μm
(Soroka, 2002). Tinplate is nontoxic and corrosion
resistant and is well suited for conversion into
packaging due to its excellent ductility and
Tin-free steel comprises of low carbon steel and
a thin coating of chromium, aluminum, or enamel.
Cans made from this material can no longer be soldered and must be welded or cemented.
Tinplate and tin-free steel are commonly used to
manufacture three-piece cans. These cans can be
mechanically seamed, bonded with adhesive,
welded, or soldered (Soroka, 2002). Soldered food
cans are no longer permitted in North America.
Three-piece cans are the most popular worldwide
because they are cheap to produce, and since all
pieces are made from flat sheets with no stretching
Aluminum is the most abundant metallic constituent used for packaging. Often referred to as the
transportation metal, aluminum alloys with magnesium for strength provides one-third the strength
of steel at one-third the weight. Among its
notable properties, aluminum is light, weaker than
steel, easy to work with, inexpensive, nontoxic, a
good barrier down to 1 ml thickness, nonmagnetic,
does not rust, no “taste”, and has an excellent recycle record.
Aluminum cans are often two piece in construction with a seamless body plus a top cap. They are
very popular in the US beverage industry. The
machinery used to manufacture these cans is costly
compared to three-piece cans because the process
stretches metal. The two most commonly used processes in manufacture of two-piece cans are draw
and iron, and draw and redraw.
Glass refers to an inorganic material fused at
high temperature and cooled quickly so that it solidifies in a vitreous or noncrystalline state. The
main constituent of glass, silica, is an abundantly
available element because it exists in the form of
sand. Lime and soda are the other two major components of glass. Cullet or recycled glass is often
desired as one of the primary constituents because
it provides excellent energy efficiency and saves
time for the manufacturers. Large-scale glass
manufacturing for food products was introduced in
the late 1800s. Today’s glass containers are lighter
and stronger than their predecessors. Amber and
green glass provides light protection for sensitive
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Glass is impermeable to gases, moisture, odors,
and microorganisms and is probably the most inert
packaging material available today. Glass also provides other benefits such as it can be molded into a
variety of shapes and sizes, is ideal for high-speed
filling lines, is made from abundant raw materials,
and is reusable, recyclable, and resealable. Among
its greatest drawbacks are the facts that glass is
brittle and usually breaks under an applied tensile
strength and has the least ability to withstand sudden temperature change, unlike other packaging
The manufacture of glass containers involves
either blow-and-blow process used in manufacturing narrow mouth containers, press-and-blow process used for wide mouth applications, and the
most recent one, narrow-neck-press-and-blow process gaining favor for manufacture of narrow
mouth containers, due to its ability to distribute the
material more evenly thereby requiring less
11.7 “Smart” Packaging
With modern development and enhancements in
packaging technology, today’s packaging is providing more than just the basic functions. Smart packaging is a term coming into use more frequently
and covers a number of functionalities, depending
on the product being packaged, which includes
food, beverage, pharmaceutical, and household products (Butler, 2001). Examples of current and
future functional “smartness” include the following
• packages that retain integrity and improve the
• enhances the product attributes such as its flavor, aroma, and taste;
• assists with product access and indicates seal
• responds actively to changes in product or
package environment; and
• confirms product authenticity.
11.7.1 Active Packaging
Traditional “passive” packaging techniques that
only allow for a short shelf life are being
consistently improved upon to play an “active” role
by slowing down quality-impairing processes
within the packaging itself, due to the advances in
polymer chemistry. Examples of active packaging
systems include use of oxygen scavengers, ethylene
absorbers, moisture regulators, taint removal systems, ethanol and carbon dioxide emitters, and
In active packaging, a substance or substances
are incorporated into the packaging to fulfill an
active role in protecting the foodstuff against contamination, such as aroma components of microorganism growth. Until recently, carbonated
beverages in plastic bottles tended to have limited
durability compared with conventional glass bottles. With recent developments, the shelf life of
beer in 0.33 l PET bottles has been increased from
6 to 9 months (Beverage Machines Magazine,
As a majority of food products are light sensitive, ultraviolet light barriers, which preserve the
transparency of the bottles or containers, are being
incorporated into the substrates of the packages. As
related to informative packaging, external or internal indicators that document quality alterations during the storage period, such as temperature changes
or interruptions in the cold chain, are rapidly coming into use. Active packaging is also being used as
security features in the form of labels that track
manipulation or misuse of the product prior to its
11.7.2 Modified Atmosphere
Food preservation technology accounts for two
main factors of ever-increasing importance, extending product life and reducing the amount of additives used. Modified atmosphere packaging (MAP)
allows for these demands to be met. MAP involves
modifying the atmosphere surrounding the product
inside the package. This in turn allows chemical,
enzymatic, or microbiological reactions to be controlled and therefore reduces or eliminates the main
processes of deterioration in the product. The package usually has a low permeability to gas, so that
the initial concentrations of the added gases remain
unchanged after the package is sealed.
MAP can be used to extend the shelf life of
many fruit and vegetables. Most fruit and
vegetables age less rapidly when the level of
oxygen in the atmosphere surrounding them is
reduced. This is because the reduced oxygen slows
down the respiration and metabolic rate of the products and therefore slows down the natural aging
process. Elevating the level of carbon dioxide to
levels of 2% or more can also be beneficial.
Elevated CO2 levels can reduce the product’s sensitivity to ethylene and can also slow the loss of
chlorophyll. High CO2 levels can also slow the
growth of many of the postharvest fungi that cause
rot. All these effects can help to extend the storage
and shelf life of fresh produce (Joblin, 2001).
11.8 Trends in Protective Food
Packaging of 2000 and Beyond
11.7.3 Controlled Atmosphere
The following sections discuss some of the food
packaging trends and damage reduction trends in
food packaging (Figures 11.13À11.15).
The major difference between controlled atmosphere packaging (CAP) and MAP is that the concentrations of the gases in a MAP package may
change after sealing, due to use of oxygen and the
expelling of carbon dioxide by microbes and
because of the slightly permeable nature of the
package. In a CAP package, the gas concentrations
do not change during storage. To achieve this, the
use of a gas-impermeable package, such as metal
or glass is preferred, and also provides a way of
controlling the atmosphere inside the package.
11.7.4 Intelligent Packaging
The stakes in food cold chains are high and the
loss of a trailer of food due to improper handling or
transport is measured in hundreds of thousands of
dollars. Because of the financial pressure and
increasing regulatory demands for better recordkeeping resulting from the Bioterrorism Act, suppliers and logistics service providers are turning to
systems that combine radio-frequency identification
(RFID) with temperature and humidity sensors.
RFID is an age-old technology that has recently
realized its potential in supply chain systems.
Traditional supply chain management systems produce information regarding “transactions” (orders,
shipments, and payments) and “location” (warehousing, traffic, and inventory). However, perishable goods also require information regarding their
“condition” (time and temperature) as they change
in value while in the supply chain. RFID promises
to provide real-time tracking of goods while in
transit, thereby providing a clearer picture of the
With mandated use of this technology by major
suppliers to industry giants such as WalMart,
Albertsons, and Tesco, this technology is already
being adopted in the consumer goods supply
chains. With standardization and reduced costs, this
noncontact technology is set to be as commonplace
11.8.1 Food Packaging Trends
This is a broad overview of major packaging
changes that have occurred in recent years and are
playing a dominant role in food packaging. While
the general transition to plastics rather than glass
and metal as primary packaging materials continues, the more recent and revolutionary introduction of biobased and biodegradable plastic materials
continues to lead. Innovations are going on every
day, leading the effort in specialty coatings directly
on food products to enhance shelf life and quality
aspects such as texture, aroma, and flavor. In addition, the US market continues to develop more
cost-effective packaging methods for palletized
quantities led by club stores such as Costco Inc.
Figure 11.13 A packed CCF tray with four
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FOOD PRODUCTS DURING TRANSPORTATION
Figure 11.14 A pallet load of grapes being
protected until shipment.
Figure 11.17 Flexible pouch and metal can
packaging for seafood.
and Sam’s Club (WalMart Stores Inc.). These concepts significantly reduce the amount of secondary
and tertiary packaging compared to retailers that
display merchandise on store shelves. Some key
primary packaging evolutions of recent times are as
Figure 11.15 Palletized loads of grapes being
prepared for shipment.
Figure 11.16 Stand-up pouch and juice box.
1. Stand-up pouches replacing metal cans:
High-barrier foil laminated or metalized flexible packaging continues to replace metal
cans. Multilayer plastics in flexible pouches
are replacing traditional paperboard juice
boxes. Examples include CapriSun fruit juice
for young children and tuna fish introductions
by Star Kist (Figures 11.16 and 11.17).
2. Plastic bottles replacing glass bottles: There
is a continuous shift in the beverage industry
from glass to plastic bottles. Most blowmolded plastic bottles can be made in-house
which reduces dependency on external suppliers and shrinks the supply chain. Also, by
using shrink-sleeve labels, multiple product
lines can be filled in the same blow-molded
bottle without major changeovers. Glass bottles are still holding their competition for
high value and premium beverage launches.
Shaped primary packages are easy to produce
with plastic, provide new product launches
with shorter lead times and provide market
share in a competitive environment. Heinz
used this to launch specialty ketchups and
sauces for children (Figure 11.18).
3. Convenience for on-the-go food packages:
The US customer continues accepting packaging launches that provide convenience
while driving and placing in cup holders in
automobiles (Figure 11.19). Products range
from snack foods, cereal with milk, and salads. An examples range is Frito Lays Inc.,
who offer a range of snack foods in blowmolded plastic bottles with shrink labels that
fit automotive cup holders and allow consumption while driving. These replace the traditional bag and pouch.
4. Clear plastics packaging: The consumer continues to demand more esthetically pleasing
containers for food packaging. Product
Figure 11.18 Some plastic ketchup bottle forms.
Figure 11.19 Convenience-driven snack food
visibility plays a key role from bagged salads,
to fresh produce in thermoformed containers,
to spices. However, the gas transmission
requirements for these plastics vary from
extremely high barrier in the case of spices to
low barrier for salads. The customer wants
more visibility of the actual product being
purchased (Figures 11.20 and 11.21).
11.8.2 Damage Reduction Trends
The various innovations and trends discussed in
the previous section all lead to a reduction of damage in shipment. Protection (physical and chemical)
is an underlying function of a package, and generally all package improvement and changes will usually result in reduction of damage as protection is
increased. In addition, there are some key changes
that clearly can help reduce damage beyond the primary package change.
Use of good-quality pallets is the key to reducing
damage to both rigid and flexible primary
packages. The most widely used pallets to distribute food products, both fresh and processed, are
made of wood. Low-quality lumber, protruding
nails, insufficient deck or base coverage, moisture
content, and infestation are all factors that can lead
to damage of food products and packages when
shipped on wooden pallets. For this reason, most
retailers use reusable plastic pallets in downstream
shipping between distribution centers to stores. An
alternate to a single-use wooden pallet are highquality wooden pallets that can be leased and
reused. These are often an economically better
choice but also offer additional benefits due to the
Figure 11.20 Vine ripe tomatoes in a biodegradable
PLA plastic thermoformed container.
11: DAMAGE REDUCTION
FOOD PRODUCTS DURING TRANSPORTATION
reduction solutions than launch a massive new
product in a retail distribution and be subject to a
major recall or loss.
Figure 11.21 Bagged salads with brand identity in
Today, most companies leasing wooden pallets
to the food industry (CHEP USA Inc.) offer a
picture-frame bottom section and a large percentage
of the top deck covered with deck-boards to reduce
damage from stacked products and packages. Also
these are true four-way entry block-style pallets
that can be easily handled with fork trucks and pallet jacks. Reduced handling results in lower damage
as compared to products on conventional stringer
pallets. In addition to the quality of pallets, the
placement of products on pallets is critical. Both
underhang and overhang can greatly affect the load
transfer in stacked loads and thereby result in damage. Use of slip sheets to distribute load among
layers and the pallet surface is a common way to
address these issues.
The unitization method of loads on a pallet is
also critical. Choice of appropriate shrink-wrap,
stretch wrap, banding, netting, gluing, and strapping
are all choices that need to be examined for specific
product and packaging needs. Use of corner posts
and top caps can reduce damage in caseless palletized loads designed for club store shipments.
Most of these issues and potential solutions
should be addressed by using lab-based accelerated
test evaluations. The use of test methods developed
by American Society of Testing and Materials and
the International Safe Transit Association allow
users to conduct preshipment tests on palletized
configurations to simulate different distribution
methods from truckload to less than truckload to
single parcel shipments. It is important to test a
few pallets of the product and identify damage
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12 Food Packaging Machinery
Harold A. Hughes
Michigan State University, East Lansing, MI, USA
Packaging is an essential activity in the food
industry. Virtually every food product is packaged
one or more times before it reaches the ultimate
consumer. Packages are used at each stage in the
process of production and distribution of food products: from farms to processing plants, between
processing plants, from processing plants to warehouses to retail outlets, and from retail outlets to
consumers. A package can hold a food product,
several food products, or packages of food products. There are many package forms including
wraps, pouches, bags, boxes, cups, trays, cans,
tubes, and bottles.
Packages perform one or more of the following
four basic functions: containment, protection, communication, and utility. Each function is discussed
briefly in the following sections.
Every package communicates information. The
communication may be simple and straightforward,
such as a label listing the contents and showing the
source and destination. However, most retail food
packages include expensive and elaborate multicolored
labels, bar codes, and radio-frequency tags. Every
retail food package must include a nutritional label.
Many food products, especially liquids and free
flowing solids, are contained in packages to facilitate convenient handling and to avoid spillage and
loss of the product. Table salt and granulated sugar
are examples of free flowing solids. Liquid food
products include water, milk, fruit juices, and a
wide assortment of other products.
Food products must be protected against contamination by microorganisms and a wide array of
other hazards. Depending on the characteristics of
the product and other factors, it may be necessary
to provide protection against gain or loss of moisture, oxygen, CO2, and other constituents, from
crushing and other distribution damage, from
improper temperature, from light, from tampering
and theft, and against numerous other hazards.
Some packages and package components are
designed to add value to the packaged product.
Spout shakers and similar fitments enable consumer
to apply spices, salt, and similar materials more
easily and accurately. Printed directions add convenience. Handles enable small children to handle
large packages conveniently and safely.
The modern food production and distribution
system could not function without packaging. Even
fresh food, such as bananas, oranges, tomatoes, or
lettuce, is packaged for transport from the store to
the consumer’s residence. The packages may be
made of corrugated board, mesh bags, paper bags,
or plastic containers. A large percentage of the
fresh products are packaged by hand.
However, unlike the fresh products mentioned
above, most modern food products are prepared or
processed in factories and then packaged for distribution to warehouses and stores and ultimately to
consumer’s residences. Most of the packaging is
done by machines set up into systems. The packaging equipment often receives the prepared product
from an adjacent preparation area. Four example
production and packaging systems are described in
The descriptions illustrate two important principles about packaging machines. The first is that
packaging machines are generally set up as a system. It is unusual for a packaging operation to have
only one machine. Rather, there is nearly always a
Ebnesajjad: Plastic Films in Food Packaging. DOI: http://dx.doi.org/10.1016/B978-1-4557-3112-1.00012-0
© 2013 Elsevier Inc. All rights reserved. Adapted from a chapter in: Kutz, Handbook of Farm, Dairy, and Food Machinery (2008).
Table 12.1 Description of Some Typical Food Packaging Systems
Steps in the Preparation/Packaging System
Milk in one gallon plastic
1. Milk is received at the plant, filtered, processed as necessary, and
stored in large stainless steel tanks
2. Plastic jugs are manufactured on site by blow molders and placed into
3. The jugs and the milk are conveyed to a filling machine, which meters
one gallon of milk into each container
4. The filled jugs are capped, washed, and labeled
5. The completed gallon packages of milk are placed into plastic crates
6. The crates are stacked and conveyed to a refrigerated temporary
Soup in metal cans
1. The constituents for the soup are delivered to the plant
2. The metal cans, labels, and other packaging components are
delivered to the plant
3. The soup is prepared and conveyed to the packaging line
4. The cans are depalletized and conveyed into the packaging line
5. The cans are cleaned as necessary
6. Empty cans and the soup are conveyed to a filling machine and the
soup is metered into the cans
7. The can end is applied
8. The filled cans are retorted
9. Labels are applied to the cans
10. Completed cans are packed into corrugated trays
11. The filled trays are wrapped with shrink-wrap and palletized
Granulated sugar in multiwall
1. Sugar is extracted from sugar cane or sugar beets and transported to
a temporary holding area
2. Preprinted, multiwall paper bags and rolls of heavy Kraft paper are
delivered to the plant
3. Empty bags are held open by the filling machine and the specified
weight of sugar is metered into the bag
4. The top of the bag is rolled over, crimped, and glued shut
5. Bags of sugar are bundled together and wrapped in Kraft paper
6. The bundles of sugar are palletized and moved to a warehouse
Assorted chocolates in
1. Decorated paperboard cartons, plastic trays, plastic overwrap,
corrugated shipping containers, labels, and other packaging
components are delivered to the plant
2. Chocolates are manufactured and placed into temporary holding
locations in the packaging area
3. Empty cartons are conveyed past the filling station where a robot
picks up individual pieces of chocolate and places them into particular
locations in a thermoformed plastic tray
4. Filled trays are placed into cartons
5. A lid is placed on the cartons
6. Completed cartons are wrapped in plastic film
7. Wrapped cartons are placed into the shipping containers, which are
closed, taped, labeled, and palletized
8. The loaded pallets are moved to a warehouse for temporary storage