Technology now under control
The recycling of packaging materials used for food contact applications has to take several factors into account. Even though the technology is now fully functional, certain materials require additional sanitary inspections. Over time, intensive recycling risks saturating the existing application market with certain types of material. So, finding new food contact applications is particularly important to develop material networks ‘from cradle to cradle’ for selectively collected packaging.
The intention of many companies to use more and more recycled packaging for food contact is partly driven by economic considerations. Given the rising cost of raw materials, using recycled materials can generate savings. Unfortunately, the legal framework surrounding recycled materials still differs from country to country, although the European Union is working towards harmonization. Consequently, the EU has published a regulation on the use of recycled plastic in food contact applications. This dossier gives an overview of the various types of recycled packaging for food contact applications. It evaluates the potential, the challenges and the opportunities for each material.
In order to structurally develop recycling for food contact purposes, clear and harmonized legislation is required at the European Union level. Currently, not all countries accept the use of recycled materials in food packaging. This lack of harmonization is a barrier to the free circulation of goods.
The European Union, however, has published a regulation regarding the use of recycled plastics for food contact. This regulation not only aims to harmonize national legislations, but also to ensure public health. The paper/cardboard sector has already anticipated changes by defining a code of good practice for the packaging of food products. The aim of this code is to avoid migrations and organoleptic changes (such as gas transfers, alterations in taste, etc.), as well as the contamination of packaged products.
Good to remember
- Food contact is a useful application for various recycled packaging materials.
- For sanitary and/or technical reasons, the re-use of paper/cardboard and plastic in packaging that has direct contact with food presents greater challenges than glass and metal.
- The legislation and codes of good conduct that are being worked out at the European level favour the development of new recycling markets.
More than 50% of glass containers are recycled
Glass, out of all the various packaging materials, has the longest recycling tradition for food contact. Hollow glass shapes have been almost entirely recycled into new packaging for decades. In Europe, glass containers contain an average of 50% recycled glass, but this can rise to 90% in coloured glass. The percentage is lower in colourless glass because recycling increases the risk of a coloured tint. Glass manufacturers have gradually improved the recycling of glass over the years so that today it poses no sanitary threat. The recycling process always involves a high temperature fusion stage, which eliminates any risk of bacterial contamination. In addition, any pollutant present in recycled glass remains encapsulated and does not spread to the contents of the packaging. These days, the recycling of glass functions efficiently, with a good balance between supply and demand. Consequently, the European legal initiatives regarding food contact are not expected to influence this market.
Interesting potential for metallic packaging
More than half of metallic packaging in Europe is recycled. There are numerous applications for recycled metallic packaging: the construction and automobile industries are just two that make use of it. Applications also exist for food contact purposes, but these account for a relatively small part when compared to other possible uses. As is the case with glass, the recycling of metallic packaging goes through a high temperature fusion stage. This fusion makes metallic packaging more suitable for food contact than recycled cardboard, for instance, which can only be recycled at low or medium high temperatures.
With the increasing cost of raw materials,packaging made from recycled materials provides cheaper alternatives.
Choosing the right paper/cardboard packaging for food
The recycling of old papers has always been an integral part of the paper industry. Over the past few years, an increasing number of collection systems have been established in Europe. Applications for paper and cardboard are numerous although they are mainly used in newspapers and packaging. Packaging contains more than 70% of recycled fibres on average, so cardboard packaging producers indirectly use large quantities of old papers and cardboard. As a result, it is not necessary to find new market outlets in food contact applications, especially since the recycling of paper and cardboard is limited for this type of application.
The use of paper and cardboard in food contact applications also depends on the type of food to be packaged. ‘Recycled paper and cardboard can be used in packaging for dry and unpeeled food products. There are, however, limitations for greasy or wet products,’ explains Ilse Vervloet, Environmental Advisor at the Belgian federation of paper and cardboard transforming industries (FETRA). ‘Fruits, vegetables, pasta and rice are ideal applications for recycled packaging. Drinks, butter and chocolate are not. However, there is no limitation to using recycled materials for packaging not destined for direct food contact.’
‘The fibres get shorter after every recycling cycle. The presence of virgin fibres in addition to recycled fibres, therefore, remains essential. It is also possible to use a layer of recycled cardboard between two layers of virgin cardboard.’
Designing packaging with a view to recycling
Drinks carton producers prefer to design cardboard packaging from renewable materials rather than recycled materials. ‘Drinks cartons contain an average of 75% virgin wood fibres, which are naturally renewable. The fibres must be of high quality and strong enough for the packaging to fulfil its role. Feasibility studies have shown that recycling fibres from drinks cartons into new drinks cartons is not economically and environmentally sound,’ explains Magda Buelens, Director of Recarton. ‘Drinks cartons are increasingly recycled into other types of paper and cardboard packaging. In Belgium, 76.2% of drinks cartons are recycled. They include bags, foldable boxes, corrugated cardboard boxes, as well as numerous other products and packaging in paper and cardboard.’
‘Cardboard packaging made from recycled materials must be heavier than packaging made from virgin materials if it is to achieve the same resistance. This means two basic prevention rules contradict each other: increasing the use of recycled materials and reducing the quantity of packaging. The trick is to find a good balance between recycled fibres on the one hand and lightness and robustness on the other hand.’
PET: creating new material networks for recycling
The recycling of PET in food contact packaging remains limited. The vast majority of recycled PET is currently used in the textile industry and for specific plastic applications. However,
for the moment, the amount of PET collected in Europe exceeds demand. It is, therefore, important to find other material networks. That is the goal of the Alliance for plastic Beverage Containers sustainability (ABC), which includes Coca-Cola, Danone Waters, Nestlé Waters, Orangina and Spadel. ABC was created in 2007 to promote the collection of recycled PET and its use in beverage packaging.
‘The amount of PET recycled in the coming years is expected to increase sharply,’ declares Philippe Diercxsens, President of ABC. ‘Today, 34,6% of all PET bottles produced are collected in Europe. In ten years time, thanks to the efforts of all recycling players, this figure should exceed 60%. The Belgian rate currently exceeds 68%. Therefore, the sector wishes to develop the use of recycled PET in bottles. Certain recyclers are already capable of supplying recycled PET with a purity rate that is equivalent to or higher than that of virgin PET. ‘Bottle-to-bottle’ is, therefore, technically feasible.’
The beverage industry developed the first bottle-to-bottle recycling application in the early nineties. However, certain technical constraints make its implementation complex. Nevertheless, several beverage brands today offer bottles in partially recycled PET. Yet the number of recyclers with access to certified technology is still limited. As for the companies, they are generally in favour of using recycled PET for food contact applications. It reduces CO2 emissions and improves their image.
ABC collaborates closely with other European associations covering the recycling network. One of their joint projects is ‘Design for Recycling’, a code of good practice for the manufacturing and marketing of PET bottles.
For additional information:
- Code for Good Manufacturing Practices for Flexible and Fibre-based Packaging for Food, a Flexible Packaging Europe initiative realised in close co-operation with CITPA, November 2007, www.citpa-europe.org.
- Packaging and Packaging Waste Directive 94/62/EC. Revised 2004/12/CE directive, European Commission.
- European Commission regulation 282/2008 of 27 March 2008 on recycled plastic materials and articles intended to come into contact with foods and amending regulation (EC) No.2023/2006. More details on www.preventpack.be.
- Alliance for Plastic Beverage Containers sustainability, ABC@eimservices.be.
- Cradle to cradle’, Michael Braungart & William McDonough, 2002
Improve protection without compromising recyclability
In recent years, PET (polyethylene terephthalate) has been the packaging material of choice for water and soft drinks. Plastic bottles are increasingly being used for beer, juices, sports drinks, and aromatized alcoholic drinks. But each product requires specific qualities in its bottles. It is sometimes difficult to find an appropriate solution especially since the bottling sector aims for maximum recyclability
All plastics are to varying degrees permeable for gasses and most allow a certain spectrum of light (UV radiation) to pass through. These are two major factors that limit the shelf life of drinks in plastic bottles. The CO2 content of carbonated soft drinks goes down slowly. Oxygen penetrating can lead to oxidation and thus to vitamin loss, colour changes, and flavour and aroma degradation. Visible light as well as UV light can also cause changes in colour, taste, and aroma. In addition, PET bottles slowly allow vapour to pass through, albeit very slowly. This means that the net volume can eventually drop below the indicated amount.
The impact of all these influences is different for each product. For example, the taste of milk is particularly susceptible to UV and visible light. Carbonated soft drinks and beer suffer from CO2 loss. Beer and juices tend to oxidize with the O2 in the air. These different sensitivities lead to a variety of bottle designs adapted to the product at hand, including opaque bottles for milk and transparent brown bottles for beer.
Adapting the bottle design
In order to reduce the effect of gasses, the bottle manufacturer can modify the design of both the bottle and the cap. In most cases, the cap has already been optimized for minimizing CO2 and O2 penetration.
For best results, the amount of contact surface between product and bottle must be as small as possible. In this respect, imaginative designs often work out badly. So do small bottles, because they have a larger surface to volume ratio. Yet, small bottles are gaining market share: in 1990, the average volume of a plastic bottle was 1,5 litres. In 2005, it was down to only 0,8 litres. It was obviously necessary to further improve the packaging itself.
In order to use as little material as possible in the fabrication of the bottle, the thickness of the sidewall of the bottle is made as thin as possible. As a result, the average weight of a 1,5 litre plastic bottle dropped from 42 grams down to 30 grams in the past fifteen years. However, thinner bottle sides inevitably offer less protection. This was another reason for new design and material measures.
Good to remember
- There are many new techniques to improve the barrier against gasses and UV, but these techniques tend to prevent easy recycling at end of life.
- Plastic bottles are increasingly being used for beer, juices, sport drinks, and aromatized alcoholic beverages. Each type of use requires a well adapted bottle design and material to guarantee the product’s shelf life.
- Manufacturers are increasingly making plastic bottles out of multiple layers or a single layer of a polymer compound.
New techniques to improve barriers
Research is ongoing to find additional barriers against CO2 and O2. Passive as well as active barriers are being used to improve product protection.
• Passive barriers reduce permeability in the sides of the bottle. The side is often made of three to five layers, usually a combination of PET/EVOH or PET/MXD-6. Furthermore, an increasing number of bottles are made out of one layer of a polymer compound. In some cases, a plasma coating is being added to the inside of the bottle. Research is also being carried out to find the optimal external coatings and the effect of adding nano-compounds (inorganic particles as small as one thousand millionth of a metre).
• Active barriers are particles that are added to the bottle material and react with the permeating O2 molecules. This process is called ‘oxygen scavenging’. It slows down the effects of O2 and increases shelf life by several months.
Design for recycling
Not all barrier technologies are recycling compliant,which is a primary point of interest nowadays. The sector is increasingly following a ‘design for recycling’ strategy. They urge designers to keep in mind recyclability at end of life. The following aspects require attention:
The design must encourage the use of recyclable and mutually
The design must be such that the packaging can be dismantled
easily after use.
The design maximizes the amount of recycled content and
stimulates investing in the special machinery required for
processing recycled materials.
- Material use is carefully documented.Utiliser des plastiques recyclables et compatibles entre eux
In a recent study, four authoritative PET recycling support organizations (ABC, EPRO, EUPR, and PETCORE) analysed existing plastic bottle manufacturing techniques and made an assessment regarding ‘design for recycling’. The next Preventpack edition will present a new tool that will enable you to assess the recyclability of your packaging. You will be informed about all aspects to consider for enabling an efficient recycling process.Questions regarding recyclability of packaging can be addressed to firstname.lastname@example.org or email@example.com
For additional information:
- European Organization of Plastics Recycling and Recovery Organisations (EPRO): www.epro-plasticsrecycling.org.
- European Plastic Recyclers (EUPR): www.plasticsrecyclers.eu.
- PET Container Recycling Europe (PETCORE): www.petcore.org.
- Plarebel: http://www.plarebel.be.European Organization of Plastics Recycling and Recovery Organizations (EPRO) : www.epro-plasticsrecycling.org.