The carton of the future

15 March 2005 (Last Updated September 12th, 2017 11:47)

Paperboard and plastic are the two most popular packaging materials for recyclable materials. Members from both sides of the industry put forward their arguments for long-term sustainability.

The carton of the future

Beverage cartons are available in many different forms and fulfil different purposes in this sector of the packaging industry. There is fierce competition for market share; some systems are clearly better at what they do than others.

However, government regulations are seeking to influence the direction of the packaging industry to fulfil environmental recycling targets. For example, PET bottles are the system of choice for carbonated beverages, while paperboard cartons have a proven track record in milk, fruit juice and other types of liquid food packaging for both aseptic and refrigerated use.

When choosing a packaging system for a liquid food or beverage, the following principles should be considered:

  • Fitness for purpose
  • Sustainable resources
  • Transportation and storage efficiency
  • Graphics printing
  • Recycling and environmental impact
  • Product shelf life

If two popular packaging systems, such as plastic bottles (low-density polyethylene, (LDPE), and PET) and paperboard cartons are compared for these principles, they are both suited for the purpose.

Plastic relies upon supplies of oil for production – oil resources are not sustainable or renewable. Paperboard-based cartons are produced from high-quality fibre from sustainable forest resources (forests are managed and for every tree harvested several more are planted).

Plastic bottles are a light, easily transportable form of packaging (as efficient as glass bottles, but lighter to transport) that saves fuel resources in transportation. Paperboard cartons have a square or rectangular shape, are light – thereby allowing more to be packed into a given space – and allow for fuel savings.

Graphics on plastic bottle labels can be effective for brand recognition. However, there is more graphics potential on paperboard cartons, as the whole package can be covered with high-quality printed graphics. There are already definite advantages and disadvantages to both PET and paperboard.

Next, there is the recycling potential. Plastic bottles can be recycled using established techniques and routes. One of the main problems is educating and encouraging consumers to separate and collect the bottles for recycling. Having achieved this, the logistics of collection and processing must be considered. Probably of greatest importance is the cost-effectiveness of the process – is it cheaper to use virgin or recycled PET?

There is a common misconception that paperboard cartons cannot be successfully recycled. However, the schemes for recycling paperboard (ongoing since 1990) show the EU recycles over 21 per cent of cartons (success stories include Belgium, Germany and Luxembourg with 55 per cent, 65 per cent and 46 per cent, respectively) and Canada over 20 per cent. The EU has a specific target of 60 per cent recycling for paperboard, to be achieved over the next 15–20 years.

Paperboard is made from high-quality long fibre, which can be recycled for use in a number of new purposes through the use of a hydrapulper and filter screens to separate the polymer and foil scrap (paper forms the bulk of the package).

The shelf life of products in aseptically packed paperboard cartons will be greater than the equivalent in PET packaging because they exclude light, which can cause chemical changes in the products. (Colour changes occasionally occur in PET-bottled products – milk can develop an off taste if left exposed to light.) It is a mistake to think of paperboard cartons as outmoded or on the decline, as they are a modern, progressive packaging medium.

Resources and recycling

Paperboard manufacturers are proud of the sustainability of the forest resources used in the production of the board. In recent interviews with two major manufacturers, Potlatch Corporation of the USA and AssiDomän Frovi of Sweden, the two companies were quick to mention their sustainable forest resources and environmentally sound production.

Chris Elskamp, Idaho pulp and paper project manager of Potlatch Corporation, says that at the Potlatch Idaho plant, ‘resources are renewable with well-managed forests. Over 85 per cent of the fibre used in Idaho for liquid packaging grades is recovered from other processes at the sawmills.

‘The process uses forest residuals and other waste to generate over 65 per cent of energy requirements. Cooking chemicals at the mill are also recovered for reuse and the bleaching process is elemental chlorine free, which is also good for the environment.’

Bjarne Solberg, manager of business development for liquid board at Assi Doman Frovi, comments: ‘Drinks cartons are made from virgin fibre produced from sustainable forest resources and the recycle value is high.’

Richard Dreshfield, a sales director at Potlatch, adds, ‘The key to successful recycling is that the product has to have intrinsic value.’ A recent interview with Ed Klein, environmental manager at Tetra Pak Inc, confirmed their commitment to the recycling of both aseptic and gable top cartons. He maintains that, ‘Many Tetra Pak cartons are recycled, and currently the figure stands at 12–13 per cent worldwide. The collection process is the most important factor. Currently 15 million households in the USA recycle cartons.

These are mostly in metropolitan areas where the process is more economically viable, and it is self-sustaining with no intervention from Tetra Pak.’ Tetra Pak is a company committed to a policy of recycling 25 per cent of these cartons by 2008 worldwide. This is a very large commitment considering they sell over 0.3 billion paperboard cartons worldwide every day.

Environmental impact

The environmental impact of a packaging system needs to be considered as a whole. Typically, the consumer focuses on the recycling of the end product – but every stage needs to be examined, including quantity of material used for the package and the energy used in its transportation.

The Tellus Institute, an independent environmental research firm in the USA, has published an article on the environmental impact of various packaging materials. The study reviewed the entire life cycle of packaging – from manufacture to usage and disposal.

The study showed that aseptic cartons are one of the best packaging choices for the environment. This is because of a principle called source reduction, where aseptic packages and gable top cartons are made with the minimal required materials from the start and consequently they create less waste in the end.

Aseptic packages are 97 per cent product and only 3 per cent packaging material by weight. This means that paperboard aseptic packaging uses far less energy to manufacture, fill, transport and store than virtually any other comparable package.

The paperboard aseptic carton’s lightweight, efficient block design and ability to preserve beverages without refrigeration (due to the excellent barrier properties of the aluminium foil layer, which need only be a few microns thick) are some of the key factors in saving energy.

Energy input of recycling

Glass bottles and metal cans consume a great deal of energy in the recycling process since they need to be melted down prior to reuse. The big exception to this is reusable bottle schemes showing a resurgence in Europe for mineral water and beer (particularly in Germany) – but sadly in the UK, where schemes used to run for reusable bottles in beer, soft drinks and milk, only the milk bottle scheme survives, and this is in decline because of consumer indifference and lack of convenience.

Milk bottles can be washed and reused eight times before being considered worn out and having to be melted down and remoulded, whereas beer bottles can be reused over 70 times.

Paperboard can be recycled with little energy input (the process does use a lot of water, but this can also be recycled) the scrap plastic and foil from the process could also be recycled, but there is little left following the removal of the paper and so it may not be economical to do so.

New products and advantages

The paperboard used for cartons is of a laminated structure, with a polyethylene coating on the outside giving integrity and protecting the graphic printing. Paperboard forms the main structure of the package, with an aluminium foil layer (possibly combined with a polymer as well) for aseptic packages and a polymer coating for non-aseptic packages.

Bjarne Solberg comments that, ‘The quality of the paperboard used for aseptic needs to be very high and consistent because of the rigours and efficiency of the converting process, and the great demands required of it.’

AssiDomän Frovi manufactures Frovi Liquid, a high-quality liquid paperboard for beverage package converters It also produces Frovi Bright, Frovi Light and Frovi Carry, packaging board for the manufacture of secondary packaging (containers, sleeves and holders). Potlatch Corporation has developed a new liquid carton-board called GablePak Gold, which uses a clay coating on the external surface that provides a superior surface for flexographic and other commercial high-quality graphics printing methods.

This allows premium high-end products to stand out from standard cartons. For example, a popular Japanese saki manufacturer has switched to gable top cartons for its product. Mark Ohleyer, director of marketing at Potlatch, adds, ‘A significant problem on grocery store aisles is that products tend to look too much alike. GablePak Gold is unique in that it invites high-quality print graphics and therefore promotes differentiation and a distinctive brand identification. Moreover, in packaging, consumers appreciate a product that links environmental harmony with superior utility and beauty.’

Of course, paperboard is not the end of the story; these laminated products also rely on superior adhesive systems to bond the paper to the barrier layers on the external and internal surfaces. Henkel Technologies offers one of the widest ranges of adhesives available for paperboard carton laminates.

Natural winner

Ohleyer believes that the future of paperboard packaging lies in increased material recycling, sustainable resources for raw materials, increased market share, the challenge of traditional beliefs about packaging shapes and types (for example, the movement of more foods into gable top and aseptic packaging – an example of which is the Tetra Recart aseptic carton that is beginning to challenge the supremacy of the metal can in the grocery market).

Bjarne Solberg of AssiDomän Frovi believes that the future lies in renewable and sustainable resources, high-quality paperboard, superior graphics and printing on paperboard cartons, favourable costs and good logistics.

Although it is established that recycling of all types of packaging materials is on the increase, recycling paperboard cartons would still be better for the environment. Estimated figures indicate that the breakdown of various materials under natural conditions would take:

  • Glass – one million years
  • PET – 30,000 years
  • Metal cans – 500 years
  • Paperboard cartons – five years

Paperboard must not be seen as a throwaway material; the fibre contained within it is a high-quality and valuable resource that could be used for more than it is already. The gable top and aseptic packaging systems have superior qualities, allowing them to fulfil many different functions in the packaging world.

Their utility is proven and their development is continuous. They use fewer resources than other systems; the resources they do use are sustainable; they are lighter and more efficient to transport; they use less packaging material per stock unit; and they are an efficient aseptic medium, meaning products do not require refrigeration (an energy saving).

In an environmentally conscious world paperboard is a packaging material of the future.