ILSI Europe Report Series

Packaging Materials 9. Multilayer Packaging for Food and Beverages

Report

Commissioned by the ilsi Europe Packaging Materials Task Force About ILSI / ILSI Europe

Founded in 1978, the International Life Sciences Institute (ILSI) is a nonprofit, worldwide foundation that seeks to improve the well-being of the general public through the advancement of science. Its goal is to further the understanding of scientific issues relating to nutrition, food safety, toxicology, risk assessment, and the environment. ILSI is recognised around the world for the quality of the research it supports, the global conferences and workshops it sponsors, the educational projects it initiates, and the publications it produces. ILSI is affiliated with the World Health Organization (WHO) as a non-governmental organisation and has special consultative status with the Food and Agricultural Organization (FAO) of the United Nations. By bringing together scientists from academia, government, industry, and the public sector, ILSI fosters a balanced approach to solving health and environmental problems of common global concern. Headquartered in Washington, DC, ILSI accomplishes this work through its worldwide network of branches, the ILSI Health and Environmental Sciences Institute (HESI) and its Research Foundation. Branches currently operate within Argentina, Brazil, Europe, India, Japan, Korea, Mexico, North Africa & Gulf Region, North America, North Andean, South Africa, South Andean, Southeast Asia Region, as well as a Focal Point in China.

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This publication is made possible by support of the ILSI Europe Task Force on Packaging Materials, which is under the umbrella of the Board of Directors of ILSI Europe. ILSI policy mandates that the ILSI and ILSI branch Boards of Directors must be composed of at least 50% public sector scientists; the remaining directors represent ILSI’s member companies. Listed hereunder are the ILSI Europe Board of Directors and the ILSI Europe Task Force on Packaging Materials industry members.

ILSI Europe Board of Directors

Non-industry members Industry members

Prof. A. Boobis, Imperial College of London (UK) Mr. C. Davis, Kraft Foods Europe (CH) Prof. P. Calder, University of Southampton (UK) Mr. R. Fletcher, Kellogg Europe (IE) Prof. G. Eisenbrand, University of Kaiserslautern (DE) Dr. M. Knowles, Coca-Cola Europe (BE) Prof. A. Grynberg, Université Paris Sud – INRA (FR) Dr. G. Kozianowski, Südzucker/BENEO Group (DE) Prof. M. Kovac, Ministry of Agriculture (SK) Dr. G. Meijer, Unilever (NL) Prof. em. G. Pascal, National Institute for Agricultural Research – Prof. J. O’Brien, Nestlé (CH) INRA (FR) Prof. C. Shortt, McNeil Nutritionals (UK) Prof. G. Rechkemmer, Max Rubner-Institut – Federal Research Dr. J. Stowell, Danisco (UK) Institute of Nutrition and Food (DE) Dr. G. Thompson, Danone (FR) Dr. J. Schlundt, National Food Institute (DK) Dr. P. Weber, DSM (CH) Prof. V. Tutelyan, National Nutrition Institute (RU) Prof. G. Varela-Moreiras, University San Pablo-CEU of Madrid (ES)

ILSI Europe Packaging Materials Task Force industry members

Coca-Cola Europe Nestlé Danone SABMiller Dow Europe Swiss Quality Testing Services DuPont de Nemours Tetra Pak Research Kraft Foods Europe Unilever Mars PACKAGING MATERIALS: 9. MULTILAYER PACKAGING FOR FOOD AND BEVERAGES

By John Dixon

Report COMMISSIONED BY THE ILSI EUROPE PACKAGING MATERIALS TASK FORCE

july 2011 © 2011 ILSI Europe

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D/2011/10.996/23

ISBN 9789078637264 Contents P ackaging

INTRODUCTION 4 PACKAGE DESIGN REQUIREMENTS 5

materials THE PROPERTIES OF DIFFERENT MATERIALS 7 THE RATIONALE FOR MULTILAYER STRUCTURES 9

METHODS OF PRODUCTION 15 : 9.

CHEMISTRY 22 multilayer MIGRATION OF SUBSTANCES FROM MULTILAYERS 24 REGULATORY ASPECTS WITHIN THE EUROPEAN UNION 26

p SAFETY EVALUATION 29 ackaging ENVIRONMENTAL ASPECTS 32

GENERAL CONCLUSIONS 34 for

ANNEX ­– FURTHER EXAMPLES OF MULTILAYER STRUCTURES 35 food LIST OF ACRONYMS 38

GLOSSARY 39 and

REFERENCES 41 beverages

Author: John Dixon, Consultant (UK) Scientific reviewers: Roland Franz, Fraunhofer Institute (DE), Mark Vints, Amcor Flexibles Europe (BE) Report Series Editor: Kevin Yates (UK) Coordinator: Tanja Wildemann, ILSI Europe (BE)

3 introduction beverages

he last 50 years have seen major changes in the way that food is produced and and T retailed. Self-service supermarkets have grown to dominate the market, with a corresponding growth in pre-packaged food. More food is prepared before retail food sale, even to the extent of ready-to-eat dishes. Such food production has become concentrated into

for fewer sites, with more products being distributed and marketed on a pan-European basis. At the same

time, there has been a significant reduction in the number of food manufacturers and retailers.

These changes have driven an increasing sophistication in food packaging. Self-service demands ackaging p products that stand out on the supermarket shelf. Consumers place increasing value in being able to see the product they are buying and in the freshness of the food at the time of purchase. Processed and part-processed foods require new packaging techniques to achieve an adequate shelf life. The concentration of food production facilities results in longer distribution lines and thus creates a need for multilayer packaging that can extend the shelf life, especially for fresh and chilled products. The fewer but larger : 9. 9. : manufacturers and retailers have driven down packaging costs by using better pack design, thinner materials and faster, more automated packaging processes. materials These changing requirements for packaging have become more and more difficult to achieve with single materials. To achieve the required performance it has become necessary to combine the properties of different materials. This report deals with the way in which multilayers achieve this. ackaging P The report includes both flexible and rigid multilayer packaging. It does not cover: • Metal packaging, which was the subject of the seventh report within the ILSI Europe Report Series on Packaging Materials. • The contribution of printing inks, which are covered by the eighth report in the ILSI Europe Report Series on Packaging Materials. • Two-component packs, i.e. those consisting of two different materials but that can exist separately, e.g. bag-in-box as used for breakfast cereals, labels applied to bottles and other containers.

4 P PACKAGE DESIGN REQUIREMENTS ackaging

The use of multilayer materials is driven by the need to design a pack that combines different functional materials requirements.

Collation : 9.

A package must collate and contain the food. To do this, it may need: multilayer • Strength. This term covers a number of properties. Examples include resistance to puncture, impact and tear.

• Sealing. The pack must be closed by some means. Traditional techniques such as tying, taping or p gluing have largely given way to materials that can be sealed to themselves. ackaging • Dead-fold. A pack may be formed from a material that stays folded when creased, with or without additional sealing.

for

Preservation food Very importantly, the packaging must help preserve the food, protecting it from external influences that

could cause a deterioration in quality: and • Moisture: The moisture content of many foods must be controlled. For example, breakfast cereals will

absorb moisture from the atmosphere to become soft. Bread will lose moisture to become dry. In such beverages cases, packaging materials are required to provide a barrier to the transmission of water vapour in or out of the pack. Different materials have different permeabilities to moisture, which are expressed as water vapour transmission rates (WVTR) with units of g/m²/day. Because transmission rates vary with both temperature and relative humidity (RH), these parameters must be defined for a given WVTR value. • Oxygen: Most foods are susceptible to exposure to oxygen. For example, fats can be oxidised to produce off-flavours. Fruit juices can lose vitamin C or become discoloured. The technique of modified atmosphere packaging (MAP) is used to extend the shelf life of foods such as fresh meat and fish, creating a pack environment where the ratio of atmospheric gases has been altered in order to reduce microbial activity and spoilage. In such cases, the packaging material must provide a barrier to gas transmission. Oxygen transmission rates (OTR) are generally used to measure permeability and are expressed as cc/m²/day/bar. Again, the temperature and RH must be specified. Other gases, e.g. carbon dioxide and nitrogen, have different transmission rates but these are often in proportion

to the OTR (with CO2 typically migrating through a material faster than O2, and N2 slower). • Light: Both visible or UV light can be an initiator of oxidative reactions. For some foods, it is important that the packaging materials provide a physical light barrier to prevent light-induced changes in flavour or nutritional quality. • Other flavours, odours and chemicals: A barrier to flavour, odour and chemicals can be important to prevent the food absorbing unwanted odours or substances from the outside environment. It is also needed to prevent flavour loss during storage. • Seal quality: The way the pack is closed or sealed must match the barrier properties of the materials. A low-barrier pack will not need hermetic seals. However, a pack made from high-barrier materials must also have high quality, leak-free seals. This is particularly important when there is a requirement to prevent microbial contamination or in the case of MAP. At the most basic level, a pack must keep the food as clean and hygienic as it was when packed. However, if the food has been sterilised or pasteurised by in-pack heat treatment or by aseptic processing, it is vital that both the packaging material and the seals prevent micro-organisms from entering the pack.

5 Promotion The appearance of a pack is important to attract the consumer and to present a quality image that beverages is consistent with that of the product it contains. Print plays a major role in this as well as providing statutory and other information, but the packaging materials also play a part. They can be required and to protect the ink from abrasion or to provide high gloss or matt finishes. White, coloured or metallic materials can provide a background for the ink. food for

The rigidity of a material can be important to allow it to stand up on the shelf and prevent it looking creased and “tired”.

ackaging Machineability p Food is packed on high speed automated machinery. Efficient operation requires the use of packaging materials with precisely defined characteristics. Different machines make different demands on the material. A comprehensive list is beyond the scope of this report but examples of required characteristics

multilayer include:

: 9. 9. : • Tensile strength to prevent stretching or snapping. • Softening or melting when heated to provide a sealing medium. • Conversely, heat resistance to prevent stretching or other damage during the sealing operation. materials • Rigidity, pliability or dead-fold to allow the shape of a pack to be formed. • Slip, e.g. to allow materials to pass over static machine parts – or lack of it, e.g. to allow materials to be gripped firmly or to be stacked. ackaging P Convenience Ideally, the package will include design features that make it easier for the consumer to handle, to open easily and, in some cases, to reclose. Another focus is on design elements that help in the preparation of the food, e.g. steam valves for microwave reheating, susceptors, boil-in-bag packaging, etc.

Cost There is a continuous pressure from food manufacturers and retailers to reduce packaging costs, both of the materials themselves and of the packaging operation. This forms a major design requirement for all packs.

Increasingly, the industry is not just thinking in terms of the monetary costs of packaging but also of its environmental impact. This issue is discussed further in the chapter on Environmental Aspects.

Food safety As will be discussed more fully in the chapters on Regulatory Aspects and Safety Evaluation, the package must be designed so as to ensure the safety of the eventual consumer of the packed food and to comply with all food contact and other legal requirements.

6 P THE PROPERTIES OF DIFFERENT MATERIALS ackaging

materials n many cases, it is not possible to meet all the packaging design requirements I using a single monolayer material. The whole rationale for the use of multilayers is to create a single packing structure that will combine the different properties of different base materials in order to meet these design requirements. This chapter gives some examples of : 9. these properties, albeit in general terms rather than quoting precise specifications. multilayer

As has been mentioned, a barrier to moisture and gases such as oxygen is needed for many packs. The different barriers provided by some commonly used base materials are illustrated by Figure 1, which

p shows their permeabilities to water vapour and oxygen. ackaging

Figure 1. Permeabilities to water vapour and oxygen of some base materials Source: Typical values taken from industry data sheets.

for

food

and

beverages /day/bar) 2 at 38°C and 90% RH transmission rate (g/m rate transmission vapour Water

Oxygen transmission rate (cc/m2/day/bar) at 25°C and 50% RH

Note that log scales have been used. WVTR values are given in tropical conditions of 38°C and 90% RH, an industry standard. In normal ambient conditions (23°C and 50% RH) the actual WVTR would be about 75% lower.

Note that the above values are only illustrative and the actual permeability will depend on the precise grade, thickness and the final structure in which the material is used. Material thicknesses used for the examples are shown in Table 1.

The size of the boxes for each material approximately indicates the range of barrier properties possible, using different grades and thicknesses. It will readily be seen that moisture barrier and oxygen barrier do not go hand in hand. For example, metallised OPP with a WVTR of <1 g/m²/day has a good moisture barrier but only a moderate oxygen barrier (OTR of 10–100 cc/m²/day/bar). EVOH has less moisture barrier (WVTR of 50–200 g/m²/day) but much better oxygen barrier (OTR around 2 cc/m²/day/bar). It should be noted that, for this material, OTR is noticeably dependent on its moisture content and hence the RH.

7 Table 1. Typical thickness of some commonly used base materials

beverages Abbreviation Material Thickness (microns)

Met. OPP Metallised oriented polypropylene 20 and Met. OPET Metallised oriented polyethylene terephthalate (polyester) 12 LDPE Low density polyethylene 25–100 food OPP Oriented polypropylene 15–50 for OPA Oriented polyamide 12–30 OPET Oriented polyethylene terephthalate (polyester) 12–50 PVdC OPP Polyvinylidene chloride-coated oriented Polypropylene 32 ackaging p

EVOH Ethylene vinyl alcohol 2–10

For polymers, transmission rates are inversely proportional to the layer thickness. For multilayers, the total transmission rate can be calculated in good approximation by reciprocal addition of the transmission multilayer rates of individual layers, i.e. 1/TR(multilayer) = 1/TR(layer1) + 1/TR(layer2) + …. Note that such considerations do

: 9. 9. : not apply to thin coatings of polymers or to non-polymers. In these cases, the continuity of the coating or the presence/absence of pinholes might be more important in determining transmission rates. materials

Table 2 compares some other properties of a selection of web materials. In the example below, the more pluses, the better the material displays that property. Or in the case of “Cost”, the more expensive it is. “0” indicates a complete lack of the property. ackaging P Table 2. Comparison of properties of web materials

Material Tensile Light Heat Heat Dead- Relative strength1 barrier sealing resistance fold cost2 40–70 g/m² Paper +++ + 0 ++++ ++ ++ 6.3–12 μm Aluminium foil + ++++ 0 ++++ ++++ +++ 15–30 μm OPP film +++ 0 05 ++ + + 15-20 μm Met. OPP film +++ +++ 05 ++ + ++ 12–19 μm OPET film +++ 0 05 +++ + ++ 12 μm Met. OPET film +++ +++ 05 +++ + ++++ 12–20 μm OPA film ++++ 0 05 +++ + ++++ 30–70 μm Blown LDPE + 0 ++++ + + +++ film3 40–70 μm Cast PP film ++ 0 ++++ + + ++++ 3–10 μm EVOH layer4 0 0 + + +++

1 Strength is compared at the actual thicknesses indicated. 2 Relative cost is compared for thinnest grade mentioned. 3 In this case, “LDPE” includes not only low density polyethylene but also linear low density polyethylenes and copolymers with vinyl acetate etc. 4 Would not be used on its own; must be supported by other layers made of different resins. The relative cost reflects this. 5 Based on monolayer films; coextruded or coated films could be heat-sealable.

Tensile is only one measure of strength; for other measures, such as resistance to puncture, impact or tear, the relative performances will be different.

The light barrier scores for the films are based on transparent, unpigmented films. Incorporating pigments such as titanium dioxide increases opacity to be comparable with that of paper. The use of black pigments results in films with a light barrier similar to that of the metallised films.

8 P THE RATIONALE FOR MULTILAYER STRUCTURES ackaging

Combining the properties of materials materials When the design requirements for a pack demand two or more properties that cannot be found in a single material, there are two ways of proceeding. : 9.

Firstly, the pack can be made of two components, each one contributing at least one of the desired properties. multilayer For example, a bag based on 40 μm HDPE provides the moisture barrier needed to keep a breakfast cereal crisp throughout its shelf life. However, it lacks the rigidity to prevent the cereal from being crushed when stacked for transport, to enable the pack to stand up on a supermarket shelf, and to be easy to handle. The

p addition of an outside carton box provides these properties. By itself, the carton would lack the necessary ackaging moisture barrier. Such two-component packs are often the most cost-effective way to combine properties, especially if the thicknesses of materials required to provide the properties means that they are easy to handle on their own. Such packaging is not covered by this report; information on the individual mono-materials

for is given in other ILSI Europe Reports, which cover paper and board (Packaging Materials 6) and the most commonly used plastics (Packaging Materials 1–5). food

This report looks at the second approach, whereby two or more components are combined to make a and multilayer material. The following examples illustrate why and how this is done.

beverages Heat-sealable coextruded oriented polypropylene film Table 2 shows that OPP is one of the lowest cost packaging materials. Hence, it is well suited to the task of over-wrapping a tray containing foods such as bread rolls, croissants or cakes, where there is a moderate requirement for water barrier to prevent the food drying out for its shelf life of a few days. OPP is also glossy and transparent, giving an attractive sparkle to the pack and allowing the consumer to see the product. The high-speed horizontal form-fill-seal machines used for efficient packaging of this type of product require a heat-sealable film. However, the orientation process that is used to make OPP thin – and hence low cost – results in a film that shrinks before it can heat-seal.

To add this capability, a multilayer structure is used. A thin layer of material is added to one or both sides of a core of homopolymer polypropylene. This material must heat-seal at temperatures below that at which the homopolymer will shrink. Historically, this was achieved by coating polymers such as polyvinylidene chloride (PVdC) onto pre-made film, but nowadays this technique is only used where some additional property is required of the coating, e.g. an oxygen barrier from the PVdC.

Most heat-sealable OPP is now produced by a coextrusion process whereby thin layers of sealant polymers are coextruded with the thicker central core, as shown in Figure 2.

Figure 2.

9 These sealant polymers are typically ethylene-propylene copolymers or ethylene-propylene-butene terpolymers, which seal at temperatures of 110–125°C or lower. Any shrinkage in these thin layers is resisted by the much thicker homopolymer which is thermally stable up to around 145°C. beverages

With only a few microns of material that can flow during the sealing process, it is likely that there will and

remain channels through the seals where there have been folds or creases in the material, product contamination, or unevenness in the heat seal jaws. Hence the seals cannot be guaranteed completely food airtight or watertight but they will be adequate to hold the product and prevent the moisture loss in the for applications mentioned above.

Oriented polyester/ polyethylene laminate

ackaging The prevention of mould growth and other undesirable changes in blocks of hard cheese is often achieved by p

packing in a vacuum or in a modified atmosphere of CO2 or CO2/N2 mix. In the MAP case, the acidification

caused by CO2 impregnation of the food has a preservative effect; residual CO2 left in the headspace readily escapes the pack and results in a “pseudo-vacuum”. Horizontal form-fill-seal machines are often used for

multilayer this. The key design requirements for the packaging material are:

: 9. 9. : • Moderate moisture barrier to prevent the cheese drying out. Around 10 g/m²/day is adequate. Note that some drying out of the cheese is often desirable as the reduced water activity helps in preventing spoilage. Thus, too good a moisture barrier can be counter-productive, or must be balanced by improved hygiene. materials

• Gas barrier to limit oxygen entering the pack. The precise requirement will depend on cheese type, gas mixture used and shelf life required. In some cases, an OTR of around 100 cc/m²/day/bar is low enough; in others, a value nearer 10 cc/m²/day/bar is needed. The water activity of the cheese is decisive here. ackaging

P Sliced or grated cheese would also be more sensitive. • Hermetic seals to prevent gas exchange and stop micro-organisms entering the pack. The fold pattern of the end seals, potential creasing of the material, and the possibility of seal contamination by crumbs of cheese (as illustrated in Figure 3) pose particular challenges for the packaging machine and material. The sealant needs to be able to flow into any channels to close them up and to flow around or through any contamination. To achieve this flow, the sealant must be present in sufficient quantity and it must be heated and pressure applied for long enough for the gaps to be filled.

Figure 3.

10 P

• Appropriate slip levels on the inside and outside of the material, adequate tensile strength and the ackaging shortest possible seal dwell time are other factors contributing to efficient packaging machine operation. • Depending on the marketing strategy, the appearance requirements for these packs vary widely, from

the plain transparent pack with a label for basic information, to fully printed creations with perhaps materials matt/gloss effects or a simulated paper look.

The following structure is often used to satisfy the above requirements: : 9. 12 μm OPET multilayer Ink Adhesive 40–70 μm “PE”

p ackaging The inside layer, a film of 40–70 μm “PE” (e.g. LDPE, LLDPE or a PE-based copolymer) gives the moisture barrier required and the use of slip additives can give it the necessary coefficient of friction (CoF) for good

machineability. Grades are available that start to seal at 100–120°C and possess the flow properties needed for for hermetic seals. However, on their own, they would thin and weaken at the seal edge and stick to the heat seal jaws. food

The oriented polyester is dimensionally stable to more than 200°C and so protects the sealant from the and

heated sealing jaws. It is available in thin gauges; at 12 μm, it will minimise its contribution to channelling beverages when the material is folded but still will have sufficient tensile strength, both for the packaging machine and to act as a base for the printing process (if required). A 12 μm film will also have some gas barrier properties. Its OTR of 110 cc/m²/day/bar could be low enough to give the pack the required shelf life.

If this barrier level is not sufficient, OPET is an excellent base onto which to coat a thin layer of barrier material such as: • Silicon oxide or aluminium oxide applied to the inner side of the OPET by vacuum coating. This can reduce the OTR to around 1 cc/m²/day/bar. These coatings have the advantage of being transparent. • Aluminium applied by vacuum metallisation. This would give a similar OTR but the pack will be opaque (metallic); it would force any print to be on the surface of the pack, probably requiring an overlacquer to protect the ink – an additional cost. • PVdC copolymer applied by coating and drying an aqueous dispersion. This is transparent; the OTR will be reduced to around 5–10 cc/m²/day/bar. Other ways of increasing the gas barrier of this structure include: • The use of an OPA film, typically 15 µm thick, in place of the OPET. It would improve the OTR to about 30 cc/m²/day/bar but has less dimensional and thermal stability. • Inclusion of a barrier layer, such as EVOH, into the “PE” sealing layer by means of coextrusion.

It is necessary to bond the OPET film firmly to the PE-based sealant so that the resulting structure acts as a whole. This is normally achieved by means of a dry bond adhesive, either solvent-based, water-based or 100% solids. See the chapter on Methods of Production for more details.

Beverage carton The use of cartons to pack liquids such as milk and fruit juices is well established. Extended shelf life of six or more months can be achieved by the aseptic packing of UHT products. The key requirements for such a pack are: • High quality, leak proof seals. • Barrier to gases to prevent oxygen ingress, as well as barrier to prevent flavour loss. • Light barrier, to prevent light-induced off-flavours as well as accelerated oxidation, is needed for some products.

11 • Rigidity, so that the pack can stand on shelf and be easily handled by the consumer. • Easy opening and reclosure of the pack. beverages Typical structures that satisfy these requirements are: and Structure A (from outside to inside) Structure B (from outside to inside) 15 g/m2 PE 2–3 g/m2 Ink food

2–3 g/m2 Ink 15 g/m2 PE for 230–400 g/m² Board 230–400 g/m² Board 10–30 g/m² PE 10–30 g/m² PE 6–9 μm Aluminium foil 6–9 μm Aluminium foil ackaging p

2–8 g/m² Tie polymer or primer 2–8 g/m² Tie polymer or primer 30–60 g/m² PE 30–60 g/m² PE

The outer layer of PE protects the board from moisture. In some cases, the method of manufacturing the multilayer pack requires the outside of the pack to seal to the inside. This coating allows a PE-to-PE seal. : 9. 9. :

The board is primarily used to give structural rigidity for display and handling. It is the cheapest way of achieving this. The challenge of making leak-proof seals is similar to that faced for the cheese pack – except materials made worse by the presence of the board whose rigidity and thickness will tend to increase the size of potential channels in the seals. Furthermore, if heated seal jaws were used, the board would act as an insulator between them and the sealant. ackaging P As with the cheese pack, PE is still the material of choice for making the seal. To overcome the insulation issue, hot air may be used to soften the PE, while the very heat resistant board maintains the material structure. Alternative sealing techniques, such as ultrasonic or induction sealing, may also be used. In the latter case, the aluminium foil plays a dual role. Firstly, it absorbs the electromagnetic energy, heating the PE to the point at which it will seal. Secondly, it provides the effective barrier to gases and light that is needed for long shelf life products.

Extrusion coating is the most cost-effective way to apply both the outer coating and the sealant layers of PE. For the latter, good adhesion to the aluminium foil can be obtained by the use of a coextruded tie layer, e.g. an acid copolymer that will bond to both aluminium and PE. Such bonds must resist attack by substances in the food (e.g. fats, oils, aroma compounds such as limonene, and acids) that may migrate through the PE. Alternatively, a coating of primer can be applied to the foil from solution or dispersion prior to application of the PE.

Tandem extrusion coating and laminating techniques allow the whole structure to be produced in one operation, excluding the printing. Firstly, a laminating station uses extruded PE to bond the aluminium to the board. A tie layer or primer is not needed because the strength of the paper fibres is the limiting factor for bond strength and the aluminium protects the bond from chemical attack. Secondly, extrusion coating stations apply the PE sealant and outside coating.

In Structure A, the board is printed prior to the coating and laminating operation. In Structure B, the laminate is made first and then printed.

Not all requirements can be met through using multilayers. At the moment, the most effective easy open and reclose systems still rely on adding separate components, such as caps and spouts, to the main body of the pack.

12 P

Multilayer bottle ackaging Many consumers have struggled to pour the correct amount of viscous sauces, like tomato ketchup or mayonnaise, when they have been packed in glass bottles. A “squeezy” plastic bottle offers increased

convenience. However, many such sauce products are susceptible to oxidation, causing discolouration and materials off-flavours. So, the design requirements may be summarised as: • A level of rigidity that allows the bottle to be squeezed.

• Resistance to “flex cracking”, potentially caused by repeated squeezing of the bottle in the presence of : 9.

fats and acids in the food product. multilayer • Barrier to moisture to prevent product drying out. • Barrier to oxygen to maintain product quality.

• Reclosure system to allow multiple use in the home. p ackaging • Transparency to allow the contents to be seen, as with glass.

These requirements are met by a bottle with the structure shown in Figure 4:

for

Figure 4. food

and

beverages

PET provides the necessary balance of rigidity and flexibility with the required chemical resistance and adequate moisture barrier. However, its oxygen barrier is inadequate to prevent spoilage of the product. This is provided by a layer of EVOH. Polyamide or oxygen scavengers could also be used. The bottle shape is made by coextrusion blow moulding or co-injection stretch blow moulding.

A separate, “snap open” closure is often used to give the consumer easy access. This could be a point for oxygen to enter the pack. To prevent this, at least within the retail distribution chain, an impermeable membrane is sealed across the mouth of the bottle, to be removed by the consumer before use. Such a membrane could be made of: • Polyester – for strength and heat resistance. • Aluminium foil – for barrier. • Peelable polymer blend – to achieve a hermetic seal to the PET, preventing loss of product and ingress of oxygen, yet with a sufficiently weak peel strength to allow easy removal by the consumer.

13 Protecting the properties of materials Some materials with excellent barrier properties are, nevertheless, relatively fragile. During the normal handling of the pack, the barrier would be rapidly degraded unless protected by other, more robust materials. beverages In the beverage carton example, the PE on either side of the thin aluminium foil helps to cushion it against

and mechanical damage and consequent cracking and pinholes, which would otherwise reduce its effectiveness.

food As mentioned earlier, the gas barrier properties of a polar polymer such as EVOH are reduced if it absorbs

too much moisture. Such an effect can be minimised by sandwiching it between two layers of moisture- for resistant polymer such as PE.

Metallised films have a very thin layer (40–100 nm) of soft aluminium deposited on their surface, which ackaging

p gives them their barrier properties. However, this thin layer can be easily scratched and damaged, with

a consequent increase in permeability. “Burying” the metallised layer within a laminate protects it from mechanical damage and preserves its barrier.

multilayer Enhancement of barrier properties

: 9. 9. : In some cases, laminating thin barrier layers of aluminium or oxides can have an effect that goes beyond their protection. A thin layer of, say, silicon oxide would be absolutely impermeable were it not for discontinuities in the coating, creating microscopic channels or pinholes. The process of permeation through an impermeable layer with pinholes, as opposed to diffusion through a homogeneous layer, is such that the materials

barrier properties of the oxide-coated film are noticeably improved by contact with a neighbouring layer. Although polyurethane-based adhesives intrinsically possess quite good gas barrier properties, a typical 3 g/m² application weight will by itself not add much to the overall barrier of the laminate. However, the ackaging

P continuous coating of adhesive will, in effect, seal up any holes in the oxide coating, thus creating a synergy whereby the barrier of the laminate is better than that of the base-coated film.

14 P METHODS OF PRODUCTION ackaging

There are many ways of combining different materials to form packaging structures. This chapter will materials mention the most important and give some detail on four of them.

Coextrusion : 9. In this process, two or more different plastic granules are heated and melted separately. The melts are multilayer brought together either before or at the die lips so that the combined plastics are extruded as a single product – a multilayer web of plastic film or sheet.

The two methods for extruding multilayer films are cast extrusion and blown extrusion. As an example, a p ackaging cast or flat die coextrusion line is illustrated in Figure 5.

Figure 5.

for

food

and

beverages

In this case, there are three extruders processing plastic granules A, B and C to produce a film or sheet with the structure ABCBA. For example, A could be LDPE, B a tie layer, and C EVOH. In the example shown, melts A and B are first split (so they can each form two separate layers) and then brought together with melt C in a combining adaptor or feedblock. The geometry of the feedblock can usually be adapted to reflect the desired relative layer thicknesses. The multilayer melt is fed into the die, whose “coat-hanger” design spreads the melt flow to the full width of the die lips. The rheological properties of the resins are chosen so as to maintain laminar flow and an even layer thickness during this stage. The web is cooled in a controlled manner on one or more chill rolls, as shown in Figure 6.

15 Figure 6. beverages and food for ackaging p multilayer : 9. 9. :

The thickness is controlled at a number of points: materials

1. The speed and hence the output of the extruders. Their relative outputs control the relative layer thicknesses. 2. The speed of the chill roll. The faster it turns, the more it draws down and thins the web as it emerges ackaging

P from the die lips. 3. The profile of the web. The thickness variation in the transverse direction is controlled by the separation of the die lips.

In the so called “stenter” or “tenter” production of oriented film (e.g. OPP), which can be seen as an add-on process to the cast coextrusion line, the initial coextrusion is a sheet of 1–2 mm thick. At carefully controlled temperatures, the sheet is heated and then stretched by a factor of 4–6 times in the machine direction by a series of rolls turning increasingly rapidly. Two endless chains of grippers then clasp the film on both edges. While continuing to move in the machine direction, and continuing to control the web temperature, the distance between the two sets of grippers is increased so as to stretch the sheet in the transverse direction, generally by a factor of 8–10. Thus, a 1.35 mm thick sheet may be reduced to a 30 μm film. After controlled cooling to anneal the film, the edges are trimmed and the film wound up.

In the alternative coextrusion technique of blown film extrusion, two or more resins are extruded through an annular die, with the melts being brought together just before the die lips. The melt coming out of the die is pulled upwards several meters high and fed through a nip formed by two rollers. The nip closes the system off so that air pressure can be applied on the inside to blow the material up in a giant bubble. At the same time, the bubble is air-cooled on the outside and, in some cases, from within. The film thickness is controlled by the blow-up ratio, i.e. the width of the bubble compared to the die diameter. The bubble collapses at the nip and is further processed in the same way as a mono-film, i.e. it is sliced open and the two halves separated and wound up into two reels of film.

Films with up to ten or more layers can be made by the blown extrusion technique. Since the resins stay separate until just before the die lips, it is less crucial to match the rheology of the resins than in the cast process. In this respect, it is a more flexible process. However, the geometry of the complex and expensive coextrusion dies is fixed, so they must be designed with a limited range of layer thickness ratios in mind. There are limitations on how much these ratios can be varied. As a trade-off, a blown extrusion line can cover more reel widths than a cast extrusion line.

16 P

Next to the fundamental choice of film thickness and width, there are several important parameters ackaging governing the choice between cast and blown film extrusion, including: • Polymer type: PA, PET and PP are traditionally better suited for cast extrusion; PE is typically better

suited for blown extrusion. materials • Thickness of film: Very thick (above ca. 200 µm) or very thin (below ca. 30 µm) films are difficult to produce on a blown film line.

• The two processes can result in different degrees of crystallinity, degree and direction of orientation, : 9.

gloss, transparency etc. multilayer

Co-injection stretch blow moulding This process is used to make the PET/barrier material/PET bottle mentioned earlier (see Figure 4). Injection

p stretch blow moulding is a two-stage process in which a preform is first made by injection moulding. The ackaging preform has the shape of a test-tube with a neck moulded with a finished thread. In the second stage, the thread of the preform is held while the body is first heated by infrared radiation and then placed in a blow mould. It is simultaneously stretched using a stretch rod inserted through the neck and blown into the final

for shape by compressed air. The blow mould is cooled to freeze the material in the correct shape.

food At the injection moulding stage, there are different technologies for the co-injection of different polymers:

• Sequential injection: PET is first injected into the mould, followed immediately after by the barrier resin and

and then again by more PET. Following this manufacture of the three-layer preform, the subsequent beverages blowing step proceeds in the normal way as described above. • Simultaneous injection: PET and the barrier resin are injected together, and the barrier material is directed to the middle of the preform. Following this manufacture of the three-layer preform, the subsequent blowing step proceeds in the normal way as described above.

Lamination Coextrusion can only combine two or more plastics, starting with them as resins (granules or pellets). To combine two or more materials in web form, possibly including non-plastics, a lamination process is required. This section describes some different lamination processes.

Extrusion lamination As illustrated in Figure 7, a curtain of molten polymer, e.g. LDPE, is extruded from a flat die, similar to that used in the casting process, onto the primary web of material. At the same time, the secondary web is fed in from the other side. The three layers are pressed against a chilled drum by an impression roll. The molten polymer solidifies, bonding the two webs together. After trimming of the edges, the laminate is wound.

Figure 7.

17 As with the cast film process, the variation of thickness of the extrudate across the web is controlled by die bolts and feedback from a thickness measuring device. Overall thickness is a function of the speed and output of the extruder balanced against the overall line speed. Polymer can be extruded at 10 μm or less at beverages line speeds up to 600 m/min or more. The bonding of the extrudate to the webs depends on:

and • Chemical compatibility of the polymer and the webs: This can be improved by:

– Corona discharge treatment of a web to increase the surface tension.

food – Coating the web with a chemical primer.

– Coextruding the polymer, using a thin surface layer of copolymer with chemical groups that promote for bonding (typically acid copolymers). • Line speed: Bonding becomes more difficult at higher line speeds, mainly because adhesion requires a certain degree of oxidation of the polymer surface. The less time it takes for the polymer curtain to travel ackaging p

from the die lips to the nip, the less oxidation and the worse the bond. • The temperature of the polymer also affects the degree of oxidation. In addition, the hotter the polymer when it enters the nip, the better it will flow and adhere to the webs. On the other hand, relatively high temperatures (~300°C) are needed to achieve these effects, so care is needed in polymer selection and multilayer processing conditions to minimise cross-linking or thermal breakdown and generation of off-odours. : 9. 9. : • The thickness of the extrudate: The thicker the extrudate, the more it retains its heat on its travel to the nip. This helps the bonding process. materials Due to the relative ease of bonding PE to paper fibres, extrusion lamination is particularly suited to paper- and board-based structures.

ackaging The need for a careful balancing of the process conditions means that extrusion laminating is best suited for P long runs of standard structures.

Adhesive lamination For shorter runs and for plastic-film-based structures (including laminates with aluminium), adhesive lamination is often used. Different techniques are available; “dry bond lamination” is described to illustrate the process and is shown in Figure 8.

A coating of solvent- or water-based adhesive is applied to the primary web. The coated web is passed through an oven where hot air is blown onto the web to dry off the solvent or water and raise its temperature.

Figure 8.

18 Packaging materials: 9. multilayer packaging for food and beverages 19 to give a surface energy that will to give a surface energy or other treatment corona discharge need

polyolefins,

e.g.

that minimise residual solvents and ensure sufficient heat transfer at the heat transfer sufficient solvents and ensure machine conditions that minimise residual webs, , both in terms of the chemical compatibility with the webs to be laminated, and in and laminated, be to webs the with chemical compatibility the of terms in both Adhesive selection, or chemically temperatures elevated e.g. will be exposed, terms of the conditions to which the laminate foodstuffs. aggressive nip. allow the adhesive to “wet out” (spread evenly) properly. evenly) (spread “wet out” allow the adhesive to the surface of the web, uneven the more 2.5–6 g/m²; in general, Adhesive dry weight should be around is needed. the more At the exit of the oven, the adhesive is warm and tacky, but “dry” because the solvent was removed – hence removed solvent was because the “dry” but and tacky, is warm the adhesive of the oven, At the exit resultant The web. to bond it to the secondary is used A heated nip roll bond lamination”. “dry the name the immediate bonding (called the adhesive viscosity and hence to increase a chill roll laminate is cooled on separating. to minimise the chance of the webs under pressure wound and then tack”), “green be some improvement will usually although there is the end of the process, this adhesives, non-reactive For for these, and, used are adhesives reactive bonds, stronger For cools further. roll in the bond as the finished reactions cross-linking While in the roll, period is an essential part of the process. a subsequent curing and the the bond strength both weight of the adhesive and increase the molecular take place to increase weeks, or more to two one day This takes from and chemicals. temperature of the laminate to resistance quickly at higher temperature, more proceeds The reaction employed. chemistry depending on the precise are this chemistry Details on the time. to reduce at 40°C, e.g. rooms”, “hot in be cured so laminates may given in the next chapter. so it is usual to choose the is heated, the machine and through web has the longer journey The primary materials, stretchable heat-sensitive, The more less-extensible material for this role. heat-resistant, more web. will be the secondary such as LDPE, of factors: The quality of the bond depends on a number • • Some lamination so as extrusion adhesive lamination is quicker to set up and not so difficult to control In general, suitable to in-line It is also more of webs. variety it is better suited to shorter runs and the use of a greater printing or coating operations. bond lamination except that the adhesive used is 100% solids so Solventless lamination is similar to dry the viscosity and then applied to heated to reduce The adhesive is generally process. no drying is there cooled and wound web, to the secondary It is immediately nipped system. a roller web by the primary to give and cure reactive weak but all solventless systems are bond will be relatively The initial green up. the webs or atmosphere. from with moisture reacting on One-component systems rely bonds. stronger of The advantages with each other. application and react mixed just before systems are Two-component withdealt be to emissions solvent no costs, and running capital include lower method the solventless of include a need for tighter control Disadvantages and the use of lower adhesive weights (below 2 g/m²). to high temperatures and resistance strengths high bond conditions and less ability to deliver very process and chemicals. starch a as such adhesive, water-based A paper-based. be must webs the of one bond lamination”, “wet For The laminate is applied to one web and the other web is immediately nipped in. dispersion, or protein the permeable paper. through passing dried off by and the water an oven can then be passed through theabsorbs simply substrate the board, e.g. used, are grades thicker when especially and Alternatively, and dries the adhesive to form a bond. water • • Correct Packaging materials: 9. multilayer packaging for food and beverages uniform densityofvapour across thewholewidthofweb. silicon oxide, is to fire a beam of electrons onto a solid source. In all techniques, the aim is to produce a electrically heatedceramic “boats” intowhichwires ofaluminiumare fed. Another technique, asusedfor oxide are alsousedandresult intransparent films. A commontechniqueforheatingaluminiumistouse have ametallicappearance andprovide alight, moisture andgasbarrier. Siliconoxideandaluminium vapour onto a moving web. Aluminium is the most commonly used source. The resultant metallised films fundamentally different. The principleistoevaporate asource materialinahighvacuum anddepositthe Although theabove coatingtechniquesare similartothoseusedforlamination, vacuumcoating is Wax andhotmeltcoatingscanbeappliedusingthesametechniquesasforlamination. as infrared andultrasonics canbeused, aswell ashotair. Figure 9. temperature sufficiently, reactive coatingsystemscanalsobecured duringthistime. and theprocess is illustrated inFigure 9. Again, thesolventisdrivenoffinanoven; by raising theweb Solvent basedcoatingsare appliedtowebs by techniquessimilartothoseusedforadhesivelamination common exampleispaper/PEorboard/PE. simply appliedontoasingleweb. This results inatwo-layer asopposedtoathree-layer structure. The most Extrusion coating is essentially extrusion lamination without nipping in a secondary web. The extrudate is A numberofcoatingtechniquesare usedtoproduce multilayers. Coating material isfoldedorgluedrather thanheatsealed. dies. The wax remains heat-sensitiveandhencesuchtechniquesare ideallysuitedtopacktypeswhere the method ofapplicationdependsontheviscositylaminantandincludesroller systems, gravure andslot A layer ofmoltenwax orhotmeltisappliedbetweentwo websandthencooledtobondthemtogether. The Wax andhotmeltlamination Aqueous dispersionsare alsoappliedascoatingsinthisway. For aqueouscoatings, heatingtechniquessuch 20 Packaging materials: 9. multilayer packaging for food and beverages 21

Figure 10 shows how the base web is unwound from a reel and held on a cooled cylinder during its held on a cooled cylinder and a reel from 10 shows how the base web is unwound Figure in the coating thicknesses are Typical solid coating. which condenses to form a to the vapour, exposure capable only is a batch process coating Vacuum then rewound. The coated material is nm. of 40–100 range to to be returned the chamber needs has been run, the reel When of material at a time. of handling one reel and the chamber pumped down loaded roll target a new unloaded, the coated roll atmospheric pressure, the most are such as 12 μm OPET or 15 or 20 μm OPP, thin films, Therefore, again. vacuum to the required commonly used substrates. Figure 10. Figure Packaging materials: 9. multilayer packaging for food and beverages

a. A numberofotherreactions cantakeplace, themostimportantofwhich are: with theisocyanate groups onthepre-polymer: of theadhesiveare mixed, chainlengtheningandcross-linking occurthrough reaction ofthese–OHgroups The othercomponentwillbeadiolorpolyol, possessingtwo ormore –OHgroups. When thecomponents Aliphaticdiisocyanates • Aromatic diisocyanates • Common startingdiisocyanates include: with polyester orpolyether polyols. The pre-polymer willpossesstwo ormore free isocyanate groups. One component of the adhesive will be a pre-polymer, which has been made by reacting a diisocyanate of anisocyanate withahydroxyl group toformaurethane linkage: two-component systems basedonreactive polyurethane chemistry. This chemistry isbasedonthereaction Many typesofadhesivescanbeusedinlaminatesbutby farthemostimportantforfoodpackagingare Adhesives to makemultilayer structures. Adhesives andcoatingsare anexceptiontothis. Previous reports intheILSIEuropeReportSerieshave covered thechemistry ofmostthematerialsused CHEMISTR (b) willnottake place. Thus, aminescouldbepermanently formedinthefood(before possiblyreacting layer intothefood. Here it willreact withwater toformanamine. Inthefood, water isinexcessandreaction laminate is used to pack a food before the cure is complete, the diisocyanate can migrate through the sealant curing reaction, eitherby reacting withthepolyol orby meansofreactions (a)to(c)above. However, ifthe of free diisocyanate monomer. Normally, thiswillbeentirely consumedwithintheadhesivelayer duringthe Of mostconcerntofoodsafety is thefactthatisocyanate pre-polymer willalways containaproportion c. R−NH b.

amine +isocyanate→ R−NCO +H Because water hasan−OHgroup, itcanalsoreact withanisocyanate: isocyanate +water→ These alsoproduce sidechainsandcross-linking. There canbefurtherreactions betweenanisocyanate andalready-formed urethane andurea linkages. The amineformedcanthenreact furtherwithanisocyanate group toformaurea linkage: 2 +R−NCO→ HDI IPDI MDI TDI … −O−CO−NH−R 2 O Hexamethylene diisocyanate Isophorone diisocyanate Methylene diphenyl diisocyanate Toluene diisocyanate → R−NH Y

primary amine+carbondioxide R−NH−CO−NH−R substituted urea

2 +CO 1 2 −NH−CO−O−R OCN−R diisocyanate +diol 1 −NCO +HO−R polyurethane ↓ 2 22 −O−CO− NH−R 2 −OH 1 −NH−CO−O− … Packaging materials: 9. multilayer packaging for food and beverages 23 include those based on reactive polyurethane systems similarsystems polyurethane reactive on based those include temperatures ambient at cure that include those based on nitrocellulose (NC) resin. Non-curing systems include those based on nitrocellulose tunnel of the coating machine to bring about in the drying Heat set systems use high temperatures bifunctional and epichlorohydrin from prepared epoxy resins example, For thermoset reactions. combinations of these. – or by resins amino or anhydride with phenolic, be cured phenols may to those described above for adhesives. to those described above Polyamide-based release coatings are applied to the opposite surface to prevent such coldseals sticking applied to the opposite surface to prevent coatings are release Polyamide-based in the reel. under pressure (“blocking”) when wound for coated “Code of Practice Annex IV of detailed descriptions of typical coatings can be found in More 2009). pp 38–52 (CEPE, is a coating” the food contact layer articles where Coldseal coatings Coldseal coatingsmake to used are latex rubber natural with resins acrylic of blends containing dispersions Aqueous smalla for used is rubber Synthetic heat. no with pressure, just using self-to-self sealed be can that of formulations. proportion lacquers Release Multifunctional coatings chloride or alkyl chloride with either vinyl based on copolymers of vinylidene which are PVdC coatings, gases moisture, to barrier and sealability heat gloss, of properties to the required tailored be can acrylates, and methacrylic polymers and copolymers based on acrylic Aqueous dispersions of and odours or flavours. similar functionality but with much less good barrier. which provide coatings, used to make acrylic acid are Primers and an otherwise incompatible coating. the bond between a substrate used to improve These are EAA dispersions or for example, also other systems, are widely used but there are Polyethyleneimines being used to prime aluminium foil for PE extrusion coating. polyethyleneamines reactive Heatseal coatings and modified polyolefins, styrene chloride, vinyl acetate, of vinyl These usually use polymers and copolymers used to ensure frequently Blends are acetate (EVA). vinyl acid (EAA) and ethylene acrylic such as ethylene material to which it will be and a different aluminium foil, e.g. both onto the substrate, good bonding, Polyester-based peelable seals. also be used to achieve Blending may pot. a polystyrene-based e.g. sealed, option. to give a chlorine-free being used in some applications increasingly systems are Protective coatings Protective resistance heat and gloss give also can these damage, mechanical from surfaces protect to used Primarily main systems: three are There chemical corrosion. from and protect • • • Systems away, especially with any alcohol or fat content in the food). If aromatic isocyanates have been used as a been have isocyanates If aromatic in the food). or fat content alcohol with any especially away, potential carcinogens. are some of which amines (PAA), aromatic primary these will be starting material, packing food. before of the adhesive takes place that a full cure to ensure it is important Hence, Coatings applied from are Many to give specific functional properties. used in multilayers of coating is A wide variety chapter. as described in the previous dried and coalesced to form a thin film which are aqueous dispersions, used but this has now been widely toluene was In the past, solvent. organic be dissolved in an Others may acetate and ethanol. ethyl ketone (MEK), ethyl such as methyl compounds less odorous safer, by replaced blends of an extensive use of proprietary is There listed below. used coatings are The most commonly chemical the hence, functional properties; the required to achieve in order chemical components different simplified. somewhat inevitably descriptions are Packaging materials: 9. multilayer packaging for food and beverages This • The • The • Thetimethattheplasticisincontactwith food. • The • data onfoodconsumptionand packaging use, toprovide probabilistic estimates ofoverall exposure. of specificcombinationspackaging andfoodorsimulants;second, inconjunction withstatistical models. There are two goalsforsuchmodels:first, toprovide worst-case estimatestoreplace physical testing An increased understandingofthetheoretical basisformigration hasledtothedevelopment ofmigration Stoermer (2008). tests andhowthey relate towhathappensinactualfoodpackagescanbefoundareview by Franz and than usingtheactualfoodandconditionsofcontact. A detaileddiscussionoftheprinciplesbehindsuch simulants rather thanactualfoods. The principlebehindthese testsisthatthey should bemore severe and costly, anunderstandingofthesefactorshasallowedthedevelopment ofmethods thatusefood Because testingactualfoodsforthepresence ofmigrants from packagingisbothtechnicallydemanding increasing withtimeuntilitislimitedby thelasttwo factorsatequilibrium. The first four factors influence the rate of migration, with the concentration of the migrant in the food MUL Residuesofstartingsubstancesusedtomakeamaterial, • packed food. Suchsubstancescouldinclude: The components of multilayers may contain chemical substances thathave apotentialtomigrate intothe MIGRA The • Theinitialconcentration ofthemigrant inthepolymer. • contact withafood, thefollowingfactorsmustbeconsidered: Starting with the simple model of a monolayer plastic containing a potentialmigrant thatisplacedin material incontactwithfood. This chaptersummarisesthefactorsthataffectmigration levels. migration. Subsequentchaptersdealwithlegislativerequirements andtheevaluation ofthesafetya To ensure the safety of consumers of the packed food, it is essential to control the amount of such Additivesusedtoachieve specifictechnicaleffects, • Non-intentionallyaddedsubstances(NIAS), • plastic tobeavailable fortransfer intothefood. medium sothatthere isahigherconcentration intheformer. for thesubstance. For example, apolarsubstancewillpartitionbetweenandnon-polar concentration inthefoodatequilibrium. Itmeasures therelative affinityofthepolymerandfood the substancewillmove. substance willbetransferred. at equilibrium. ratio ofplastictofood. The higherthemass, thehigherconcentration ofthesubstanceinfood thickness ratio partition diffusion diffusion TILAYERS of TION OFSUBST the coefficient coefficient of coefficient, surface the plastic, area is is

which defined itself

combined of the dependent describes plastic as the with to ratio the the on the e.g. ANCES FROM temperature. ratio rate of mass impuritiesinraw materials, 24 the e.g. at of of migrant anti-oxidants, which surface e.g. the

monomers. The food. the area concentration higher

The substance to slipagents. weight greater the temperature, reaction by-products. can in of this food, the move is, packaging

the

gives through

quicker the the quicker mass to the the its Packaging materials: 9. multilayer packaging for food and beverages

on can into that

non- layers, are board there, amount homogenous. outside dependent and from boards

be The

other and Paper and, not

strongly into layer are Papers migrants. might

also polymer. films but the contact layers the partition coefficient. food potential polymers. the with food i.e. of the be metallised the into and between reaction into might only foil

not move homogeneity C, A and layer 25 through

interface reactants move e.g. might

the

aluminium the

A. like might layer macroscopic migrant, layer coatings, outer of multilayers, an assume materials loss and in of contact no coated food diffusion and migrant adhesives the assume for a

properties in models models barrier reactive laminated migrant thereby reducing the concentration in the layer and, hence, the eventual equilibrium concentration in equilibrium concentration the eventual hence, and, in the layer the concentration reducing thereby the food. the food. There will be a time lag in such behaviour, which might be significant depending on the which might be be a time lag in such behaviour, will There the food. its use to pack the food. and multilayer of the between the manufacture delay homogenous aggregations of fibres. homogenous aggregations their physical continuity. Their permeability depends on the number and size of pinholes, scratches scratches pinholes, of size and number the on depends permeability Their continuity. physical their been themselves dependent on manufacturing methods and how the materials have which are etc., than on their diffusion and partition coefficients. handled rather absorb some substances thus making them unavailable for migration. absorb some substances thus making them unavailable which form a barrier between layers, entrapped air bubbles microscopic might be there example, For to migration. transfers into a food contact layer will therefore depend on the kinetics of the reaction as well as the depend on the kinetics of the reaction will therefore into a food contact layer transfers factors. migration The basic principles governing the migration from single webs into foods also apply to all plastic multilayer multilayer also apply to all plastic single webs into foods from the migration governing The basic principles to another one layer from of migration and amount The rate increases. materials but the complexity In consequence: must also be considered. is manufactured) as the multilayer (which starts as soon • A • Conversely, In a multilayer structure of the type layer A/layer B/layer C, and where layer C is in contact with the food, the food, C is in contact with layer and where C, B/layer A/layer of the type layer structure In a multilayer The Plastics Regulation C. A entering layer layer from B forms a barrier to migrants it is possible that layer of a substance of migration the level if it reduces “functional barrier” B as a (EU) No 10/2011 defines layer Note that this is a pragmatic limits. can meet regulatory it where C to a level A to layer layer from a functional a material that provides Also, migration. zero It does not necessarily require definition. and temperature given a for A layer specific a in concentration specific a at migrant specific a to barrier changed. of these factors are barrier if any time will not necessarily act as a functional another C by A can also enter layer layer substances from C, A to layer layer from Besides migration layer stacked, are sheets or reels on wound are multilayers When set-off”. “chemical called mechanism visible without any substances can be transferred whereby C with layer contact A comes into direct are: Important factors for this transfer transfer. • in layer of the substance The level • use. or stack before of the reels storage of The time and temperature • of the substance for layer affinity The relative • or stack. within the reel pressure The inter-layer some other packaging, on polymer-based has focussed on migration Even though most of the work quasi- as behave to expected be reasonably might coatings) and adhesives inks, (e.g. materials of types include: differences Some while others might not. plastics, • The • The • For • The • For The potential transfer of substances from multimaterial multilayers into food is therefore a much more a much more into food is therefore multimaterial multilayers of substances from The potential transfer It is not sufficient only to consider the food contact layer. complex issue than that for plastic monolayers. one in barrier functional What acts as a structure. the of rest the from transfer of possibility the is There or stack from in the reel The possibility of transfer cannot be assumed to do so in another. circumstance be considered. always must the outside of a material to the food contact layer Packaging materials: 9. multilayer packaging for food and beverages specific GMPrequirements forprintinginksandplasticsrecycling processes. systems andplacesspecialemphasisondocumentation. Itcurrently hastwo annexesgivingmore food contactcompliance. Itsetsoutgeneral requirements forqualityassurance systems, qualitycontrol to in Art. 3oftheFramework Regulation, anddealsonlywiththoseaspectsofGMPstrictlyrelated to (GMP) forfoodcontactmaterials. This aims toclarifywhatare “good manufacturingpractices” asreferred A furthermeasure, Regulation(EC)No. 2023/2006, lays downtherulesongoodmanufacturingpractice The • multimaterial multilayers. To summarisethemainprovisions: EC. Itappliestoplasticsmultilayers (even whencoatedorprinted)andtotheplasticcomponents of is atwo-year transition periodduringwhichexistingmaterialsmay continuetocomplywith2002/72/ and articlesintendedtocomeintocontactwithfood. It cameintoeffecton1May 2011, althoughthere from 1 May 2011by a new regulation, the CommissionRegulation (EU) No 10/2011 on plastic materials Directives onvinyl chloridemonomer, onmigration testingandonfoodsimulants, was replaced as multilayer materials. The Plastics Directive, 2002/72/EC, and its subsequent amendments, together with Of the “specific measures” thathave sofarbeenadopted, thoseforplasticsare themostimportantfor Plastics legislation Procedures • Basicrulesforactiveandintelligentmaterials. • Provision forspecific • Thetraceability ofmaterials “… shallbeensured atallstages…”. • The • Framework Regulation. The key provisions ofthislegislationare: 1935/2004 on materials andarticles intended to come into contact withfood, oftenreferred to asthe Multilayer materials, likeallfoodcontact materialsandarticles, are subjecttoRegulation(EC)No General requirements UNION REGULA The • • may includeexposure considerations. not beenofficiallyreviewed needtoundergo ariskassessmentby the manufacturer. This assessment on theirinclusionin Annex I. Substancespresent inthematerial(even unintentionally)thathave food/chemicalsafety/foodcontact/documents_en.htm) cancontinue tobeused, pendingadecision has beenreceived before 1January 2007thatare onthe “provisional list” (http://ec.europa.eu/food/ requirements atnationallevel may exist. Additives for which avalid application for EU authorisation the Regulation). For substancesotherthanadditivesandmonomers, e.g. polymerproduction aids, substances andadditives)thatare containedinthe “Union list” ofauthorisedsubstances(AnnexI covered by specificmeasures do, indeed, complywithalltherules. organoleptic characteristics thereof” (Article3). about anunacceptablechangeinthecompositionoffoodorbringadeterioration inthe not transfer their constituents tofoodinquantitieswhichcouldendangerhumanhealthorbring with goodmanufacturingpractice sothat, undernormalorforeseeable conditionsofuse, they do Labelling requirements. (EFSA). Safety Authority general safetyrequirement thatfoodcontactmaterials “shall bemanufactured incompliance principle plastics for TOR layers of the a authorisation ofsubstancesincludingasafetyassessmentby theEuropean Food written measures forgroups ofmaterials orthesubstancesusedinmakingthem. may Y ASPECTSWITHIN only Declaration ofCompliance(DoC)confirmingthatmaterialswhichare be manufactured

26 from substances THE (monomers, EUROPEAN

other starting

Packaging materials: 9. multilayer packaging for food and beverages overall overall the is this – mg/dm² 10 exceed and other strategies modelling and other strategies migration not for may be manufactured from from manufactured be functional barrier may a should allows by food 27 to food the Regulation plastics from the of

(SML) and must not transfer to the food in food in to the must not transfer (SML) and limits specific migration to separated materials, subject constituents are are of such that multilayers must comply with the compositional requirements but the but the comply with the compositional requirements must multimaterial multilayers with the above limits. Food simulants (test media) and testing (test media) and testing simulants Food limits. with the above rules for assessing compliance transfer in layers screening substances are total ). mutagenic or toxic to reproduction as CMR (carcinogenic, not classified are They The limit on vinyl chloride monomer is respected. nanoform. not in are They of unlisted substances is not detectable the migration only, for all plastics multilayers In addition, with a detection limit of 0.01 mg/kg. that the material complies with the rules shall be made available to the customer. to the customer. be made available that the material complies with the rules shall written declaration – – – – amounts exceeding this limit. limit. amounts exceeding this (OML). limit (OML). migration important to note that It is given for the testing of materials. are temperature) conditions (time and by 85/572/EEC (as amended to Directives compared regime some changes to the testing are there is a there this reason For 93/8/EEC and 97/48/EC). (as amended by 2007/19/EC) and 82/711/EEC to be fully implemented. testing regime the new for period of five years transition to replace actual testing for specific migration. actual testing for to replace Supporting documentation must be kept, and made available to the authorities on request. The The to the authorities on request. and made available Supporting documentation must be kept, IV to the Annex detail in some Compliance (DoC) is specified in of content of this Declaration Regulation. migration limits do not apply for these structures (except the limit on vinyl chloride monomer). chloride monomer). the limit on vinyl (except limits do not apply for these structures migration in plastic multilayers may be made from unlisted substances. However, if if However, unlisted substances. be made from may coatings and adhesives in plastic multilayers Inks, to supply adequate have the suppliers SML, to an subject listed substances that are contain any they compliance. of the finished material to ensure information on them to enable the manufacturer unlisted monomers and additives provided that: unlisted monomers and additives provided Other measures 2007/42/EC Directive e.g. dealing with individual materials or substances, In addition to some measures two are there epoxy derivatives, on 1895/2005 No (EC) Regulation and film, cellulose regenerated on packaging for food. to multilayer of particular relevance further regulations materials and articles plastics used to manufacture Regulation (EC) No 282/2008 concerns recycled shall only be they processes, mechanical recycling by When produced intended for food contact. a authorised in the EU following processes using plastics recycled grade contact food from obtained an shall be managed by process It also states that the recycling EFSA. safety assessment performed by The Regulation sets out the conditions under which a process system. quality assurance appropriate and for Member for a Community Register of authorised processes can be authorised and provides an made by must state that it was plastics material containing recycled for a The DoC State auditing. plastic article Labelling of the recycled Register number. and quote the relevant authorised process legislation national is adopted, processes recycling authorised EU list of the first Until voluntary. is itself plastic can be if the recycled Note that, years. more take a few It is anticipated this will is applicable. chemical recycling, to be used behind a functional barrier or if it has been obtained by demonstrated this Regulation does not apply. • Some • The • There • When • Plastic • A which Guidance Document to the Plastics Regulation, will be an official EU It is intended that there It should and competent authorities to understand and implement these provisions. will help industry on the migration information more Articles of the Regulation, explanations on include definitions, details on the information flow in the supply chain. in the context of the DoC, and, testing regime • • Plastics Packaging materials: 9. multilayer packaging for food and beverages is required togiveanadequatewarning totheconsumer. article couldconceivably bemistakenforafoodingredient (e.g. asachetcontainingpowder), labelling required to be “suitable and effective for the intended purpose of use”. When the active or intelligent As afirstforsubstancesauthorisedfoodcontactmaterials, activeorintelligentsubstancesare Substances • Substances • used astheactiveorintelligentcomponentsofsuchpackaging. However, there are exceptions: that only substances that are in a “Community list” of authorised substances (not yet published) can be Regulation (EC)No450/2009dealswithactiveandintelligentpackagingincontactfood. Itstates Regulation, substancesclassifiedasCMRorinnanoformare excluded. Framework Regulationandtofoodlegislation. that that are are intended tobereleased tothefoodare subject tospecificprovisions givenin the separated fromthefoodbyafunctionalbarriercanbeused. As withthePlastics 28 Packaging materials: 9. multilayer packaging for food and beverages

at levels exposure the cut-off with

level, compromising

migration available, the on generally depend 29 not is process use TION A material petitioning on the in n this context, “safety” means the safety of the consumer, arising from any possible possible any from arising consumer, the of safety the means “safety” this context, n in been seen As has food packaging. and multilayer between food interaction Regulation with its the heart of the Framework this lies at chapter, the previous I information requirements of the consumer to the substance, i.e. the amount of that substance ingested through the amount of that substance ingested through i.e. of the consumer to the substance, exposure of a substance, conventionally characterised by toxicological studies that ideally allow a a allow that ideally studies toxicological by characterised conventionally substance, a of hazard The quantity of the substance in the packaging material. The quantity of the substance in the packaging material into the food – as described in the the from The extent to which the substance transfers Multilayers. of Substances from chapter on Migration packaging material is used. of foods in the diet for which this The fraction to food weight. of the pack surface area The ratio The amount of food consumed. the diet over his/her lifetime. This depends on: his/her lifetime. the diet over tolerable daily intake (TDI) or acceptable daily intake (ADI) to be derived. The TDI/ADI is obtained TDI/ADI is obtained The intake (ADI) to be derived. daily intake (TDI) or acceptable daily tolerable a safety factor of 100 or more. divided by (NOAEL) level” effect adverse “no observed the from ppb, 5 ppm and 60 ppm. For migration below 50 ppb three mutagenicity tests should be performed. mutagenicity tests should be performed. below 50 ppb three migration For 5 ppm and 60 ppm. 50 ppb, below is When the migration be included. should study toxicity oral a 90-day at least 50 ppb, Above but ADI, an define to able be not will consequently and dataset full a receive not will EFSA ppb, 50 excluded. are properties considers an intake below 50 ppb not to be a health risk when mutagenic assessment. Reduced datasets can also lead to restrictions on the materials (and sometimes foods) on the materials (and sometimes foods) lead to restrictions Reduced datasets can also assessment. for which the substance is allowed to be used. – – – – – U Y EVAL SAFET In the EU, EFSA is responsible for the risk assessment of component substances used to make plastic of component substances used to make plastic for the risk assessment EFSA is responsible In the EU, the ideal risk assessment scenario as outlined from some deviations are There materials and articles. Specifically: above. • Data requirement that materials “… do not transfer their constituents to food in quantities which could could which quantities in food to constituents their transfer not do “… materials that requirement …”. endanger human health including of a substance, the intrinsic hazard one must consider the safety of a structure evaluate To together allow one to carry which to the substance, exposure and the consumer’s potential impurities out a risk assessment: • The • The • Reliable In summary, EFSA’s proposal for a specific restriction on a substance is not always a measure of its of its a measure on a substance is not always for a specific restriction proposal EFSA’s In summary, Furthermore, assessment. exposure a refined and does not incorporate properties, intrinsic hazard a standard based on with some exceptions, is, risk management approach the EU Commission’s pack and a standard weight per day consumption of 1 kg of packed food per consumer of 60 kg body 60 × TDI = SML equation: the in results This food. kg per material dm² 6 of ratio weight area-to-food other than food packaging exist routes significant exposure where In exceptional cases, weight. kg body from TDI to exposure decide to allocate only part of the may the regulator exposure), background (e.g. food contact materials. cases many the SML is in of exposure, the overestimation and the safety factors involved, With compliance with the plastics legislation Nevertheless, than a safety limit. a compliance limit rather demonstrate can food packer and manufacturer packaging the which with tool important an remains of multimaterial multilayers. and of the plastic components the safety of all plastic multilayers Packaging materials: 9. multilayer packaging for food and beverages For • Certain • The • An • Impurities • alternative assessmentssuchasthefollowingexamplesare notavailable: scientific methodsincludingexposure considerations. Inpractice, thisonlyneedstobedonewhere carry outtheirownsafetyassessmentaccording totheabove principles, usinginternationallyrecognised to Article 3oftheFramework Regulationremains tobedemonstrated. Manufacturers are obligedto inks, adhesivesandpaper)inwhichothersubstancesmay beused. For allofthesethesafetyaccording Additionally, a wide range of non-plastic components are used in multilayer materials (such as coatings, plastics, e.g. aidstopolymerisation, processing aids, solvents, andreaction ordegradation products. to monomersandadditivesusedinplasticsforfoodcontact. However, othersubstancesare present in The above procedure –EFSAevaluation followedby European Commissionauthorisation–onlyapplies EFSA • For • The • and complianceassessmentfor theirmembers. Someexamplesrelevant formultilayer packaginginclude: for their products. Increasingly, industry sector associations issue detailed guidelinesonsafety evaluation In theend, they are responsible forarrivingatawell-foundedconclusiononsafetyandlegalcompliance particular challenge to makesenseofalltheinformation coming from different raw materialsuppliers. Manufacturers ofsemi-finishedcomponentsandfinishedmultilayer packagingmaterialsfacea countries. if thematerialhasbeenlegallymarketedinthatcountry, itshouldalsobelegaltomarketinotherEU recognition, compliancewiththenationalregulations ofanEUMemberStatehastheadvantage that, observe thespecifiedconditions ofuseandany additionaltesting needed. With theprincipleofmutual be quotedtodemonstrate thesafetyofasubstanceormaterial, butmanufacturers mustbecareful to (http://ec.europa.eu/food/food/chemicalsafety/foodcontact/documents_en.htm). Such compliance can XXVIII (BfR, 2010). A listofnationallegislationisavailable attheEuropean Commission’s website Assessment RecommendationXXXVI(BfR, 2009), oranadhesivecouldcomplywithRecommendation For example, apaperbeingusedinmultilayer couldcomplywiththeGermanFederal InstituteforRisk or needstobeassessedseparately. exposure tothesubstance. Also, theimpurityprofile needstomatchthatofthefoodgrade substance, safety. Care mustbetakentoensure thatthisadditional usedoesnotcompletelychangeconsumer observed. 21 CFR175.105(FDA, 2009). Again, specifiedconditionsofuseandany additionaltestingmustbe adhesive manufacturer mightseektodemonstrate safetyby quoting compliancewithFDA section Notably, the US Food and Drug Administration (FDA) Regulations are often referred to. Thus, an to theauthorisationinanon-EUstateifbasedoninternationallyacceptedriskassessmentmethods. hazard assessment withuseandexposure informationobtainedfrom othersources. safety assessmentofthosesubstancesandneednotberepeated. substances’ hazard properties. Although notcurrently listedinEUlegislation, thoseevaluations remain areference pointforthe (CEPE, 2009). (Council ofEurope, 2004a, b). have proven theirvalue are AP(89) 1oncolourants inplasticsand AP(92) 2onaidstopolymerisation minimal, andfurthermore theResolutionshave nolegalstatus. Two Resolutionswhich, nonetheless, covered by specificEUlegislation. The relevance ofinventory listsnotbasedonasafety assessmentis authorisation substances the coatings Council (or materials use its and of of industry’s predecessor or Europe reaction/decomposition evaluated or in materials substances the has “Code EU the substances published as not direct of have SCF) regulated practice been food have Resolutions in products authorised for additive in non-plastics, evaluated the coated EU 30 of or on articles or by EU-regulated flavouring a some its the

number the Member national substances where manufacturer is of seen the substances States, legislation substances food as and

sufficient the can contact materials of manufacturer are used combine an included EU demonstration layer in that Member non-plastics. is the are a in can coating” not EFSA’s official State. refer yet of

Packaging materials: 9. multilayer packaging for food and beverages

of and surface fibre-based materials and contact board & flexible for non-food paper of the to practices applied compliance the inks for manufacturing 31 printing good on Guideline for “Code “Guideline “Industry

Europe’s sector’s inks manufacturers’ Packaging printing paper : The type of food to be packed, the target consumer, the food storage conditions, conditions, storage the food consumer, the target to be packed, The type of food Up the supply chain: pasteurisation, both packer and consumer (e.g. by conditions carried out and the in-pack processing of the pack). reheating microwave sterilisation, of the structure substances in the components migratable The identity of any Down the supply chain: modelling tests, of migration and/or the results their concentrations subject to a restriction, that are calculations. worst-case and any analysis, packaging for food” (FPE, 2011). (FPE, packaging for food” food packaging materials and articles” (EuPIA, 2009). 2009). (EuPIA, and articles” food packaging materials articles for food contact” (CEPI, 2008). 2008). (CEPI, articles for food contact” For multimaterial multilayers, manufacturers of the final structure need to combine compliance need to combine compliance of the final structure manufacturers multimaterial multilayers, For compositional plastics, incorporating structures For types of components used. various aspects from It in multimaterial multilayers. for plastic layers is required compliance with the Plastics Regulation even provisions to the regulatory stick – to legal requirement if not a – even is most often convenient contact layer or the food finished structure and to subject the is present, layer when a functional barrier logical a make to able be may they Often, plastic. a is layer contact food that when testing migration to on analogous results quoting satisfactory by structure for the safety and compliance of a argument of tests and with the results approach “building block” using a or by family” “product in a structures assessments on individual components. (e.g. process conversion the during place takes reaction chemical a when that, is point important An reactions The possible chemical that reaction. that is controlling it is the converter adhesive curing), clearly in This is seen most conditions controlled. processing must be understood and the production foods in PAAs with their capability to generate adhesives, polyurethane the use of isocyanate-based of safety the imply cannot laminate of batch one on test PAA “non-detectable” A cured. fully not if under identical or better conditions, produced are other batches unless it can also be shown that they of cure. including the time and temperature a i.e. check of the compliance information received, is the food packer’s The final step in the process to their actual food material in relation packaging verification of the conditions of use of the multilayer influence of the packaging on the food. on the organoleptic and a clearance packaging application, Communication along the supply chain is essential. A vital tool in this process is the DoC, which which the DoC, is process this in tool vital A is essential. chain supply the Communication along also has certain supplier the upstream Equally, compliance. to investigate user enables the downstream information should be exchanged: the following Ideally, their safety assessment. information needs for • • • Flexible • The • The Packaging materials: 9. multilayer packaging for food and beverages using LifeCycle Analysis techniques, hasshownthatmultilayer packaginghasaminorenvironmental sustainability. A study by ESU-services Ltd for Flexible Packaging Europe (Büsser and Jungbluth, 2009), No discussiononenvironmental aspectscanbecompletewithoutlooking atthewidercontextof choice formoststructures. meets therequirements ofEN13431:2004onenergy recovery. This iscurrently thedisposalmethodof On the other hand, almost all multilayer packaging contains well over 50% organic materials and so implications ofdegradable materialsbeingdivertedtolandfill. implications tobeconsidered ontheconsequencesoflossresources duetodegradation andonthe view, waste foodisstillmuchmore ofaproblem thanpackagingwaste andthere are lifecycle assessment very visible in the environment because it degrades so slowly. But, from an environmental impact point of performance develops. A drivingforce isthefactthatpackagingwaste from traditional plasticsremains It isexpectedthatbiodegradable andcompostable materials willstarttoplay abiggerrole astechnical likely tobeslowandthere willremain many structures forwhichmaterialrecycling isnotanoption. collection infrastructure develops, more multilayer packagingmaterialswillberecycled, butprogress is Smaller volumes per pack type, and a more diverse composition, are other disadvantages. As the waste in bothfinancialandenergy terms, ofgettingtheusedpackfrom theconsumertorecycling plant. other multilayer structures suchastheotherexampleslistedin thisdocument. The problem isthecost, in composition. This facilitates the collection and sorting process. There are viable recycling processes for Beverage cartons are ahigh-volumeproduct andare relatively large insize. They are alsofairlystandardized containers have hadtobeput inplace, aswelltherecycling facilitiesthemselves. use incement, andPEisincinerated forenergy. To achieve this, systemsforcollectionandsortingofthe fibre isre-used inpaperandboard products, aluminiumasmetal powderorasaluminiumtrioxidefor containers. This equatesto350,000tonnesor33%ofthemarketforthesecontainers(ACE, 2009). Paper be doneandisbeingdone;forexample, in2008thebeverage cartonindustry recycled some13billion multilayer thanasinglematerial, becausetheindividualcomponentsmustfirstbeseparated. But, itcan logistics. However, theissueofrecovery ismore complex. Itisundoubtedlymore difficulttorecycle a Re-use ofmultilayer packagingismostlyout ofthequestion, forseveral reasons includinghygiene and of packaging. of machineability, convenience andcost. Multilayers play akey role inminimisingtheweightandvolume be achieved by amonolayer plasticifitwere very thick, butitwould undoubtedlyfailontherequirements that would otherwise bevery difficulttoachieve. For example, product collationandpreservation might Earlier, itwas shownhowthinlayers ofdifferent materialscanbecombinedtofulfildesignrequirements 3. 2. 1. should bemadesoasto: Waste (anditsamendments)whichestablishesthree “Essential Requirements”. Insummary, packaging Like allpackaging, multilayer materials mustcomplywithDirective 94/62/EConPackaging andPackaging ENVIRONMENT

metals andeco-toxicsubstances)whenitisincinerated orlandfilled. Minimise theimpactonenvironment ofany noxiousandotherhazardous constituents(heavy biodegradation and tominimiseitsimpactontheenvironment whenitisdisposedof. Permit itsre-use orrecovery, includingmaterialrecycling, energy recovery, compostingor safety, hygiene andacceptanceofthepackedproduct. Prevent packagingwaste by minimisingthepackageweightandvolumetothatwhichisadequatefor AL ASPECTS 32 Packaging materials: 9. multilayer packaging for food and beverages 33 impact compared with other factors such as the production of food and the way in which it is stored and in which it is stored and the way of food as the production with other factors such impact compared foil/PE laminates in polyester/aluminium coffee packed instant and at ground looked The study used. for calculated were of the study The results laminate. in aluminium foil/wax/paper and butter packed all for that, showed They 2002). (Guinée, method 2001 CML the using indicators environmental eight the coffee or butter production, with that of minor compared of the packaging was the impact indicators, of the butter. and storage transport and the of the coffee, brewing impact of the extra coffee, For contribution of the packaging is greater. relative the small pack sizes, For in the reduction a significant than off-set by the single portion pack is more and packaging producing coffee not the brewed of When including the typical fraction of the coffee. needed for preparation energy pack. of the single portion in favour more balance tips even the energy to waste, consumed but going such scenarios such as catering and hotels (where in certain is that, the argument the butter example, For the than offset by impact of the packaging is also more the extra used), predominantly small packs are in food waste. reduction to take analysis, when looking at sustainability and life cycle highlights the importance, study The above packaging in isolation. than looking at the rather into consideration lifecycle product the entire Packaging materials: 9. multilayer packaging for food and beverages can makeamultilayer anenvironmentally effectiveoption. recycling isnotpossible, energy recovery, minimisationofsource materialsandreductions infoodwaste can currently be met only for some high volume products such as beverage cartons. Evenwhere such their packaging function has ended. The separation of such layers for recycling presents a challenge that Multilayer packagingmaterialsare alsoformulatedtohave minimalimpactontheenvironment after and codesofpractice inorder todemonstrate thesafety andcomplianceoftheirproducts. covered by specificmeasures, andmanufacturers may have tolookavariety ofdifferent regulations multilayer materials must comply with Regulation (EC) No 1935/2004. However, they are not always components andsecondlyby thetechniquesusedtocombinethem. As withallpackagingforfood, The consumersafetyofsuchpackagingisdeterminedfirstlyby thesafetyofmono-material and coextrusiontechniquesare commonlyusedproduction techniques. polyamide, togetherwithancillary components suchasinks, coatingsandadhesives. Lamination, coating Materials usedincludepaper, metalandplasticssuchaspolyethylene, polypropylene, polyester and achieve themby combiningthinlayers ofdifferent materialsintoasinglemultilayer packagingstructure. GENERAL CONCLUSIONS F material cannotprovide alltherequired properties anditismostcosteffectiveto strength, rigidityandbarriertolight, moisture andgases. Inmany cases, asingle ood packagingcanrequire avariety ofperformance characteristics suchas 34 Packaging materials: 9. multilayer packaging for food and beverages

withstand to able

jaws, ER TILAY heat constant with fitted 35 the consumer. by peelable yet Hermetic peelable seal moisture process, for retort thermal resistance Rigidity, barrier Bonding Oxygen barrier Bonding sealability process, retort for resistance thermal Rigidity, of EVOH protection moisture to lid, Bonding Strength and tear resistance to aid peeling of lid and tear resistance Strength Bonding and synergistic improvement of SiOx barrier improvement Bonding and synergistic Transparent oxygen and moisture barrier and moisture oxygen Transparent Thermal resistance for retort process and heat seal jaws process for retort Thermal resistance machines form-fill-seal Moisture barrier and temperature resistance relative to the sealant relative resistance barrier and temperature Moisture layer which allows a bond between the HDPE and ionomer, Controlled peel mechanism “burst” with compared temperature sealing (differential Low temperature the HDPE) and excellent hot tack to withstand the weight of product on hot seal dropping vertical of Polypropylene layer Tie EVOH layer Tie Polypropylene Polyolefin-based sealant Polyolefin-based Adhesive OPA Adhesive Silicon oxide OPET HDPE blend Polymer Ionomer-based blend the consumer. opening by peelable seals for easy yet operation the drop of up to 750 g of cereal on the hot seal. of up to 750 g of cereal the drop Cup (from outside to inside) Lidding (from outside to inside) 40–50 μm 3–5 g/m² 15 μm 3–5 g/m² 40–100 nm 12 μm 5–10 μm 5–10 μm 25–60 μm Breakfast cereal liner cereal Breakfast The latter carton. is a plastic bag within a paperboard cereals breakfast A common pack for ready-to-eat for the inner bag are: requirements The main rigidity for handling and transport. provides • Efficient Fruit, e.g. pineapple, is sealed into a cup that is retorted to give an extended shelf life under ambient give an extended shelf life under ambient to is sealed into a cup that is retorted pineapple, e.g. Fruit, is an The lid shape. thermoformed to the required which is cup is a coextruded sheet, The conditions. are: requirements Key adhesive laminate. • Hermetic, UL ES OF M HER EXAMPL X: FURT ANNE STRUCTURES cup fruit Retorted • barrier. barrier and some moisture Good oxygen • conditions. the retort Resistance to • Rigidity of cup. meet these requirements: The following example structures • adequate to hold the product, Seals that are • crisp. to keep the cereal Good barrier to moisture • of the opened liner bag. of dead-fold for reclosing Some degree by: can be provided These properties Packaging materials: 9. multilayer packaging for food and beverages Bags madefrom thefollowingtwo-ply laminatemeettheserequirements (outsidetoinside): Easyopeningby theconsumer. • In • Insidetoinsideandoutsidesealing. • Barriertolightwhichcaninitiateoxidationreactions. • Barriertomoisture inbothmaterialandseals. • that is, sealingtheoutsideofmaterialtoinside. Key requirements are: jaws. For reasons of economy and machine efficiency, the vertical or back seal is generally of the lap type, Potato crisps are packedathigh speedonverticalform-fill-sealmachinesfittedwithconstantheatsealing Crisp packet The followingstructure iswidelyused: biscuit requires protection from moisture ingress. inside toinside, insidetooutside, andoutsidetosealingare allneeded. To keepitsfreshness, the body tomakeitlie flat. The endsealsare foldedandsealedflatagainsttheendbiscuits. For thisoperation, inside toinside, alongthelengthofstack. Often, theresultant sealisthentackeddownontothepack Round biscuitsare oftenpackedinaroll. The materialiswrapped around thebiscuitstackandsealed, Biscuit rollwrap 2–3 g/m² 35–40 μm 3–5 g/m² 1–2μm 12–17μm 1–2μm 1.5–2.5 g/m² 40–100 nm 1–2μm 12–17μm 1–2μm 15–20 µm 15–20 µm and/or shelflife. Inthiscase, gasbarrierisrequired inthematerialandanimproved qualityofseals. some cases, PVdC coating Cavitated OPP Ink PVdC coating Co-orterpolymerPP HomopolymerPP Ink Co-orterpolymerPP Adhesive Aluminium metallisation Co-orterpolymer HomopolymerPP Co-orterpolymer Coextruded OPPfilm, madeupof: Coextruded OPPfilm, made upof:

gas flushing is Provides additionalmoisture barrierandsealability weight-to-thickness/stiffness ratio fold, asuitablebackground fortheprinteddesign, andalow to themoisture barrier. Itiscavitated toprovide adegree ofdead- Gives thebasicstrength ofthepack, heatresistance andcontributes heat sealingjaws and correct slipcharacteristics Provides glossandprintprotection, sealability, goodrelease from used to remove Low temperature sealingtoinsidelayer Strength andheatresistance moreover protects theinkfrom abrasion Visible from theoutsidethrough theclearOPPfilm, which Surface tobeprinted Bonding, usually100%solidsforeconomicreasons damage by beingsandwiched betweenthetwo OPPs Note thatthisthinlayer isprotected from mechanical Light andmoisture barrierandsomedegree ofgasbarrier. Surface foraluminiumdeposition Strength andheatresistance Low temperature sealingtoitselfandoutsidelayer oxygen 36 from the packs and improve product quality Packaging materials: 9. multilayer packaging for food and beverages and light 2 37 Thermal resistance for the heat seal jaws, flatness and rigidity. flatness and rigidity. for the heat seal jaws, Thermal resistance Excellent barrier heat seal Peelable flatness and rigidity. for the heat seal jaws, Thermal resistance Some barrier heat seal Peelable tearing on opening to resist strength Print base, Bonding Barrier and appearance tearing to resist strength for the metallisation; provides Substrate Some barrier properties on opening. heat seal Peelable Thermal resistance for the heat seal jaws and mechanical heat seal jaws for the Thermal resistance and packaging machine for the printing operation strength Printed design Bonding Barrier to O Bonding Hermetic peelable seal Ink Embossed aluminium foil Lacquer Ink Embossed OPET Lacquer Ink Paper Adhesive Metallisation OPET Lacquer OPET Ink Adhesive Aluminium foil Adhesive PE-based sealant 30–40 μm 3–10 g/m² film Pre-cut lids based on polyester 50 μm 3–10 g/m² Laminate option for reel-fed lidding 40–50 g/m² 2.5–4 g/m² 12 μm 3–8 g/m² Pre-cut lids based on aluminium foil 12 μm 2.5–4 g/m² 7–9 μm 2.5–4 g/m² 40–70 μm Yoghurt pot lidding Yoghurt depending lids, pre-cut with or material reel-fed with lidded be can cups polystyrene in packed Yoghurt rigid and the lids must be flat, that requires handling In the latter case, on the packaging machine. while the consumer, be easily peelable by should they In all cases, each other. from easily separable greater a products, fresh for required is barrier moisture and oxygen moderate A seals. liquid-tight giving common: solutions are Three barrier is needed for long-life products. Ground roast coffee pack roast coffee Ground environment. oxygen-free packed to give an is either gas flushed or vacuum coffee shelf life, prolonged For leak-free and excellent, good oxygen and light barriers packaging are for the The prime requirements coffee beans, packaging of roast vacuum For peelable for easy opening. the seals are In some packs, seals. is needed. resistance a good puncture is: One widely used structure Packaging materials: 9. multilayer packaging for food and beverages LIST WVTR TDI (2) TDI (1) SML SiOx SCF RH PVdC PP PET PE ppm ppb PPA PAA OTR OPP OPET OPA OML NIAS Met. OPET Met. OPP MDI MAP LLDPE LDPE IPDI HFFS HDPE HDI GMP FDA EVOH EFSA EAA DoC CoF CMR CML CED BOPP BfR ACE OF ACRONYMS moisture. Usedasameasure ofbarrier, thelowerfigure, thebetter thebarrier. Water vapour transmission rate –ameasure ofthepermeabilityamaterialto Toluene diisocyanate Tolerable dailyintake–normallyexpressed asmg/kgbody weight Specific migration limit(mg/kgfood) Silicon oxide, aninorganic barriercoatingmaterial Commission priortotheestablishmentofEFSA Scientific CommitteeonFood –theriskassessmentgroup organised by theEU Relative humidity Polyvinylidene chloride Polypropylene Polyethylene terephthalate (polyester), shortforPETP. Polyethylene Parts permillion(normallyby weight, mg/kg) Parts perbillion(normallyby weight, μg/kg) Polymerisation production aid (asubtypeofprocessing aids). Primary aromatic amine as ameasure ofbarrier, thelowerfigure, thebetterbarrier. Oxygen transmission rate –ameasure ofthepermeabilityamaterialtooxygen. Used Oriented polypropylene –oftenusedasanabbreviation forBOPP(q.v.) Oriented polyethylene terephthalate (polyester) Oriented polyamide Overall migration limit Non-intentionally addedsubstance Metallised orientedpolyethylene terephthalate (polyester) Metallised orientedpolypropylene Methylene diphenyl diisocyanate microbial activityandhencefoodspoilage Modified atmosphere packaging–packingafoodindefinedgasmixture toinhibit Linear low-densitypolyethylene Low-density polyethylene Isophorone diisocyanate Horizontal form-fill-sealmachine–typicallyusedtopacksolidproducts High-density polyethylene Hexamethylene diisocyanate Good manufacturingpractice Food andDrug Administration (oftheUnitedStatesof America) Ethylene vinyl alcohol European Food Safety Authority Ethylene acrylic acid Declaration ofCompliance (inthecontextoffoodcontactlegislation) divided by thenormalforce betweenthesurfaces Coefficient offriction–theratio ofthetangentialforce required toproduce sliding Carcinogenic, mutagenicortoxictoreproduction Institute ofEnvironmental Sciences, University ofLeiden Cumulative energy demand Biaxially orientedpolypropylene –oftenabbreviated toOPP(q.v.) Bundesinstitut fürRisikobewertung –theGermanFederal InstituteforRisk Assessment The Alliance forBeverage CartonsandtheEnvironment 38 Packaging materials: 9. multilayer packaging for food and beverages -particles to measure the thickness of a moving of a moving the thickness -particles to measure 39

web. extrusion line. on a blown Plastic film produced on a cast extrusion line. Plastic film produced monomers. different or more the polymerisation of two formed by Polymer to in order pressure in air at atmospheric of a web to a plasma created Exposure to the application of coatings and receptive making it more modify the surface, better bonding. promoting its shape when folded. Ability of a material to retain which the slot through has a narrow Component of an extrusion machine that die, Cast extrusion uses a flat (straight) polymer is extruded to form a film or sheet. and blown extrusion an annular die. dispersion of adhesive is applied to thesolution or a Lamination technique where The the solvent or water. to remove an oven and then passed through web primary adhesive. but tacky, web is nipped into the dry, secondary repeated by e.g. stress, that can be induced in plastics under and cracking Crazing temperature. chemicals and/or and is often exacerbated by flexing, barrier consisting of“a No 10/2011 as Defined in the Plastics Regulation (EU) that the final material material which ensures type of any of layers one or more Article 3 of Regulation (EC) No 1935/2004 and with the or article complies with of this Regulation”. provisions adhesives inks, used for papers, Generally of the basis weight of a material. Measure and coatings. it is fully cured. of an adhesive before Bond strength the polymerisation of a single monomer. formed by Polymer the thickness of to measure radiation that uses the absorption of infrared Device web. a moving a machine. through in which the web is moving Direction a multilayer of one layer from Chemical substance that has the potential to transfer into the packed foodstuff. the food contact layer and from into another, structure of thickness for unit of measurement The conventional Equal to micrometre. to µ. abbreviated Often also aluminium foil and thin films. Regulation (EC) No 450/2009 on active and yet. No official definition available to engineered “substances deliberately intelligent packaging uses the phrase that and chemical properties particle size which exhibit functional physical description. scale”; this is a good working those at a larger significantly differ from a further but intended to undergo Starting substance that is itself a polymer, polymerisation or crosslinking). (usually a larger-scale chemical reaction the bonding or Coating that is applied onto a web with the purpose of improving another coating). (e.g. adhesion to a subsequent non-web layer or else the part of the package heat, usually by of sealing, Either the operation the heat-sealing operation. from resulting Polymeric material applied by coating technology, with the primary function of function primary the with technology, coating by applied material Polymeric webs together. bonding two is packed in a sterile (q.v.), UHT by treated usually a sterile food, whereby Process hence extend shelf that will maintain that sterility and container under conditions life. of β that uses the absorption Device y Blown film Blown Cast film Copolymer Corona discharge treatment Dead-fold Die Dry bond lamination Flex cracking Functional barrier g/m² Green bond or green tack Homopolymer Infrared Gauge Machine direction Migrant Micron (µm) Nanoform Pre-polymer Primer Seal Adhesive Aseptic packaging Beta Gauge ar Gloss Packaging materials: 9. multilayer packaging for food and beverages lamination Wet bond Web UHT direction Transverse Tie layer Terpolymer Tenter Stenter adhesive Solventless Slip substrate. is dried either by absorption into the substrate or by permeation through the the primary web. The secondary webisimmediatelynippedinandtheadhesive Lamination techniquewhereby asolutionor dispersionofadhesiveisappliedto Continuous sheetoffilm, foilorpaper, generally wound ontoreels. used incombinationwithasepticpackaging(q.v.). milk may beUHT-treated by heatingtomore than135ºCfor1–5seconds. Usually high temperature, holdingitthere forashorttimeandthencoolingit. For example, technique whereby afoodisfullyorpartiallysterilisedby rapidly heatingittoa Abbreviation forultra-heat treatment orultra-high temperature. A processing Direction across theweb, atrightanglestothemachinedirection (q.v.). Polymer Bisatielayer thatbondsPolymer A toPolymer C. two otherlayers. For example, intheconstructionPolymer A/Polymer B/Polymer C, In a coextruded film, sheet or coating, a layer of polymer that acts as an adhesive for Polymer formedby thepolymerisationofthree different monomers. See “Stenter”. sometimes knownas “tenter”. of grippersclaspeachedgethewebandseparate, thusstretching it. Also Process fororienting filminthetransverse direction whereby anendlesschain viscosity tobeappliedawebwithoutreduction by solventorwater. Also knownas100%solidsadhesive. Suchadhesiveshave asufficientlylow coefficient offrictionorCoF(q.v.). Ability ofawebtoslideagainstitselforanothersurface, generally measured by the 40 Packaging materials: 9. multilayer packaging for food and beverages 41 growth in recycling rates. Press release of 6.7.2009. ACE, Brussels. Brussels. ACE, of 6.7.2009. release Press rates. in recycling growth at http://www.beveragecarton.eu/uploads/Library/ACE%20Recycling-rates%20-%20 Available 2008-4.pdf on plastics intended to come Assessment Institute for Risk of the Federal Recommendation XXXVI Berlin. BfR, for food contact. and board Paper into contact with food. at http://bfr.zadi.de/kse/faces/resources/pdf/360-english.pd Available to come Assessment on plastics intended for Risk Institute Recommendation XXVIII of the Federal for food packaging materials. as adhesive layers polyurethanes Cross-linked into contact with food. Berlin. Bfr, at http://bfr.zadi.de/kse/faces/resources/pdf/280-english.pdf Available of Life Cycle Assessment 14 (Suppl.1): 80–91. International Journal of including specification recovery, in the form of energy for packaging recoverable – Requirements Brussels. CEN, minimum inferior calorific value. is a coating. the food contact layer for coated articles where Code of Practice (2009). at http://www.cepe.org Available Brussels. CEPI, 2010. March Issue 1, materials and articles for food contact, paper & board at http://www.eurosac.org/eurosac/pdf/11796_Industry-Guideline-Food-Contact- Available %28CEPI-and-CI.pdf for testing migration basic rules necessary down the 82/711/EEC laying amending Council Directive contact with foodstuffs. of constituents of plastic materials and articles intended to come into 22. p. 14.04.1993, L090, Official Journal for down the basic rules necessary 82/711/EEC laying amending for second time Council Directive intended to come into contact of the constituents of plastics materials and articles testing migration 0010-0015. p. 12.08.1997, L222, Official Journal with foodstuffs. with foodstuffs. to plastics materials and articles intended to come into contact 2002 relating 18. p. 15.08.2002, L220, Official Journal in materials and articles of use of certain epoxy derivatives 2005 on the restriction 18 November 28. p. 19.11.2005, L302, Official Journal intended to come into contact with food. for materials and articles intended to come into December 2006 on good manufacturing practice p 75. 29.12.2006, L384, Official Journal contact with food. ces Referen carton maintains Beverage (2009). Cartons and the Environment) Beverage Alliance for (The ACE (2009). für Risikobewertung) Assessment; Bundesinstituts for Risk Institute BfR (German Federal (2010). Assessment; Bundesinstituts für Risikobewertung) Institute for Risk BfR (German Federal of coffee and butter. in the life cycle of flexible packaging The role (2009). N. and Jungbluth, S. Büsser, Packaging EN 13431:2004, Standard European (2004). Committee for Standardisation) CEN (European colours) printing inks and artists’ of paints, and importers Council of producers CEPE (European Guideline for the compliance of Industry Industries) (2010). Paper of European CEPI (Confederation 1993 93/8/EEC of 15 March Commission Directive Communities (1993). Commission of the European 1997 97/48/EC of 29 July Commission Directive Communities (1997). Commission of the European August 2002/72/EC of 6 Commission Directive Communities (2002). Commission of the European Commission Regulation (EC) No 1895/2005 of Communities (2005). Commission of the European Commission Regulation (EC) No 2023/2006 of 22 Communities (2006). Commission of the European Packaging materials: 9. multilayer packaging for food and beverages FPE (FlexiblePackaging Europe) (2011). Codeforgoodmanufacturingpractices forflexibleandfibre- FDA (USFood andDrug Administration) (2009). Regulation 21CFR175.105 Adhesives. USGPO, European Parliament andCounciloftheEuropean Union(2004). Regulation(EC)No. 1935/2004ofthe European Parliament andCounciloftheEuropean Union(1994). European Parliament andCouncil EuPIA (European PrintingInk Association) (2009). Guidelineonprintinginksappliedtothenon-food Council oftheEuropean Communities(1985). CouncilDirective 85/572/EECof19December1985 Council oftheEuropean Communities(1982). CouncilDirective 82/711/EECof18October1982laying Council ofEurope (2004b). Resolution AP(92) 2oncontrol ofaidstopolymerisationforplasticmaterials Council ofEurope (2004a). Resolution AP(89) 1ontheuseofcolourants inplasticmaterialscoming Commission oftheEuropean Union(2011). CommissionRegulation(EU)No10/2011of14January Commission oftheEuropean Communities(2009). CommissionRegulation(EC)No450/2009of29 Commission oftheEuropean Communities(2008). CommissionRegulation(EC)No282/2008of27 Commission oftheEuropean Communities(2007). CommissionDirective 2007/42/ECof29June 2007 Commission oftheEuropean Communities(2007). CommissionDirective 2007/1//ECof2 April 2007 Available athttp://www.flexpack-europe.org based packagingforfood. FPE, Düsseldorf. Available athttp://cfr.vlex.com/vid/175-105-adhesives-19706270 Washington, DC. L338, 13.11.2004, p4. come intocontactwithfoodandrepealing Directives 80/590/EECand89/109/EEC. OfficialJournal European Parliament andoftheCouncil27October2004onmaterialsarticlesintendedto 31.12.1994 p. 10. Directive 94/62/ECof20December1994onpackagingandwaste. OfficialJournal L365, Available athttp://www.eupia.org contact surfaceoffoodpackagingmaterialsandarticles. EuPIA, Brussels. and articlesintendedtocomeintocontactwithfoodstuffs. OfficialJournal L372, 31.12.1985, p. 14. laying downthelistofsimulants tobeusedfortestingmigration ofconstituentsplasticmaterials articles intendedtocomeintocontactwithfoodstuffs. OfficialJournal L297, 23.10.1982, p. 26. down thebasicrulesnecessary fortestingmigration oftheconstituentsplasticmaterialsand and articles. CouncilofEurope, Strasbourg. into contactwithfood. CouncilofEurope, Strasbourg. 15.1.2011, p. 1. 2011 onplasticmaterialsandarticlesintendedtocomeintocontact withfood. OfficialJournal L12, Official Journal L135, 30.5.2009, p3. May 2009onactiveandintelligentmaterialsarticlesintendedto comeintocontactwithfood. amending Regulation(EC)No2023/2006. OfficialJournal L86, 28.3.2008, p9. March 2008onrecycled plasticmaterialsandarticles intended tocomeintocontactwithfoodsand with foodstuffs. OfficialJournal L172, 30.06.2007, p. 71. relating tomaterials andarticlesmadeofregenerated cellulosefilmintendedtocomeintocontact foodstuffs. OfficialJournal L97, 12.04.2007, p. 50. testing migration of constituentsplasticmaterialsandarticlesintended tocome intocontactwith contact withfoodandCouncilDirective 85/572/EEClaying downthelistofsimulantstobeusedfor amending Directive 2002/72/ECrelating toplasticmaterialsandarticlesintendedcomeinto 42 Packaging materials: 9. multilayer packaging for food and beverages 43 . Wiley-VCH, Wiley-VCH, . with foods and pharmaceuticals Plastic packaging – interactions Chapter 11: eds. A.L. 349–416. pp. Weinheim. Kluwer Academic, Dordrecht. Franz, R. and Stoermer, A. (2008). Migration of plastic constituents. In: Piringer, O.-G. and Baner, Baner, and O.-G. Piringer, In: constituents. of plastic Migration (2008). A. Stoermer, and R. Franz, the ISO standards. guide to Operational assessment. on life cycle Handbook (2002). et al. J.B., Guinée, Packaging materials: 9. multilayer packaging for food and beverages 44 Other ILSI Europe Publications • Food Safety Objectives – Role in Microbiological Food Safety Management Concise Monographs • Functional Foods in Europe – International Developments in Science and Health Claims • Alcohol – Health Issues Related to Alcohol Consumption • Functional Foods – Scientific and Global Perspectives • A Simple Guide to Understanding and Applying the Hazard • Guidance for the Safety Assessment of Botanicals and Analysis Critical Control Point Concept Botanical Preparations for Use in Food and Food Supplements • Calcium in Nutrition • Impact of Microbial Distributions on Food Safety • Carbohydrates: Nutritional and Health Aspects • Markers of Oxidative Damage and Antioxidant Protection: • Caries Preventive Strategies Current status and relevance to disease • Concepts of Functional Foods • 3-MCPD Esters in Food Products • Dietary Fibre • Method Development in Relation to Regulatory Requirements • Food Allergy for the Detection of GMOs in the Food Chain • Food Biotechnology – An Introduction • Micronutrient Landscape of Europe: Comparison of Intakes • Functional Foods – From Science to Health and Claims and Methodologies with Particular Regard to Higher • Genetic Modification Technology and Food – Consumer Consumption Health and Safety • Mycobacterium avium subsp. paratuberculosis (MAP) and the • Healthy Lifestyles – Nutrition and Physical Activity Food Chain • Microwave Ovens • Nutrition in Children and Adolescents in Europe: What is the • Nutrition and Genetics – Mapping Individual Health Scientific Basis? • Nutrition and Immunity in Man • Overview of the Health Issues Related to Alcohol • Nutritional and Health Aspects of Sugars – Evaluation of New Consumption Findings • Overweight and Obesity in European Children and • Nutritional Epidemiology, Possibilities and Limitations Adolescents: Causes and consequences – prevention and • Oral and Dental Health – Prevention of Dental Caries, Erosion, treatment Gingivitis and Periodontitis • Packaging Materials: 1. Polyethylene Terephthalate (PET) for • Oxidants, Antioxidants, and Disease Prevention Food Packaging Applications • Principles of Risk Assessment of Food and Drinking Water • Packaging Materials: 2. Polystyrene for Food Packaging Related to Human Health Applications • The Acceptable Daily Intake – A Tool for Ensuring Food Safety • Packaging Materials: 3. Polypropylene as a Packaging Material • Threshold of Toxicological Concern (TTC) for Foods and Beverages • Type 2 Diabetes – Prevention and Management • Packaging Materials: 4. Polyethylene for Food Packaging Applications Reports • Packaging Materials: 5. Polyvinyl Chloride (PVC) for Food • Addition of Nutrients to Food: Nutritional and Safety Packaging Applications Considerations • Packaging Materials: 6. Paper and Board for Food Packaging • An Evaluation of the Budget Method for Screening Food Applications Additive Intake • Packaging Materials: 7. Metal Packaging for Foodstuffs • Animal-Borne Viruses of Relevance to the Food Industry • Recontamination as a Source of Pathogens in Processed Foods • Antioxidants: Scientific Basis, Regulatory Aspects and Industry – A Literature Review Perspectives • Recycling of Plastics for Food Contact Use • Applicability of the ADI to Infants and Children • Safety Assessment of Viable Genetically Modified Micro- • Application of the Margin of Exposure Approach to organisms Used in Food Compounds in Food which are both Genotoxic and • Safety Considerations of DNA in Foods Carcinogenic • Salmonella Typhimurium definitive type (DT) 104: A multi- • Approach to the Control of Entero-haemorrhagic Escherichia resistant Salmonella coli (EHEC) • Significance of Excursions of Intake above the Acceptable • Assessing and Controlling Industrial Impacts on the Aquatic Daily Intake (ADI) Environment with Reference to Food processing • The Safety Assessment of Novel Foods • Assessing Health Risks from Environmental Exposure to • The Safety Assessment of Novel Foods and Concepts to Chemicals: The Example of Drinking Water Determine their Safety in use • Beyond PASSCLAIM – Guidance to Substantiate Health Claims • Threshold of Toxicological Concern for Chemical Substances on Foods Present in the Diet • Campylobacters as Zoonotic Pathogens: A Food Production • Transmissible Spongiform Encephalopathy as a Zoonotic Perspective Disease • Considering Water Quality for Use in the Food Industry • Trichothecenes with a Special Focus on DON • Consumer Understanding of Health Claims • Using Microbiological Risk Assessment (MRA) in Food Safety • Detection Methods for Novel Foods Derived from Genetically Management Modified Organisms • Validation and Verification of HACCP • Emerging Technologies for Efficacy Demonstration • Evaluation of Agronomic Practices for Mitigation of Natural To order Toxins ILSI Europe a.i.s.b.l. • Evaluation of the Risks Posed in Europe by Unintended Mixing Avenue E. Mounier, 83, Box 6 of Food Crops and Food Crops Developed for Non-Food Uses B-1200 Brussels, Belgium • Exposure from Food Contact Materials Phone: (+32) 2 771 00 14 • Fax: (+32) 2 762 00 44 • Foodborne Protozoan Parasites E-mail: [email protected] • Foodborne Viruses: An Emerging Problem • Food Consumption and Packaging Usage Factors ILSI Europe’s Concise Monographs and Report Series can be • Food Safety Management Tools downloaded from: www.ilsi.eu ISBN 9789078637264