1

Índice Packaging ................................................................................................................................................ 2

Functions of packaging ....................................................................................................................... 2

Primary Function ............................................................................................................................ 2

Secondary functions ....................................................................................................................... 3

Tertiary functions ........................................................................................................................... 4

Packaging terminology ....................................................................................................................... 4

Dimensional standards ..................................................................................................................... 10

Marking of packages ........................................................................................................................ 17

1. Shipping mark ........................................................................................................................... 17

2. Information mark ..................................................................................................................... 17

3. Handling instructions ............................................................................................................... 17

Packaging materials and packaging containers made from paper, cardboard, millboard and

corrugated board ................................................................................................................................. 20

Terminology ..................................................................................................................................... 20

Treatment ......................................................................................................................................... 22

Paper types in packaging .................................................................................................................. 23

Types of corrugated board ............................................................................................................... 24

Flutes and flute sizes .................................................................................................................... 26

Designs, styles and delivery forms of cartons .................................................................................. 27

Cushioning materials ............................................................................................................................ 41

Required characteristics of cushioning materials ............................................................................ 41

Selection criteria for cushioning materials....................................................................................... 41

Description of various kinds of cushioning materials ...................................................................... 44

Classification of corrosion protection methods ................................................................................... 45

1 – Active corrosion protection .................................................................................................... 45

2 - Passive corrosion protection ................................................................................................... 46

3 – Permanent corrosion protection ............................................................................................ 46

4- Temporary corrosion protection .............................................................................................. 46

2

Packaging

http://www.tis-gdv.de/tis_e/verpack/inhalt1.htm

Correct selection, design and construction of the packaging is just as important for loss-free

transport as are the requirements placed on the product itself. Savings are often made on

packaging in order to reduce total costs. These packages often do not fulfill the requirements

placed upon them, such that they cannot withstand the mechanical, climatic, biotic and

chemical stresses to which they are exposed during transport, storage and cargo handling.

Simply because packaging is incapable of withstanding such stresses does not, of course,

mean that a loss will inevitably occur, but the risk will in some cases be greatly increased.

The following sections contain helpful hints and information relating to packaging.

Functions of packaging

The various functions of packaging are divided into primary, secondary and tertiary

functions. In contrast with the primary functions, which primarily concern the technical

nature of the packaging, secondary functions relate to communications. Primary, secondary

and tertiary functions are divided into the following sub-functions: Primary, Secondary and

Tertiary functions.

Primary Function

Protective function

The protective function of packaging essentially involves protecting the contents from the

environment and vice versa. The inward protective function is intended to ensure full retention of

the utility value of the packaged goods. The packaging is thus intended to protect the goods from

loss, damage and theft.

In addition, packaging must also reliably be able to withstand the many different static and dynamic

forces to which it is subjected during transport, handling and storage operations. The goods

frequently also require protection from climatic conditions, such as temperature, humidity,

precipitation and solar radiation, which may require "inward packaging measures" in addition to any

"outward packaging measures".

The outward protection provided by the packaging must prevent any environmental degradation by

the goods. This requirement is of particular significance in the transport of hazardous materials, with

protection of humans being of primary importance. The packaging must furthermore as far as

possible prevent any contamination, damage or other negative impact upon the environment and

other goods.

The inward and outward protective function primarily places demands upon the strength, resistance

and leakproof properties of transport packaging.

Storage function

The packaging materials and packaging containers required for producing packages must be stored

in many different locations both before packaging of the goods and once the package contents have

been used. Packaging must thus also fulfill a storage function.

3

Loading and transport function

Convenient goods handling entails designing transport packaging in such a manner that it may be

held, lifted, moved, set down and stowed easily, efficiently and safely. Packaging thus has a crucial

impact on the efficiency of transport, handling and storage of goods. Packaging should therefore be

designed to be easily handled and to permit space-saving storage and stowage. The shape and

strength of packages should be such that they may not only be stowed side by side leaving virtually

no voids but may also be stowed safely one above the other.

The most efficient method of handling general cargo is to make up cargo units. Packaging should

thus always facilitate the formation of cargo units; package dimensions and the masses to be

accommodated should where possible be tailored to the dimensions and load-carrying capacity of

standard pallets and containers.

Where handling is to be entirely or partially manual, packages must be easy to pick up and must be

of a suitably low mass. Heavy goods must be accommodated in packages which are well suited to

mechanical handling. Such items of cargo must be forkliftable and be provided with convenient load-

bearing lifting points for the lifting gear, with the points being specially marked where necessary

(handling marks).

The loading and transport function places requirements upon the external shape of the package,

upon the mass of the goods accommodated inside and upon the convenient use of packaging aids.

The strength of the package required for stowing goods on top of each other demonstrates the close

relationship between the loading and transport function and the protective function.

Secondary functions

Sales function

The purpose of the sales function of a package is to enable or promote the sales process and to

make it more efficient.

Promotional function

Promotional material placed on the packaging is intended to attract the potential purchaser's

attention and to have a positive impact upon the purchasing decision. Promotional material on

packaging plays a particularly important role on sales packaging as it is directly addressed to the

consumer. This function is of subordinate significance in transport packaging. While product

awareness is indeed generated along the transport chain, excessive promotion also increases the

risk of theft.

Service function

The various items of information printed on packaging provide the consumer with details about the

contents and use of the particular product. Examples are the nutritional details on yogurt pots or

dosage information on medicines.

The package may also perform a further function once the contents have been used (e.g. storage

container, toy).

Guarantee function

By supplying an undamaged and unblemished package, the manufacturer guarantees that the

details on the packaging correspond to the contents. The packaging is therefore the basis for

branded goods, consumer protection and product liability. There are legislative requirements which

demand that goods be clearly marked with details indicating their nature, composition, weight,

quantity and storage life.

4

Tertiary functions

This function relates to the extent to which the packaging materials or packaging containers may be

reused once the package contents have been used. The most significant example is the recycling of

paper, paperboard and cardboard packaging as waste paper.

Packaging terminology

Package contents: The item which is packaged is known as the package contents.

Packaging materials: These are the materials which constitute the packaging. Examples are

paper, cardboard, millboard, corrugated board, lumber, sheet metal, plastics, glass etc.. These

are, however, only generic terms. If packaging materials are to be precisely defined, a more

exact description must be given:

Wooden packages may be made of wood species such as spruce, fir, pine,

European beech or poplar.

Plastic packaging is made from polyethylene (PE), polypropylene (PP),

polyurethane (PU), polystyrene (PS), polyamides (PA) etc..

Corrugated board is specified, amongst other things, by the number of flutes, flute

size, material thickness and basis weight.

Paper is classified into different varieties depending upon its properties, such as

packaging paper, wet strength paper, crepe paper, coated grades of paper with a

barrier material or treated grades of paper, for example treated with VCI (Volatile

Corrosion Inhibitor).

Packaging container: The container in which the package contents (cargo) are packaged.

The following are examples of packaging containers: cartons, boxes, crates, sacks, cans,

drums, jars, bottles, jerricans, bags, shrink covers etc..

Packaging aids: Packaging aids are materials which reinforce or permit the production of

packaging containers, such as nails, adhesive tapes, staples and strapping which hold boxes

and cartons together.

Packaging aids also include labels such as those on beverage bottles and sleeves on cans and

bottle and jar closures, markings (e.g. warning labels), desiccants, securing means (e.g. metal

and other seals) or cushioning materials (corner pads, airbags etc.).

Transport packaging: Pursuant to § 3, para. 1, clause 1 of the German packaging

regulations, transport packaging includes:

" drums, jerricans, boxes, bags including pallets, cardboard packaging, foamed trays, shrink

films and similar coverings which are constituents of transport packages and the purpose of

which is to protect goods from damage while in transit between the manufacturer and

distributor or which are used for reasons of transport safety."

Unlike sales packaging, transport packaging is removed after transport to the trader

(wholesaler, retailer etc.) and the goods are sold on to the consumer or other third party

5

without the transport packaging.

Packaging which is delivered to the consumer and in which the consumer has no interest is

also classed as transport packaging.

Examples of transport packaging are:

Paperboard trays and films as packaging for beverage cans

Boxes for capital goods, such as machinery, engines etc.

Cartons and films acting as packaging material for furniture

Cartons holding a relatively large number of individual items, such as toothpaste

tubes, canned foods

Outer packaging: Pursuant to §3, para. 1, clause 3, of the German packaging regulations,

outer packaging includes:

"blister packs, films, cardboard packaging or similar coverings which are intended as

additional packaging around sales packaging which

serve to facilitate self-service retailing of the goods or

serve to deter or prevent theft or

predominantly serve promotional purposes."

Examples:

Cartons in which toothpaste tubes are packaged

Cartons in which high-value beverage bottles are packaged

Cartons in which several cigarette packets are packaged

Sales packaging: §3, para. 1, clause 2 of the German packaging regulations defines sales

packaging as follows:

"Closed or open containers and coverings for goods, such as pots, bags, blister packages,

cans, pails, drums, bottles, jerricans, cardboard packaging, cartons, sacks, dishes, carrier bags

or similar coverings which are used by the consumer for transport or kept until the contents

are consumed. For the purposes of the regulations, disposable crockery and cutlery are also

classed as sales packaging."

Sales packaging is packaging which only loses its function when it reaches the consumer,

unless the packaging is delivered to the consumer, who has no interest in this packaging.

Package contents, packaging material, packaging container and packaging aid

Package contents: The item which is packaged is known as the package contents.

Packaging materials: These are the materials which constitute the packaging. Examples are

6

paper, cardboard, millboard, corrugated board, lumber, sheet metal, plastics, glass etc.. These

are, however, only generic terms. If packaging materials are to be precisely defined, a more

exact description must be given:

Wooden packages may be made of wood species such as spruce, fir, pine,

European beech or poplar.

Plastic packaging is made from polyethylene (PE), polypropylene (PP),

polyurethane (PU), polystyrene (PS), polyamides (PA) etc..

Corrugated board is specified, amongst other things, by the number of flutes, flute

size, material thickness and basis weight.

Paper is classified into different varieties depending upon its properties, such as

packaging paper, wet strength paper, crepe paper, coated grades of paper with a

barrier material or treated grades of paper, for example treated with VCI (Volatile

Corrosion Inhibitor).

Packaging container: The container in which the package contents (cargo) are packaged.

The following are examples of packaging containers: cartons, boxes, crates, sacks, cans,

drums, jars, bottles, jerricans, bags, shrink covers etc..

Packaging aids: Packaging aids are materials which reinforce or permit the production of

packaging containers, such as nails, adhesive tapes, staples and strapping which hold boxes

and cartons together.

Packaging aids also include labels such as those on beverage bottles and sleeves on cans and

bottle and jar closures, markings (e.g. warning labels), desiccants, securing means (e.g. metal

and other seals) or cushioning materials (corner pads, airbags etc.).

Transport packaging: Pursuant to § 3, para. 1, clause 1 of the German packaging

regulations, transport packaging includes:

" drums, jerricans, boxes, bags including pallets, cardboard packaging, foamed trays, shrink

films and similar coverings which are constituents of transport packages and the purpose of

which is to protect goods from damage while in transit between the manufacturer and

distributor or which are used for reasons of transport safety."

Unlike sales packaging, transport packaging is removed after transport to the trader

(wholesaler, retailer etc.) and the goods are sold on to the consumer or other third party

without the transport packaging.

Packaging which is delivered to the consumer and in which the consumer has no interest is

also classed as transport packaging.

Examples of transport packaging are:

Paperboard trays and films as packaging for beverage cans

Boxes for capital goods, such as machinery, engines etc.

Cartons and films acting as packaging material for furniture

Cartons holding a relatively large number of individual items, such as toothpaste

tubes, canned foods

7

Outer packaging: Pursuant to §3, para. 1, clause 3, of the German packaging regulations,

outer packaging includes:

"blister packs, films, cardboard packaging or similar coverings which are intended as

additional packaging around sales packaging which

serve to facilitate self-service retailing of the goods or

serve to deter or prevent theft or

predominantly serve promotional purposes."

Examples:

Cartons in which toothpaste tubes are packaged

Cartons in which high-value beverage bottles are packaged

Cartons in which several cigarette packets are packaged

Sales packaging: §3, para. 1, clause 2 of the German packaging regulations defines sales

packaging as follows:

"Closed or open containers and coverings for goods, such as pots, bags, blister packages,

cans, pails, drums, bottles, jerricans, cardboard packaging, cartons, sacks, dishes, carrier bags

or similar coverings which are used by the consumer for transport or kept until the contents

are consumed. For the purposes of the regulations, disposable crockery and cutlery are also

classed as sales packaging."

Sales packaging is packaging which only loses its function when it reaches the consumer,

unless the packaging is delivered to the consumer, who has no interest in this packaging.

Ordinary commercial, seaworthy and fit for purpose packaging

Packaging has frequently been described in the past, and to some extent still is described, as

"ordinary commercial" or "seaworthy". However, since these terms are rather vague and

provide no precise definition of such packaging, they should be avoided. Even poor

packaging may be described as "ordinary commercial".

Ordinary commercial packaging merely refers to certain practices which are customary in the

consignor's country. The conditions which the product will be expected to withstand during

transport, which are determined by the route, duration of transport, destination, duration of

storage, possible onward transport, must be taken into account.

Using the term seaworthy packaging is intended to indicate that the packaging must

additionally withstand the conditions of maritime transport and thus more severe stresses.

However, this often disregards the fact that the most severe stresses do not occur during

maritime transport itself, but instead during cargo handling (due to impact, pushing,

overturning etc.).

When problems arise, the terms "ordinary commercial" and "seaworthy" packaging always

cause dispute because they are not defined. It is thus advisable to stipulate the exact nature of

the packaging when making contractual agreements. This may be achieved by specifying the

following parameters:

Packaging material

8

Packaging container

Packaging aid

Mandatory standards and legislation

Package design

Strength requirements

Insurance terms now mention packaging which is "fit for purpose", which provides a more

precise definition of the packaging and, in the event of loss, allows an assessment to be made

as to whether the packaging was adequate or not adequate.

Shrink and stretch packaging

Both these types of packaging are used to group together individual packages, containers or

items of cargo on a pallet to form a cargo unit.

Shrink packaging: involves enclosing the package contents in shrink film (flat or tubular

film), heat sealing any unsealed portions and separating the package from the film web or

covering the package contents with a shrink cover. Depending upon the shape and weight of

the package contents, the shrink material used should be PE or plasticized PVC film of a

thickness of 0.01 to 0.2 mm, with PE films being particularly suitable for heavy items. The

film is heated from the outside in a shrink oven or with hand-held heat gun, so releasing the

"frozen in" tension in the film. Shrink films are produced in forms which are oriented either

monoaxially (in a single direction) or biaxially (in two directions). As the film cools down, it

shrinks around the package contents, applying a very slight pressure per unit area. The tear

strength of shrink films to DIN 53371 is 1.8 to 3.2 Nm/mm² in machine direction and 1.6 to

2.5 Nm/mm² in transverse direction. If the shrink packaging is intended to secure loads in

transit, compliance with VDI guideline 3968, sheet 4 must be ensured. There are no

restrictions either with regard to the compressive strength of the packaged item or with regard

to differing loading areas, heights and weights. Sharp-edged items should be shrink wrapped

either with film of an appropriate thickness or using edge protectors. When shrink wrapping

pallet loads, the film should be placed such that it extends over the lower edge of the pallet

deck (see Figure 1), so ensuring that the cargo cannot slip and may be described as a

functional cargo unit. If the base area of the packaged item is smaller than the area of the

pallet, care must be taken to ensure that the item is firmly attached to the pallet before it is

shrink wrapped. Shrink wrapping provides protection from dust and moisture in indoor

storage. Particularly hygroscopic goods must stand on a film on the pallet or be otherwise

protected. Shrink packaging provides a psychological barrier to theft.

Figure 1

9

Stretch packaging: In stretch wrapping, one or more flat films are placed under mechanical

tension and wound helically around the item to be packaged. Depending upon the shape and

weight of the package contents, the stretch material used should be PE or plasticized PVC

film of a thickness of 0.01 to 0.05 mm, with stretch packaging only being suitable for light

weights and firmly consolidated items. The ends of the film web are heat sealed or coated.

The cargo unit is held together by the tension of the film. If the stretch packaging is intended

to secure loads in transit, compliance with VDI guideline 3968, sheet 5 must be ensured.

Pretensioning of the film when stretch wrapping should not exceed the compressive strength

of the item being packaged. However, if low levels of pretensioning are applied, securing of

the cargo in transit is also reduced. Securing of the cargo in transit is also reduced by over- or

understacking of the pallet base area. There are no restrictions with regard to differing

loading areas, heights and weights. Sharp-edged items should only be stretch wrapped using

edge protectors, as the film may tear during the stretch wrapping operation. When stretch

wrapping pallet loads, the film should be placed such that it extends over the lower edge of

the pallet deck, so ensuring that the cargo cannot slip and may be described as a functional

cargo unit. Stretch wrapping provides protection from dust and moisture in indoor storage

only if an additional cargo cover sheet is used. Particularly hygroscopic goods also require an

additional cargo cover sheet and must stand on a film on the pallet or be otherwise protected.

Stretch packaging provides a psychological barrier to theft.

Disposable packaging: Disposable packaging is intended only for a single transport

operation. Possible reasons for using disposable packaging may be, for example, that return

and reuse is not economic, that the package will not withstand further transport operations or

that the packaged item is unique and requires a specially tailored package (e.g. wooden box

for machinery). If a disposable package is reused, problems may occur in the event of loss as

the packaging would be considered not adequate due to the repeated use.

Examples of disposable packages are:

Disposable bottles

Yogurt pots

Food cans

Wooden boxes

Corrugated board cartons

Disposable pallets

Returnable packaging: Unlike disposable packaging, returnable packaging is intended for

repeated use, so reducing the volume of packaging and thus also of packaging waste.

Returnable packaging must be made more strongly than disposable packaging as it is exposed

to stresses more often.

Another requirement placed upon returnable packaging systems is that they should be

straightforward and cheap to return, i.e. the packages must be designed such that they are

foldable or collapsible.

Examples of returnable packaging are:

Beverage crates

10

Returnable bottles

Glass yogurt pots

Returnable wooden boxes with clip closures

Collapsible corrugated board/wooden composite structures

Dimensional standards

The aim of the modular system is to tailor the various technical components in the

transportation chain, such as packages, cargo units, pallets, containers, transport vehicles to

each other so as to optimize the economic viability and safety of transport operations.

Packaging sizes are in particular adjusted to the internationally standard pallet dimensions of

800 mm x 1200 mm (Europallet) and 1000 mm x 1200 mm. Using pallet dimensions firstly

has economic advantages (better utilization of payload area). Secondly, there are also

technical advantages because the cargo may accordingly more readily and safely be secured

on the pallet.

Current DIN standards make a fundamental distinction between the following terms:

- Area module: The area module in the transportation chain is a rectangle of 600 mm x 400

mm.

- Area module multiple: The area module multiple is defined as any rectangle which may be

formed without gaps from an integral multiple of the area module. This includes, for

example, the internationally usual pallet dimensions of 800 mm x 1200 mm.

- Sub-multiples: Sub-multiples are obtained by integral division of the area module into

identically sized areas. These dimensions are defined in so-called selection series.

Depending upon the size of the item to be packed, the packaging may be designed such that

its external dimensions match those of the area module or a sub-multiple, such that the

payload area of the pallets is 100% utilized. It is often difficult or impossible to adopt the

modular system for large items, such as fridges etc.. It is simpler to package small items or

bulk cargoes in accordance with the modular system.

The following tables show an overview of the number and arrangement of packages of

varying sizes on pallets of dimensions 800 mm x 1200 mm and 1000 mm x 1200 mm. Please

click on the appropriate package size.

Pallet size 800 mm x 1200 mm

Package

size [mm]

600 x 100 600 x 133 600 x 200 600 x 400

300 x 100 300 x 133 300 x 200 300 x 400

200 x 100 200 x 133 200 x 200 200 x 400

150 x 100 150 x 133 150 x 200 150 x 400

120 x 100 120 x 133 120 x 200 120 x 400

Pallet size 1000 mm x 1200 mm

Package 600 x 100 600 x 133 600 x 200 600 x 400

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size [mm] 300 x 100 300 x 133 300 x 200 300 x 400

200 x 100 200 x 133 200 x 200 200 x 400

150 x 100 150 x 133 150 x 200 150 x 400

120 x 100 120 x 133 120 x 200 120 x 400

Table 1: Selection series for certain package sizes and arrangement of packages on an 800

mm x 1200 mm pallet

Size of

package

[mm]

Number of

packages

per layer

Arrangement Alternative

600 x 100 16

600 x 133 12

600 x 200 8

600 x 400 4

300 x 100 32

300 x 133 24

12

300 x 200 16

300 x 400 8

200 x 100 48

200 x 133 36

200 x 200 24

200 x 400 12

150 x 100 64

150 x 133 48

150 x 200 32

13

150 x 400 16

120 x 100 80

120 x 133 60

120 x 200 40

120 x 400 20

Table 2: Selection series for certain package sizes and arrangement of packages on a 1000

mm x 1200 mm pallet:

Size of

package

[mm]

Number of

packages

per layer

Arrangement Alternative

600 x 100 20

600 x 133 15

14

600 x 200 10

600 x 400 5

300 x 100 40

300 x 133 30

300 x 200 20

300 x 400 10

200 x 100 60

15

200 x 133 45

200 x 200 30

200 x 400 15

150 x 100 80

150 x 133 60

150 x 200 40

150 x 400 20

16

120 x 100 100

120 x 133 75

120 x 200 50

120 x 400 25

The following is a list of the most important DIN standards relating to modularity:

DIN 30 783, Pt. 1: Modular order in the transportation chain; horizontal

dimensional coordination; terminology, principles

DIN 30 798, Pt. 1: Modular systems; modular coordination; terminology

DIN 55 509: Payload areas in packaging; terminology

DIN 55 510: Packaging; modular coordination in packaging; modular sub-

multiples of the 600 mm x 400 mm area module

DIN 55 511, Pt. 1: Packaging containers; cartons manufactured from millboard or

corrugated board, adjusted to 600 mm x 400 mm (area module); folding cartons

with bottom and top flaps.

DIN 55 511, Pt. 3: Packaging containers; cartons manufactured from millboard or

corrugated board, adjusted to 600 mm x 400 mm (area module); telescope cartons

DIN 55 520: Payload areas for shipping packages derived from the 800 mm x

1200 mm and 1000 mm x 1200 mm payload areas

DIN 55 521, Pt. 1: Packaging containers; cartons manufactured from millboard or

corrugated board, adjusted to 800 mm x 1200 mm or 1000 mm x 1200 mm

(payload area); folding cartons with bottom and top flaps

DIN 55 521, Pt. 2: Packaging containers; cartons manufactured from millboard or

corrugated board, adjusted to 800 mm x 1200 mm or 1000 mm x 1200 mm

17

(payload area); telescope cartons

DIN 55 522: Packaging containers; cartons manufactured from cardboard; folding

cartons with tuck-in bottom and lid; determination of carton dimensions

Marking of packages

Correct and complete marking of packages helps to prevent incorrect handling, accidents,

incorrect delivery, losses of weight and volume and Customs fines.

Marking must be clear and precise. Its color should stand out clearly from that of the

package; it is usually black in color. Alternatively, it may also be applied on adhesive labels.

Where possible, black symbols on a white background should be used. Both when the

marking is applied directly onto the package and when adhesive labels are used, care must be

taken to ensure that marking is applied in a legible and durable manner.

Adequate marking is an indispensable component of the package. If the marking is at

variance with the details on the shipping documents, objections may be raised by the

Customs authorities. If handling marking is inadequate, those parties whose actions during

transport, handling or storage of the cargo have caused damage may be excluded from

liability.

Complete marking must comprise the following three parts:

1. Shipping mark

Identification mark: e.g. initial letters of receiver or shipper or of receiver's

company name

Identification number: e.g. receiver's order number

Total number of items in the complete consignment

Number of the package in the consignment, e.g. 5/12 or 5 - 12

Place and port of destination

2. Information mark

Country of origin: The country of origin must be stated in accordance with the

provisions of the particular countries. Statement of the country of origin is often

mandatory. In some cases it is not desired and, if contractually agreed, may even

have to be omitted. Failure to comply with such agreements entails a risk of

blacklisting.

Indication of weight of package: from a gross weight of 1000 kg, packages must

be marked with details of weight. With regard to ease of transport, handling and

storage, the relevant standards also recommend indicating weight from a lower

threshold.

Dimensions of packages: standards specify that dimensions be stated in

centimeters.

3. Handling instructions

"Handling marks" help to ensure that greater care is taken with cargo handling. It must be

possible to tell,

18

whether the package is sensitive to heat or moisture

whether it is at risk of breakage

where the top and bottom are and where the center of gravity is located

where loading tackle may be slung

The symbols for package handling instructions are internationally standardized in ISO R/780

(International Organization for Standardization) and in DIN 55 402 (DIN, German Institute

for Standardization). The symbols must never be omitted as they are self-explanatory and so

overcome language problems in international transport operations.

Designation Symbol Explanation

Fragile, Handle

with care

The symbol should be applied to easily broken cargoes.

Cargoes marked with this symbol should be handled

carefully and should never be tipped over or slung.

Use no hooks

Any other kind of point load should also be avoided with

cargoes marked with this symbol. The symbol does not

automatically prohibit the use of the plate hooks used for

handling bagged cargo.

Top

The package must always be transported, handled and

stored in such a way that the arrows always point

upwards. Rolling, swinging, severe tipping or tumbling or

other such handling must be avoided. The cargo need not,

however, be stored "on top".

Keep away from

heat (solar

radiation)

Compliance with the symbol is best achieved if the cargo

is kept under the coolest possible conditions. In any event,

it must be kept away from additional sources of heat. It

may be appropriate to enquire whether prevailing or

anticipated temperatures may be harmful. This label

should also be used for goods, such as butter and

chocolate, which anybody knows should not be exposed

to heat, in order to prevent losses.

Protect from

heat and

radioactive

sources

Stowage as for the preceding symbol. The cargo must

additionally be protected from radioactivity.

19

Sling here

The symbol indicates merely where the cargo should be

slung, but not the method of lifting. If the symbols are

applied equidistant from the middle or center of gravity,

the package will hang level if the slings are of identical

length. If this is not the case, the slinging equipment must

be shortened on one side.

Keep dry

Cargoes bearing this symbol must be protected from

excessive humidity and must accordingly be stored under

cover. If particularly large or bulky packages cannot be

stored in warehouses or sheds, they must be carefully

covered with tarpaulins.

Center of

gravity

This symbol is intended to provide a clear indication of

the position of the center of gravity. To be meaningful,

this symbol should only be used where the center of

gravity is not central. The meaning is unambiguous if the

symbol is applied onto two upright surfaces at right

angles to each other.

No hand truck

here

The absence of this symbol on packages amounts to

permission to use a hand truck on them.

Stacking

limitation

The maximum stacking load must be stated as "... kg

max.". Since such marking is sensible only on packages

with little loading capacity, cargo bearing this symbol

should be stowed in the uppermost layer.

Clamp here

Stating that the package may be clamped at the indicated

point is logically equivalent to a prohibition of clamping

anywhere else.

Temperature

limitations

According to regulations, the symbol should either be

provided with the suffix "...°C" for a specific temperature

or, in the case of a temperature range, with an upper

("...°C max.") and lower ("...°C min.") temperature limit.

The corresponding temperatures or temperature limits

should also be noted on the consignment note.

20

Do not use

forklift truck

here

This symbol should only be applied to the sides where the

forklift truck cannot be used. Absence of the symbol on

other sides of the package amounts to permission to use

forklift trucks on these sides.

Electrostatic

sensitive device

Contact with packages bearing this symbol should be

avoided at low levels of relative humidity, especially if

insulating footwear is being worn or the ground/floor is

nonconductive. Low levels of relative humidity must in

particular be expected on hot, dry summer days and very

cold winter days.

Do not destroy

barrier

A barrier layer which is (virtually) impermeable to water

vapor and contains desiccants for corrosion protection is

located beneath the outer packaging. This protection will

be ineffective if the barrier layer is damaged. Since the

symbol has not yet been approved by the ISO, puncturing

of the outer shell must in particular be avoided for any

packages bearing the words "Packed with desiccants".

Tear off here

This symbol is intended only for the receiver.

Packaging materials and packaging containers made from paper, cardboard, millboard and corrugated board

Terminology

Paper:Flat packaging material largely consisting of fibers, generally of vegetable origin; basis weight

less than 225 g/m2.

Cardboard: Flat packaging material, largely consisting of fibers, generally of vegetable origin, the

basis weight of which (150 g/m2 to 600 g/m

2) overlaps the basis weight range of both paper and

paperboard. Cardboard is stiffer than paper and is generally produced from higher quality materials

than is paperboard. Cardboard is produced as a continuous web.

Paperboard: Generic term covering both millboard and corrugated board.

Millboard: Solid paperboard (unlike corrugated board) with a basis weight (weight per unit area) of

21

> 225 g/m2; single ply or couched; also laminated, glued, impregnated or coated; produced as

continuous paperboard or wet machine board.

Corrugated board: Paperboard made from one or more plies of fluted paper which is glued onto

paper or cardboard. A distinction is drawn between single and multi-wall corrugated board:

Single face corrugated board consists of one ply of fluted paper which is glued onto

paper or cardboard.

Single wall corrugated board consists of one ply of fluted paper which is glued between

two plies of paper or cardboard (also known as double face corrugated board).

Double wall corrugated board consists of two plies of fluted paper which are glued

together by one ply of unfluted paper or cardboard and the exposed outer surfaces of

which are each covered with one ply of paper or cardboard.

Tri-wall corrugated board consists of three plies of fluted paper which are glued together

by two plies of paper or cardboard and the outer surfaces of which are likewise each

covered with one ply of paper or cardboard.

Carton: Single or multipart, usually cuboid, closable packaging container available in various designs,

styles and delivery forms as basic (individual), consolidating, outer (shipping), sales or multipurpose

packaging. Cartons are classed as follows:

Self-erecting carton: Pre-glued, one-piece carton with attached tuck-in top or

overlapping top (hinged top carton) or pre-glued, two-piece telescope carton consisting

of a lower part (bottom) and upper part (top). The side walls or tongues of the carton

are provided with oblique scores and are glued together such that the carton may be

supplied in flat form and is then made ready for use by being unfolded and erected.

Folding carton: As delivery form: generic term for sales, storage and shipping packages

of various designs which are delivered ready-to-use in flat form and are first squared up

or erected by the user.

As design: foldable carton which consists of a tube (frame) with a (prefabricated) side

seam running parallel to the carton height and with attached bottom and top flaps or

attached tuck-in bottom and top.

Die-cut carton blank: Packaging container blank of a specific shape and style, also pre-

or edge-glued, which is provided with groove, score, perforation or cutting lines and,

possibly, punched out portions. The blank is used to produce a carton or carton

component.

22

Tray: Stackable, stable packaging container for transport and storage, mainly for highly perishable

foodstuffs (e.g. fruit, vegetables, fresh fish):

wooden: made from a bottom, two side parts and two end parts joined together with

corner posts. The corner posts generally extend above the walls.

made from molded plastics or box-shaped foamed plastics

made from millboard or corrugated board, usually in box shape

in combinations of materials of various designs

Strength characteristics of paperboard packaging materials:

Bursting strength: Resistance exerted by a specimen of packaging material against

bursting on exposure to pressure.

Puncture resistance: Force which must be applied for a puncture tool of specified shape

and dimensions to pass completely through a test specimen. This force is expended to

pierce, tear and bend open the test specimen.

Edgewise crush resistance: Resistance to crushing of a perpendicularly arranged test

specimen of paperboard (usually corrugated board) of a defined size.

Treatment

The properties of paper, cardboard and paperboard are sometimes considerably improved by

special treatment methods. The aims of these treatment methods are, for example, to increase

tearing and wet strength, impermeability to fat and moisture or to repel microorganisms. The

following table shows three of the most important treatment methods:

Treatment

method Aim

Impregnation Impregnation involves saturating paper products with waxes,

dissolved salts or similar substances, so creating a protective

layer which provides protection from insect infestation and rot.

Impregnation may also render paper products impermeable to

moisture and fat and also flameproof them.

Coating The purpose of coating paper products is primarily to achieve

moisture and fat repellency. Common coating materials are

plastics and waxes, which are applied, for example, by brushing

or other coating methods.

23

Lamination In packaging applications, lamination is the bonding together of

two or more plies of different packaging materials. In contrast

with coating, lamination involves the application of pre-formed,

flat products (films etc.). Lamination is principally performed

with adhesives, waxes, latex products and polyethylene

compounds. Lamination provides a protective layer on the paper

products and moreover combines the various positive

characteristics of the packaging materials used.

Paper types in packaging

Numerous different types of paper are used in packaging applications, some of which have

very different properties. The appropriate type is selected depending upon the requirements

placed upon the packaging by the package contents and transport conditions. Some of the

most important types of paper are described in the following table:

Paper grade Characteristics and applications

Asphalt paper Asphalt is a black/brown bituminous mixture of flammable

hydrocarbons. Asphalt paper comprises a layer of this

substance between two plies of paper. Asphalt paper is highly

waterproof and is only slightly permeable to water vapor.

Consequently, it is most particularly used for packaging goods

which are susceptible to corrosion. Asphalt paper cannot be

heat sealed, so water vapor permeability is always a critical

factor, which in turn means that it cannot be used as the sole

means of corrosion protection. Asphalt paper is merely water-

repellent, but is not impermeable to water vapor.

Kraftliner Due to its high strength and moisture resistance, kraftliner is

used as an outer and intermediate ply, especially in corrugated

board. The high strength is achieved thanks to the virgin fiber

used in the production of kraftliner, which has a low recycled

fiber content.

Kraft sack

paper

As its name would suggest, kraft sack paper is primarily used

for sack/bag production. It is distinguished by elevated

elasticity.

Wet strength

paper

Special type of paper which has been specially treated, e.g. by

coating, lamination or impregnation, to improve its resistance

to water and water vapor. Wet strength paper types are in

particular used in sacks/bags in order to maintain their tensile

strength when exposed to moisture and for cartons if

condensation is anticipated in transit.

24

Parchment

paper

In addition to moisture resistance, parchment paper's most

significant advantage is its completely greaseproof nature. It is

thus mainly used for packaging greasy or oily or grease-

sensitive products. Glassine and imitation parchment paper

have similar grease-repellent properties.

Gray chip Gray chip, also known as schrenz, is used, like kraftliner, in

corrugated board manufacture, but for the fluting instead of the

outer or intermediate plies. Its recycled fiber content is

relatively high.

Testliner Testliner, like kraftliner, is used for the outer and intermediate

plies of corrugated board. However, its strength is not quite as

high as that of kraftliner, as it has a higher recycled fiber

content.

VCI paper

(Volatile

Corrosion

Inhibitor)

VCI paper provides protection from corrosion. The paper acts

as a support for the inhibitors which actually provide protection

from corrosion. Further information may be found in the

Corrosion Protection section.

Types of corrugated board

Corrugated board consists of one or two outer plies, the flutes and, in multi-ply types of

corrugated board, of one or more intermediate plies. Corrugated board is classified as follows

according to the number of outer/intermediate plies and flutes:

Figure 1: Single face corrugated board consists of one ply of fluted paper, onto which paper

or cardboard is glued.

25

Figure 2: Single wall (double face) corrugated board consists of one ply of fluted paper

which is glued between two plies of paper or cardboard.

Figure 3: Double wall corrugated board consists of two plies of fluted paper which are glued

together by one ply of unfluted paper or cardboard and the exposed outer surfaces of which

are each covered with one ply of paper or cardboard.

Figure 4: Tri-wall corrugated board consists of three plies of fluted paper which are glued

together by two plies of paper or cardboard and the outer surfaces of which are likewise each

covered with one ply of paper or cardboard.

As is clear from the structure of the various types of corrugated board, they differ most with

regard to strength, which increases with the number of plies and/or the quality of the paper

used. The strength of corrugated board is determined by the following three characteristics:

26

Bursting strength [kPa]

Puncture resistance [J]

Edgewise crush resistance [kN/m]

The strengths are divided into classes which are defined in DIN standard 55468.

Cartons are usually made from double wall and single wall corrugated board. Cartons made

from high strength corrugated board, generally tri-wall (or ultra-heavy) corrugated board, are

used for transport operations involving severe climatic conditions and mechanical stresses

and for those involving heavier cargoes. Moreover, corrugated board made with moisture-

resistant glue and wet strength paper is used in particular for maritime transport. Wet strength

grades of corrugated board are marked with the following quality stamp:

Figure 5

(Click to enlarge)

When making cartons, it is vital for the flutes in the end and side walls to be arranged upright

so that they can withstand the greatest possible pressure when stacked. In contrast, if the

flutes are horizontal, they have very poor rigidity and can be crushed very easily (see Figure

6).

Figure 6: When arranged in this way, the

flutes would collapse when exposed to

pressure from above. Carton strength is

then compromised and entire stacks may

collapse.

Flutes and flute sizes

The commonest flute shape is a sine wave. Flute size is determined on the one hand by flute

pitch and on the other by flute height. The flute pitch is the horizontal distance between

adjacent flute troughs. The flute height is the vertical trough to peak distance of a flute.

27

Figure 1: Diagram of flute pitch and height

DIN 55468 recognizes the following flute types:

Flute shape Flute pitch Flute height

Coarse flute (A flute) 8.0 - 9.5 mm 4.0 - 4.9 mm

Medium flute (C flute) 6.8 - 8.0 mm 3.2 - 4.0 mm

Fine flute (B flute) 5.5 - 6.5 mm 2.2 - 3.0 mm

Microflute (E flute) 3.0 - 3.5 mm 1.0 - 1.8 mm

Due to its size, coarse flute has the best cushioning characteristics (largest spring travel) and

the greatest edgewise crush resistance. However, like medium flute, it is not ideally suited to

direct printing of the outer facing.

Designs, styles and delivery forms of cartons

DIN 55 429, Pt. 1 and the FEFCO/ASSCO Code (international shipping package code)

describe the internationally usual designs, styles and delivery forms of cartons made from

cardboard, millboard and corrugated board. The designs and styles have been defined by

ASSCO (Association Européenne des Fabricants de Caisses d’Expédition en Carton

Compact), FEFCO (Fédération Européenne des Fabricants de Carton Ondulé) and the ECMA

(European Carton Makers Association).

The DIN standard lists the designs and styles shown in the following table, but these are only

a selection of the possible styles. Further variants may be found in the DIN standard. The

various designs are primarily delivered as die-cut carton blanks, folding cartons or as self-

erecting cartons.

28

Figure 1: Folding cartons with bottom and top flaps: the outer top and bottom flaps meet, but

the inner ones do not. This is the most widely used design.

Figure 2: Folding cartons with bottom and top flaps: both the outer and inner top and bottom

flaps meet.

29

Figure 3: Folding carton with bottom flaps and tuck-in top: the top is provided with a tuck-in

tongue used to close the top. In this style, the bottom flaps abut, while the inner top flaps

cover only a proportion of the area of the carton top.

Figure 4: Folding carton with tuck-in bottom and tuck-in top: both the top and the bottom are

provided with a tuck-in tongue. In this case, the inner top flaps cover only a proportion of the

total area.

30

Figure 5: Pull-through cartons: in this design the top, bottom and two side-walls consist of a

single piece.

Figure 6: Tube and slide cartons: the inner part is known as the slide, the outer part as the

tube.

31

Figure 7: Hinged top cartons with tuck-in top: in this style, the front side wall can be tilted

forwards. The hinged top has a tuck-in tongue.

Figure 8: Hinged top cartons with overlapping top: the hinged top overlaps the side walls on

three sides.

32

Figure 9: Telescope cartons: the top is made as a separate part. It overlaps the side walls of

the carton on all four sides.

Figure 10: Double cover cartons: these consist of three separate parts (top, bottom, tube). The

top and bottom both overlap the tube.

33

Figure 11: Folder cartons, one-piece: in this style, both the inner and outer flaps meet.

Figure 12: Folder cartons, multipart: the carton consists of an outer and an inner sleeve. In

this case, too, the flaps meet.

34

Figure 13: Open-top (unclosable) cartons or carton components: the top, which has only very

short flaps, is virtually completely open. The bottom has abutting flaps and is closed.

Packaging materials and packaging containers made from plastic

Types of plastics

Plastics are natural/synthetic materials. They are produced by chemically modifying natural

substances or are synthesized from inorganic and organic raw materials. On the basis of their

physical characteristics, plastics are usually divided into thermosets, elastomers and

thermoplastics. These groups differ primarily with regard to molecular structure, which is

what determines their differing thermal behavior. The following Table lists the characteristics

of the various types of plastics.

Type of

plastic

Molecular structure Characteristics and applications

Thermosets

Thermosets are hard and have a very tight-

meshed, branched molecular structure. Curing

proceeds during shaping, after which it is no

longer possible to shape the material by

heating. Further shaping may then only be

performed by machining. Thermosets are used,

for example, to make light switches.

35

Elastomers

While elastomers also have a crosslinked

structure, they have a looser mesh than

thermosets, giving rise to a degree of elasticity.

Once shaped, elastomers also cannot be

reshaped by heating. Elastomers are used, for

example, to produce automobile tires.

Thermoplastics

Thermoplastics have a linear or branched

molecular structure which determines their

strength and thermal behavior; they are flexible

at ordinary temperatures. At approx. 120 -

180°C, thermoplastics become a pasty/liquid

mass. The service temperature range for

thermoplastics is considerably lower than that

for thermosets. The thermoplastics

polyethylene (PE), polyvinyl chloride (PVC)

and polystyrene (PS) are used, for example, in

packaging applications.

Plastics welding processes

In plastics welding, films are fused together under the action of heat and pressure, resulting in

crosslinking of their molecular chains. A distinction is drawn between the following welding

processes:

Welding

process Application

Hot gas

welding

In hot gas welding, a hot gas (usually air) is directed onto the films to be

joined, so making them plastic at this point. When the films are pressed

together and allowed to cool, the molecular chains of the films crosslink, so

producing the joint. The disadvantage of hot gas welding is the high level

of energy losses and the consequent low level of efficiency.

Contact or

impulse

welding

Contact welding is carried out using pincer-like contact rails. The films to

be welded are placed between the contact rails and the necessary heat and

pressure applied by closing the pincers. If the period of heating is

adjustable on the welding equipment, the process is known as impulse

welding.

Contact welding is a discontinuous process as it is only possible to weld

small areas and the welding equipment must be reapplied for each welding

operation.

The disadvantage of contact welding is that heat is applied directly only to

36

the outside of the films, although it is actually used on the inside, so

resulting in energy losses and reduced efficiency.

High

frequency

welding

High frequency welding exploits the chemical structure of some plastics. A

distinction is drawn between neutral types of plastics (without dipoles),

such as polyethylene (PE), polypropylene (PP) and polystyrene (PS), and

polar plastics (with dipoles), such as polyvinyl chloride (PVC), polyamides

(PA) and acetates. A dipole is a pair of opposing electric or magnetic poles.

The films to be welded using this process are exposed to a high frequency

alternating electromagnetic field which excites the dipoles in the plastics.

This excitation causes heating and, on subsequent application of pressure,

the films are joined together.

The advantages of this process are firstly that it is a continuous welding

process, in which large areas may be processed without removing the

welding equipment. Secondly, this process may be applied very precisely,

i.e. only those areas which are actually to be joined are heated.

The disadvantage is that it can only be used to weld plastics with dipoles.

Ultrasound

welding

In this process, ultrasound waves generate internal friction in the films, so

heating the plastic. In this case, the same temperatures are obtained on both

the inside and the outside, so minimizing losses. The heated surfaces are

then joined together by application of pressure. Ultrasound welding, like

high frequency welding, is a continuous welding process.

Additives in plastics processing

Additive Characteristics

Antistatic

agents

Antistatic agents are added to plastics in order to prevent electrostatic

charging of the packaging. Such charging causes plastics to attract and retain

particles of dust and dirt.

Colorants Colorants, whether soluble or insoluble (pigments), inorganic or organic, are

used to color plastics. Addition of colorants may sometimes have a

considerable impact upon the properties (e.g. strength) of the plastic.

Flame

retardants

Addition of flame retardants modifies the combustion behavior of plastics, it

being possible to limit not only flammability and ignitability but also the

combustion process itself. Polyethylene and polypropylene, for example,

intrinsically support combustion and flame retardants prevent this reaction

from occurring. On the other hand, other plastics, such as PVC are self-

extinguishing and stop burning by themselves.

37

Fillers The purpose of fillers, such as glass fiber, chalk, graphite, carbon black etc.,

is, on the one hand, to extend the plastics and so reduce their cost and, on the

other, to improve the qualities of the plastic. Such qualities are strength,

resilience and hardness.

Lubricants The purpose of lubricants is to facilitate plastics processing, for example by

increasing surface slip during extrusion and so improving shaping results.

Stabilizers The task of stabilizers is to protect plastics from the effects of light, UV

radiation, heat, aging. Stabilizers protect plastics from premature

decomposition or impairment of their properties.

Plasticizers Addition of plasticizers modifies certain properties of a plastic: resilience is

increased, while its embrittlement temperature, and likewise hardness, falls.

However, the effects of plasticizers are not only positive. There are health

issues associated with plasticizers and, due to their tendency to vaporize out

of plastics, they are not suitable for food use.

Mechanisms of formation of plastics

Plastics are formed by three different reaction mechanisms: addition polymerization,

polycondensation and polyaddition.

Type of reaction Explanation

Addition

polymerization

Addition polymerization involves joining several small molecules

together into a chain to form a large molecule. In this case, the

molecules are merely arranged in succession. The product retains the

same composition as the starting materials and no secondary products

are eliminated. If the starting materials consist of identical molecules,

the product is known as a homopolymer, while if they consist of

different molecules, the product is known as a copolymer. The addition

polymerization reaction is initiated by heat, pressure and catalysts.

Addition polymerization gives rise, for example, to polystyrene (PS),

polypropylene (PP) and polyethylene (PE)

Polycondensation In polycondensation, differing starting materials are combined to yield

a single molecule with elimination of a secondary product (usually

water). If the reaction yields only linear chains, polycondensation may

give rise to thermoplastics. However, if the individual molecules of the

starting materials link together at several points, a three-dimensional

structure is obtained, giving rise to thermosets.

Polyaddition Polyaddition is defined as the joining together of several molecules of

different starting materials with migration of hydrogen atoms, but

without secondary products being formed. Polyaddition gives rise, for

38

example, to polyurethane (PU), which is highly environmentally

friendly and is used for strapping tapes in packaging applications.

Processes used in plastics manufacturing

Process Application

Extrusion Extrusion is performed in extruders. This process is used to produce tubes,

profiles, films etc. from thermoplastics. Extrusion proceeds as follows:

The starting material (mainly polyethylene, polypropylene, polyvinyl

chloride and polystyrene), which is usually in powder or pellet form, is

placed in a feed hopper. The material is then heated and homogeneously

mixed in the extruder to form a melt and a conveying screw expels the melt

through a shaping die at the end of the extruder. Dies of differing shapes

produce the various products.

Injection

molding

Injection molding is used not only for thermoplastics and thermosets but

also for elastomers. As in extrusion, the starting material, which is usually in

pellet form, is placed in a hopper, heated, plasticized and expelled through a

nozzle by a screw conveyor. On the far side of the nozzle, there is a mold

cavity which serves to shape the plastic molding. Injection molding is

frequently used for mass-producing relatively small parts (e.g. screw caps

for beverage bottles).

Calendering Calendering or rolling is used for film production. The calender consists of

several highly polished and very rapidly rotating rolls. The rolls may be

chilled or heated as required. Calendering is used in particular when film

thickness specifications are particularly tight. Films with embossed patterns

or the like may, for example, be obtained by using special calenders.

Blow

molding

Blow molding is used to produce hollow articles. One particular kind of

blow molding is extrusion blow molding, in which an extruded parison or

preform is inserted into a two-part mold, where it is inflated with

compressed air and so pressed against the cold mold wall, where it cools.

The mold halves are then separated and the finished hollow article may be

removed.

In packaging applications, blow molding is primarily used for producing

plastic bottles.

Special packaging plastics

39

Plastic Explanation

Cellulose

acetate (CA)

Unlike the other plastics mentioned here, this thermoplastic is produced

from a natural raw material, namely cellulose.

Cellulose acetates frequently contain special plasticizers, which may give

rise to problems in food packaging applications, since the plasticizers,

which may be harmful to health, can migrate out of the plastic. CA is also

highly transparent (crystal clear) and has good toughness and strength. Its

water absorption capacity is problematic as there is an associated risk of

swelling. CA films may be waterproofed by coating them with certain

other plastics or waxes, so combining the positive features of the

materials.

The temperature range over which CA may be used is between approx. 0

and 90°C.

CA is primarily converted into films for packaging applications.

Polyamide (PA) PA is a synthetic polymer obtained by polycondensation. Depending

upon the number of carbon atoms present, this thermoplastic is divided

into various grades, most of which share the same properties.

PA is used in packaging applications for producing films. Due to its

resistance to very low temperatures (down to -40°C), PA is used for

packaging frozen goods. The oxygen and aroma barrier properties of PA

film also make it suitable for vacuum packaging. Amorphous polyamides

yield crystal clear films, while partially crystalline polyamides exhibit a

milky haze when uncolored.

Plasticizers are added to PA films made from certain grades of PA, so

excluding them from use in foodstuffs packaging. The absorption and

release of water may also have negative effects.

Polyethylene

(PE)

PE is a member of the polyolefin family, which are partially crystalline

thermoplastics. PE is classed by density as

PE-LD, low density polyethylene, density approx. 0.92 - 0.94 g/ cm3,

produced by the high pressure process, and

PE-HD, high density polyethylene, density approx. 0.94 - 0.96 g/cm3,

produced by the low pressure process.

Both PE-LD and PE-HD exhibit a milky haze when uncolored (nearly

crystal clear only when converted into thin films) and are insensitive to

water. The temperature range over which PE may be used is approx. -50 -

+60°C for PE-LD, while the upper limit for PE-HD is approx. 90°C,

thanks to its higher density.

PE films are in particular characterized by good water vapor barrier

properties. Their permeability to gases and aroma substances is, however,

40

disadvantageous. Thanks to its higher density, PE-HD has better barrier

properties towards oxygen, carbon dioxide, water vapor and aroma

substances than does PE-LD.

PE is not only converted into films (PE films, composite films, shrink

films), but is also used to produce bottles, bottle crates, drums, jerricans,

boxes, bowls etc..

Polypropylene

(PP)

PP is a partially crystalline thermoplastic. Like polyethylene, PP is a

member of the polyolefin family.

Uncolored, PP exhibits a milky haze. PP may be used at temperatures of

approx. 0 to 160°C.

PP is used in packaging applications for producing films, transport boxes,

packaging tapes, pots and bottles. Thanks to its high upper temperature

limit, it is suitable for foodstuffs which are heated in the container in a

microwave oven and for hot filling of liquids into bottles.

Polyvinyl

chloride (PVC)

PVC, which is a thermoplastic polymer, is primarily divided into two

groups: firstly, plasticized PVC, to which certain plasticizers have been

added, and, secondly, rigid or unplasticized PVC (without plasticizers).

Both have the same amorphous molecular structure. Depending upon the

production process and the incorporated additives, various grades of PVC

are obtained with sometimes differing properties.

For example, the temperature range within which PVC may be used is

determined amongst other things by the plasticizer content. Plasticizer

content also has an impact upon suitability for food contact (only in the

case of plasticized PVC) for foodstuffs packaging applications.

Depending upon grade, PVC ranges in color from crystal clear to a milky

haze. Rigid PVC is relatively impermeable to water vapor.

PVC is used in packaging applications for producing films, bottles, pots,

skin and blister packages.

Polystyrene

(PS)

PS is an amorphous thermoplastic formed by addition polymerization. Its

most valuable characteristic is its very clear and glossy surface which is

used, for example, in sales packaging (blister packs).

Disadvantages of PS films are their high permeability to gases and water

vapor. PS is not suitable for high temperature applications (e.g. hot

filling) as vapors may be released that contain the monomer styrene,

which is classed as an irritant.

PS is primarily used for blister packaging and as a base layer for

composite films.

41

Cushioning materials

Goods are frequently transported which are particularly sensitive to mechanical stresses and which

must consequently be protected from damage due to impact, jolting or vibration in transit. They are

thus additionally protected by cushioning materials inside the shipping packaging.

Fragile goods, such as glass, ceramics, porcelain, or sensitive electronic products, such as computers

and electronic home entertainment equipment, are particularly susceptible to mechanical stresses

and should be protected.

In addition to protecting the package contents, cushioning materials may also be used to adjust the

packages to a standard size, in which case they act as adapters between nonstandard package

contents and the packaging (modularity of shipping packages).

Cushioning materials absorb a proportion of the kinetic energy arising when the package suffers

impact or is dropped and increase the braking distance of the package contents. Correct selection

and sizing of the cushioning material thus ensure that the package content suffers no damage.

Required characteristics of cushioning materials Cushioning materials must in particular fulfill four main requirements:

Recovery is one of the most important properties of a cushioning material; it

ensures that the package contents continue to be protected even when repeatedly

subjected to similar stresses. If recovery is too low, the braking distance declines

on constant exposure to stress, such that the resultant kinetic energy can no longer

adequately be absorbed and the package contents may be damaged.

Cushioning materials must be insensitive to climatic conditions, such as moisture

due to elevated relative humidity, direct solar radiation and extreme variations in

temperature and their action must not be impaired by such exposure.

Especially in the case of package contents which are at risk of corrosion, it is

important that the cushioning materials are not hygroscopic and consequently do

not promote corrosion. They should furthermore not contain any aggressive

constituents (neutral pH), which could contribute towards corrosion. The

cushioning material and package contents should not interact and possibly impair

each other's properties.

Use of the cushioning material should be effective, simple, environmentally

compatible and cost-effective.

Selection criteria for cushioning materials

Sensitivity classification of package contents

If it is to be possible to dimension the cushioning material properly, it is essential

to know what stresses it can withstand without suffering damage. Since industrial

equipment in particular today consists of many different components of differing

42

levels of sensitivity, it is very difficult to provide a general classification of goods.

The manufacturer will in each instance be able to provide precise details about the

sensitivity of their product.

The sensitivity classification of a product is determined by the admissible g value.

1g is the acceleration due to gravity (9.81 m/s2), i.e. the force which usually

applies to an object on the earth.

If an acceleration of 2 g is applied (for example during fast cornering), the weight

of the object doubles. This is precisely what happens to an item for transport

which is secured on the loading area of a truck or stowed in a sea container.

However, in addition to acceleration, the duration of any impact must always also

be taken into account. The longer the duration of any impact, the greater is the risk

of damage.

Stresses during transport

The stresses arising during transport are the second important parameter in

selecting a cushioning material. These stresses may be highly variable and it is

extremely difficult to determine exactly what they will be. The greatest stresses

occur if the packaged items are thrown or dropped. This is why the potential drop

height of a package as a function of its weight is used as a measure of stress.

The regulations of Deutsche Bahn (German railroad operator) and Deutsche Post

(German postal authorities) define maximum drop heights for packages as

follows:

Regulations Weight of package Maximum drop height

Deutsche Bahn 50 kg 52 cm

75 kg 46 cm

100 kg 40 cm

150 kg 27 cm

200 kg 15 cm

Deutsche Post no weight limit 60 - 80 cm

Static area load

The cushioning material is exposed to both dynamic and static forces during

transport and cargo handling, but only static stresses apply during storage. These

stresses are known as the static area load acting upon a cushioning material, which

is calculated from the weight of the package contents and its bearing area:

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The static area load is important for the purpose of selecting a suitable cushioning

material, as the material must not lose its recovery when at rest merely under the

weight of the package contents.

Recovery

As mentioned above, recovery is a decisive indicator of the loading capacity of the

cushioning material on repeated exposure to stresses. If recovery is too low, the

braking distance declines on constant exposure to stress, such that the resultant

kinetic energy can no longer adequately be absorbed and the package contents

may be damaged.

Specific weight

Specific weight is stated in kg/m3 and is a measure of the hardness of a cushioning

material; the higher is the specific weight, the harder is the cushioning material.

Resonance behavior

The stresses arising due to the transport of an item on a vehicle are composed of

many different and simultaneously acting vibrations and impacts.

If theses vibrations are at the natural frequency of the package contents, resonance

may occur. The item is consequently exposed to greater acceleration in the vertical

direction, the protective action of the cushioning material is canceled out, so

exposing the cushioned item to greater risk.

Especially when transporting sensitive items, such as instruments or electronic

components, the frequency values of the means of transport used and the natural

frequencies of the cushioning material and item for transport must be known and

adjusted to each other. In this way, by using a truck with air suspension, it is

possible to avoid the "excitation" frequency when transporting electronic

components. Under unfavorable transport conditions, this excitation frequency

would occur during transport on a leaf-sprung vehicle, so increasing the amplitude

of vibration of the package contents and, once the resonant range of the

cushioning material had been reached, damaging the package contents.

Stress range of the cushioning material

Every cushioning material has a stress range within which it exhibits optimum

effectiveness. Cushioning curves, which are the plot of maximum impact

deceleration against static area load, are used to select suitable cushioning

materials. These cushioning curves may be used to determine the cushioning

thickness which will provide sufficient shock absorption. Cushioning curves are

plotted for a specific drop height. These curves indicate, for example, that a 5 cm

thickness of plastic foam cushioning is required to reduce impact forces to the

admissible level of at most 30 g. The area required to provide cushioning beneath

a packaged item may then easily be calculated.

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Description of various kinds of cushioning materials

Airbags

Airbags consist of an elastic film which is inflated with air. When at rest, only the static load

generated by the weight of the package contents bears upon the cushioning. When dynamic

loads occur, these are absorbed by compression of the cushion.

The quantity of inflation air may be varied in accordance with the particular properties and

requirements of the package contents. Airbags are commercially available in various sizes

and designs, ranging from spheres, standard cushions to corner and edge cushioning and

tubular cushioning.

Airbags are mainly used in containers and railroad freight cars and only rarely in trucks.

Advantages of airbags:

ease of handling

nonhygroscopic

highly versatile

largely insensitive to extreme climatic conditions (heat, cold)

elevated recovery and ideal shock absorption characteristics

Disadvantage of airbags:

susceptible to pointed and sharp articles, such as nails or the like

Bubble films

Bubble films function in essentially the same way as airbags. They consist of two plastic

films, one of which is completely flat and the other has small, round indentations, which,

once the two films have been heat sealed together, contain the necessary air. Bubble films are

mainly used inside packaging containers. The advantages and disadvantages are the same as

for airbags.

Rubberized fiber cushioning

Rubberized fiber cushioning provides high quality protection for demanding items. This

cushioning is made from animal hair or coconut fiber, which is cleaned, converted into

nonwoven mats, coated with rubber and vulcanized to form solidly bonded sheets.

Rubberized fiber cushioning is relatively insensitive to the effects of moisture and high or

low temperatures and exhibits very good recovery even on long-term exposure to loads.

Plastic foam cushioning materials

Plastic foam cushioning materials are mainly made from polystyrene (PS), polyurethane (PU)

and polyethylene (PE). Plastic foams are available in flexible, semirigid and rigid forms.

Their cushioning characteristics are determined not only by their specific weight but also by

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their cell structure. The particular characteristics of the various starting materials are briefly

described below.

Polystyrene (PS):

PS is a somewhat soft, elastic foamed plastic with closed cells containing the air required to

provide resilience. Recovery is, however, rather limited.

PS is not itself hygroscopic and thus remains fully functional on exposure to moisture. It

should be noted, however, that, due to its structure (enclosed capillaries), PS cushioning

material nevertheless has a certain tendency to absorb or release water vapor. Appropriate

action must accordingly be taken to protect package contents which are at risk of corrosion.

PS cushioning material is produced both as relatively large moldings, such as cushioning

frames, edge or corner pads, and as a loose fill cushioning material, known as PS chips.

When large moldings are used, the cushioning area often has to be reduced as the static area

loads of the package contents are not sufficient to ensure effective cushioning.

Polyurethane (PU):

Polyurethanes are produced in flexible, semirigid and rigid forms with an open cell structure.

It is primarily flexible and semirigid grades of polyurethane which are used in packaging

applications.

The shock absorbing properties of PU foams increase with foam hardness, while recovery

and elasticity decline.

Especially on repeated exposure to identical stresses, this characteristic may cause problems

with an excessively rigid grade of foam as there is a continual decline in recovery.

Polyurethane foams are produced as relatively large moldings, generally by direct foaming

around the item to be packaged. If this is not feasible, the moldings may also be prefoamed.

One disadvantage of PU foams is their relatively complex production process. Their ideal

application is thus not for mass-produced items, but instead for packaging and cushioning

constantly differing items.

Polyethylene (PE):

Like polystyrenes, polyethylene foams are closed-cell products. They exhibit excellent

cushioning characteristics, which are comparable with those of rubberized fiber cushioning.

Even when exposed to major loads, they retain their cushioning capability.

PE foams do, however, have two considerable disadvantages. Firstly, they are costly, which

excludes them from many applications, secondly they do not have good weather resistance.

Classification of corrosion protection methods

1 – Active corrosion protection

The aim of active corrosion protection is to influence the reactions which proceed during

corrosion, it being possible to control not only the package contents and the corrosive agent

46

but also the reaction itself in such a manner that corrosion is avoided. Examples of such an

approach are the development of corrosion-resistant alloys and the addition of inhibitors to

the aggressive medium.

2 - Passive corrosion protection

In passive corrosion protection, damage is prevented by mechanically isolating the package

contents from the aggressive corrosive agents, for example by using protective layers, films

or other coatings. However, this type of corrosion protection changes neither the general

ability of the package contents to corrode, nor the aggressiveness of the corrosive agent and

this is why this approach is known as passive corrosion protection. If the protective layer,

film etc. is destroyed at any point, corrosion may occur within a very short time.

3 – Permanent corrosion protection

The purpose of permanent corrosion protection methods is mainly to provide protection at the

place of use. The stresses presented by climatic, biotic and chemical factors are relatively

slight in this situation. Machines are located, for example, in factory sheds and are thus

protected from extreme variations in temperature, which are frequently the cause of

condensation. Examples of passive corrosion protection methods are:

• Tin plating

• Galvanization

• Coating

• Enameling

• Copper plating

4- Temporary corrosion protection

The stresses occurring during transport, handling and storage are much greater than those

occurring at the place of use. Such stresses may be manifested, for example, as extreme

variations in temperature, which result in a risk of condensation. Especially in maritime

transport, the elevated salt content of the water and air in so-called seasalt aerosols may cause

damage, as salts have a strongly corrosion-promoting action. The following are the main

temporary corrosion protection methods:

A. Protective coating method

The protective coating method is a passive corrosion protection method. The protective

coating isolates the metallic surfaces from the aggressive media, such as moisture, salts, acids

etc..

The following corrosion protection agents are used:

Solvent-based anticorrosion agents

Very high quality protective films are obtained.

Once the anticorrosion agent has been applied, the solvent must vaporize so that

the necessary protective film is formed.

Depending upon the nature of the solvent and film thickness, this drying process

may take as long as several hours. The thicker the film, the longer the drying time.

If the drying process is artificially accelerated, there may be problems with

adhesion between the protective film and the metal surface.

Since protective films are very thin and soft, attention must always be paid to the

dropping point as there is a risk at elevated temperatures that the protective film

47

will run off, especially from vertical surfaces.

Since solvent-based corrosion protection agents are often highly flammable, they

may only be used in closed systems for reasons of occupational safety.

Water-based anticorrosion agents

These contain no solvents and thus do not require closed systems.

Drying times are shorter than for solvent-based anticorrosion agents.

Due to their elevated water content, water-based anticorrosion agents are highly

temperature-dependent (risk of freezing or increased viscosity).

The advantage of this method is that the protective film is readily removed, but

the elevated water content, which may increase relative humidity in packaging

areas, is disadvantageous.

Corrosion-protective oils without solvent

Corrosion-protective oils without solvent produce only poor quality protective

films. Good quality protection is achieved by adding inhibitors. Since these

corrosion-protective oils are frequently high quality lubricating oils, they are

primarily used for providing corrosion protection in closed systems (engines etc.).

Dipping waxes

The protective layer is applied by dipping the item to be packaged into hot wax.

Depending upon the type of wax, the temperature may have to be in excess of

100°C. Removal of the protective film is relatively simple as no solid bond is

formed between the wax and metal surface. Since application of dipping waxes is

relatively complex, its use is limited to a few isolated applications.

B. Desiccant method

According to DIN 55 473, the purpose of using desiccants is as follows: "desiccant bags are

intended to protect the package contents from humidity during transport and storage in order

to prevent corrosion, mold growth and the like."

The desiccant bags contain desiccants which absorb water vapor, are insoluble in water and

are chemically inert, such as silica gel, aluminum silicate, alumina, blue gel, bentonite,

molecular sieves etc.. Due to the absorbency of the desiccants, humidity in the atmosphere of

the package may be reduced, so eliminating the risk of corrosion. Since absorbency is finite,

this method is only possible if the package contents are enclosed in a heat sealed barrier layer

which is impermeable to water vapor. This is known as a climate-controlled or sealed

package. If the barrier layer is not impermeable to water vapor, further water vapor may enter

from outside such that the desiccant bags are relatively quickly saturated, without the relative

humidity in the package being reduced.

Desiccants are commercially available in desiccant units. According to DIN 55 473:

"A desiccant unit is the quantity of desiccant which, at equilibrium with air at 23 ± 2°C,

adsorbs the following quantities of water vapor:

min. 3.0 g at 20% relative humidity

min. 6.0 g at 40% relative humidity

The number of desiccant units is a measure of the adsorption capacity of the desiccant bag."

Desiccants are supplied in bags of 1/6, 1/3, 1/2, 1, 2, 4, 8, 16, 32 or 80 units. They are

available in low-dusting and dust-tight forms. The latter are used if the package contents have

48

particular requirements in this respect.

Calculation of required number of desiccant units

The number of desiccant units required is determined by the volume of the package, the

actual and desired relative humidity within the package, the water content of any hygroscopic

packaging aids, the nature of the barrier film (water vapor permeability).

Formula for calculating the number of desiccant units in a package (DIN 55 474):

n = (1/a) × (V × b + m × c + A × e × WVP × t)

n number of desiccant units

a

quantity of water absorbable per desiccant unit in accordance with the maximum

admissible humidity in the package:

admissible final

humidity 20% 40% 50% 60%

factor a 3 6 7 8

e

correction factor, relative to admissible final humidity in %:

admissible final

humidity 20% 40% 50% 60%

factor e 0.9 0.7 0.65 0.6

V internal volume of the package in m3

b absolute humidity of enclosed air in g/m3

m mass of hygroscopic packaging aids in kg

c factor for the moisture content of hygroscopic packaging aids in g/kg

A surface area of barrier film in m

2 (calculated on the basis of the area of the internal

sides of the Package)

WVP water vapor permeability of barrier film under anticipated climatic conditions in

g/m2d, measured to DIN 53 122, Pt. 1 or Pt. 2 (d = day)

t total duration of transport in days

Barrier films

Barrier films are available in various forms, for example as a polyethylene film or as a

composite films with two outer polyethylene layers and an aluminum core. The composite

film performs far better with regard to water vapor permeability (WVP), achieving WVP

values of below 0.1 (g/m2d). In the composite film, the barrier layers are arranged so as to

bring about a considerable reduction in permeability in comparison with a single layer.

In accordance with current DIN standards, water vapor permeability is always stated for both

20°C and 40°C. According to information from the manufacturer, it may be concluded that

water vapor permeability rises with increasing temperature and falls with increasing

thickness. This problem occurs most particularly with polyethylene films, while aluminum

composite films are largely insensitive to rises in temperature.

Placement of desiccant bags

49

The desiccants should be suspended from strings in the upper part of the climate-controlled

package to ensure good air circulation around them.

It is essential to avoid direct contact between the desiccant bag and the package contents as

the moist desiccant would promote corrosion.

It is advisable to use numerous small bags rather than fewer large ones, as this increases the

available surface area of the desiccant and so improves adsorption of the water.

In order to ensure the longest possible duration of protection, the barrier film must be heat

sealed immediately once the desiccant bags have been inserted.

Desiccant bags are always supplied in certain basic package sizes which, depending upon the

desiccant unit size, may contain a single bag (of 80 units) or up to 100 bags (of 1/6 unit). The

basic outer package should only be opened directly before removal of a bag and must

immediately be heat sealed again.

Advantages Disadvantages

• Desiccants provide excellent corrosion

protection to both metallic and

nonmetallic items

• Removal of the desiccant on delivery

to the receiver is straightforward,

unlike the removal of protective films

in the protective coating method. The

package contents are immediately

available.

• No particular occupational hygiene

requirements apply as the desiccant is

nonhazardous.

• Placement of the desiccant bags and heat

sealing of the barrier films are relatively

labor-intensive.

• The slightest damage to the barrier layer

may negate the effectiveness of corrosion

protection.

• Calculating the required number of

desiccant units is not entirely simple and

it is easy to overcalculate. However, too

much protection is better than too little.

• Humidity indicators inside the package

are not very reliable as they are only

valid for certain temperature ranges.

C. VCI (Volatile Corrosion Inhibitor) method

Inhibitors are substances capable of inhibiting or suppressing chemical reactions. They may

be considered the opposite to catalysts, which enable or accelerate certain reactions.

Unlike the protective coating method, the VCI method is an active corrosion protection

method, as chemical corrosion processes are actively influenced by inhibitors.

In simple terms, the mode of action (see Figure 1) is as follows: due to its evaporation

properties, the VCI substance (applied onto paper, cardboard, film or foam supports or in a

powder, spray or oil formulation) passes relatively continuously into the gas phase and is

deposited as a film onto the item to be protected (metal surfaces). This change of state

proceeds largely independently of ordinary temperatures or humidity levels. Its attraction to

metal surfaces is stronger than that of water molecules, resulting in the formation of a

continuous protective layer between the metal surface and the surrounding atmosphere which

means that the water vapor in the atmosphere is kept away from the metal surface, so

preventing any corrosion. VCI molecules are, however, also capable of passing through pre-

existing films of water on metal surfaces, so displacing water from the surface. The presence

of the VCI inhibits the electrochemical processes which result in corrosion, suppressing

either the anodic or cathodic half-reactions. Under certain circumstances, the period of action

may extend to two years.

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Figure 1: Mode of action of VCI

The mode of action dictates how VCI materials are used. At item to be protected is, for

example, wrapped in VCI paper. The metallic surfaces of the item should be as clean as

possible to ensure the effectiveness of the method. The VCI material should be no further

than 30 cm away from the item to be protected. Approximately 40 g of active substances

should be allowed per 1 m³ of air volume. It is advisable to secure this volume in such a

manner that the gas is not continuously removed from the package due to air movement. This

can be achieved by ensuring that the container is as well sealed as possible, but airtight heat

sealing, as in the desiccant method, is not required.

The VCI method is primarily used for articles made from carbon steel, stainless steel, cast

iron, galvanized steel, nickel, chromium, aluminium and copper. The protective action

provided and compatibility issues must be checked with the manufacturer.

N.B.: The use of water-miscible, water-mixed and water-immiscible corrosion protection

agents, corrosion protection greases and waxes, volatile corrosion inhibitors (VCI) and

materials from which volatile corrosion inhibitors may be released (e.g. VCI paper, VCI

films, VCI foam, VCI powder, VCI packaging, VCI oils) is governed by the German

Technical Regulations for Hazardous Substances, TRGS 615 "Restrictions on the use of

corrosion protection agents which may give rise to N-nitrosamines during use".

Advantages Disadvantages

• Since the gas also penetrates holes and

cavities, these areas also receive

adequate protection.

• The period of action may extend to

two years.

• The wrapping need not be provided

with an airtight heat seal.

• On completion of transport, the

packaged item need not be cleaned,

but is immediately available.

• The VCI method is not suitable for all

metals. It may cause considerable

damage to nonmetallic articles

(plastics etc.).

• Most VCI active substances may

present a hazard to health, so it is

advisable to have their harmlessness

confirmed by the manufacturer and to

obtain instructions for use.